Rail Engineer - Issue 186 - September/October 2020

r by rail engineers for rail engineers

SEPT/OCT 2020 – ISSUE 186

THE LIFE OF AN REB

In the middle of a global pandemic may not be the best time to move offices, but Total Rail Solutions did it.

Relocatable equipment buildings contain highly complex equipment that needs careful installation and thorough testing before delivery.

www.railengineer.co.uk

STRUCTURES/ INFRASTRUCTURE

MOVING ON

PLANT & EQUIPMENT

Not modular bridge decks, but modular abutments and other substructure elements that make installing a new bridge simpler, quicker and safer.

FOCUS FEATURES SIGNALLING/ TELECOMS

DIGITALLY ENABLED MODULAR BRIDGES

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Our managed services means we can assist you with complementary products and services such as traffic management, site welfare and communications.

FIND OUT MORE AT WWW.SUNBELTRENTALS.CO.UK

30 CONTENTS

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News

10|

The day the railway became a canal

18|

Digitally enabled modular bridges 18

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Hydrogen train, Bristol Old Station, Levenmouth, Alstom/Bombardier, Environmental Sustainability Strategy

David Shirres struggled through undergrowth to see the damage a breached canal had caused to the Edinburgh-Glasgow line.

Mungo Stacy looks, not at modular bridge decks, but at modular abutments and other substructure elements.

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Modular passenger lifts for temporary access

When a temporary footbridge also needs step-free access, RECO Lift Solutions can help.

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What the eye cannot see

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Moving on

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Rhomberg Sersa’s list of successes

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Chiltern ATP obsolescence

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Emergency power – why settle for standard?

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The life of an REB

40|

What next for Vivarail?

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Fond farewell to a favourite power box

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Combatting signalling failures

70|

Low-adhesion modelling

52|

Driving innovation in signalling

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The long history and exciting future of railway systems thinking

Graeme Bickerdike describes how cosmic rays can help locate hidden, and dangerous, tunnel vent shafts.

Total Rail Solutions has moved offices, to brand-new premises in Newbury, despite the uncertainties of the pandemic.

Grahame Taylor looks back at what Rhomberg Sersa’s Machine Group has achieved – and still has to offer.

The provision of emergency power supplies, such as Relec’s DC-AC inverters, shouldn’t be an afterthought.

With trains now in service, what will Britain’s smallest and most innovative rolling-stock manufacturer come up with next?

Clive Kessell looks at the challenges of degraded-mode working, and the system that makes it possible.

LNER on bringing ETCS onto the ECML, along with TMS and C-DAS. Rail Engineer explains all the acronyms.

Paul Darlington considers what to do when 1990’s cutting edge technology becomes obsolete in 2020.

They may not look exciting, but, as Steve Barry explains, relocatable equipment buildings contain highly complex equipment.

London Bridge was home to one of the first, and largest, power signal boxes. Now empty and silent, it’s the end of an era.

Malcolm Dobell explains friction coefficients, wheel slide and wheel slip, and how the latter can actually be a good thing.

Felix Schmid's inaugural address as chairman of the IMechE Railway Division looked both backwards and forwards.

Rail Engineer | Issue 186 | September/October 2020

Rhomberg Sersa Machine Group Drainage Solutions Head Upstream Precision placement of ballast and pipe bedding material is possible with the UMH

Dedicated fleet of MFS wagons supplying aggregate to specialist material handling equipment, controlled by a multiskilled team

Efficient Drainage is a key part of maintaining the UK rail infrastructure, with this comes the challenge of achieving sustainable economic volumes within what is usually a small possession window.

RSUK utilises a specialist material handling unit (UMH) that is able to place both pipe bedding material and ballast into a drainage excavation safely and efficiently with speed, precision and minimum waste.

The benefit of using the UMH means that larger distances of drainage can be achieved in a short period of time.

Depending on the site layout you can also achieve simultaneous activities such as excavation and backfill over greater distances with little to no material wasted.

The UMH can be used for the precise placement of bottom ballast, top stone and shoulders, as well as drainage-trench and landslip materials. The machine is unique in the versatility and speed at which it can operate.

■ ■ ■ ■ ■ ■ ■

One of the most versatile railway materials handlers available Delivers pipe bedding material and ballast infill fed from standard MFS wagons Capacity of up to 400m³/hr Materials can be spread whilst on the move Improves on safety and reduces risk onsite Integrated Dust Suppression System Reduces the requirement for excessive Plant and ground staff in and around the excavation

Bringing innovation and engineering excellence to the rail sector Rhomberg Sersa UK Ltd | T +44 (0)300 30 30 230 Unit 2 Sarah Court, Yorkshire Way, Armthorpe, Doncaster DN3 3FD www.uk.rhomberg-sersa.com | enquiries@rsrg.com

EDITORIAL

RAIL ENGINEER MAGAZINE

A risk that cannot be eliminated Installing rock netting anchors at Carmont cutting in June 2010.

Ten years ago, we reported on the installation of 14,000 square metres of rock netting on the near-vertical 15-metre high rock cutting at Carmont. Rocks had been falling from the cutting as a result of it being overtopped by the runoff from steep adjacent fields. This was due to ineffective field drains and an increased area of farmland.

Whilst this work eliminated the derailment risk from rock fall, in a sad irony, the crest drain installed to prevent the overtopping was a factor in the terrible accident here on 12 August, when an exceptional storm washed gravel from its trench onto the track.

Ninety miles away at Polmont, the same storm system deposited 44mm of rain in one hour. The consequent runoff into the Union Canal overwhelmed its waste weirs, causing it to overtop and breach an embankment through which tens of thousands of tonnes of water flooded onto the Edinburgh to Glasgow main line. As we report, it took 40 days to repair the resultant damage.

In both these events, the earthworks had not been considered to have a high risk of failure and drainage systems were overwhelmed by the runoff from surrounding areas. These two incidents also highlighted the vulnerability of earthworks to severe weather events and illustrate the challenges of managing earthworks. These are well-explained in Network Rail’s report ‘Resilience of rail infrastructure’, the interim report that Transport Secretary Grant Shapps requested after the Carmont derailment.

This report explains why historic earthworks are less robust than their modern-day equivalents. It shows the action taken over the past decade to improve extreme weather resilience and reduce the earthworks failure risk. This includes new specialist engineering departments and applying new technologies.

Although the £1.3 billion earthworks spend in the current five-year control period is twice that of ten years ago, this funds work on only 0.7 per cent of earthwork assets each year. The ORR’s annual safety performance report implicitly acknowledged that it is not possible to eliminate the risk from historic earthworks, stating: “It is simply not possible to renew these assets to modern resilient design standards in any wholesale way.”

The previous fatal earthworks derailment was at Ais Gil in 1995 – since then, there have been over 30 such derailments. The tragedy at Carmont was due to a particularly unfortunate combination of factors and an exceptionally violent collision as the train came to a sudden stop from 75mph.

Reports from RAIB and Network Rail’s independent task forces will, no doubt, result in further worthwhile actions to further minimise this risk. Whilst the focus of these reports is to improve safety, the joint investigation by Police Scotland, BTP and the ORR concerns possible breaches of health and safety law. Police Scotland was in charge of the

crash site for 38 days before handing it back to Network Rail to start repairs. Yet the agreed protocol states that this should only be the case if there is a clear indication of serious criminality.

Another historic infrastructure concern is unknown tunnel construction shafts. In 1953, two houses in Manchester collapsed into a failed hidden shaft, killing the five people. In this issue, Graeme Bickerdike has been to Ramsgate to see how cosmic rays can locate such shafts.

The intriguing title of this year’s address by the incoming IMechE Railway Division Chairman, Professor Felix Schmid, is “The Long History and Exciting Future of Railway Systems Thinking.” Felix’s talk describes how the close-coupled wheel/rail interface contributes to the interdependency of these sub-systems. Modelling low adhesion in the one-square-centimetre contact patch between wheel and rail is also the subject of a feature by Malcolm Dobell.

Vivarail’s battery powered Class 230 units, converted from withdrawn London Underground trains, are the UK’s only self-powered non-diesel trains certified for passenger use. Our report provides the background to this conversion and considers Vivarail’s future plans for its innovative trains.

Innovation in signalling is considered in two features by Clive Kessell.

In one, he describes the Degraded Mode Working System, to keep trains running during signal failures. The other concerned a ‘Driving innovation in signalling’ conference which Clive felt was not so much about innovation but rolling out the developed ETCS system on the East Coast main line.

The innovative Automatic Train Protection installed on the Chiltern route in the early 1990s as a pilot system for national use remained the only such system and was declared obsolete in 2012. Paul Darlington describes its history and its forthcoming replacement by an enhanced TPWS system.

Also redundant is London Bridge power signalbox, which, after 45 years’ service, was recently replaced by Three Bridges Rail Operating Centre. In a fond farewell, we describe its history and the new features it introduced.

Finally, we have two features showing how both signalling and civil engineering benefit from modular construction. Steve Barry explains the benefits of using modular equipment to produce and test the ubiquitous Relocatable Equipment Buildings (REBs) in a factory environment. The off-site manufacture of modular bridge products also brings similar benefits as Mungo Stacy describes. These include better environmental and ergonomic working arrangements as the DAVID workforce transfers from site to factory.

SHIRRES

RAIL ENGINEER EDITOR

Rail Engineer | Issue 186 | September/October 2020

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THE TEAM

NEWS

Editor David Shirres david.shirres@railengineer.co.uk

Production Editor Nigel Wordsworth nigel.wordsworth@railengineer.co.uk

Production and design Adam O’Connor adam@rail-media.com Matthew Stokes matt@rail-media.com

Engineering writers bob.wright@railengineer.co.uk clive.kessell@railengineer.co.uk collin.carr@railengineer.co.uk david.bickell@railengineer.co.uk graeme.bickerdike@railengineer.co.uk grahame.taylor@railengineer.co.uk lesley.brown@railengineer.co.uk malcolm.dobell@railengineer.co.uk mark.phillips@railengineer.co.uk paul.darlington@railengineer.co.uk peter.stanton@railengineer.co.uk stuart.marsh@railengineer.co.uk

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Part of: ®

UK hydrogen train runs on main line HydroFlex, the UK's first hydrogen-powered train, ran on the main line today, signalling a big step forward towards the UK's net zero targets.

Developed jointly by the University of Birmingham and train owner Porterbrook, the conversion of a Class 319 all-electric train has been supported with a £750,000 grant from the Department for Transport.

Its development took almost two years of work and more than £1 million of investment from the two partners.

Hydrogen-powered trains use hydrogen and oxygen to produce electricity, water and heat. The ground-breaking technology behind the trains will also be available by 2023 to retrofit current in-service trains to hydrogen, helping decarbonise the rail network and make rail journeys greener and more efficient.

Transport Secretary Grant Shapps visited the development site to meet with leading rail experts from the University of Birmingham’s Birmingham Centre for Railway Research and Education (BCRRE) and to see first-hand HydroFLEX on the mainline.

He also announced his ambition for Tees Valley to become a trailblazing Hydrogen Transport Hub. Bringing together representatives from academia, industry and government to drive forward the UK’s plans to embrace the use of hydrogen as an alternative fuel could create hundreds of jobs, while seeing the region become a global leader in the green hydrogen sector.

Tees Valley is perfectly placed to reap these benefits, following the development there of the world’s largest versatile hydrogen refuelling facility made possible through government funding.

www.rail-media.com

Rail Engineer | Issue 186 | September/October 2020

To kick start the development in Tees Valley, the Department for Transport has commissioned a masterplan to understand the feasibility of the hub and how it can accelerate the UK’s ambitions in Hydrogen.

The masterplan, expected to be published in January, will pave the way for exploring how green hydrogen could power buses, HGV, rail, maritime and aviation transport across the UK. The aim would then be for the region to become a global leader in industrial research on the subject of hydrogen as a fuel as well as an R&D hub for hydrogen transport more generally, attracting hundreds of jobs and boosting the local economy in the process.

The next stages of HydroFLEX are already well underway, with the University of Birmingham developing a hydrogen and battery-powered module that can be fitted underneath the train, which will allow for more space for passengers in the train’s carriage.

NEWS

Network Rail acquires Brunel's 'Bristol Old Station' Network Rail has acquired 'Bristol Old Station', the iconic Grade I listed building, designed by Isambard Kingdom Brunel, that was Bristol's first railway station when it opened in 1840 as the western terminus of the Great Western Railway from London Paddington. It remains one of the oldest surviving railway stations in Britain.

Its acquisition from Bristol City Council allows Network Rail to bring the building back into railway ownership for the first time since rail privatisation in the mid-1990s.

The Old Station is currently home to Engine Shed, a business incubator which supports a cluster of innovative start-ups, and the Passenger Shed, an events space which hosts a wide range of events including exhibitions and weddings.

Network Rail plans to maintain current commercial uses in the building, while implementing a programme to maintain and restore the Grade 1 listed facilities. Its aspirations for the buildings will complement proposals for the wider station area under the emerging Bristol Temple Quarter masterplan.

Stuart Kirkwood, acting group property director at Network Rail Property said: “We are very pleased to have brought this iconic building back into railway ownership. This is a landmark site with historical significance for the nation and for Network Rail as a company. We are looking forward to revitalising the building for the enjoyment of passengers, tenants and the local community. “This refurbishment is part of our wider strategy to create great places for business and communities to thrive, supporting economic growth and regeneration in towns and cities across the UK.�

Structural Precast for Railways

Rail Engineer | Issue 186 | September/October 2020

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FEATURE

Alstom signs agreement to purchase Bombardier

Work on reconnecting the line to Levenmouth gets underway The first phase of work which will lead to the reinstatement of passenger services to Leven will begin shortly.

The first stage of the project, which will see the reinstatement of 19 singletrack-kilometres of railway and two new modern accessible stations for the east of Fife, will include vegetation clearance and site survey and geological investigations.

Ahead of work starting, Network Rail has undertaken all necessary environmental and ecological surveys. Where any species have been identified, appropriate methods of working are in place to safeguard species, roosts and habitats of value.

The equipment which will be used to clear the vegetation will include chainsaws, and chipping machines as well as plant and machinery. This phase of work will also include surveying, drilling boreholes, sampling ballast and extracting core samples to assess the condition of the ground under the railway. A variety of equipment including boring rigs, and drills will be used all along the line with work ongoing until early 2021.

Graeme Stewart of Network Rail’s Levenmouth project team said: “Although still at a very early stage, it is fantastic to see work happening,

literally preparing the ground and to inform the design of the line.

“We have been working on developing a range of options which will define what the project looks like and how it is delivered and, as part of this, we have been meeting with and listening to local groups and organisations in the area.

“The development and delivery of the project will be in discreet phases with the first visible work; removal of vegetation to enable site and geological investigation SI/GI the start of a process which will culminate in the community once again having access to the mainline rail network.

“As well as the promise of better connectivity this scale of investment to improve our transport infrastructure will help to deliver benefits to the economy. It will act as an enabler for growth, provide better access to employment and education opportunities and expanded social and leisure options for people all across the area.”

As part of the Scottish Government’s rail decarbonisation agenda, the line will also be prepared for future electrification.

Rail Engineer | Issue 186 | September/October 2020

The takeover of Bombardier Transportation by Alstom moved closer as Alstom announced that it signed the sale and purchase agreement with Bombardier Inc and Caisse de dépôt et placement du Québec (CDPQ).

Henri Poupart-Lafarge, chairman and CEO of Alstom, said: “The acquisition of Bombardier Transportation represents a transformational change for Alstom. It will enable the Group to accelerate on its strategic roadmap and strengthen its leadership in the context of a dynamic market, at a time where sustainable transportation is at the heart of the global agenda.”

Bombardier Transportation will bring to Alstom complementary geographical presence to broaden Alstom’s commercial reach in key growing markets, strong product complementarities in rolling stock, strategic scale in services and signalling, industrial capacity in key countries, a leading portfolio offering and additional R&D capabilities to invest in

green and smart innovation.

Alstom will also welcome new talent and expertise, with the arrival of Bombardier Transportation employees.”

A €300m reduction in the price range has been agreed with Bombardier Inc and CDPQ. Excluding any further downward adjustments linked to the net cash protection mechanism, the price range for the acquisition of 100 per cent of Bombardier Transportation shares will be therefore €5.5 to €5.9 billion.

Following positive progress on antitrust regulation process, the closing of the transaction is now expected for Q1 2021 subject to regulatory approvals and customary closing conditions, with an extraordinary shareholders’ meeting to be held on 29 October 2020.

NEWS

Network Rail publishes Environmental Sustainability Strategy Network Rail has published its Environmental Sustainability Strategy, which forms a key part of its ambition for rail travel to be the cleanest, greenest form of mass transport. Although rail is already one of the greenest ways to travel, Network Rail wants to make it even greener so it can help tackle climate change and play a leading role in helping to build a green economy.

This is particularly important in the wake of the coronavirus pandemic.

Though the long-term effects of the pandemic are not yet known, the railway has a huge role to play in supporting the government’s ambitions to build better. Network Rail wants passengers to know that it is committed to making the network as environmentally sustainable as possible.

The Environmental Sustainability Strategy is a guide to how Network Rail plans to manage the way the railway is run, to leave a lasting, positive environmental legacy for future generations.

It also sets out important commitments around protecting the railway from the effects of climate change,

improving biodiversity and minimising waste. Planting more trees and developing long-term strategies to improve the railway’s resilience in the face of climate change are just some of the ways the infrastructure owner will maximise the positive contribution of rail for its passengers, society and the UK economy, while minimising any negative impact on our natural environment.

Commenting on the launch of the Environmental Sustainability Strategy, Martin Frobisher, director of safety, technical and engineering at Network Rail, said: “Our aim is to serve the nation by providing the cleanest and greenest form of mass transport.

“We begin from a strong

starting point. Rail is already green compared with other modes of transport but there is still a lot more that we can do. Today we are launching ambitious plans to reduce our emissions, improve our resilience to climate change and to be good for nature in

the places where we operate.

“It is an exciting plan with many detailed commitments which will enable us to meet our targets. We will be working closely with our suppliers and with other industry partners to deliver these commitments.”

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Rail Engineer | Issue 186 | September/October 2020

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STRUCTURES/INFRASTRUCTURE

DAVID SHIRRES

C

anals were a real problem for the early railway builders, as is illustrated by the steep gradients on the approaches to Euston and King’s Cross, where the railway was built respectively over and under the Regent’s Canal. The Midland Railway avoided this problem by building an elevated station at St Pancras.

In Scotland, the Monklands canal forced the Edinburgh to Glasgow railway to build a tunnel with a 1 in 41 gradient to reach its Glasgow Queen Street terminus whilst various bridges and tunnels were needed to cross the Forth and Clyde canal which cut across central Scotland.

It could have been worse if Robert Stephenson, of lighthouse fame, had had his way. In 1817, Stephenson proposed a level canal between Glasgow and Edinburgh. This was to have a basin where Edinburgh Waverley station is now, following the line of what was to be the railway through Princess Street gardens to Haymarket and then continuing along the 155-foot contour to join the Forth and Clyde canal at its summit pound, seven miles west of Falkirk, which extends to Port Dundas in Glasgow.

A canal without any locks between Scotland’s two main cities was a commercially attractive proposition for both passengers and freight.

However, there was a snag – it required the construction of a three-mile-long two-way canal tunnel at Winchburgh. The costs and risks of such a tunnel were too much for the canal’s promoters, who chose Hugh Baird’s line to build the Edinburgh and Glasgow Union Canal, which opened in 1822. A swift passenger boat was then introduced that took eight hours between the two cities and carried 200,000 passengers a year.

Rail Engineer | Issue 186 | September/October 2020

The Union Canal is a level canal that follows the 240-foot contour from Fountainbridge in Edinburgh to Falkirk. There, it joined the Forth and Clyde canal by a flight of 11 locks, which were demolished in the 1930s. The Millennium Link restored these two canals and, in 2002, re-joined them by the Falkirk Wheel, which is Scotland’s 15th most visited tourist attraction.

When the Edinburgh and Glasgow Railway opened in 1842, it took away all of the canal’s passenger traffic and much of its freight traffic.

Eventually, in 1849, the railway took over the whole Union Canal. Evidence of this common

STRUCTURES/INFRASTRUCTURE

ownership can by seen at the Linlithgow Union Canal Society’s basin, where the railway’s original stone block sleepers line the quayside.

As railways were built, the canal companies were gradually put out of business and, for many years, there has been little interaction between canals and the railway. However, in August 2020, there was a significant exception.

12 August In the early morning of 12 August, eastern Scotland experienced exceptionally severe storms that tragically resulted in the fatal train crash at Carmont, where 52mm of rain had fallen between 05:00 and 09:00. Further south, near Polmont, 80mm of rain fell between midnight and 06:00, with 44mm falling in one hour around 05:00. The Scottish Environmental Protection Agency subsequently considered this to be a 1-in-240-year event, although, during the night of the storm there was only a Yellow warning in place.

At 05:46, multiple track circuit failures on the Edinburgh to Glasgow main line between Polmont and Bo’ness junction were reported to Network Rail Scotland control. The driver of 2J53, the 05:03 from Edinburgh to Glasgow, reported that water was above the rail head on both lines at this location and was flowing fast. 2J53 was the first, and the last, train over the line that day.

Scottish Canals received a report that the Union Canal had been breached at Muiravonside, between Linlithgow and Polmont, at 08:00. The breach was initially a few metres across, eventually growing to a 30-metre gap in the six-metre-high canal embankment, through which a vast amount of water was flowing.

At 08:52, the Cathcart Electrical Control reported an overhead line trip in the area as overhead line structures collapsed after their foundations were washed away.

By 11:00, Scottish Canals had put stop planks under bridges at Brightons, near Polmont, and Linlithgow. This restricted the loss of water to six kilometres of the 51-kilometre level canal.

By this time, the level of the canal at Linlithgow, 4.6 kilometres from the breach, had dropped by half a metre.

Later that afternoon, Scottish Canals contractors Mackenzie Construction installed emergency sandbag dams under bridges either side of the canal to contain the leaking section to one kilometre, which significantly reduced the water flow through the breach. By this time, tens of thousands of cubic metres of water had poured onto the adjacent railway line.

The next day, clay dams were installed 100 metres either side of the breach to completely stop the water flow through it. As the canal is fed only from its eastern end, a pumping system was provided at the east end of the breach to pump water to the west side of the breach through pipes that bypassed the drained section of the canal. A week-long fish rescue exercise was then undertaken to move over eleven thousand trapped fish, including a one-metre-long 30-year old eel, to unaffected sections of the canal.

Clay dam and pumps 150 metres east of the breach.

Rail Engineer | Issue 186 | September/October 2020

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STRUCTURES/INFRASTRUCTURE

(Above) Cutting suffered little damage where canal water poured into it.

(Inset) 1. Worksite No 3 - QTS. 2. Cutting.

3. Worksite No 2 - Track Alliance.

4. Major embankment failure.

5. Worksite No 1 - QTS. 6. Main flooding after canal breach.

7. Site compound.

8. Canal breach.

Canal Asset Management Scottish Canals manage the Caledonian, Crinan, Forth & Clyde, Monkland and Union canals, which total 140 miles of waterway.

Its 2018/19 accounts show that £9.1 million (£65,000 per mile) was spent on major infrastructure and core waterway works, and note that its historic assets have been in a steady state of decline, with the risk of asset failure ever present. Unlike Scotland’s canals, it would be wrong to describe railway earthworks as being in decline as Network Rail’s investment in them has doubled in the past ten years to £1.3 billion in Control Period 6 (2019-2024). However, canal and railway assets are both at risk from severe weather events.

To address this risk, the Scottish Canals’ asset management strategy shows how work on their 4,100 assets is prioritised through a risk assessment process. This had identified that 175 assets presented a ‘high’ or ‘severe’ risk of failure.

Scottish Canals director of infrastructure Richard Millar told Rail Engineer that these high/severe risk assets did not include the failed embankment at Muiravonside. He noted that this 200-metre long embankment was a “substantial, chunky” earthwork with much clay in its cross section. It had received a principle examination by a qualified engineer in 2018.

Rail Engineer | Issue 186 | September/October 2020

Such examinations are undertaken every three to ten years according to risk. Each part of the canal also receives a monthly inspection and an annual detailed inspection.

The 51-kilometre Union canal has 13 ‘waste’ weirs along its length to regulate the level of water in it. Richard advised that, during the storm, significant flows were generated in the upstream catchment resulting in large uncontrolled flows into the canal which had overwhelmed these weirs resulting in the canal overtopping at several locations. At Muiravonside, this eroded the embankment to create a 30-metre wide breach. He considers the repair of this breach repair is a big job that will take some months.

Following the Muiravonside breach, Scottish Canals are considering how canals can be made more resilient to such severe weather events.

Richard advised that Scottish Canals are working closely with Network Rail in respect of the railway flood repair work and envisages that the two infrastructure companies will share their strategies to improve the resilience of their 19th century infrastructure.

He also pointed out that canals can also be part of the solution for severe weather events as they can accommodate and move large volumes of water. As an example, he mentions the ‘Glasgow Smart Canal’ scheme that has paved the way for 3,000 new homes in Glasgow by contributing to a wider scheme to mitigate flood risk. This will be done by actively and autonomously lowering the water level in the Forth & Clyde canal by up to 10cm to accommodate 55,000 cubic metres of floodwater when severe weather is predicted.

STRUCTURES/INFRASTRUCTURE Après le déluge As the fast-flowing water escaped from the canal, it flowed down through a wood for 300 metres before pouring over the south side of a one-kilometre long shallow cutting on the Edinburgh to Glasgow main line. Little One of two OLE damage was done at masts that had foundations washed away. this point as the wood had spread the flow.

At this point the line is on a very slight, 1 in 882 gradient that falls eastwards towards Edinburgh.

The flood water covered the rails in the cutting and poured out of both ends of it with most flowing out of the east end of the cutting. It was here that most of the damage was done as the water poured down a 10-metre high embankment on the north side of the line to flood the fields below. The scour of tens of thousands of tonnes of water changing and speeding up dug out OLE mast foundations and about 150 metres of trackbed, leaving sagging, unsupported track in a scene reminiscent of Dawlish in 2014.

Network Rail’s project manager for the flood repair works, Mark Wilson, advised that it took three days for the water to filter through the site before a full damage assessment could be made.

This found that there was: » One kilometre of contaminated ballast; » 1.3 kilometres of track formation to renew; » Two embankment failures, one of which was up to nine metres deep, and significant soil cutting failures; » 3.5 kilometres of signalling cable requiring renewal and location cases damaged from water ingress; » Two collapsed OLE masts with associated wiring damage; » 8,000 to 10,000 tonnes of track formation debris from the main failure site that had been deposited on non-arable third-party land. A decision on whether this has to be moved has yet to be taken.

Photograph shows failed cutting slope.

Aerial view shows scour under both tracks where flood water left the cutting.

Rail Engineer | Issue 186 | September/October 2020

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STRUCTURES/INFRASTRUCTURE Preparing the main embankment failure for its infill.

Design

Infilling main embankment failure.

Network Rail’s geotechnical framework contractor QTS, supported by COWI, which provides geotechnical engineering services, was immediately mobilised to establish a site compound below the main embankment failure.

For Mark, the urgent timeframe to prepare the design was particularly challenging. He advised that the geotechnical design was derived from designer’s sketches from which retrospective Form 001 and 002s were produced, as allowed by the civil engineering assurance standard.

Geotechnical designers were also on site throughout to supervise the works.

The design for the new formation at the main embankment failure area required an infill of between 1.5 and nine metres, which consisted of a compacted primary fill layer of 6B (100-300mm) stone followed by incremental layers (130mm to

Rail Engineer | Issue 186 | September/October 2020

150mm thick) of compacted 6F5 stone to reach final formation level. In all, approximately 9,500 tonnes of stone would be needed.

The Rail Systems Alliance Scotland, a threeway joint venture of Network Rail, Babcock Rail and Arcadis, designed the track renewal, signal and telecoms remediation works as well as the soil cutting damage repair within the track renewals worksite. It was agreed with the route asset manager that a category 11 track renewal (rerail, resleeper and reballast) was required. A combined form A/B for track design was produced, reviewed and accepted to allow approved for construction drawings to be issued six hours before work started.

The scope of the signalling and telecoms work was informed by advice from the local maintenance team. The S&T cables were located in two separate troughing routes, one in the cess and one at the crest of the soil cutting. To improve maintainability and increase resilience it was decided to rationalise this by cutting and relocating the cables into one cable trough within the cess with new location cabinets installed at appropriate locations.

This required several signalling cables to be cut and 3,000 metres of new cables to be run in. One saving was that it was found that the fibre optic telecoms cable, installed during the Edinburgh to Glasgow improvement programme (EGIP), could be reused.

The remedial overhead line equipment work was designed by SPL Powerlines and was aided by the use of EGIP records for the design of foundations for the two new twin track cantilever overhead line structures on the south side of the track.

These replaced single track OLE masts at the two locations where masts on the north side of the track had had their foundations washed away.

It was considered that twin track OLE gantries were a more robust and ‘future proof’ solution in accordance with what Mark described as “Scotland’s railway ethos of building back better”.

This decision also aided the programme, as it meant that the mast’s foundations were away from the embankment remedial work.

STRUCTURES/INFRASTRUCTURE

Delivery Mark considers that the most significant challenges in delivering these remedial works were compliance with the Construction, Design and Management Regulations (with three different contractors on site), finalising remits from the various asset managers with very short timescales, liaison with the many parties involved and engineering train planning. Furthermore, having initially estimated six and a half weeks to complete the work, his team were challenged to achieve five and a half weeks. He advised that the project planning needed to achieve this was quite demanding.

The CDM issues were resolved by having three distinct sites of work. QTS was the principal contractor for the embankment remediation sites at each end of the cutting. Between these two sites, the Rail Systems Alliance Scotland was the principal contractor for the track renewals site. Other contractors on site included Story Contracting, which provided rail plant, and SPL Powerlines for the installation of the twin track cantilever masts and OLE repairs.

Although Scottish Canals contractors have their own compounds and separate access arrangements, there was a requirement for some common site access, for example visits of the loss adjusters. There are also ongoing discussions with Scottish Canals regarding the mitigation of any repeat occurrence, especially as the canal lies above and close to the railway for several kilometres.

Achieving the formation level in time for track renewal works was very much on the critical path and did happen just in time. Once the embankment works were complete, the three worksites were merged into one track renewals site.

The 27 engineering trains for the track renewals work were also on the critical path and required the replanning of train moves and engineering work across the network. One such train was that with Rhomberg Sersa’s MFS+ (material conveyor and hopper unit with transfer conveyor belt and caterpillar track) which was sent to Polmont from its deployment on Scotland’s Far North line. As reported in issue 180 (December 2019), the MFS+ is a highoutput conveyor/hopper wagon that can lift itself clear of the running line and then wander off into an excavation. At Polmont, it was used to deposit ballast away from the railhead.

(Above) Work is almost complete at the minor embankment remediation worksite at the western end of the cutting.

(Inset) Rhomberg Sersa’s MFS delivering ballast at the railhead.

(Left) Preparing Down line trackbed, photograph shows the abandoned crest troughing route.

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(Above) SPL Powerlines installing contact wire on the Up line.

(Inset) Work complete - photograph shows the two new twin-track cantilever OLE masts, new cess troughing route and cutting repair.

At the track renewal site, the contaminated ballast was excavated out and existing formation level was cleaned. 10,000 tonnes of new ballast was laid on a geotextile layer on top of the cleaned new formation.

The existing rails were not re-used as they had to be cut into panels to enable efficient removal from site. New rails were run in by engineering trains and laid in the four-foot of the opposite line. The Down line renewal was completed first, followed by the Up line. Work then transferred to the embankment failure site where both lines were renewed once formation level was achieved. The track renewal required 4,500 metres of new rails and 4,424 concrete sleepers.

During the flood repair works, there were no passenger trains between Falkirk and Linlithgow. Whilst the line was closed, other work was carried out to take advantage of this possession, including signalling upgrade works at Falkirk High tunnel, devegetation through the Polmont area and other minor earthwork repairs elsewhere following the storm on 12 August.

After all work had been completed, all the relevant handback paperwork was gathered to show that the new and repaired assets are “suitable, sufficient and correctly configured to provide for the safe functional operational requirements of the railway infrastructure” as required by Network Rail’s ‘Entry into operational service’ standard.

Rail Engineer | Issue 186 | September/October 2020

Once this was done, services on the main Edinburgh to Glasgow route resumed on 21 September with a temporary 60mph speed restriction, 40 days after the line’s inundation by the Union Canal. Commenting on the work, Michael Matheson, the Scottish Government’s Cabinet Secretary for Transport, Infrastructure and Connectivity, stated “The scale of the challenge faced by those repairing the damage to this vital route was huge and that they have delivered this so promptly is testament to the hard work and dedication of staff across Scotland’s Railway.”

It’s hard to disagree with him.

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Digitally enabled modular bridges

Rail Engineer | Issue 186 | September/October 2020

STRUCTURES/INFRASTRUCTURE

MUNGO STACY

B

uild, build, build! – heartening words for construction.

Better, greener, faster – the imperatives for the industry.

But what remains unspoken is the poor past-performance of the sector. Since the mid-1990s, the productivity of manufacturing has improved by 50 per cent. In the same period, construction productivity has remained unchanged.

The uptake of manufacturing-style techniques, so-called ‘modern methods of construction’, is being promoted as a means of closing the productivity gap. These methods include off-site manufacture.

The use of transporters to ‘drive in’ prefabricated bridge decks is widespread in the rail industry, to permit construction within short possession constraints. But can similar techniques be adopted for the substructures?

In a 12-month, £1 million development project, Laing O’Rourke, supported by WSP and Ramboll, created a set of pre-approved modular bridge products to enable more off-site manufactured components to be used in the delivery of bridges. The project is a result of the competition that Highways England launched in February 2019, alongside Innovate UK, to encourage new ideas aimed at revolutionising roads and driving. HS2 enabling works contractor LMJV (Laing O’Rourke and J Murphy & Sons Joint Venture) used these products in the construction of the M42 bridge installed over the weekend of 8-9 August 2020.

Precast modular abutment shells leaving Laing O'Rourke's state-of-the-art factory in Nottinghamshire.

Off-site advantage Phil Robinson, civil engineering leader at Laing O’Rourke’s Dartford headquarters, commented: “Off-site manufacturing is at the heart of Laing O’Rourke’s business.

Over a decade ago, we invested in a state-of-the-art precast factory in Nottinghamshire, and it remains the most automated concrete production facility in Europe. We have a target of 70 per cent of the construction being conducted off-site, leading to a 60 per cent improvement in productivity, and a 30 per cent improvement in delivery schedule.

“We have been recognised for many years for our modular products in the buildings sector,” Phil continued. “The Highways England funding offered a perfect opportunity for us to accelerate our efforts to grow our product range and achieve a step-change in the delivery of bridges.”

An obvious key benefit of using off-site products is faster construction, saving indirect costs and reducing disruption to

The precast unit forms voids for in-situ concrete.

the transport network. But there are other inherent benefits to using off-site modular products.

The repetition of assembling standard units, with site teams familiar with working with the components, reduces construction risk compared to one-off solutions. The transfer of labour hours from site into the controlled conditions of the factory improves well-being, with better environmental and ergonomic working arrangements. Also, safety is designed into the system, with reduced work at height.

Modular abutments Recognising that standardised precast deck beams have been used for decades, the focus of this work has been a modular system for abutments, wing-walls and piers. It is based on precast shell units that are two metres high, 1.75 metres deep and form a two-metre horizontal grid. The units can be stacked to create the required height of abutment or wall, with matching sloping L-wall units to form wing-walls.

A challenge for off-site construction is forming the connections between prefabricated units, particularly given the high forces present in bridges. The shell system provides a relatively thin precast wall around internal voids, and delivers a high-quality factory-formed finish. The structural strength is provided by in-situ concrete poured within the voids.

The current system is an evolution, already on its third iteration. Phil Robinson explained: “We used off-site techniques on the A453 road widening scheme back in 2013. Then came the Staffordshire Rail Alliance. Now we are applying the system on the East West Rail and HS2 projects.

With each deployment, we have been using the lessons learned to refine the system.”

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STRUCTURES/INFRASTRUCTURE A key engineering choice is whether to make the precast unit participate structurally. Earlier iterations included this composite behaviour, making the section structurally efficient but requiring reinforcement across the interface and more complex assembly. The current shell solution treats the precast unit as non-participatory formwork. The overall volume of concrete is therefore higher than for a comparable in-situ solution, but all the benefits of rapid installation are gained. In addition, since early strength gain is no longer needed to strip the formwork, then a lower cement content can be used, giving a lower carbon content.

The approved installer scheme defines requirements to ensure critical tolerances are met.

Design for Manufacture and Assembly With off-site manufacture, the details of installation need to be carefully thought through at the design stage since ‘technical adjustments’ are not possible on site. The units are designed for manufacture, with lifting points cast in and the potential product variations accommodated within the limitations of the moulds.

The shell units are installed over starter bars projecting from the pilecap. Setting out of the starter bars is absolutely critical, otherwise the shells will not fit.

Guide frames were developed to align the starter bars and maintain the relative positions.

Likewise, the lap between the starter bars and the down-hole cage is designed as a non-contact lap, to provide tolerance as the cage is slid down the void. Getting such details right allows the system to be repeated successfully across multiple structures.

Pre-assured system

Configuration tool

The full title of the innovation project is ‘digitally enabled and assured productbased bridges’. The title captures two key aspects – the pre-assurance through certification of the product set, and the digital enabling through an online configuration tool.

Certification is being progressed through BBA (British Board of Agrément), the UK construction certification body.

Certification has defined performance characteristics of the products that can be relied upon, for example, the suitability of the shells to withstand the internal pressure applied from an eight-metre head of concrete when filling the void. It is supported by a manufacturing quality plan, with ongoing monitoring by BBA to ensure the requirements of the quality plan are fulfilled. In addition, an approved installer scheme defines requirements for installation.

The second aspect of the project was to develop a digital configuration tool. Enter the parameters of the bridge – span, skew, height, width – and the tool outputs the set of products needed to build the bridge. With the aim of streamlining concept design, the tool also outputs a 3D model in IFC format, the Approval in Principle document and provides the cost. The tool enables the modular design option to be considered alongside other forms of construction, but the detailed design of the bridge is still carried out by the project designer.

The value of the tool is in configuring the arrangement of products, including the variable features, to suit the site requirements. The concept of ‘mass customisation’ captures the adaptation, within defined limits, of a set of standard products to a particular need. For example, variation in abutment height is obtained using a stop-end in the mould to adjust the height of the lowest, below-ground, unit. Similarly, variations in the height of the uppermost units can be used to follow the crossfall of a bridge.

The tool covers typical cases for singlespan integral bridges using industrystandard prestressed concrete beams, but also introducing the abutment shells and other modular bridge products. It covers spans of between 15 and 40 metres, using Y and W beams. Skew can range from 0 to 30 degrees, corresponding to the application of the standard limit equilibrium approaches for integral bridge design. Abutment heights of four to ten metres cover typical clearance envelopes for highway and rail schemes including, at the low end, river crossings.

The precast shell units allow rapid installation of abutments adjacent to live traffic.

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STRUCTURES/INFRASTRUCTURE Parametric analysis John Armitage, technical director at Ramboll, said: “Analysis of integral bridges is complex, because all the effects are interdependent - the behaviour of the deck, the abutments and the ground. We have pre-engineered the products by running a parametric analysis covering the range of different geometries. The benefit of using this tool is that it provides confidence to a user that a valid solution can be developed, short-cutting an analysis that would normally take up to two weeks to perform at preliminary design stage.”

The configuration tool works with a lookup table based on the results of numerous analysis runs. A pair of sophisticated parametric models were developed by WSP and Ramboll, with design automation allowing set-up of model geometry, analysis, and results extraction to occur without manual input.

Independence of the models allowed cross-checking of results between the two design organisations to guard against error.

Gbenga Oludotun, project manager for WSP, added: “The project was delivered during lockdown, but we were still able to make use of the desktop computers locked in offices. We used virtual remote access and ran batches of analysis on half a dozen machines in parallel. Ultimately, we set up to run 1,500 different bridge configurations and generated the results over a weekend.”

Application to HS2 The modular bridge products have been used to speed up the installation of four of the first bridges to be built for HS2. Laing O’Rourke, in joint venture with J Murphy & Sons as LMJV, are the contractors for the Enabling Works

The 2,750 tonne superstructure was installed over the M42, with the motorway reopening 22 hours early.

North. The four bridges are part of major highway improvements around the future HS2 Interchange Station in Solihull, which will be the heart of the new high-speed railway.

The largest bridge, with a 65-metre span, was installed over the M42 motorway over the weekend of 8-9 August 2020. The deck, weighing 2,750 tonnes, was constructed alongside the motorway and manoeuvred into place on self-propelled modular transporters.

Thanks to an immaculately planned operation, the motorway was reopened to traffic a full 22 hours early. This success illustrates the flexibility of the modular bridge system, where the same abutment shells were used with a steel-concrete composite deck supported on bearings.

Future development Next steps for the project team include extending the cases covered by the product certification and configuration tool. Additions could include steel beams to supplement the prestressed concrete beams, extension to multi-span bridges using the shells to form central piers, and including other products, such as precast deck panels and a range of parapet stringcourse beams. The team continues to use each deployment to

improve the system and products for the benefits of the design, construction and maintenance of bridges.

The system is attracting interest from many clients and sectors, with use demonstrated on these HS2 bridges, applications well advanced on East West Rail, and the innovation funding support from Highways England.

Paul Doney, director of innovation and continuous improvement, said: “At Highways England, we are committed to support innovations that enable better ways of working, particularly if they are safer for our workforce and reduce disruption for road users. Projects such as this support our ambitions for digital design and construction that will benefit the whole construction industry, and we're already seeing benefits with less disruption drivers.”

The adoption of digital technologies to allow configuration and customisation of the standard units offers the flexibility to adapt the use of the products to each particular site arrangement, whilst realising the benefits of quality and efficiency through the application of a manufacturing approach to construction – exactly as required to build better, greener, faster.

Mungo Stacy is head of profession, civil bridge and ground, at WSP.

The modular abutment delivers a high quality precast finish.

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Modular passenger lifts FOR TEMPORARY ACCESS

A

cross the country, simple footbridges at stations, which cross the tracks from one platform to another, are being replaced as part of the ‘Access for All’ scheme. Typically, the new bridges have a passenger lift for each platform, so that the disabled, passengers with heavy luggage, families with prams and pushchairs and anyone else with mobility difficulties can access all of the platforms and the trains.

However, when a temporary footbridge is needed, this can be a problem. Traditional styles made from scaffolding don’t have lifts, so those with mobility problems can be disadvantaged.

When Deutsche Bahn had this problem in Germany, it turned to RECO Lift Solutions, which supplied three type PP passenger lifts for a temporary pedestrian bridge crossing the tracks in Berlin.

PP stands for Plug & Play, which means that the lift shaft can be installed with just one crane lift and is then ready to be used. All that is needed is a foundation and a power supply, then the temporary RECO passenger lifts provide a step-free and safe access for railway passengers using the temporary passenger bridge.

Safe and step-free Based in the Netherlands, RECO Lift Solutions specialises in renting out temporary passenger lifts all over Europe.

“In the international infrastructure market, we work a lot for the railway companies,” explained Jakob Ebbens, RECO’s international accounts manager. “All over Europe, we see a trend that customeroriented railway companies want to maintain full step-free track access for their passengers in all circumstances.

“This is also the case for temporary structures like temporary pedestrian bridges. Due to overhead line equipment, these temporary pedestrian bridges need a minimum height of 7.5 to 8 metres. For passengers with prams, bikes or disabled people in wheelchairs, the stairs leading up to such a bridge are an impregnable barrier.

“With the use of a temporary RECO passenger lift, we offer railway passengers the comfort of a passenger lift with an enclosed lift shaft.”

Railway station Berlin Schöneweide Having been part of the Deutsche Bahn network for more than 100 years, Berlin Schöneweide railway station no longer meets contemporary standards. As a consequence, DB is modernising the station to make it more appealing and comfortable for passengers.

Rail Engineer | Issue 186 | September/October 2020

STRUCTURES/INFRASTRUCTURE The station features a passenger tunnel with lifts for those that need them. As these lifts would be out of service throughout the modernisation works, Deutsche Bahn decided to install a temporary footbridge, courtesy of engineering contractor Spitzke, which has its eastern regional headquarters at Großbeeren, just south of Berlin.

Spitzke cast concrete foundations for three temporary lift shafts. Directly after lifting in the temporary footbridge, a 500-tonne crane, on hire from another Berlin company, Thömen, lifted in the three temporary RECO PP passenger lifts.

The lift shafts were anchored to the concrete foundation using Hilti chemical-glue anchors.

RECO temporary lift shafts that are under 12 metres high can be free standing, However, one of these three was 14.6 metres high, so it needed to be tied into the bridge structure for added stability.

“Using temporary RECO type PP passenger lifts, all customers will be able to use the temporary footbridge,” said Mr. Springer from infrastructure owner DB Netz. “In only 24 hours, RECO installed three temporary passenger lifts without disturbing train traffic. The temporary lifts use the same lift technology and operation as our existing lifts at the railway station, adding to the comfort and user friendliness for our users.”

“Engineering firms and specification writers that operate in Germany’s infrastructure sector are increasingly seeking us out for temporary lift solutions,” commented Jakob Ebbens. “To make travelling by train more appealing, railway operators are not only improving rolling stock and timetables, but stations as well.”

Research has shown that the station experience contributes a hefty 25 per cent towards overall passenger satisfaction. Given that safe and step-free access to trains is a basic passenger need, its influence on passenger satisfaction is considerable.

Modular set up RECO’s PP passenger lifts are modular in concept. Jakob Ebbens explained: “Depending on the needs of our clients in number of stops or travel height for the cabin, we can simply adjust the height of the lift shaft. For this project, for example, we have installed two nine-metrehigh lift shafts and one at 14.6 metres.

“We also have flexibility in the cabin configuration. For this project, Deutsche Bahn preferred a walk-through cabin for a better traffic flow.”

RECO is using standard lift technology for its passenger lifts. “Since we work all over Europe, and our engineers are based in the Netherlands, we always want to make sure that a local elevator service company is familiar with the lift technology that we are using. This enables us to provide prompt customer service in case there is a technical problem,” Jakob Ebbens stated.

For the project in Berlin, elevator service company Schmitt & Sohn is both assisting RECO with technical support and taking care of maintenance.

With safety being paramount, all RECO temporary passenger lifts are commissioned by a local notified body before use. In the UK, Bureau Veritas UK is undertaking this service.

All of the lift cabins are fitted with an emergency call button in the lift cabin. While RECO offers clients use of its emergency call system, station owners and operators often want to build in their own, which are fully compatible with the systems they are already using.

In the UK, RECO has supplied projects such as Crossrail, Docklands Light Railway and Manchester Airport, and is working on several projects for Network Rail. When needed, additional support can be provided by sister company RECO Hoist Ltd of St Ives, Cambridgeshire.

Rail Engineer | Issue 186 | September/October 2020

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What the eye

PHOTOGRAPHY: FOUR BY THREE

CANNOT SEE

GRAEME BICKERDIKE

Dr Chris Steer and Dr Patrick Stowell check data below the ventilation shaft.

S

ome things make my brain hurt: Channel Four’s Naked Attraction, all Apple products, the cost of HS2. But, most recently, I’ve found myself befuddled by a scientist’s assertion that we are constantly being rained upon by subatomic particles which pass through anything and everything as they head deep into the Earth.

What’s even more baffling is that these particles have value in asset management terms. In fact, they have the potential to help the railway draw a line under a longstanding concern both of Network Rail and the Office of Rail and Road, by confirming the location of many-dozen hidden construction shafts, sunk when our inventory of tunnels was driven during the Victorian era but for which records no longer exist.

Science lesson Cosmic rays are produced where solar and extra-galactic particles collide with the upper atmosphere, causing a further shower of particles which fall towards the Earth’s surface.

Of those that make it all the way, the majority are muons; these typically have a rate of

Rail Engineer | Issue 186 | September/October 2020

10,000 per square metre per minute - that’s the approximate equivalent of one passing through your hand every second, if held horizontally.

The energy range of the particles is quite broad; a fraction hit the ground and stop, whilst the remainder penetrate the rock and can continue downwards for hundreds of metres.

Their presence can be recorded by means of a detector wherein they deposit small amounts of energy which is converted into light and captured by a photosensor.

If the equipment is moved through a tunnel, any low-density features within the overburden - such as a shaft - will coincide with a higher rate of penetrating muons than elsewhere, although the results have to be adjusted to take account of variations in the depth of the overburden.

STRUCTURES/INFRASTRUCTURE The harder they fall Talking me through the basics of the technique known as muon radiography - was Dr Chris Steer, a Royal Society of Edinburgh Enterprise Fellow - based at Surrey University - and now managing director of Geoptic, a spinout company from the universities of Sheffield, Durham and St Mary’s (Twickenham). Its four founders have backgrounds in nuclear and particle physics instrumentation, advanced data analytics and geophysics.

I encountered Chris with his colleague, Dr Patrick Stowell, in a disused railway tunnel under Ramsgate that is now a visitor attraction, recounting its wartime role offering shelter to the townsfolk. Had I ventured through the portal early in 1941, I’d have found 1,700 people living in ‘Tunnel Town’.

Significant enterprise enabled the Kent Coast Railway to reach Ramsgate in 1863, where it established a terminus next to the harbour and beach. The Parliamentary plans record an approach tunnel descending from the Dumpton area of the town on a gradient of 1:80, extending for 1,420 yards. However, as built, it’s rather longer at 1,638 yards, with a 1:75 gradient.

Newspaper reports suggest the tunnel was constructed from three shafts, the central one being retained for ventilation although it’s now buried beneath a garden. The location of the other two shafts is not currently known; there’s no obvious sign of them within the tunnel.

We know that 19-year-old John Morgan from North Wales was working with a fellow labourer at the bottom of No.3 Shaft on the morning of 22 December 1862. At around 07:40, Morgan was left alone whilst a skip-load of chalk was despatched to the surface; when his workmate returned, he was lying face-down with injuries to his head. Two or three pieces of chalk were scattered about.

Surgeon John Edward Cartwright soon attended the scene but the casualty had already succumbed. Cartwright told the inquest that he’d found a small incised wound over Morgan’s left temple and blood oozing from his mouth, the result of a blow attributed to chalk falling from the skip.

(Below) The tunnels are now a tourist attraction, recounting their varied history.

(Inset) The 1936 spur tunnel, driven for a 2-foot electrified railway.

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Around the world

Part of the network of ARP tunnels.

Around 1,700 people lived in 'Tunnel Town' by early 1941.

To draw visitors back to the seafront, the developers laid a 2-foot gauge electrified railway northwards to the tunnel’s midpoint, diverging thereafter into a new bore which was pushed 235 yards through the chalk in just seven weeks, emerging into a 15-foot deep cutting in which the terminus platforms were sited.

The line was officially opened on 31 July 1936 and an estimated 20,000 passengers were carried over the Bank Holiday weekend, considerable use being made of a passing loop in the main tunnel.

The route was well lit, with tableaux alongside the track depicting scenes from across the globe, earning itself the unofficial title of the World Scenic Railway.

Whilst popular with passengers, the cramped beach-side terminus proved difficult operationally and its capacity could not meet demand at peak times. The turntable was only capable of handling smaller locomotives so heavy trains generally had to be double-headed as far as Margate, a constraint compounded by the tunnel’s stiff gradient. Braking inadequacies resulted in the death of oyster seller Jabez Grainger, when an empty train ran through the station wall and onto the road beyond.

Restructuring of the town’s railway provision brought closure of the harbour terminus and tunnel on 2 July 1926, having retained their operational status for just 63 years. Both were acquired by Ramsgate Corporation and the station site soon became a funfare, zoo and music hall known as Merrie England.

Life-saving role

PHOTO: RAMSGATE TUNNELS COLLECTION

Rail Engineer | Issue 186 | September/October 2020

In 1936, as conflict loomed with Germany, Ramsgate’s strategic importance brought with it the possibility of aerial bombardment. To address the implications, the town’s Mayor and Borough Engineer planned a network of Air Raid Precaution (ARP) tunnels beneath the town, with the railway tunnel serving as the hub.

Around 2½ miles of tunnels were subsequently driven from a series of shafts sunk in the streets, at a typical rate of 23 feet per 12-hour shift. A local workforce complemented miners from Betteshanger Colliery, with their total number reaching 120. The Duke of Kent opened a section at Queen Street on 1 June, with the remainder completed later in the year.

Life in the tunnels was basic, but families commandeered their own space to fashion makeshift rooms from wood and hessian. Relics of this occupation can still be seen, including recesses in the sidewalls and a full-height brick chimney.

STRUCTURES/INFRASTRUCTURE Back from the dead The narrow-gauge railway was refurbished prior to services resuming in 1946; patronage was initially good. But a sense of neglect took hold as its popularity waned through the 1960s, closure coming at the end of the 1965 season, following an accident in which a train ran through the beach station, demolished the buffer stops and launched itself onto the roof of the staff toilet. The driver and several passengers were hurt.

In 2011, the town’s Mayor formed the Ramsgate Tunnels Heritage Group to consider whether they could be reopened for tourism. A bid was made for feasibility funding via the Big Lottery/Jubilee People’s Millions scheme, which involved TV coverage and a public vote. The proposal won in the Meridian East region and netted £53,000.

Under normal circumstances, the tunnels are open five days a week and throughout the school summer holidays, offering a museum, café, guided tours of the ARP system and occasional special events. Whilst Covid restrictions have curtailed the offering, incursions can still be made as far as the railway tunnel’s midpoint.

Tunnel vision And it’s there I met up with Chris and Patrick, close to the ventilation shaft. Installed on a trolley were two layers of detectors, one above the other.

Each detector took the form of a tube containing a sensitive medium, with a photomultiplier

Rail Engineer half page aug.sept advert.indd 1

coupled at one end to amplify the weak pulse of light into a strong electrical signal, which is then converted into a digital measurement.

When a cosmic ray muon enters the tunnel, it passed through one of the detectors in the upper layer - causing a flash - before doing the same in the lower layer. Whilst most travelled vertically, “they come in at all angles,” revealed Chris, “but the intensity reduces approximately as the cosine squared from the zenith.”

The equipment used to detect cosmic ray muons.

27/07/2020 2020 13:52:04 Rail Engineer | Issue 186 | September/October

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A tour group, with the collar of full brick lining behind.

It was in another disused railway tunnel at Alfreton, Derbyshire, that the system underwent a field trial in October 2018, covering the structure’s 768-metre length in 10 shifts of eight hours. The kit was positioned, switched on for half-an-hour and then moved ten metres further along the tunnel, with the interval reduced to five metres in areas of interest. It’s a repetitive process requiring little human intervention so a good book keeps the mind stimulated. The survey identified a hidden shaft 80 metres from the south portal, one which Network Rail already knew about but had not revealed to the team.

Although he didn’t know it, C T R Wilson, a Scottish physicist and meteorologist, recorded cosmic rays in 1901 when he observed the rate at which his gold leaf electroscope lost its charge within Neidpath railway tunnel, Peebles, which he entered - hopefully with permission - after the day’s last train had passed.

He described “no evidence of any falling off of the rate of production of ions in the vessel [compared with the rate outside], although there were many feet of solid rock overhead”, drawing Wilson to errantly conclude that the ionisation was a property of the air itself. It wasn’t until 1912, when Victor Hess took three electroscopes to an altitude of 17,000 feet in a balloon during a near-total eclipse of the sun, that the existence of cosmic rays was fully demonstrated.

Eyes open So, what of Ramsgate Tunnel? Both ends of it are horseshoe-shaped in profile and fully lined in brick. The intervening majority mostly comprises a segmental brick arch springing off exposed chalk sidewalls, with occasional patch repairs. There’s almost no water ingress. For about 300 yards at the southern end, the tunnel curves to the west and within this section is a collar of full brick lining extending for 105 feet.

Rail Engineer | Issue 186 | September/October 2020

The team’s visit lasted five days, sufficient only to capture data close to the ventilation shaft and through a 200-metre section around the collar.

Whilst the results of deeper analysis are awaited, the initial finding was of a weak anomaly within the collar region, but extending around 90 metres further in and 60 metres back towards the portal.

The shape of the anomaly is distinctly different to that associated with an unfilled shaft, although a filled one could not immediately be ruled out.

Over the years, a number of techniques have been investigated in the search for hidden shafts ground penetrating radar, conductivity, resistivity, thermography - but the results have been patchy, often providing evidence of anomalies but only rarely pinpointing shafts. In contrast, the detection of cosmic ray muons offers stronger confidence because the recorded particles have passed through the whole of the overburden.

It can be used to measure the diameter of a shaft and extent of any infill. And the team is now developing equipment for longer-term installation, potentially offering insight into whether the infill changes over time, perhaps due to seasonal water ingress.

Almost 70 years have elapsed since the catastrophic failure of a hidden shaft in a quiet Manchester suburb led to the loss of five souls who were sleeping in the houses above (see Issue 118, August 2014). It was a loud wake-up call for the railway; you can’t manage major infrastructure assets with your eyes closed and fingers crossed.

Whilst muon detection isn’t a silver bullet, it might offer a ray of hope.

Sorry, I’ll get my coat.

STRUCTURES/INFRASTRUCTURE

Confidential Reporting for Safety This is Dave Dave works trackside and is concerned about his PPE Dave spoke up but was told to make do Dave called CIRAS and now has new gloves Dave is smart Be like Dave The name we’ve used is fictional. We share your concern so the company can address it. You will not be identified.

Work environment

Rules & procedures

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23/09/2020 16:43:26

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06/10/2020 12:12 Rail Engineer | Issue 186 | September/October 2020

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PLANT & EQUIPMENT

GRAEME BICKERDIKE

MOVING ON

I

t’s an inescapable reality that life is unpredictable; generally, though, its ups and downs impact uniquely on each individual. Yes, recessions hit periodically and make their presence felt broadly, but it’s many decades since an event caused the world to stop turning in the way coronavirus has, prompting a mass retreat into our homes.

I recently took my first train since lockdown - an evening peak service out of Leeds on the TransPennine main line.

Conventionally, I’d have to jemmy myself into the vestibule and cower beneath the armpit of a stranger as far as Huddersfield.

Not this time though. In a carriage offering 88 seats, there were seven of us. Second wave or not, one thing’s for certain - uncertainty will be with us until an alternative normality can establish itself.

But how do you plan and resource?

How do you remain efficient? How do you service the needs of a client who doesn’t know what their needs might be? These are amongst the challenges that will face the rail supply chain as, and when, Covid-19 loosens its grip.

Into the unknown There must have been a temptation for Total Rail Solutions (TRS) to just hunker down and wait for the storm to pass.

The company is known, historically, as a road-rail plant provider, with upwards of a hundred machines; now, though, it’s becoming increasingly visible for its contracting services and labour provision, with a workforce exceeding 300 in total.

TRS changed hands in 2018 and, under new management, has undergone a reprofiling from a successful ‘family business’ to something sitting very comfortably within the professionalised rail market. There’s been a determined effort to heighten brand awareness and introduce systems that deliver management and operational improvements.

The hiatus of lockdown was used as an opportunity to relocate to new premises at Greenham, near Newbury, served by the M4 and located perfectly for works along the Great Western main line corridor. A few years ago, the route’s electrification programme proved transformational for the company and it continues to build on the financial and reputational benefits that brought.

The main building accommodates core operations and administrative staff whilst

a nearby yard and workshop is home to the engineering team. The site offers improved logistics over TRS’ previous base at Basingstoke. “It’s a really good showcase for the business,” asserts Paul Bateman, the firm’s chief executive officer. “We plan on hosting a number of client engagement events here when circumstances allow.”

Spreading wings Whilst the company is a national player with a go-anywhere attitude, any map showed it to have a presence only in southern England, with a satellite depot at Cwmbran. This had the potential to impact on perceptions. “So, it was a strategic move for us to put something in the North”, says Paul, who

I

Rail Engineer | Issue 186 | September/October 2020

PLANT & EQUIPMENT

met at the firm’s new office near Doncaster, where a business development manager is now located.

There’s a workshop here, storage space for a handful of machines and room for growth. And other bases could be established elsewhere if a particular client or project warrants it. Responsiveness is the watchword.

The move reflects broadening horizons on the back of securing a framework contract with Network Rail which continues to gain traction within the local maintenance teams. “There’s a positive message to send out from that,” Paul suggests, despite the difficulties affecting the industry. “If you perform, work is there.” Securing more of it will soon see the recruitment of a head of business development, whose role will involve being persistent!

Golden accolade TRS is a service business, not just a provider of big, shiny plant. The Great Western Electrification Programme (GWEP) gave the company continuity of business and enabled it to grow the fleet. But now it wants to be the ‘go to’ supplier for a broader community of clients where there’s an opportunity to collaborate - embedding staff within a project team from the outset to find solutions. “We’ve had a lot of work off the back of GWEP,” reflects Paul, “because

we were reliable and always said ‘yes’. But we won’t put salesmen into teams - these are operational guys who’ll be out on the Saturday night doing the work.”

Client expectations have evolved over the years. It’s no longer just a case of delivering to a kit list; as a qualified POS (Plant Operations Scheme) provider, it generally now involves an assessment of the job requirements to ensure they can be met in the safest, most efficient and cost-effective way. “But the three key things are still reliability, delivery and attitudes on the night,” says Paul.

The company’s plant failure rate is particularly good - in part, a function of the fleet’s low age profile - resulting in the recent award of Gold status on Network Rail’s online plant reliability system, which was implemented to monitor performance of supply chain equipment. “It’s great for

us and a testament to Fitzgerald Plant Services who maintain our kit,” Paul acknowledges. “The key for me, though, is to retain gold status.”

Going forward, a strategic decision has been taken to bring some maintenance in-house to address risk to the business.

Fitters have been recruited and an engineering team is being built up at Greenham to manage the fleet’s servicing needs, although Fitzgerald will remain a crucial player to the business.

No going back Everyone in the plant sector feels the pressure to innovate. Beyond the natural programme of fleet refreshment is the search for the next big thing that will bring commercial advantage. Network Rail actively encourages innovation in response to practical constraints

Rail Engineer | Issue 186 | September/October 2020

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PLANT & EQUIPMENT

encountered on site. Times are tough, though, and, with no guarantee of returns in the current climate, making sustainable investment decisions is acutely challenging.

“You’ve got to trust your instincts,” Paul believes. “Clearly, we’ve paused a few things with everything that’s going on, but it would be a failure on our part if we weren’t ready as and when the work comes back online. So, we’re progressing several R&D projects behind-the-scenes which utilise existing equipment and, we believe, will generate interest in a specific area. You’ve got to look forward.”

Growth spurt Punching above its weight is one of TRS’ longstanding attributes, a function of persistent successful delivery, effective relationship building and the right level of kit. Whilst there’ll be no compromise in those areas, Paul’s keen to achieve more coverage across the UK and to become operationally slicker.

The firm has recently launched a new platform, TRS Digital, to allow POS packs, method statements and risk assessments to be retrieved and returned via smart devices, whilst a US developer is currently creating a system to integrate all aspects of running the business on a day-today basis, from resourcing and fatigue management to transport and accounts.

That should be in place for the next financial year.

A big push, though, will see more prominence of TRS’ contracting division through which it is able to deliver labour, plant, materials and supervision for delivery of complete civil engineering projects, such as earthworks,

platform extensions, drainage schemes and car parks. From nothing, this has established a new revenue stream - and client base - around the company’s core strengths in people, plant and process.

“It complements what the main business does,” says Paul, “and over the past few months - during the pandemic - things have really taken off. We’d like to think this will help to get where we want to be.”

Facing the future The emerging picture for the railway contrasts a rather gloomy foreground against a positive backdrop. There’s no escaping the short-term challenges presented by Covid and signs of revenue recovery are - if my personal experience is anything to go by - difficult to spot. But society cannot remain fundamentally distanced forever; we’ll have to find a way to move beyond this.

Rail Engineer | Issue 186 | September/October 2020

Logic dictates that there will be opportunities for the railway’s supply chain, and lots of them. The issue testing many companies is how best to handle the prevailing constraints whilst waiting for that work to land.

For Total Rail Solutions, an enforced period of consolidation has not halted its continued evolution into a smart, ambitious and responsive provider, not just of reliable plant but - perhaps more valuably - of effective solutions.

Serious planning TRS offers a complete project management service that takes you all the way from plan to plant.

Grounded in our unrivalled industry knowledge and expertise, we can save time, protect budget and improve quality on your next project – helping you get the job done safer and better than ever before.

Call 01962 711642 for more or go online. totalrailsolutions.co.uk

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PLANT & EQUIPMENT

Rhomberg Sersa’s GRAHAME TAYLOR

list of

s e s s e c suc

Rail Engineer | Issue 186 | September/October 2020

PLANT & EQUIPMENT

I

t seems a world away. December 2019 was so uncomplicated, with the agonies of Christmas shopping being just one of the rather minor issues to cope with. It was back in December that avid readers of the Rail Engineer magazine were introduced to the Rhomberg Sersa machine group project, with expansions on the theme being added in February, March and then May/June of this year.

This month we have a ‘Grand Summary’, a recap of the whole system along with some fine examples of where, when and how the machines - individually or in combination - have been used in real life.

But for new readers, or for those whose memory span is shortening by the day, here is a brief reminder of what is meant by the machine group and what those six machines can actually do.

The ITC-BL4 At the ‘front’ of the machine group is the ITC-BL4. This is an upscaled ‘dustpan and brush’. Evolved from the tunnelling and quarry industries, it is used to excavate a track bed ahead of itself and to shift spoil between its legs into awaiting in-line material conveyancing machines.

It is transported by haulage contractors by road and does not need movement orders as it is neither over-length nor over-width.

It runs on ‘caterpillar-type’ tracks as well as flanged rail wheels, and so can operate on the track bed where the rails have already been lifted.

The MFS+ machines These are special in-line material conveyancing machines. These have been based on conventional MFS wagons – the ones in a consist of hopper-cum-conveyor-belt vehicles that have been used for many years in re-ballasting works.

Their unique selling point is that they are fitted with caterpillartype tracks that can be lowered to carry the entire machine off-track and into an excavated worksite. In fact, this rather understates their true capabilities as, once released from the confines of the rail system, they can be manoeuvred with surprising nimbleness – or, at least, nimble for something that weighs up to 110 tonnes fully loaded.

The UMH Finally, there is the UMH – Universal Materials Handling machine – or the ‘Swiss Army Knife’ of material distribution vehicles. The UMH is rail mounted but, unlike its companion machines, the ITC and the MFS+, it does not have retractable caterpillar tracks.

It is marshalled conventionally within a rake of MFS wagons – usually at the end. It can travel at 60mph and has an RA1 route availability. It is a material handling machine kitted out with several systems of conveyor belts.

Rail Engineer | Issue 186 | September/October 2020

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PLANT & EQUIPMENT New or spent material is fed by the conveyors of adjacent wagons onto an initial lower handling conveyor at one end of the UMH. The UMH is thus direction sensitive - which is another way of saying that it has to be marshalled the right way round within a train and the whole train has to be the right way round as well!

From the initial handling conveyor, the material is directed to one of three other conveyor systems. The upper conveyor takes material and delivers it up to 6.5 metres either side of the track centre line. This has a capacity of up to 400 cubic metres per hour (about 800 tonnes/ hour) and can be used to feed materials into wagons on adjacent lines or onto an adjacent excavated track bed, such as depositing bottom ballast for spreading by dozers, or to the trackside. The upper conveyor can swing out to 90° to the machine - an arc of 180°.

Keep to just half a dozen...

These, then, are the machines. They are large, yellow... and unusual. Large, yellow and unusual machines have appeared before - several times over the years.

Some are still with us. Some have been shunted into the long grass. So, how have the Rhomberg Sersa machines got on?

Who better to ask than Tom Cherryholme, lead supervisor with Rhomberg Sersa and someone who has been directly involved with their use for the past five years – right from the start, in fact.

When asked how many sites he’s been involved in and which ones would be best to include in this article there was a pause.

Then, a muttered: “Two… three... six... eight... twelve... about fifteen probably... maybe more.”

OK, hang on. With a wordcount of about 1,500 words, perhaps we should concentrate on half a dozen!

The single line platform Liverpool Lime Street station Platform 7 is a single line platform in an extremely confined area. Approached through narrow tunnels, it was the first outing for the machine group. Ballast for the formation was placed by the MFS+’s taking delivery of material from a rake of conventional MFS wagons.

Single line platforms and the like are the system’s forte. They are forever on the ‘difficult’ pile. They cannot benefit from materials or plant being fed from an adjacent line using conventional machinery. Hitherto, the working methods have been clumsy, imprecise and timeconsuming.

On the other hand, an ITC can make short work of the excavation and materials are shifted straightaway into waiting MFS wagons. MFS+ machines can deliver ballast precisely.

The island platform The ITC was first deployed on a platform track-relaying job ‘under the wires’ through the island platform at Acton Bridge in Cheshire. The overall project was a relaying job of about 500yds.

The track at one end of the platform was excavated conventionally, with the 265yds through the platform being dug with the ITC feeding the MFS+ machines which, in turn, fed the awaiting MFS wagons.

Grading of the formation was done by a dozer feeding the ITC. This first project was a composite effort between conventional and new methodologies.

Working with geotextiles Geotextiles are great for separating layers of material – it is what they are designed for.

They are not so great at withstanding being trampled on directly by heavy machinery.

MFS+s are very large, very heavy machines and yet, with some clever research and experimentation, geotextile membranes easily survive their encounter.

The trick is to set the belts running and sprinkle a 4” layer of ballast on the geotextile just ahead of the MFS+ as it enters the excavation. Effectively installing its own haul road, the MFS+ makes its way to the far end of the excavation before gathering full loads of 60 tonnes which is then placed on the bottom ballast for dozers to grade. The offloading rate outstrips the dozing rate and so the MFS+ output doesn’t figure on the critical path for the project.

This method was used successfully on a single line at Park South curve near Barrow.

Working with high cant A project at Holton curve in Cheshire showed that track/formation superelevation does not cause a problem with the precise dropping of ballast by MFS+ machines. The alignment of the top belt has an adjustment of about five degrees

Rail Engineer | Issue 186 | September/October 2020

PLANT & EQUIPMENT Is this a guess? Has this been tried before? Indeed it has. This method of drainage works has been trialled at Tyne Yard and so there is confidence that ballast placing will be effective.

Another job in Scotland using exactly the same method would have taken place already, but for the rapid introduction of the lockdown.

Off-loading large quantities in a small space either side of the centre line. This is a feature designed primarily to allow precise alignment of belts in a marshalled consist.

Happily, it can also be used in the dropping of ballast so that there is no tendency for there to be a bias towards the low side of the formation and for there to be a need for further grading by a separate dozer.

Ballast spreading At Cambuslang in Scotland, at a site called Hoover (it’s opposite a Hoover factory), the UMH, in a consist with MFS wagons, was trialled as an alternative for the SKAKO train. The SKAKO train has been used extensively to spread top ballast throughout Scotland, but it is now getting old. It runs in a formation of ten 60-tonne wagons, each of which has a small side-belt that reaches out 2½ metres – not quite far enough to reach the cess.

The UMH has a selection of belts, all have a distribution capability of reaching up to 6.5 metres from the centre line (that’s around 5.25 metres from the sleeper ends). The control of the output is precise so that ballast delivery can be started or stopped at any time.

At Hoover, the train ran through at a steady 1mph with the belts being adjusted to cope with high or low spots in the ballast. Even though the top belt is large, it was still possible to drop between the rails.

The drainage project At Stanley Joiners Shop in Perth, two UMHs, working in tandem, were used in a drainage project. Each UMH was marshalled with a consist of MFS wagons.

One MFS consist was loaded with pea gravel, for pipe bedding, and the other part of the consist was loaded with track ballast.

The bottom bed of pea gravel was laid by the UMH. The drainage pipes were then installed and the remaining pea gravel placed over the pipes. The second UMH then ran through the site placing ballast to backfill to cess level. There were no problems reaching any part of the drainage channel – even over the track on which the road-rail vehicles travelled.

The bottom belt-end was over the sleeper ends. When the belt started running, the speed of the belt propelled the stone into the drain.

A novel use of the UMH was near Kincardine, where there was a requirement to concentrate 700 tonnes of excavated material in an area of about a tennis court.

Again, the reach of the belts made this straightforward, with all of the material laid clear of the running lines and with no need for further dozing or double handling.

This ability to process and concentrate large quantities of material in a small area is ideal for backfilling earthworks and material distribution on bank slips.

The 700 tonnes at Kincardine was placed in about an hour in a virtual quarry approximately four metres high.

The game changer By now, Tom Cherryholme’s half a dozen sites has become seven, with crossreferencing to another two! Tom’s list was of real-life projects and real-life successes - the Rhomberg Sersa machine group has left its experimental stage far behind.

Right at the start of this series of articles, Network Rail’s Steve Featherstone called the project a ‘game changer’. Even though the world, as we presently know it, has been turned upside down, this deserved accolade remains as valid as ever.

Rail Engineer | Issue 186 | September/October 2020

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FEATURE

Emergency power why settle for standard?

JOHN STONE

F

or too long, power supplies have been treated as an after-thought to the main design project. It is when all the other features and functions, as well as aesthetics, are finalised that the power supply is specified, and then has to be designed in. By that point, the desired specifications may be unattainable and/or the allocated space insufficient for the optimal power supply.

This can be avoided by putting power supply design higher up the design project criteria.

Using the resources of specialists in power conversion can also benefit a project. Such specialists have access to products from different manufacturers, and the technical expertise to customise a power supply for a specific application can make all the difference to an effective project being delivered on-time and on-budget.

Emergency power systems

The ODX-3000 series of DC-AC inverters from Premium is available from Relec Electronics.

An example of sourcing application-specific products for the demanding rail environment is DC-AC inverters for emergency HVAC (heating, ventilation, air-conditioning) systems. A ventilation circuit is vital to ensure fresh air is supplied to passengers and staff in the event that a train should lose its main power source midroute.

Relec’s portfolio includes single and three-phase DCAC inverters from Premium – manufactured to be particularly suitable for operation in extreme temperature and humidity, shock and vibration conditions, yet in a compact size for use in small spaces.

All Premium DC/AC inverters comply with EN50155, guaranteeing performance for electronic equipment used in rolling stock.

Emergency HVAC systems are equipped with DC-AC

Rail Engineer | Issue 186 | September/October 2020

inverters which are supplied by batteries that can range from 24V to 110V. The input power is converted into three-phase AC power, to allow the inverter to feed a three-phase motor which switches on fans in the carriages to maintain the ventilation system. Failures under extreme mechanical stress cannot be tolerated.

The conformally coated inverters withstand the harshest of environments, whether mobile or static, for example in ‘at seat’ power in carriages and network security systems.

In addition to the conventional 24V and 110V inputs, the company offers a variety of inverters operating from 12V, 36V, 48V or 72V battery systems, all approved to EN50155 and EN50121-3-2, with options to meet RIA 12 surges and transients.

Premium has supplied DC-AC inverters (ODX-1300) for the emergency fans in CAF´s Civity fleet of commuter and regional trains in the UK (Class 195, 196, 197, 331, 397). It has also supplied the ODX-3000 and ODX-6000 DC-AC inverters for HVAC emergency systems in Bombardier´s streetcars in Cologne, Germany.

Communications systems Another series of DC-AC inverters is designed for trackside communications and to manage services on IP networks.

The Cotek SR-1600 Plus series of modular, intelligent DC-AC inverters is available with Simple Network Management Protocol (SNMP) communication for use in trackside applications as well as data centres. The SNMP Internet standard gathers and organises data about managed devices, regardless of hardware and software variations, to monitor and modify device behaviour.

The DC-AC inverters offer true sine-wave output with minimal total harmonic distortion (THD) of less than two per cent, to

FEATURE ensure power factor, low peak currents and efficient operation.

The standard 19-inch, 2U rackmount inverters are scalable, providing up to 6.4kVA per rack, based on 1600VA modules.

They have redundancy and hot swap features as standard and DC or AC mode can be selected with zero transfer time for uninterrupted power supply.

In DC mode, efficiency is 95 per cent.

The inverters are protected against reverse polarity connections and will also shut down, without damaging the systems, if the input levels rise outside specified parameters.

Both AC and DC outputs are protected against overload, short circuit and overtemperature conditions.

For both series of DC-AC inverters, Relec provides technical and practical support for power design to ensure that exacting conditions for extreme environments are met, while balancing passenger comfort and operator efficiency.

Relec Electronics has been providing specialist power conversion and display products to support professionals for over 40 years. Its team of experts is able both to source and provide standard products and to use its technical expertise to deliver a power supply with bespoke features and benefits that can make a measurable difference by delivering optimum performance.

In addition to sourcing standard solutions, the company’s experienced engineers are able to understand an application and its specifications to source the most appropriate products. All members of the sales and technical support team are engineers and can help with modifications to standard products or features for power conversion.

For trackside communications, the Cotek SR-1600 Plus series of intelligent DC-AC inverters are modular in design.

John Stone is sales director at Relec Electronics.

Rail Engineer | Issue 186 | September/October 2020

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FEATURE

DAVID SHIRRES

Vivarail?

WHAT NEXT FOR

Vivarail Transport for Wales unit on a test run.

D78 stock when on London Underground.

T

he imperative to decarbonise the railway has been the subject of various reports, conferences, and research grants, although, in reality, little new operational hardware has been produced to meet this challenge since Jo Johnson’s call to remove diesels in February 2018.

Nevertheless, without any industry action, since then there has been a 37 per cent reduction in CO2 emissions from electric trains as carbon emissions from UK electricity generation fell from 276 to 177 grams per kWh. Carbon emissions from electric rail passenger vehicles are now only a fifth of those of diesel vehicles. This illustrates why electrification is needed if there are to be further significant carbon reductions. However, other than in Scotland, no further electrification schemes have been authorised.

Yet electrification cannot be a universal solution and self-powered alternatives to diesel traction are also required.

Currently only one such train is approved for passenger service. This is the class 230 unit produced by Vivarail, the UK’s smallest train manufacturer.

Rail Engineer | Issue 186 | September/October 2020

Vivarail’s vision Vivarail’s chief executive Adrian Shooter was chairman of Chiltern Railways for 18 years before he retired in 2012. He is clearly enormously proud of his company’s trains. This much was clear when he invited Rail Engineer to visit his company’s facilities at Long Marston in Warwickshire to see trains being produced for Transport for Wales and the Isle of Wight.

Adrian explained that Vivarail was founded in 2012 to address the shortage of diesel trains.

His solution to this problem originated from a discussion with a school friend, none other than Rail Engineer writer Malcolm Dobell. At the time, Malcolm had just retired as London Underground’s head of train systems engineering and LU was about to replace its sub-surface D78 stock. In the late 1970s, Malcolm had been part of the engineering team that had introduced these trains and, as mentioned later, he agreed that they were ideal for conversion into main line diesel units.

FEATURE There were, however, two drawbacks. The D78 is limited to 100km/h (62mph) and there were concerns that the converted units might be considered to be ‘London Underground cast offs’.

However, Adrian was not deterred. He knew that there are a number of routes on which 100km/h was not a constraint, provided that the new units had high acceleration and, on Chiltern, his experience was that passengers liked suitably refurbished older trains.

Thus, in November 2014, Vivarail signed a contract with London Underground for the purchase of 156 driving motor cars and 70 trailers of D78 stock, the first of which arrived in Long Marston in January 2015.

Vivarail’s prototype Class 230 diesel multiple units used three D78 vehicles and first ran on Long Marston’s test track in April 2016. Adrian explained that the train is intended for use on lines which could be some distance from maintenance depots.

For example, West Midland Train’s Class 230 service on the Bedford to Bletchley line is remote from its Tyseley diesel depot in Birmingham. Hence, the requirement is to build a train that can be maintained trackside. This was done by providing an effective remotecondition-monitoring system, which, for example, activates an auto oil top-up system, and having equipment within easily detachable modules. Using a fork-lift truck, a Class 230 engine module can be replaced within ten minutes.

With over crowded diesel trains, a situation made worse by the cancellation of electrification projects, Adrian is sure of the demand for Class 230 units which, with its modular concept, can be used for any combination of traction, for example a diesel / battery hybrid. Furthermore, Vivarail’s patented fast-charging system could significantly increase the range of Class 230 battery trains on rural routes.

He has no doubt that Vivarail can make a significant contribution to railway decarbonisation and has become increasingly aware of the benefits of battery traction.

He does not envisage diesel modules being used on future Class 230 units.

He stresses that the Class 230s also have the further environmental benefit of minimal embedded carbons from the reuse of bodyshells and bogies. Fitting new equipment to withdrawn vehicles with many years’ life

remaining also offers significant economic benefits. Vivarail claim that the lease cost of their trains is half that of a new DMU. Vivarail currently employs about 200 and has its workshop at the Quinton Rail Technology Centre in Long Marston and a centre of excellence at Seaham in County Durham. This opened in 2018 to undertake engineering design, component overhaul and the manufacture of subsystems, with emphasis on bogies and wiring.

Having secured a £1.5 million loan from the Midlands Engine Investment fund, the company is now able to move from Long Marston to a new manufacturing facility at Southam, near Leamington Spa. This will enable production, engineering, design, and stores to be in one building.

Vivarail has also signed a contract with Cambrian Transport for the use of a oneand-a-half-mile test track at Barry in South Wales.

Unit 230002 was originally a prototype 2-car battery EMU and became the UK’s first diesel/battery hybrid train when a trailer car with 4 engine modules was added. It was then used to test this hybrid concept prior to the delivery of hybrid trains for Transport for Wales.

D78 stock London Underground’s D78 stock fleet consisted of 75 six-car trains, built by MetroCammell at Washwood Health in Birmingham, which entered service between 1980 and 1983. Each six-car train was made up of two, 55-metre long, three-car units. Each unit consisted of a driving motor coach (DM), a trailer car (TC)

Vivarail’s workshop at Long Marston.

Rail Engineer | Issue 186 | September/October 2020

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FEATURE Class 230 crash test.

Flexible-framed D78 stock bogie fitted with shoegear for use on the Isle of Wight third-rail system.

and an uncoupling non-driving motor car (UNDM). They are lightweight vehicles, the tare-weight of the DM and TC cars sold to Vivarail were respectively 30.7 and 21.2 tonnes.

They have a riveted aluminium underframe and bodyshell with four single-leaf doors per car, per side. As the trains operated on London’s District line, they were built to a loading gauge only slightly smaller than that of the main line.

Their 650-volt DC supply was provided from 3rd and 4th rails.

Each motor bogie had two 300V DC traction motors in permanent series. A pneumatic camshaft-controlled traction resistor configured each bogie set in series or parallel control and provided two stages of weak field. A Train Equipment Panel monitored the operation of essential equipment.

In the late 1990s, the trains were fitted with new bogies as the original bogies were prone to fatigue cracking. The new bogies have a flexible frame design with a knuckle joint in each side frame. Brake equipment was renewed at the same time.

Between 2005 and 2008, the D78 fleet was refurbished at Bombardier’s Derby works in a £77 million contract to create a modern passenger environment equivalent to that on a new train. This included new seat shells and cushions, floor coverings, grabrails and more

Rail Engineer | Issue 186 | September/October 2020

substantial metal armrests, as well as the provision of CCTV and improved public address.

London Underground’s wish to standardise its sub-surface fleet with S7 and S8 stock, which is compatible with its new signalling and control systems, resulted in the D78 stock being withdrawn ahead of its intended lifespan. Hence, Vivarail purchased trains with many years’ life left in them that were refurbished just over ten years ago and had relatively new bogies with little corrosion in their aluminium bodies. It seems they got a bargain.

Converting the D78s Readying the D78 stock for diesel propulsion on the main line required a number of modifications. One of these was improved crashworthiness, as the converted D78 stock will be exposed to collision hazards, such as those at level crossings, that do not occur on the closed

London Underground system.

This required the provision of a cage in the driving cab and redesigning fittings around it. Additional plating was also installed below the window panel to prevent objects piercing the cab.

This arrangement was tested at Long Marston in May 2015 when a modified D78 driving motor car was pushed to a speed of 36km/h (22mph) and released 80 metres from a three-tonne tank of water placed at cab level. The test was monitored by TRL and showed that the enhanced safety structure preserved the driver’s survival space.

With mainline operation also presenting greater adhesion challenges than experienced on LU, automatic sanding and a modern wheel slide/slip system was also fitted. Gauging was another issue that had to be resolved before D78 stock could run on the main line. This required the body height of the unit to be lifted by 73 mm, which was achieved through the use of a suspension rubber on the bogie centre pivot and on the vertical dampers.

The original camshaft control was replaced by modern power electronics to improve efficiency and to enable the train to be powered from different power sources. The Dutch company Strukton supplied a traction inverter combined with an auxiliary power supply and a fast battery-charger for each power-car.

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FEATURE

PHOTO: MALCOLM DOBELL

The traction system upgrade also included the replacement of the original DC traction motors with AC motors manufactured by Traktionssysteme Austria for improved efficiency and fine control of regenerative braking.

The diesel generator set was designed to fit within a standard raft of 2.9 x 0.9 x 0.9 metres with a common mechanical interface. It has a 110 kW Ford 3.2 litre engine, compliant to EU stage IIIB emission standards, which is coupled to an axial-flux threephase alternator. The generator raft weighs 1.3 tonnes and the diesel-powered Class 230 units have two engine rafts under each driving motor coach.

Similarly, the protype battery train, 230002, has two battery rafts under each motor coach.

This was built to test the concept of battery operation, rather than for a specific order, and initially used batteries from the 2015 Independently Powered EMU (IPEMU) trial.

The units are configured for up to three rafts per motor car and five rafts per trailer car. On diesel units, the fuel tank, which supplies two engine modules, takes up the space of one raft.

The generator and battery rafts weigh 1.3 and 1.7 tonnes respectively. An assessment of the vehicles’ dynamics confirmed that this extra weight was not a problem, given that the repurposed units will not experience the Underground’s crush loading.

Class 230 orders The first planned passenger service for a Class 230 unit was a trial on London Midland’s Coventry to Nuneaton route from early 2017 until the end of the company’s franchise in October 2017. Much work had been done during the previous two years to obtain ORR authorisation to place the prototype diesel unit, 230001, into service. In December 2016, it was based at Tyseley for mainline testing and mileage accumulation as the final part of the authorisation process.

Unfortunately, it then suffered an engine fire. Vivarail’s report on the fire identified various issues with the original generator set which was a third-party design. These were addressed by the in-house redesign of the generator set.

After the fire had thwarted the Coventry to Nuneaton trial, 230001 carried its first passengers in June 2017 whilst running the ‘Honeybourne shuttle’ at Rail Live.

In May 2018, Vivarail entered into an agreement to supply three two-car Class 230 diesel units for use on the Marston Vale line between Bedford and Bletchley. Units 230003, 230004 and 230005 entered service on this route in April 2019, immediately after receiving their OOR authorisation to operate. Each unit has a fully accessible toilet, dedicated space for cycles, wheelchairs, and pushchairs. They have a mix of airline seats, bays of four seats around tables, and some remaining tube-style sideseats. There is a USB socket at every seat.

In July 2018, it was announced that Vivarail was the preferred bidder to supply five three-car Class 230 units to KeolisAmey for the Wales and Borders franchise, to operate WrexhamBidston and Chester-Crewe services. These units, 230006 to 230010, are the UK’s first diesel/ battery hybrid units. They have two 100kWh battery rafts on each driving motor car and four diesel generator rafts under the trailer car. This configuration has been tested on the prototype battery unit, 230002, which achieved a range of 40 miles under battery power only.

These units are geofenced to ensure that their diesel engines will only idle in built-up areas. As they are hybrid units, their engines can be limited to 2,000rpm for improved reliability. The diesel-only units have a maximum speed of 2,500rpm.

Unit 230004 on 23 April 2019, its first day of passenger service on the Marston Vale line.

Diesel generator raft on show at Railtex.

Rail Engineer | Issue 186 | September/October 2020

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FEATURE

Class 230 units for Transport for Wales services.

(Top) Interior arrangement.

(Right) Walk through gangway and toilet.

(Bottom) Driver’s cab.

(Right) Work on Class 484 units for Isle of Wight at Long Marston.

Their interiors feature a power supply at all seats, air-conditioning, high-speed Wi-Fi, air-cooling, wheelchair and bike spaces, an accessible toilet, and a new walk-through gangway design. After slippage in the testing programme, these three units received their authorisation to operate from the ORR in August and will then be ready to transfer to Transport for Wales Rail Services.

Rail Engineer | Issue 186 | September/October 2020

In September 2019, Vivarail received an order that did not require modular traction rafts.

Instead, their repurposed D78 stock will become Class 484 units, refitted with collector shoes, to operate on the Isle of Wight’s third-rail network.

Five of these two-car units will replace the 80-year old tube stock that currently operates on the Isle of Wight. These new trains will be introduced in April 2021 after a three-month blockade of the 14-kilometre line for enhancement works, which includes raising platforms for the new units.

Adrian advises that Vivarail had suggested that it could supply its Class 230 battery

trains to operate the route to enable the 53-year old third rail system to be decommissioned.

However, this was not considered to be the best option perhaps because of the high initial cost of battery rafts.

Fast charging As the class 320 concept was developed, it became increasingly clear to Adrian that battery electric multiple units (BEMUs) were the future for shorter distance services.

However, their utility is limited by slow battery charging. To address this issue, Vivarail teamed up with Petalite, which specialises in high-speed, high-power battery charging,

FEATURE to apply for an award from Innovate UK’s Accelerating Innovation in Rail initiative.

Their project was for an innovative rapid-charging technology with static-energy storage to exploit low-rate cheap energy for high-rate charging. In July 2017, Innovate UK announced that it would fund £642,000 of this project, with Vivarail and Petalite contributing respectively £185,000 and £100,000.

This project used Vivarail’s protype two-car battery unit, 230002, which was sent to the Bo’ness preserved railway in Scotland for tests in October 2018, including three days of free public trials.

During these trials, the train’s batteries only needed charging for a few hours overnight from a mobile charging unit.

This trial gathered useful performance data and demonstrated that the battery train could provide a reliable service and the functionality of the electronic control systems.

It also demonstrated that the unit could accelerate at 1m/s² up the steep gradient on the Bo’ness railway.

In December 2018, Vivarail announced it would be working with Hoppecke to design and integrate batteries for its trains.

This includes the provision of air and water-cooling systems in the raft and battery packs to dissipate heat from the charging current, which is in excess of 1,000 amps.

Adrian explained that the fast charging system uses short lengths of 3rd and 4th rails These are only energised after a ‘handshake’ between the train and the charging system, which uses proximity sensors and RFID tags, has proved that it is safe to do so. The shoe gear is made of ceramic carbon to withstand the heat from the large charging current, which is controlled by the train.

The problem of supplying such high currents at wayside charging locations is overcome by having a large battery bank

that is trickle charged between train charging. Typically, this will be the size of a 20-foot container for a half-hourly service on a short branch line.

The final hurdle for the fast charge system is its approval for use. As would be expected for such a novel system, this has its challenges. However, after much work, it is expected that approval will be granted soon.

The end of the 12-month fast charging project was marked by a demonstration at Long Marston in March 2019, when representatives of Innovate UK and the Department for Transport observed a Class 230 being recharged in seven minutes.

Class 230 BEMU Vivarail’s battery trains and their fast charging system is an impressive concept, yet questions remain about range and the cost of batteries.

Adrian advised that a Class 230 BEMU has a range of between 60 and 100 kilometres, depending on the number of stops. This could be extended if it was acceptable for trains to stop every 80 kilometres or so for a seven-minute fast charge.

Network Rail’s Traction Decarbonisation Network Strategy (TDNS) has concluded that, of the 15,400 single track kilometres of UK unelectrified network, the elimination of diesel traction requires, respectively, 13,040, 800 and 1,300 single track kilometres of electrification, battery, or hydrogen traction. TDNS, like Vivarail, considers that battery

trains have a maximum range of 100 kilometres, although TDNS did not seem to consider the potential of fast charging systems. As an example, Adrian points out that the 196 kilometres between Glasgow and Fort William could be powered by a battery train if trains stopped at the mid-way point of Crianlarich for a sevenminute fast charge.

The cost of batteries also determines the most appropriate decarbonisation option. A two-car Class 230 BEMU has four battery packs, each costing around £100,000, with a seven-year warranty that requires a 20 to 80 per cent state of charge to be maintained. The unit monitors battery output and charge status and provides this information to the manufacturer to confirm that batteries are being operated as required for the warranty. The cost of the wayside charging battery bank also has to be considered.

For customers who may be deterred by the high up-front battery costs, Vivarail offers the option of paying for batteries on a per mile basis which, as Adrian pointed out, is likely to be less than the per mile operational and maintenance cost of diesel vehicles.

Fast charging shoegear on 3rd and 4th rails.

More rafts In line with the philosophy of having removable modules for any type of traction, Vivarail has been considering powering its trains from a 25kV supply and hydrogen. Adrian advised that six months have been spent

Rail Engineer | Issue 186 | September/October 2020

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FEATURE

(Above) Proposed Class 230 hydrogen train.

(Right) Right) Pop-up metro concept for lightly used freight lines in urban areas, 16 such locations have been identified in USA. The ‘starter kit’ consists of: 1. Trains and temporary modular platforms.

2. Charging infrastructure.

developing a transformer/ rectifier raft to power a Class 230 from the overhead lines and charge its batteries. Such a unit would require at least 25 per cent of its route to be electrified to keep its batteries charged.

Vivarail have also considered how a Class 230 could be adapted to become a hydrogen train, for which the problem is storage of a large volume of compressed hydrogen gas, which has a low energy density.

This problem is exacerbated as cylindrical tanks are not an efficient storage arrangement.

Vivarail’s proposed solution is a four-car unit with a mix of 315mm and 420mm diameter cylinders underneath two trailer cars with two battery and one hydrogen fuel cell raft underneath each of the driving motor cars. This arrangement would have fuel cells with a total power output of 400kW, batteries with a capacity of 400kWh and storage for 282kg of hydrogen, giving a range of 1,000 kilometres.

Another form of hydrogen generation is Steamology’s ‘water-to-water’ concept, which is an energy-dense turbine powered by steam generated from compressed hydrogen and liquid oxygen. The company was awarded a £350,000 grant for the total cost of producing a protype that fits within a Vivarail Class 230 raft. The purpose of this innovation is not clear, as it increases the problem of fuel storage on hydrogen trains by requiring the storage of both compressed hydrogen and liquid oxygen.

Rail Engineer | Issue 186 | September/October 2020

What next?

Over the past five years, Vivarail has succeeded in producing a flexible, modular platform which offers an alternative to diesel trains on short-distance services. Indeed, the prototype battery train, 230002, is the only potentially zero-carbon self-powered vehicle authorised for main line operation. The authorisation of new innovative trains is no small task, especially for such a small company.

On routes with frequent stops, the higher acceleration of a Class 230 BEMU offers a journey time that is less than that of diesel trains with a higher maximum speed.

However, for journeys requiring more than a few miles of main line running, the Class 230’s 100km/h maximum speed is unlikely to be acceptable.

With 1,000 vehicles of the sprinter fleet reaching 40 years of age between 2026 and 2031, it remains to be seen how much of the D78 stock that Vivarail has stored at Long Marston will be used to replace these vehicles. Yet it is quite possible that this stock might find service overseas, leaving few coaches available to be repurposed as Class 230 units in the UK. Adrian reports that there has been much overseas interest in

the Class 230 concept. Indeed, on the day of Rail Engineer’s visit, a representative from an undisclosed overseas railway was assessing its potential after he had just completed his two weeks self-isolation.

The two-car battery prototype unit is also to be showcased in the United States early next year. The Railroad Development Corporation, a major investor in Vivarail, is to use the unit to demonstrate its Pop-Up Metro concept, in which the lightweight Vivarail trains could be used on little-used freight lines in urban areas with very little infrastructure expenditure.

If D78 stock is to be used overseas, perhaps the technologies that Vivarail has developed, such as the fast charging system, could be used to repurpose other rolling stock and, by doing so, remove the current 100km/h restriction on its technology. Whatever the future holds for Vivarail, the company has shown itself to be adaptable and capable of delivering innovative operational solutions for UK rail’s decarbonisation challenge.

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Rail Engineer | Issue 186 | September/October 2020

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SIGNALLING/TELECOMS

CLIVE KESSELL

Combatting SIGNALLING FAILURES S

ignalling failures have always had the ability to cause delay to train services and, whilst modern signalling technology is designed to be more reliable, when failures do occur they can be much more significant as the systems are complex, often involving software as well as hardware components.

The results from the latter were deemed successful and Network Rail is proceeding with an operational trial between Castle Cary and Westbury on the West of England main line.

Chris Fulford, who has been the lead engineer on the project for some time, gave a report of progress to the IRSE London & SE section recently and has since given more details to Rail Engineer.

Problems to be overcome

In such circumstances, the local technicians can struggle to understand the nature of the fault and to apply the right diagnostics. Technical support from specialists, often the original suppliers, has to be brought in to assist.

A recent failure of the Ansaldo system between Cheadle Hulme and Crewe lasted for three days, with the line being closed for that period.

Network Rail was left with a large bill in compensation for the delay to trains. And, of course, passengers were badly inconvenienced, which didn’t help the ‘Putting Passengers First’ programme.

Rail Engineer | Issue 186 | September/October 2020

Rail Engineer has been following the progress of a system intended to minimise the effects of such failures and three previous articles have been published. Firstly in issue 129 (July 2015) when the project was known as COMPASS – Combined Positioning Alternative Signalling System, secondly in issue 155 (September 2017) when a new name – Degraded Mode Working System (DMWS) was introduced – and thirdly in issue 162 (April 2018), describing the results from a conceptual demonstration being tested on the Hertford Loop test track.

Signalling failures take many forms – loss of the signalling power supply, cable theft or damage, track circuit or axle counter failure, loss of communication between the interlocking and external equipment, component failures, control panel failures, plus several others. Some recent improvements to signalling reliability have already been made – the use of intelligent infrastructure, more resilient power supplies and better cable management.

However, failures still occur, and it can take a long time to set up current degraded mode working methods, now generally known as Emergency Special Working. The aim of DMWS is to reduce this time of, typically, three hours to 15-20 minutes.

SIGNALLING/TELECOMS The objective for DMWS is to independently monitor the position of points and the status of ground frames along a particular route, to disconnect these elements from the normal interlocking and, once satisfied that the track ahead is safe to proceed, to send an Authority to Move (AtM) to the driver for a specific distance ahead via the screen on the cab GSM-R radio.

Components required For DMWS to work successfully, it will need a train-borne facility, an infrastructure element and robust instructions and procedures.

All of these were demonstrated at the conceptual Hertford loop trial.

The train-borne equipment is relatively easy as DMWS facilities can be incorporated in the latest GSM-R mobile from Siemens – the V4 model, which already includes an LTE 4G capability and GPS, has considerable processing power within it. The rollout of this radio to all traction units was described in issue 172 (March 2019).

Building in the DMWS requirements is relatively straight forward, the only addition hardware being a GPS aerial on the train. Siemens is the sole supplier for the whole of the UK fleets and has the contract to develop software for DMWS. The infrastructure elements are more complicated but will be designed to use as many COTS (commercial off the shelf) products as possible, with some bespoke software in the central equipment. At each location where signalling failures could cause massive disruption, trackside equipment, known as Inhibit Detect Repeat (IDR), will be provided. This will monitor the status and position of points and ground frame releases and, when activated, will disconnect the control of these elements from the local interlocking. The IDR also inhibits control of points and ground frames and will suppress TPWS transmitters in the affected area to avoid tripping the train.

A national central system will be equipped with COTS servers, PCs and the DMWS application software, which will be controlled by local DMWS workstations in the signalling centres.

To connect the subsystems together, use will be made of the GSM-R network, in combination with the FTNx IP-based digital transmission nationwide network.

Once initiated, DMWS will capture the GPS co-ordinates from the train in order that an AtM can be issued. Whilst GPS is not sufficiently accurate to determine which track a train is on, it is sufficiently accurate for DMWS, which only needs to show distance to go to the end of the AtM. GPS need not show a train’s track, as this would be known if the system fails and DMWS cannot change the lie of points.

Level crossings will not be monitored, so DMWS will not know their state. This must be conveyed to the system by the signaller, who will confirm the status. Once enabled, DMWS will transmit its outputs to RADAR (the intelligent infrastructure database), to SIEM (the security platform) and to the RDG train location system.

SMS will be used for the sending and receiving of messages and commands with data being sent over GPRS. Since GSM-R is an open system, an independent authentication and verification process is required to protect against cyber attacks.

How does it work?

When a signalling failure occurs, a train will be stopped at a red signal. If the area has the DMWS facility, the DMWS zone for its operation will be identified by the signaller. The appropriate zone will then be selected, which may have more than one block section and will include an overlap, the length of which is predetermined according to the foreseen risk.

Once satisfied that inputs from DMWS confirm the status of points or ground frames, the signaller will offer an AtM to the train, which is in the form of an electronic token to give the train permission to proceed from signal xxxx to signal yyyy, displayed on the GSM-R screen.

Before any movement takes place, the signaller and driver will have a voice conversation to confirm their mutual understanding.

If in ETCS territory, marker board identifications will replace the signal numbers.

Once satisfied, the driver may proceed and the GSM-R screen will show a ‘distance to go’ countdown derived from the GPS position of the train. As the final signal is approached, an alert is given to the signaller so that the exit signal can be cleared. If that final signal shows a proceed aspect, then the train can continue without stopping.

For the first train through the DMWS section, a speed limit of 15mph over points and crossings will be imposed with a maximum speed of 50mph for subsequent trains. Should a train fail to stop at the end of the zone, assuming a red aspect is displayed, then TPWS will trip the train. If the train overruns an AtM limit within the zone, then this will be detected and the signaller and driver will receive an emergency alarm to stop the train.

Whilst the train TPWS equipment will remain active, there will be no active train stops in the DMWS zone. Readers who require greater detail should refer to the DMWS Demonstration article in issue 162.

It must be emphasised that DMWS is not an automated process, nor does it pretend to be an alternative signalling system. It will not make decisions, as these will only be taken by the driver and signaller in consultation with each other.

Rail Engineer | Issue 186 | September/October 2020

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Approval, safety and security As can be imagined, obtaining approval for the system will be a lengthy process.

The Common Safety Method (CSM) will apply and an Assessment Body (AsBo) and Independent Safety Assessor (ISA) will be appointed. Suppliers must be ISO 9001 registered and system integrator and sub-system suppliers will need to provide a safety case.

Network Rail will manage the operational system assurance trials and will be assisted by Mott Macdonald and the internal Signalling Innovations Group to develop the design standards and practices.

The SIL has been determined from first principles and SIL2 will be the maximum required. In this, the connections to the point-operating and TPWS-suppression circuits are the most critical.

DMWS is nonetheless a signalling asset, so its integration into existing circuitry is within the same discipline. As such, the assets will be included in the Signalling Maintenance standards, likely to be a risk-based exercise but taking account of opportunities for remote condition monitoring and associated diagnostics.

In time, RSSB will produce a rail industry standard to define the interfaces between track and train, together with the requirements for the control system.

Security monitoring will be required to protect, as far as reasonably possible, any intrusion from hackers or other external attempts to gain access.

DMWS is not seen as an interoperable system so Network Rail and the TOCs/ FOCs will apply their own safety management systems. The ORR is keeping a keen interest on developments.

Procurement Since Network Rail is a public sector body, the procurement process has to be strictly governed, but an attempt to introduce a different contracting approach is being tried for the trackside equipment.

One single supplier – Siemens – is being contracted for the train-borne equipment, as it already has the contract to supply the train radios on to which DMWS operations will be grafted.

Altran has already been chosen to be the system integrator and supplier of the central equipment. The partnership with others to provide an innovative solution is all important.

Network Rail will take on the Systems Authority role, but sub system suppliers will be the design authority for the prototypes.

Reflections, constraints and future prospects The early aspirations in 2011 for the COMPASS project had to be scaled back, being regarded as ‘too far, too soon’. A system to see if trackside point monitoring could be achieved was planned for trial on the ECML in 2012, but, in the end, it did not take place. More focussed R&D work commenced with the DMWS feasibility study in 2015, followed by a system simulation and then the conceptual demonstration on the Hertford loop in 2018.

From these, the business case has been established with the intention of covering all operating scenarios, but with the requirement to use as much existing equipment as possible and avoidance of an over-engineered solution. An interim generic safety case was accepted in March 2019, with authority granted in June 2019 for the building of a prototype system together with the operational trial on the West of England route, expected to be brought into use towards the end of 2022.

DMWS applications are intended for lines equipped with track circuit block or ETCS but not for the remaining routes operated by absolute block or for single lines. It is assessed that 25 per cent of the rail infrastructure will be suitable and by default, 100 per cent of the trains will be equipped. It is estimated that DMWS will

Rail Engineer | Issue 186 | September/October 2020

be used about 200 times per year, thus potentially saving many delay minutes and millions of pounds of consequential compensation payments.

The Castle Cary to Westbury trial will have limitations, as it cannot wait for a signalling failure to occur, nor is it likely to involve service trains. As such, test trains will be run at night on a scenario-based failure. An industry working group is established with trade union involvement, where human factor aspects will be allimportant. The reliability of DMWS will be key to ongoing deployment.

As to the future, one must perhaps look back to the COMPASS aspirations.

Certainly, the monitoring of level crossings was envisaged, but this will not be pursued as either they work or an attendant is required. More significantly, the system was seen as being able to instruct a set of points to be moved if these were wrong for the route of the train. Since this would raise the SIL level, it would make the system unaffordable, so will not be pursued.

Finally, one cannot help but comment that 11 years from the original COMPASS concept to an operational trial is a very long time for something that is promoted as being simple to commission with very significant financial benefits. Admittedly, the first four years were pure R&D and only from 2015 has any serious work commenced.

It does make one wonder, however, whether all the planning, regulatory and safety requirements have become a minefield of bureaucracy and need to be streamlined.

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SIGNALLING/TELECOMS

CLIVE KESSELL

Driving innovation IN SIGNALLING

I

nnovation seems to be the latest buzz word. Recent conferences and seminars, as reported in Rail Engineer, have focussed very much on this theme, often coupling it with ‘The Digital Railway’. Having listened to a recent offering by Peloton, I did just wonder how much real innovation is actually taking place and in what areas?

Two speakers, Toufic Machnouk from Network Rail and John Doughty from LNER, explained how the deployment of ERTMS (more succinctly ETCS) would take place on the ECML. One wondered, however, just what the innovative elements are for this project, as compared with rolling out a developed system in a new environment and thinking through the likely problems that will emerge along the way.

Let’s look at what was said.

The infrastructure view Route programme director Toufic Machnouk had given an overview of the ECML project at the recent RIA conference on the digital railway (issue 185, July/ August 2020). As well as the phased approach for the implementation, starting with the Finsbury Park to Moorgate section and finishing at Stoke tunnel, just short of Grantham, he described many other factors that are going to be part of the project.

Network Rail sees six critical factors for ensuring success, of which three were explained in detail. Quite what the other three are will need to be investigated some other time.

The usual claims of ETCS being a higher performance, greater capacity and lower whole-life cost railway were trotted out, but system integration in all its aspects is the one key element where the success criteria will be judged.

Firstly, the partnership with industry needs to be changed and improved. The calculations indicate that 13 organisations will be involved in the ECML project. These include Network Rail itself, with its different groups of management, projects and maintenance; the various train operators that use the line, including passenger, freight, heritage and charter; the supply chain companies, which will include subcontract suppliers; the safety and acceptance authorities and, of course, the government as the overall paymaster.

Industry is not currently set up to enable all of this and it requires some sort of overarching structure to bring industry together. This is recognised as not being easy and it is taking many years to get in place. Lessons are being learned from what has happened with ETCS rollouts in Europe, helped by many of the companies operating on an international perspective.

Every participant will need to act differently, which requires a fundamental mindset change. Companies must step out of their traditional shell of business boundaries and short-term financial results.

Secondly, there is the need for technology centricity. Each of the suppliers need to adopt a long-term stake in the programme. This will include the capability of introducing change as technology and rail infrastructure layouts change, without the need to renegotiate contracts and

Rail Engineer | Issue 186 | September/October 2020

variation clauses. A framework relationship, including design, build, commission and maintain, will be a required commitment from each supplier. Part of this will be a better understanding between engineers/ technologists and the people who operate the railway.

Thirdly, the railway needs to recognise that actions must be orientated to outcomes. The individual capabilities of infrastructure engineers and rolling stock engineers are reasonably well known, but this is not sufficient. They must become aligned with the total change needed on how to run a railway.

SIGNALLING/TELECOMS

The benefits of the ECML project have to be progressive. New ways of operating the route have to be devised and rolled out as ETCS makes its way northwards. It is recognised that disruption is possible, but the aim must be to make the transition seamless in the way that the railway is run.

One example would be to capitalise early on the bi-directional working that will be made possible. A study has been made of the Cambrian line ETCS conversion (now 10 years old), which struggled in its early stages but which eventually came together.

Operations and not technology were the key part of this.

The train operator’s view Although many operators use the ECML, it is LNER that is the dominant operator on the line and so it will have the lead role in determining the maximum opportunities that can be

gained from introducing ETCS to the route. John Doughty, as the engineering director for LNER, indicated that the new technologies being made possible will go way beyond the introduction of just the ETCS element.

Some things are a given: safety and performance must be maintained or enhanced, financial sustainability must be ensured, a legendary customer experience must result, the business must continue to act responsibly and in partnership with others. Traffic Management Systems (TMS), Connected Driver Advisory Systems (C-DAS) and reduced energy consumption are recognised as complementary systems to ETCS. Less obvious are smart ticketing, phone catering, a simpler fare structure and, probably, no paper tickets – all things that LNER would like to see happen in parallel with ETCS introduction.

Within the company, there is an air of excitement that ETCS is coming, but no illusion exists as to some of the challenges.

Other major projects like King’s Cross remodelling and the Werrington dive under will be completed, and these and possible similar route enhancements will lead to a more reliable railway. However, a rewrite of the operating rules, an understanding of the system interfaces, the switching in and out of ETCS areas, developing the TMS and C-DAS interfaces and working in an acceptable degraded mode when failures occur, are all major considerations.

Then there is the training of thousands of staff – not just drivers and other train crew, but all the backroom jobs of timetabling, train and crew rostering, platform and station staff and, importantly, the management team.

Acronyms defined » ECML - East Coast main line » ERTMS - European Rail Traffic Management System » ETCS - European Traffic Control System » GSM-R - General System for Mobile communications - Railway » LNER - London North Eastern Railway

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06/10/2020 16:38 Rail Engineer | Issue 186 | September/October 2020

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SIGNALLING/TELECOMS The Azuma experience LNER is fortunate in that it has a brandnew train fleet, the Azumas, where many of the processes for a major system upgrade have already been faced. The new trains and their complex systems have impacted on signalling and infrastructure.

An example is the auto changeover from electric to diesel by the use of track balises.

This has proved a real challenge, but is successful now.

Train crew training was geared around recruiting drivers in advance of the main training programme, so they could then train the others. A similar opportunity has been taken for some drivers to have been trained on the Cambrian line, so that a full feel of ETCS operation can be gained, after which these drivers will become champions for the training of others on the ECML in 2022/3.

The Azumas already have ETCS fitted, so the cab layout and associated displays will be familiar. The use of simulators and rehearsal trains has helped enormously (issue 145, November 2016), as has developing a critical relationship with the train builder.

A hard lesson is to make sure everything is right before bringing it into service.

Often the temptation is to commission something, knowing that niggles still exist, and to put these right in service, which then makes the problems more difficult and adversely affects reliability. Engineeringout risk is important with any emerging requirements, as is the separation of commercial discussions from the operating control room.

Above all, operators must share their experiences, to avoid repetition of common problems and situations. For ETCS, the knowledge gained from Cambrian has been mentioned, but also learning from the Thameslink central core is proving important.

Questions and observations ETCS will, unfortunately, have to be introduced as an overlay to the existing signalling, as it is logistically impossible to introduce the system over a weekend or even an extended blockade. This situation will exist until 2024, when signals will begin to be removed. Does this mean ETCS having to have the same block sections as the conventional signalling? Or will ETCSfitted trains have movement authorities allowing closer separation?

Often taken for granted in the ETCS debate is the provision of the radio link between control centre and train. Currently this is GSM-R, which is a 2G system and will need replacement within the next 10 years. It was admitted that this link is crucial and without it, the whole system is undermined, with both control room and train equipment becoming, effectively, useless.

The replacement is seen as an ‘evolutionary process’, which is tantamount to saying that the problem has not really been thought about. This could be a future embarrassment when the new radio network is introduced if a seamless transfer of ETCS operation is not fully understood and tested.

Whilst interoperability is mandated for different suppliers’ ETCS products, interchangeability is not, so it begs the question as to whether different types of train equipment could be used as maintenance replacements for any failed

Rail Engineer | Issue 186 | September/October 2020

units? This is not regarded as a priority currently, but is recognised as a desirable feature for the future.

With ETCS likely to be rolled out on other routes during the period of the ECML project (it is already being tested as an overlay system on the Great Western main line between Paddington and Heathrow), what standards will be put in place to ensure interworking with multiple TOC fleets? And will a uniform deployment plan be put in place?

It seems that the RSSB will have a major role here, both to dictate and police the standards required. As to deployment, a catalyst will need to emerge for every route, with the first section being seen as difficult after which it will get much easier as knowledge is built up.

So where is the innovation?

In all of this, it is difficult to see where the actual innovation is. Certainly, it is not in the technology, as both the infrastructure and train equipment is well developed across Europe and beyond.

The deployment will need to be carefully thought through and the subsequent operation will need some new rules to be devised. Again, this is hardly innovation, much more a development of existing procedures and processes that will require a hefty training programme.

Similarly, for drivers, much improved information regarding the state of the line ahead will be available on the in-cab displays, and that should permit optimised driving techniques, with consequent time savings and less pronounced acceleration and braking.

As to the associated technologies of TMS and C-DAS, these, too, are well developed, but the LNER aspiration to do away with paper tickets is much more of a challenge.

Remember the crinkly brigade who might have a mobile phone but very likely not of the smart variety. Getting round this constraint could well require innovation.

Maybe we just need to redefine what the word innovation actually means, and so avoid using it in the wrong circumstances.

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56

SIGNALLING/TELECOMS

Chiltern ATP

obsolescence

PAUL DARLINGTON

I

n a signalling system with lineside signals and fitted with an Automatic Train Protection (ATP) system, a brake application will automatically be applied if a train is going too fast, thereby protecting the train from passing signals at danger. This is achieved by transmitting infrastructure data, including the maximum speed limit, to trains by a communication system.

ATP consists of equipment located trackside and on-board trains, with the communication normally delivered by using inductive ‘loops’, beacons or a radio link.

Following the investigation into the 1988 Clapham Junction Railway Accident, recommendation 46 of the report required that, after a specific type of ATP system had been selected, British Rail (BR) had to fully implement ATP nationally within five years. This would have been a huge task, but BR instigated two ATP pilot systems – one on the Great Western route and one on the Chiltern route – to help identify an ATP system that should be installed nationally.

The Chiltern route was selected for an ATP system based on the LZB system used in Germany. This was developed by Standard Elektrik Lorenz (SEL) and was called SELCAB. SELCAB used inductive

loops to communicate between the track and train on the approach to signals, using loops sometimes several hundred metres long and terminating at the foot of the signal.

SELCAB had some adaptions to fit the BR market, which made it a bespoke system and one not used elsewhere. On the Chiltern route, it was fitted between Marylebone and Aylesbury (excluding the Transport for London (TfL) section from Harrow on the Hill to Amersham) and from Marylebone to Anyho Junction on the route via High Wycombe. All the original Class 165 multiple units were fitted with the ATP system, but not locomotivehauled trains.

ATP systems may be continuous or intermittent, with the Chiltern system being an intermittent one. Continuous

Rail Engineer | Issue 186 | September/October 2020

ATP systems provide constant communication with the train throughout its journey, but, in an intermittent ATP system, the data is transmitted to the train only at specific transmission points along the track. These are normally at signals and high-risk locations between signals.

Intermittent ATP systems are mainly ‘an add-on’ to lineside signals, with their main purpose being to prevent trains from overrunning stop signals. However, the SELCAB system could also supervise train speed for Permanent Speed Restrictions (PSRs) and pre-programmed Temporary Speed Restrictions (TSRs), but not Emergency Speed Restrictions (ESRs) unlike the trial ATP system provided on Great Western route, which was based on the Belgian TBL (Transmission BaliseLocomotive) ATP system.

SIGNALLING/TELECOMS TPWS not ATP In 1994, Railtrack, the newly-privatised rail infrastructure company, took over the installation of the Chiltern ATP infrastructure system and put the deployment through its new safety review panel process. This provided independent safety assurance and moved it from a pilot system into full use.

At the same time, a study was also carried out into the cost-benefit of providing ATP across the whole national network. This concluded that the ‘cost per fatality prevented’ of £14 million could not be justified and so it was decided that ATP deployment would not proceed beyond the two trial systems.

A project was then launched jointly by Railtrack and the British Railways Board (which, at the time, was the exclusive train operator) to pursue a Signal Passed At Danger (SPAD) Reduction And Mitigation (SPADRAM) project. The main outcome of SPADRAM was the Train Protection and Warning System (TPWS).

An enhancement of the Automatic Warning System (AWS), TPWS was, and is, a simple system that reduced ATPpreventable risk by around 70 per cent but at a fraction of the cost. AWS uses an electromagnetic arrangement to provide

drivers with an indication to show if they are approaching a red signal or not. If a driver reacts to the first warning given by AWS, they will normally have time to stop at a red signal. The risk is that the warning is not enforced and can be over-ridden by the driver. In more complex situations, such as running on cautionary signals, it relies on a driver’s vigilance to initiate the brake application.

TPWS added radio frequency (RF) loops, to provide an automatic train stop, and an overspeed sensor on the approach

to the signal. TPWS does not entirely prevent SPADs from occurring, but, in the majority of cases, it reduces or avoids the consequences of drivers failing to react to signals. TPWS was mandated by the Railway Safety Regulations 1999 (RSR1999), which came into in force from January 2000.

RSR1999, and therefore the law, requires infrastructure managers and train operators to permit only trains with train protection equipment fitted to operate.

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Rail Engineer | Issue 186 | September/October 2020

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SIGNALLING/TELECOMS system which can stop a train if it passes a red signal, if it approaches a red signal at too high a speed, or if it is driven too fast.

These new regulations also said that, where it was reasonably practicable to fit ATP, then it had to be used. This meant that both the Chiltern and Great Western ATP systems were to remain in service alongside TPWS. The timescales for TPWS fitment were challenging and required it to be fitted on all trains and at all ‘selected signals’ (such as converging junctions and complex track layouts) by 1 January 2004. Today, Railtrack is criticised by some for its project management performance, but complete fitment of TPWS to all trains, and over 12,000 signals, 650 buffer stops, and around 1,000 permanent speed restrictions, was completed by December 2003.

TPWS has been a huge success and SPADs are no longer the risk they once were. The RSSB annual safety report for 2019/20 highlighted that the 10-year rolling average for fatalities caused by train accidents had fallen significantly since 1994, partly due to the reduction in signal over-run risk.

Once fitted, however, the benefits derived from TPWS undermined the economic case for providing full ATP, but TPWS trackside equipment is only fitted to signals beyond which conflicts, or other serious situations, are likely to arise. This meant there are many hundreds of signals, such as most automatic signals, with no TPWS protection.

In contrast, ATP is fitted to every lineside signal and permanent speed restriction, and provides continuous speed supervision, unlike TPWS which has limited capabilities to protect over-speeding. With ATP, the braking calculation is carried out on-board, and is therefore relevant to the characteristics of a particular train. The design of trackside TPWS is based on a general model of train braking ability, which may not be effective for all trains that operate on a particular route.

The Chiltern ATP equipment was supported by Alcatel and then Thales, but, with the system a bespoke ‘one off’ and no other systems ever deployed, keeping a complex technical system such as this one operational for longer than ten years was a major achievement. So, it was no surprise that, in 2011, 21 years after its instigation, Thales formally advised of the Chiltern ATP system impending obsolescence.

Just consider how many people have a computer or mobile phone still in use from 1990? ‘Last buys’ of equipment were initiated to create a stock of spares that would sustain the fixed infrastructure and fleet fitment. ATP equipment had originally been procured for the TfL Metropolitan Line, but was never fitted, as the line used mechanical train stops.

This unused ATP equipment has helped to keep the infrastructure part operational over the years, otherwise things would be even worse than they are.

A life extension programme for the on-track part of the system had been instigated some years ago. This consolidated documentation and training materials, with Park Signalling using its creative retro-engineering skills and modern technology to produce a replacement solution for programming and verifying the EPROMs that hold the TSR and ESR data. This was called the LEU Sequencer and replaced the ancient XS2045A machine originally supplied by GEC General Signal.

Park Signalling has prepared the TSR and ESR configuration data for Chiltern ATP since 2018.

The obsolescence problems were even worse for the on-board equipment, with no modern equivalent available and with the spares stock for the trains depleted to critical levels. Continued operation of the current level of ATP protection was becoming unsustainable and something needed to be done to replace the obsolete ATP system.

Options for obsolescence Providing a European Train Control System (ETCS) would seem the obvious solution, as ETCS Level (L) 2 delivers ATP and is also the long-term signalling solution for the country. However, the rest of the signalling assets on the Chiltern route are not life expired and there are other routes in the country with a greater need for the resource and capital required for ETCS. The planned deployment date for ETCS on the Chiltern route is around 2035, during Control Period 9.

Table 1. Comparison of system functions.

Function Supervision.

Transmission failure monitored. (Beacon or radio or inductive loop) Display to driver.

Monitors changes in permanent speed restrictions (PSR).

ATP

ETCS L2

Continuous supervision of driver using distance to go calculations.

Yes Changes to partial supervision mode with immediate brake application.

Yes Cab display and audible Warnings.

Continuous supervision of driver using distance to go calculations.

Yes Balise - failures reported on radio.

Yes Changes displayed to driver, based on braking performance.

Yes Changes displayed to driver, based on braking performance.

Yes Cab display and audible Warnings.

Standard TPWS Intermittent supervision and contact with lineside infrastructure.

Yes Failure indicated for most TPWS failures, signal on approach is held at red.

Yes Only brake demand and TPWS isolation/failure.

Some PSRs Speed checked on approach to the PSR and only Regulated PSRs.

Enhanced TPWS Intermittent supervision and contact with lineside infrastructure.

Yes Failure indicated for most TPWS failures, signal on approach is held at red.

Yes Only brake demand and TPWS isolation/failure.

Some PSRs Speed checked on approach to the PSR and only Regulated PSRs.

Monitors adherence to max line- speed.

Yes

Yes

No

No

Monitors diverging speed at junctions.

Yes

Yes

Partial Regulated PSRs when no restricting junction signal controls are provided.

Partial Regulated PSRs when no restricting junction signal controls are provided.

Monitors temporary speed restrictions (TSR).

Yes

Yes

Partial On regulated TSRs if in place more than 12 months or, less than 12 months on >100mph lines with >200 trains per day.

Partial On regulated TSRs if in place more than 12 months or, less than 12 months on >100mph lines with >200 trains per day.

Stop train if it passes signal at danger.

Yes Within overlap.

Yes Within overlap.

Some signals Only signals providing protection at junctions.

Yes All main signals fitted with TPWS TSS.

Prevent train approaching signal faster than braking performance permits.

Yes Using distance to go calculations based on train braking performance.

Yes Using distance to go calculations based on train braking performance.

Some signals If TPWS OSS fitted.

Yes TPWS OSS as fitted. Designed to stop as many trains as practical before conflicts.

Monitor position light moves (call-on).

Yes

Yes

No

No

Monitors train rolling away.

Yes

Yes

No

No

Table 1 – Function summary of ATP, ETCS L2, TPWS and Enhanced TPWS

Rail Engineer | Issue 186 | September/October 2020

SIGNALLING/TELECOMS ETCS is also best provided when new trains, fitted with ETCS on-board equipment as standard, are provided on a route, but the dates for new rolling stock on the Chiltern route also didn’t match the immediate need to manage the ATP obsolescence. Providing ETCS was therefore not seen as deliverable within the required timescales for the ATP obsolescence, or at an affordable capital cost.

A number of options were considered in detail. The chosen option would need to be affordable and offer value for money.

The technology and the skills to support the solution would have to be readily available, and, with the eventual end state of the whole UK railway being ETCS fitted, the selected option would have to fit this objective. The selected solution that met these requirements was Enhanced TPWS. A summary of the functions of ATP, ETCS L2, TPWS and Enhanced TPWS is shown in Table 1 (left).

Enhanced TPWS TPWS is an expandable system, so additional loops can be provided at automatic signals; buffer stops or speed restrictions. Therefore, it was anticipated that TPWS enhancements could make

TPWS closely match the functionality provided by the obsolete SELCAB ATP. Enhanced TPWS would provide Train Stop System (TSS) loops at signals not fitted with TPWS and Overspeed Sensor System (OSS) loops designed to stop a train short of a conflict. Enhanced TPWS would also provide optimum protection for ALL trains operating over the Chiltern route, as currently not all trains using the Chiltern route use ATP. All existing Chiltern TPWS installations would be reviewed as part of enhanced TPWS to check that the designs

implemented for the original TPWS project incorporate best practice that had been developed over the years.

On-train TPWS equipment would be upgraded to the most recent design standard, known as Mark 4 TPWS, which benefits from design changes to improve its effectiveness. Compared to earlier TPWS control panels, Mark 4 features three separate indicators to show the cause of a brake demand – SPAD, Overspeed or AWS. It also adds a covered ‘Brake Release’ button, to involve the driver in the brake release process.

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Rail Engineer | Issue 186 | September/October 2020

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SIGNALLING/TELECOMS Providing enhanced TPWS instead of ATP would, however, require an exemption from RSR1999 and a demonstration that a TPWS-based system would represent the only reasonably practicable solution. It was important that all stakeholders were made aware of the reasons and benefits of the enhanced TPWS solution, as RSR1999 says that railway regulator the Office of Rail and Road (ORR) may grant an exemption to the law, but is required to conduct a public consultation to assist the decision.

The Chiltern ATP Steering Group was formed, to work across industry boundaries and get the solution going.

ATP is a system involving both trains and fixed infrastructure and therefore must be managed as a system, so no one organisation could progress a solution without the help of the other.

The cooperation and collaboration between Chiltern Railways and Network Rail through the early formation of a steering group was instrumental in getting the project instigated for the benefit of both parties. Forming the group with a single purpose and common goals was key.

The steering group quickly decided that the minimum acceptable solution would be for a net neutral impact on safety risk across the route, which would need to be demonstrated to all stakeholders and inform the exemption and public consultation.

Any solution would need to allow the current train fleets – Class 165/0 Networker Turbo, Class 168/0/1/2 Clubman, and Class 172/1 Turbostar trains – to use the Chiltern route without SELCAB ATP.

PHOTO: STEVE FULCHER

60

Gary Faulkner and John Bartoszek maintaining the SELCAB ATP.

Independent risk assessment To provide expert independent guidance, Network Rail commissioned Mott MacDonald to complete a study into the potential solutions for an interim train protection system and Sotera Risk Solutions to provide a comprehensive, independent risk assessment to analyse a wide range of potential future risk control strategies for the route.

The Sotera assessment took into account East West Rail Phase 2, HS2 construction traffic and future passenger growth. The assessment concluded that enhancing TPWS by providing additional lineside fitment between Marylebone and Aynho Junction, together with upgrading the Chiltern cabs to Mk4 TPWS units, would provide a broadly similar, and even marginally lower, level of risk than the existing ATP fitment. It was calculated that the Fatalities and Weighted Injuries (FWI) index would be 1.9 per cent better with all trains on the route using enhanced TPWS, a figure that would be likely to increase further as the network gets busier, compared with maintaining the current ATP fleet.

Rail Engineer | Issue 186 | September/October 2020

The risk assessment looked at two strategies to deal with the unrepairable failure of ATP units on Chiltern Railways’ fleet until enhanced TPWS could be implemented. Option A would permit the trains to operate using existing TPWS and AWS. Option B would withdraw the train units from service until the enhanced TPWS upgrades could be implemented (by the end of 2023).

It was considered that, with a worst case of ATP systems failing irreparably on 20 per cent of units per year, the safety risk from Option B would exceed the risk from Option A, taking into account the potential for intermodal transfer to car or bus if trains were withdrawn from service. This strongly indicated the safer option would be Option A, and for trains to continue to operate using TPWS and AWS if their ATP systems could not be repaired.

The Office of Rail and Road (ORR) initially requested two RSR1999 exemption applications. Through close liaison between the steering group and the ORR, it was later agreed these could be made as a combined submission.

A short term (2020 to 2023) application would be led by Chiltern Railways and cover the period where ATP would remain operational on most trains, but be removed from trains that could not be repaired. The selected option (enhanced TPWS) would be implemented during this time.

The long-term application post 2023 would be led by Network Rail and cover the operation of the enhanced TPWS instead of ATP and allow ATP to be removed.

This combined exemption has been granted but is time limited to the end of 2026, to allow a review of the situation until ETCS is provided on the route.

Peter Dray, director at Sotera Risk Solutions, was pleased with the outcome.

“The obsolescence of the Chiltern ATP system presented the industry with a complex challenge… a challenge that extended well beyond the immediate

SIGNALLING/TELECOMS issue of managing a life-expired and unsupported train protection system,” he said. “The proposed way forward needed to account for planned network changes, optimising safety performance, cost, operational performance and deliverability within a tight timeframe.

“It is a credit to the industry that, from a wide range of options identified, a practical and effective solution was arrived at that could be agreed and supported by all the stakeholders and decision makers. The team at Sotera were pleased to be able to support the process through risk modelling of all the options, assisting with option selection and performing cost-benefit analysis.”

Public consultation The public consultation for “Exemption from train protection duties: Chiltern Railway routes” ran from 17 June to 15 July 2020 and invited any party to express a view on the application, with the ORR committed to consider all views in making its decision. The consultation included all the detailed proposals, risk assessments, options and safety arguments.

This process attracted constructive feedback from industry stakeholders. All of the comments were addressed to the

satisfaction of the ORR and an exemption certificate was granted that came into force on 13 August 2020.

The rail industry’s success in identifying an acceptable solution, securing exemptions from RSR 1999 and gaining support from the public consultation is a credit to all involved, is attributed to using recognised industry risk models and specialists who understood how to put together a numerate assessment of risk for the all the options identified.

This provided a solid basis for making decisions and justifying the plan for the project, one which was easily understood by all the stakeholders.

Active involvement with stakeholders before the exemption application

submission, together with incorporating feedback into those submissions, minimised the risk of objections to the formal application. The steering group ensured stakeholders, and the regulators who would make the ultimate exemption decision, were ‘taken along the journey’ as the option selection and plan were developed. This meant there were no surprises when the exemption application was submitted.

With the exemption now in place, mobilisation and design work for both trains and infrastructure is underway, with infrastructure and train upgrades to be implemented from early 2021 through to mid 2023. This will allow ATP to be turned off sometime in 2023.

Managing Risk – Optimising Performance Sotera is a leading, independent safety and risk management consultancy. Founded in 2002 to serve the rail industry, we set out our vision ‘to provide the best, most responsive and cost-effective services’ - a vision that is central to everything we do today.

Sotera works across the industry with operators, equipment suppliers, research organisations and regulators. The dedicated team helps provide solutions to the challenges that face our industry. > Risk assessment and modelling > Safety performance analysis and indicators > Safety decision making and cost benefit analysis > Research.

How can we help? Contact the Sotera team to see how we can support you.

Telephone: +44 (0)208 2890384 Email: peter.dray@sotera.co.uk

sotera.co.uk Rail Engineer | Issue 186 | September/October 2020

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SIGNALLING/TELECOMS

REB

THE LIFE OF AN

STEVE BARRY

F

irst introduced some 30 years ago, the ubiquitous Relocatable Equipment Building (REB) has become one of the most familiar pieces of trackside equipment, and, although they’re seen by millions of passengers each year, it’s likely that they’re rarely given a second thought.

Yet these modular structures contain a wealth of modern, innovative and increasingly digital technology and, on commissioning, REBs immediately deliver a huge range of benefits to passengers and operators alike.

The word ‘relocatable’ is a bit of a misnomer. Once fitted into the railway, REBs are not often then relocated. Rather, they are built up at the supplier’s factory, where the equipment can be installed in clean conditions and then checked and cross-checked, and then relocated ‘ready to go’ to their intended site.

One of those suppliers is Siemens Mobility, which has been supplying REBs from their first introduction. Over the last five years, its highly trained and highly skilled team has designed, manufactured and delivered around 60 units to projects across the UK. Although not widely recognised, all trackside equipment supplied by Siemens Mobility in the UK is actually built in the UK, with the company’s manufacturing capability for rail infrastructure extending across three dedicated sites. REBs are manufactured at the company’s largest plant, in Chippenham, Wiltshire.

REBs, or rather the systems within them, are complex and safety critical.

The manufacture of each individual unit therefore requires the involvement of a wide range of disciplines, all of which must be carefully choreographed to ensure the system meets each individual projects’ precise requirements.

Rail Engineer | Issue 186 | September/October 2020

SIGNALLING/TELECOMS Design phase The first, and arguably most important, phase of the process is the design.

Drawing on the signalling scheme plan, the team responsible for delivering the project takes responsibility for the design. This can be at any one of Siemens Mobility’s seven regional delivery offices, but the responsibility for the REB design lies firmly with the delivery team.

The design engineer translates information from the scheme plan, configuring the required REBs, Modular Equipment Housings (MEHs - if a modular solution features in the scheme) and location cases. At this stage, the details of the power and network configuration are developed and finalised. Depending on the complexity of the scheme plan, it is likely to be possible to automate some or all elements of the design work, particularly where modular, digitalready solutions feature. These systems take advantage of templated designs and standardised components to drive efficiencies and deliver cost-effective schemes.

With more than 150 years’ experience of the UK’s railway network, the Siemens Mobility team has a wealth of knowledge and technical understanding to draw on, with the ability to deliver complete turnkey solutions if required by the customer, including digital signalling, control, communications and electrification systems.

Siemens Mobility Chippenham, UK manufacturing team wiring an REB based on bespoke designs.

Manufacture Once the design has been completed and verified, the design engineers work with the company’s GB-based manufacturing team to work through the REB specification, which may well incorporate Siemens Mobility’s Trackguard Westrace MkII and Trackguard Westlock interlocking technologies, all manufactured at the company’s Chippenham production plant. Lines of communication between the relevant project, manufacturing, engineering and research and development (R&D) teams are short and clear, with each team – including around 200 R&D staff – based in the UK.

Environmental test chambers are also used to cycle the product through extreme temperature changes. This process puts thermal stress on the components, causing any weak elements to fail under controlled conditions. Any component failures are then replaced at the factory, preventing the occurrence of early-life failure on a live railway that could have the potential to disrupt service operation and impact passengers. This is just one of the test steps used to maintain high product quality, which is the whole point of an REB being built up under factory conditions.

Following an initial review by the manufacturing team, at which point any issues or concerns are raised, discussed

Siemens Mobility Chippenham, UK manufacturing site with 20 dedicated REB production bays with a throughput of 250 per year.

Rail Engineer | Issue 186 | September/October 2020

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SIGNALLING/TELECOMS and resolved, a full Bill of Materials (BoM) is produced, capturing every individual line item required to produce the REB. With around 5,000 individual components in a typical unit, this process is part automated, so that, for example, if a Train Protection and Warning System (TPWS) unit is included, the standard elements of the component can be called in to the BoM. Once complete and checked, the BoM is released and a unique part number generated for the REB, which will remain with it throughout its life.

On acceptance by the customer, and on receipt of a purchase order, the required parts are then procured either through the Siemens Mobility factory or through the company’s established UK supply chain, which largely consists of SMEs (small and medium-sized enterprises).

From initial enquiry to site delivery, the gestation period of the most complex REB can be up to six months, and so, throughout the process, the relevant teams (typically project managers, engineering managers, material interface engineers and design engineers) stay in close and regular contact to ensure smooth progress and on-time delivery.

Once built, the pre-wiring of each REB is verification-tested on site by Siemens Mobility’s team of IRSElicensed (Institution of Railway Signal Engineers) testers. Full functional testing is increasingly being carried out at the factory, with the REB powered up and trial data used to identify and correct any discrepancies before the unit is installed on site.

Not only is this an easy process to carry out in a factory environment, it also reduces the amount of time that testing

REB in use, onsite, trackside. staff are required on site, making the process safer, faster and more costeffective.

Automatic Test Equipment (ATE), much of it designed and manufactured

by Siemens Mobility’s own team in Chippenham, is also used as part of the initial testing process, ensuring that the materials are correctly wired. Whereas this would traditionally have been a two-person task, the use of ATE not only significantly speeds up the process, but also improves the quality by removing the risk of human error.

As part of a broad continuousimprovement initiative, the company is driving standardisation across its range, with fewer components leading to efficiencies in packaging, storage and delivery – all of which supports the industry’s wider decarbonisation initiatives.

The multi-skilled, multi-trained UK team has the capacity to manufacture up to 24 REBs at any one time, with communications between the various teams at each stage being key to the successful delivery of these complex systems.

Complete REB being loaded for delivery by Siemens Mobility specialised lift planning supervisors.

Rail Engineer | Issue 186 | September/October 2020

Preparing the site Before an REB is delivered to site, construction work takes place to prepare a suitable base and cables are run for the power and network connections. The vast majority of the equipment now uses flexible power systems and ethernet-style networking to connect objects and control centres up to extended distances, an example is the North Wales Coast resignalling project, which saw control transferred to the Wales Rail Operating Centre in Cardiff.

Many projects draw on the experience of the company's regional construction teams, but, where required, these teams are supplemented by supply chain partners, predominantly SMEs with a wealth of site experience.

Safe delivery to site Working with approved haulage contractors, which have specialist experience in delivering REBs to site, the company has two ‘appointed persons’ on site in Chippenham who are responsible for ensuring the safe lifting of the equipment.

Where required, these specialists create a specific lift plan, which will determine the size of crane/lorry required. It is critical that a safe system of work is created and maintained for everyone involved in the process – from loading to transit and final delivery.

Although Siemens Mobility’s logistics team does arrange delivery, it can equally accommodate the requirements of the project team, which may take that responsibility directly. In either event, the team ensures all relevant health and safety conditions, standards and requirements are met, including crane operating licenses.

As the units are all shipped within the UK, carbon emissions are kept to an absolute minimum.

SIGNALLING/TELECOMS REB being installed to site in preparation for final testing.

documentation in place to cover this. The Factory Test Copies (TC2) document is completed, which shows testing activity carried out, shortage list, sheet record and version, and a record of equipment fitted.

The future

Installation and set to work Once the unit arrives on site and is craned into position, with the wiring complete and connections prepared for power and network, the REB is ready to set to work by the company’s local installation teams.

Where possible, plug-coupled connectors and modular equipment will have been incorporated into the design, making the process of site installation as fast, efficient and cost-effective as possible. Doing so ensures safe working, reduces the time required for teams to work on site, and so minimises disruption and the impact on projects’ neighbours.

It also reduces the potential risk of passenger delays. This is particularly the case when MEH units, which use digitalisation to simplify interconnection, are built into the scheme design.

The installation and construction teams have the skillset, experience and necessary plant and equipment to complete even the most complex of installations, although, if required, supply chain partners can be drawn on as a supplementary resource.

are heavily involved in this stage of the process, together with specialist IRSElicensed testers.

The testers in the factory use Factory Test Copies to test and inspect the REB, carrying out document checks to confirm all relevant pages are correct and signing each page, then further checks are carried out to ensure all of the equipment is fitted in the correct position. They then carry out wire checks – point-to-point checking correct termination, identification and fitment. All wires are check marked for termination at each end and that the correct cable type is fitted.

On completion, all pages are signed off, noting whether there are any discrepancies and, if so, that there is the correct

In their 30 years of existing, REBs have changed considerably, perhaps not in appearance but certainly in their performance and operation, with the incorporation of digital technology bringing significant benefits.

But what will REBs look like in the future? Certainly, they will become smaller and more efficient as network-based signalling becomes more prevalent, but the need to concentrate the control systems into an easily accessible unit remains. With modular signalling schemes, where the object controllers are much smaller and self-contained, fewer, smaller REBs, MEHs, or possibly even just location cases, will be needed. As they reduce in size, the units will also have less embedded carbon and require smaller concrete bases, all of which contributes to decarbonisation.

There is also the option of moving away from separate power, signalling and comms buildings and bringing more equipment together, particularly with batteries becoming smaller, equipment becoming less power hungry and even the possibility of wireless recharging for equipment that is remotely powered.

Steve Barry is manufacturing operations director of Siemens Mobility in the UK.

Test and commissioning Once installed, the final stage in the process is the testing and commissioning of the equipment, with work carried out to test the system’s operation as well as connections to the control centre and trackside equipment.

The fact that equipment and systems testing has already been completed in the factory shortens this process considerably, to the benefit of both passengers and the operator. The company’s local teams

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CLIVE KESSELL

Fond farewell

to a favourite power box

HRH The Duke of Edinburgh visits the new London Bridge power signal box in 1976.

T

he huge modernisation of railway signalling in the UK during the 1960/70s and early 1980s came about through the introduction of Power Signal Boxes (PSB), with many covering significant miles of route. All the BR regions had them and, by the time of the last introduction, most of the trunk routes had been re-signalled, offering big increases in capacity by means of continuous track circuit block sections, as well as an element of centralised control.

However, these PSBs are now coming to the end of their economic life, being replaced by the Rail Operating Centres (ROCs).

The Southern Region was no exception and had a plan to cover its entire geographic area with 13 PSBs. The first and second of these were at Dartford and Feltham, but the third, and by far the biggest, was at London Bridge. This area had been signalled in the 1920s with individual signal boxes at all the major locations, including the notorious Borough Market Junction, where the lines to Charing Cross and Cannon Street diverged.

With the heavy and increasing suburban traffic, an urgent need existed to make permanent way alterations and centralise the signalling. So came about the London Bridge Power Box, opened in stages during the period 1975/6 with due ceremony, the Duke of Edinburgh being the guest of honour.

The box has been in service for 45 years but, in recent years, much of its operating area has been transferred to the ROC at Three Bridges. The summer of 2020 saw the very last area of control at Hither Green transferred, and so ended a remarkable period of operation that had transformed the railway service in SE London.

This article traces the technology of the London Bridge box and the innovative additions that were state of the art at that time.

Rail Engineer | Issue 186 | September/October 2020

London Bridge area The Southern had three divisional areas, SE, Central and SW. The latter was pretty much self-contained, but the South East and Central came together at a number of London terminals, London Bridge being one of them. The new PSB had to span these boundaries, so integrating the management aspects was part of the project.

SIGNALLING/TELECOMS The entire scope of the re-signalled area is shown on the attached map. The Central division section is on the left, covering the lines through New Cross Gate to Norwood Junction and Clapham, of which most trains ran into the terminus side of the station. The SE division covered the lines to Charing Cross and Cannon Street and out into the suburban area of Kent. To facilitate this split, the box had two control desks, a small one for the Central and a much larger one for the SE. Some train services from the Central division ran through to Charing Cross in the off-peak hours and thus an arrangement was made to transfer these from one panel to the other.

Statistics for the PSB area are as follows: » Route miles – 47.3, track miles – 147.8 » Total number of route settings – 926 » Point machines – 456, Colour light signals – 547, Junction indicators – 102 » Train describer berths – 456

Building the Power Box It was seen as important that the new box should be located at London Bridge station where finding the right plot of land was something of a challenge. Eventually, space was found at the country end of the station on the west side where the nine terminal platforms were situated. The site was somewhat constricted, which resulted in a long thin design, the ground floor being used for the relay rooms and other equipment areas, including the all-important power supplies, with the operating floor built above on the first floor.

The building would have been designed by the Southern Region architects with construction undertaken by a major building contractor. Security was not taken as seriously then as it is now, so there were no formalised access arrangements. This was made much more rigorous during the building’s life time.

The considerable ground area necessitated a local UHF radio system for maintenance staff to use when communicating with each other inside the box.

Signalling technology The main signalling contract had been let to Westinghouse Brake and Signal Company, based in Chippenham, which first became Invensys and is now Siemens Mobility.

Computer technology was in its infancy at the time LB box was designed and certainly did not embrace any safety critical circuitry.

As such, the main interlockings at London Bridge and the outlying relay rooms were relay-based using ‘Westpac IV’ geographical units.

This made the design simpler, although it used more relays and took up more space than a free wired alternative.

Developed in the 1960s, geographical was really a misnomer as it consisted of groups of relays assembled into a number of selfcontained modules with standardised wiring, each with a specific function, and then bolted on to traditional racks. Typical modules were a main signal, a shunt signal, a set of points and such like.

Around 20 modules were developed, which included some non-vital functions.

The inter-wiring between the modules used multicore cables, with some use of plug couplers, and had to be designed for the specific application. This included the use of some free-wired relays as an interface to external equipment such as track circuits and point machines.

At some of the remote relay rooms, the space required for the geographical racks was somewhat limited due to the size constraints of the buildings, as can be seen from the photograph of Hither Green.

Space was constricted as some remote relay rooms, like this one at Hither Green, seen in 1976.

There was much discussion at the time that the high-density routes, with trains likely to be close together moving at relatively low speed, did not justify the provision of 4-aspect signals rather than 3-aspect. In the end, 4-aspect was chosen, which proved a wise decision as the drivers used the double yellow as an indication of the position of the preceding train, thus regulating their speed accordingly and avoiding sudden stops.

The operating floor arrangement was a separate control desk and a mimic panel behind it for both the Central and SE lines.

Thus, the signaller could set routes with entrance/exit buttons from a sitting position for most of the time and watch train movements on the panel, where the route setting, track circuit occupancy and train describer berths were displayed.

The panels incorporated mosaic tiles which facilitated an easier change when any future track alterations were made.

Additional signalling features With the intense traffic in the London Bridge area, the previous signalling had permitted reduced overlap distances to enable signal clearance behind a particular train to take place earlier than would normally be the standard, thus allowing trains to ‘close up’.

To have adopted the standard overlap in the new signalling would have reduced the capacity of the line, so a number of facilities were built in to ensure this would not happen.

One was Train Operated Route Release, whereby routes were automatically set, providing approach locking conditions were met. Another was to give the signaller a choice of whether to retain the original overlap distance in heavy traffic conditions.

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Additional reversible lines were incorporated into the new signalling, but care was taken not to show clear signals within the driver’s sight line before the actual route into the reversible section was set.

Closing-up signals were another feature, whereby a train, held at a signal because of another one stopped in a platform, was allowed to proceed towards a closing-up signal once the first train began moving. If the first train proceeded as expected, the closing-up signal would clear before the second train got to it, thus saving an average of around 30 seconds.

A novel feature was automatic working at some of the outlying termini and turn back stations. At Hayes, Bromley North, Elmers End and Grove Park, terminating trains would automatically be signalled during off-peak hours into a single platform, whence, once the appropriate track circuits were occupied, the route back would be automatically set and the signal cleared, thus producing some staff savings.

Rail Engineer | Issue 186 | September/October 2020

Early use of computers The train-describer system used cathode ray tubes to show the train reporting number on the main panels, with these being driven by an early design of mini-computer. It was recognised that distributing the TD information to other desk positions on the operating floor, as well as to remote locations away from the box, would be useful, thus visual display units (VDUs) were connected, via a low speed data line, to give a selection of maps showing the various areas of the box and the movement of trains within it.

By keying in either the train number or a signal number, the outlying places could easily keep track of trains. Particularly important were the control rooms at Charing Cross and Cannon Street, where train ready to start (TRTS) buttons and the platform starting signal could be seen.

The Southern Region placed much emphasis on passenger information and this was automated at London Bridge and Waterloo East stations. A computer holding timetable information was set up in the PSB, which linked to the train describer computer to compare scheduled and actual running times of trains. This then linked to an APIS (Automatic Platform Indicator System) computer which drove the platform flap indicator displays at the two stations. Thus, ‘next train’ information could be automatically set according to the timetable with the capability of altering or deleting the displays if trains were running out of course, delayed or cancelled.

This system was refined and much improved for later Southern Region power boxes.

SIGNALLING/TELECOMS Then and now

Changing the Track Layout As with most power box projects, permanent way alterations often accompany a resignalling project. At London Bridge, some 80 stages of layout alterations were made, the major ones being at Cannon Street, Bricklayers Arms and New Cross Gate.

A main objective was to separate out the Charing Cross and Cannon Street trains before arrival at London Bridge, thus eliminating the infamous Borough Market Junction signal box.

The permanent-way stageworks commenced in 1972 and continued through until 1978, meaning that the associated signalling alterations had to be carried out, firstly on the old signal boxes, and later within the new power box. Locking alterations were kept to a minimum, making use of existing cabling as much as possible.

So ends an era. London Bridge Power Box enabled a muchimproved train service to be achieved. It epitomised the time of route relay interlockings and large display panels, as well as introducing some very welcome new features.

The Southern never achieved its 13 Power Box goal, but other large ones did come along – Victoria (located at Clapham), Three Bridges, an expanded Eastleigh, Ashford – but London Bridge set the trend. It was not perfect, as shortage of finance prevented the ultimate sorting out and expansion of lines in the Borough Market area and the grade separation at Bermondsey. It took the emergence of Thameslink and the Three Bridges ROC to finally get the layout that London Bridge warranted.

Over the years, some equipment within London Bridge would have been upgraded, the computers for the train describer and information systems in particular. Track layouts will have been changed, meaning alterations to the interlockings and control desks and displays, but the basic systems remained in place.

Since 2015, when the new plans for the wider London Bridge area began to take effect, the PSB areas of control have gradually transferred to Three Bridges, with the Central side the first to go completely. Now, in 2020, the last element has moved elsewhere and the box, in terms of operation, has closed.

Technology has moved on over the 45 years. Computer interlockings have replaced geographical relay circuitry, VDU screens with tracker ball control have replaced the big mimic panels and control desks, and computers have totally taken over the intelligence required for train reporting, regulation and information systems.

Nothing lasts for ever, but London Bridge box had a good innings.

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Rail Engineer | Issue 186 | September/October 2020 14/09/2020 15:07

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FEATURE

MALCOM DOBELL

LO AD W HE SIO N

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S

ome aspects of railways are still not completely understood, nearly 200 years after the railways were first developed. Indeed, your writer generally sees many research papers every year seeking to further advance knowledge about what is exactly happening in the tiny, one square centimetre contact patch between the wheel and rail.

The contact patch is a key reason why rail is so successful, in the form of low rolling resistance, and is also a cause of many of its challenges, such as rolling contact fatigue and, the subject of this article, adhesion issues. If there is not a complete understanding of the steel to steel contact patch, imagine the extra complication when contamination is added to the interface, be it to the rail head or the wheel or both.

Great Britain has led the way in understanding how the contact patch works in terms of vehicle dynamics and for traction and braking.

Understanding how friction works is vital. RSSB hosts a wide range of industry stakeholder groups including the Adhesion Research Group, which has sponsored excellent work to develop strategies, tactics, and techniques to improve the certainty that a train can stop on demand.

Rail Engineer has reported on many of the ARG/ RSSB activities, particularly the development and testing of double variable-rate sanders. Other work has included the development of models to predict behaviour in low adhesion conditions at both wheel-rail contact and at train level.

Low adhesion and how it affects the railway are, together, a complex problem, with simulation models and laboratory testing providing scientific understanding of complex issues confronting the operational railway.

Rail Engineer | Issue 186 | September/October 2020

Given the complexity of these issues, different models are needed to fully explore and understand the factors involved, how they contribute to low adhesion and, ultimately, how we can develop better treatment and management techniques.

A recent Adhere webinar focussed on three simulation and modelling tools for braking under low adhesion conditions. This article covers the University of Huddersfield’s work on LABRADOR and Sheffield University and Virtual Vehicle on LILAC. A presentation about DB ESG’s Wheel Slide Protection Evaluation Rig (WSPER) was also included in the Webinar, but WSPER has been covered in Rail Engineer before (issue 176, July 2019) and is not repeated here.

LILAC No model is any use unless it replicates what happens in real life. Gaining the knowledge to create the model and then to validate it is often the hardest part.

Roger Lewis from the University of Sheffield described the research carried out for RSSB (Project T1149) to understand in detail the impact of the leaf layer and to provide input to the Huddersfield’s LABRADOR low-adhesion braking model as a module called LILAC (Leaf

FEATURE Induced Low Adhesion Creep force model), which can also be used as a standalone tool or in a multi-body dynamics simulation.

This work built on the successful project to understand and model the impact of small amounts of water with iron oxide contaminants that had already been incorporated in LABRADOR as WILAC (Water Induced Low Adhesion Creep force model - RSSB project T1077).

The project started with extensive data collection, including from past low adhesion incidents. This added to the researchers’ body of knowledge about how vehicles have performed and helped form ideas for laboratory trials using Huddersfield University’s full-scale bogie test rig HAROLD (issue 145, November 2016).

In brief, HAROLD consists of a bogie with one wheelset running on a two-metre-diameter rail roller which is driven by an electric motor. Vertical load is applied by hydraulic actuators through the secondary suspension and the bogie can be moved laterally and in yaw with respect to the rail rollers. A range of sensors and instrumentation is available to collect results, which include measurement of creepage and creep forces between the wheel and rail.

A Y25 freight bogie was used for these tests, with one wheel jacked clear of the rail. This wheel was used for braking whilst the contamination (leaf layer/paper tape etc.) was applied to the other wheel. This was necessary simply because the bogie used was tread braked, and this approach avoided results being adulterated by the effect of tread braking on the contaminant.

Roger described what seemed to be a really tedious process of assembling lengths of leaves, stuck together with adhesive tape, to artificially contaminate the active wheel/rail interface, adding

that the set up took a lot longer than running the tests! These had to be carefully fed into the wheelrail “nip” and rolled into the wheel and rail of the rig at low speed.

Diagram illustrating one wheel jacked clear of the rail.

Prepared ‘leaf tape’.

HAROLD rig, noting that about 60 per cent of the rig is below the surface of the workshop underneath the bogie.

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Wheel showing black leaf contaminant - and a small flat.

Creepage vs creep forces curves for a dry wheel/ rail test (Left) compared with a moistened leaf film test (Right). Note that the Y axis for the right-hand curve has been expanded by a factor of three.

The team later found that feeding broken up leaves into the nip using a scoop was quicker and just as effective.

The surfaces only resembled that black surface seen on the real railway after a sliding event; rolling alone was insufficient.

The standard test procedure was to run the test rig up to load and velocity, apply and increase the brake force until wheel slide or maximum brake force application, and then decelerate the roller to zero velocity. A simple real-time controller was used to release the brakes when a preset level of creepage was reached, in order to avoid wheel flats forming.

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Tests were carried out in dry and wet conditions and with leaves, paper tape and soap. Paper tape and soap are frequently used for practical tests on full scale vehicles. The results below compare dry conditions with leaf film.

For dry conditions, Roger illustrated the results from the HAROLD rig. The panel on the next page describes what actually happens if the retarding force on the wheelset exceeds the available adhesion. Suffice to say, the dry results delivered characteristic creep curves with the coefficient of friction peaking at between 0.4 and 0.5.

For the leaf film tests – where the leaf film was wetted before each test, the same characteristic curves were obtained, but with an exceptionally low peak coefficient of friction of <0.02. Roger put context to this figure by explaining that best quality oil in a car’s engine does not produce a friction level this low, but he advised that leaves should not be used as engine lubricant!

Gerald Trummer of Austria’s Virtual Vehicle Research Institute described how the outputs of these tests and other information were used to create the LILAC module in a form ready for integration into LABRADOR. He demonstrated how the user interface works and the results obtained by varying input parameters, comparing the results with real world results.

For future research, the developers want to investigate the role of transients – how contamination levels, environmental conditions, wheel/rail interface conditions and surface roughness, which vary along the railway, impact on the use of the model.

LABRADOR LABRADOR - Low Adhesion BRAking Dynamic Optimisation for Rolling stock - is a modelling tool developed by the University of Huddersfield as part of its strategic partnership with RSSB. It was developed to simulate modern multiple-unit train braking in normal and low adhesion conditions and incorporates several different models for low adhesion in the wheel-rail interface.

Huddersfield’s Julian Stow described the LABRADOR model, paying tribute to his colleagues Dr Hamid Alturbeh, who developed the model, and Jose Santos, who carried out its validation.

FEATURE Julian described the many challenges that modelling braking has to overcome: 1. Braking performance depends on the complex interaction of a large number of components and sub systems on a train, with each vehicle delivering a different performance from its neighbours and, to an extent, each vehicle’s performance is influenced by the behaviour of its neighbours.

2. It is not easy to quantify the low adhesion creep force relationship, as illustrated by the WILAC/ LILAC research.

3. Creating consistent low adhesion for laboratory or field tests is costly, time consuming and hard to arrange.

4. Modelling real-life adhesion variation spatially and temporally is very difficult and there is little real-world data to feed into the models.

5. There is limited validation of the wheel/rail contact temperature model.

6. Characterising modern ‘black box’ WSP is a challenge as suppliers, understandably, may not wish to disclose detailed algorithms.

7. Speed, load and contact temperature affect braking performance and have to be taken into account.

All this means that the model has to cover variations in both the train and the infrastructure.

For the train, it needs to provide for variable train length and to model the configuration of the braking system on each vehicle, how they are controlled and the interactions between vehicles. LABRADOR can model a four-car multiple unit (extendable to any length) with user defined parameters, and user configurable braking arrangement, controller architecture and configurable WSP. It is not just braking systems that need to be considered, but also masses, suspension configuration (for weight transfer effects) and knowledge about rotating masses.

The infrastructure must also be modelled, including track gradients as well as adhesion profiles.

The next step is to model how the train model interacts with the infrastructure with constant and variable brake demand, allowing for dynamic braking with blending and over-braking, the impact of sanding and conditioning effects, and weight transfer due to pitch effects (body and bogie).

All this allows the stopping distance to be predicted, together with any tread damage due to wheel slide and the volume of compressed air used by sanding and braking (WSP). LABRADOR also generates a large amount of detailed information on what is happening to all the elements of the system throughout the simulated brake application.

The modelling software is configured in a modular structure and can ‘plug & play’ new modules. Indeed, WILAC and LILAC are modules in LABRADOR.

Creep and creep curves Creep is a term used to describe when the train wheels are not simply rolling but are slipping (traction) or sliding. Clearly, a wheel that is spinning out of control or is locked is the most extreme manifestation of this, but small amounts of creep can be beneficial.

If the applied tractive or braking effort is greater than the coefficient of friction multiplied by the vertical load, the wheel will start to slip or spin.

But, if that happens, there is a curious effect – the coefficient of friction starts to increase and continues to do so until the wheel is rotating at about 10% slower (using a braking example) than the rolling speed. At this point, known as the saturation point, if the speed of rotation continues to fall, the friction falls away quite rapidly and the wheel will lock – effectively 100% creep.

In the case of traction, creep values can be in excess of 100%, which is the effect of wheelspin.

This phenomenon is often used in locomotives to deliver more tractive effort than the nominal adhesion level would permit. With modern control systems, creep control is comparatively straightforward and, in principle, could be applied to dynamic braking. However, with pneumatic friction braking, the response times are too slow to permit creep control; the accepted method of controlling brakes in poor adhesion is with wheelslide protection.

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This graph shows that, for poor or passable adhesion levels, the effective coefficient of friction improves along the train in response to scrubbing action or creep from the wheelsets towards the front of the unit. It also shows that this effect stops or saturates by about wheelset 10. However, it also shows that none of this works for exceptionally low adhesion as this effect does not happen.

Julian then gave a professional demonstration of the software. The range of features and variables demonstrated very clearly his comment that, to get credible results, experience of braking systems and of using engineering modelling software is necessary.

He concluded that low adhesion is a complex and persistent problem, that simulating low adhesion braking presents considerable challenges, and that the LABRADOR model allows the study of specific brake-control features, including WSP strategies, sanding effectiveness, dynamic brake utilisation and traction performance. He added that good simulation tools can support industry efforts to provide reliable (“seasonally agnostic”) braking in these conditions, and that further development of the model is underway.

This work is at the forefront of the industry’s efforts to combat low adhesion problems. A point that was stressed by all the speakers is that there is now a full suite of tools for investigating and improving low-adhesion braking performance.

These range from simulation of the complex behaviour of the contact conditions and train braking system, through small and full-scale lab testing, to WSP and sander optimisation and accreditation using DB ESG’s WSPER rig. These hold out real hope for future improvements to the autumn performance problems which are the cause of so much cost to the industry and pain to its customers.

One of the key pieces of learning your writer took away from this webinar is that really low adhesion cannot be overcome by wheel/rail braking alone. It was frequently stated that, on a fairly long train, wheelside protection activity on the front cars ‘cleans’ the rail, allowing for better adhesion further back on the train, as shown in the illustration below taken from a LABRADOR simulation. The illustration (above) shows that this effect does not occur in the case of exceptionally low adhesion. Therefore, both railhead cleaning and the use of an adhesion enhancer such as sanding remain absolutely essential to manage the risk of poor braking in the autumn.

The RSSB Adhere webinars have been a very successful by-product of the coronavirus lockdown.

An added bonus is that each webinar was recorded and, as it is very difficult to describe or demonstrate software in words, it is possible for anyone interested in seeing more to watch the recording at www.rssb.co.uk/Insights-and-News/Key-Industry-Topics/Adhesion/ADHEREProgramme-Webinar-Series/Train-Braking-and-Low-Adhesion-Modelling.

Thanks to Roger Lewis and Julian Stow for their assistance, and to Paul Gray of RSSB for permission to publish.

Rail Engineer | Issue 186 | September/October 2020

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FEATURE

MALCOM DOBELL

The Long History

and Exciting Future of RAILWAY SYSTEMS THINKING

PHOTO: ELI REES-KING

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George Stephenson at Rail Live, dressed as Felix Schmid.

Rail Engineer | Issue 186 | September/October 2020

FEATURE

E

ach year, the Institution of Mechanical Engineers’ Railway Division elects an eminent engineer to be its chairman.

For 2020-2021, it is Professor emeritus Felix Schmid, recently retired programme director for the MSc in railway systems engineering and integration at the University of Birmingham.

The chairman usually addresses members at the Institution’s headquarters in Westminster and at centres around the country, but this year, due to the COVID-19 pandemic, Felix’s address is virtual. One might assume that he would deliver one address accessible from anywhere, but one would be wrong! Felix is determined to deliver his address to every Railway Division centre, with some unique content for each one, to support centre identities.

This report is based on the South East centre address given in September 2020. Felix packed a lot of interesting and educational information into his talk. At best, this report is selective and anyone interested in hearing the full address might still be able to catch one of the later dates, the last being for Ireland in early 2021. He will also present separately for an audience in India, Japan and Australia.

In time honoured tradition, Felix summarised his career from his childhood to the present day. He was brought up with his brother, Thomas, in Zurich, Switzerland, where their father encouraged them to enjoy railways. He completed a language-oriented baccalaureate with classics – Greek and Latin – before gaining a Master of Engineering equivalent degree from the Swiss Federal Institute of Technology.

After a short spell in software analysis, he moved to England to work with GEC Traction.

There, he learnt what he called “practical electricity” and had his first exposure to a management role, where he learnt valuable lessons in building mutual respect with the workforce.

Later he became a research assistant at UMIST in Manchester and then at the University of Salford, before, in 1985, moving south to Brunel University, where he became a lecturer in computer-integrated manufacturing. Felix observed that neither he nor his boss were quite

Felix and Thomas Schmid in 1963.

(Below) GEC Traction, Newton-le-Willows, 1983.

Felix is third from the right.

(Inset) Brunel University, 1990.

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Students and academics in Singapore.

sure what computer-integrated manufacturing was, but that he taught it anyway, gaining a PhD in engineering education whilst at Brunel.

Following a tip-off from his brother, Felix became a railway inspector in Switzerland in 1993. This taught him that he did not have the temperament to be a civil servant, and, in 1994, by serendipity, he was appointed as a senior lecturer at the University of Sheffield to set up a British Railways-sponsored MSc programme in railway systems engineering.

In 2005, the MSc programme, complete with Felix and his team, transferred to the University of Birmingham, where he later became first an associate and then a full professor of railway systems engineering and integration.

Gradually, additional MSc programmes were created, including an international programme in Singapore, with Felix as the director of education.

One of the features of his MSc programmes has been the international tours, intended to show participants good practice in solving railway problems. He has also organised four successful technical tours for the IMechE Railway Division. There are literally thousands of railway systems engineers who have been educated by Felix and his team.

What is a system and how does the railway fit in?

2016 technical tour to Bochum, Germany.

Felix then moved on to talk about systems, warning his audience: “This is going to be educational!”

He defined a system as “a group of interacting or interrelated entities that form a unified whole to deliver a defined purpose. A system

Rail Engineer | Issue 186 | September/October 2020

is described by its spatial and temporal boundaries; it is surrounded and influenced by its environment, described by its structure and purpose and expressed in its functioning.

A system can also be a set of principles or procedures by which something is done - an organised scheme or a method.”

He added: “A railway is a system and it has the purpose of transporting people and goods.”

A history lesson of the railway as a system combining track and train, wheel and rail Felix described some of the very earliest applications of guided wheeled transport, describing how low friction tracks with a guide slot were provided for ore trucks in German iron and silver mines in the 1600s – a sort of early push along Scalextric. They were ideal for the very narrow passageways that were a feature of those mines and the technique was brought to the English Lake District by German miners.

The early railways proper of the 1700s featured rustic tracks with longitudinal timber beams held apart by, and wedged onto, ‘ties’ – recognisable today as sleepers. Iron strips were fixed to the longitudinal timbers. These were known as ’railed ways’, railroads, tramroads or tramways.

They exhibited the key feature of all modern track construction, distributing the point loads of wheels on rails through the various components of the track.

Iron Strap 4’ 10” Tie

Mud Sill

Wedge

Rail

Trench

FEATURE As Felix said: “You’re talking about point loads of kilonewtons per square millimetre at the rail, and once you reach the natural ground, the load is in the very few newtons or fractions of newtons per mm2. That was, of course, a fantastic achievement. It’s what I call one of the very defining systems aspects of railways and it’s what allowed Stephenson to build a railway across a swamp, Chat Moss.”

The early engineers trying to develop locomotives were very concerned that iron or steel wheels on iron rails would just slip or spin. This led Richard Trevithick to machine serrations on the tread of the wheels on his 1802 steam loco.

He demonstrated one of his locomotives on a circle of track in Bloomsbury, London, in 1808, and it is thought that the high loads of the serrated wheels on the track caused rail breaks, leading to derailments and, for Trevithick, bankruptcy.

Another engineer, John Blenkinsop, developed an early rack and pinion system in 1811, the principles of which much later became very popular on mountain railways, but which was unnecessary on more reasonable gradients and imposed slow speed.

Distribution of pressure throughout a railway track system.

William Brunton’s ‘Steam Horse’ used mechanical legs to power his locomotive up steep gradients.

Richard Trevithick’s 1808 demonstration at Bloomsbury.

Trevithick was, however, more successful with the steam propulsion system, commenting: “The fire burns much better when the exhaust steam is blasted up the chimney” – the technique that made steam traction work efficiently at higher power.

More extraordinary was William Brunton’s 1813-patented Steam Horse, which used steam powered legs and feet to move the locomotive up hills, managing gradients of up to 1:36.

Felix observed that it “was a very, very limited success. The locomotive actually exploded because somebody tied down the safety valve not such a good idea.”

Stephenson’s Rocket at the Rainhill Trials of 1829.

John Blenkinsop’s rack and pinion system of 1811.

Rolling forward to 1829 and the Rainhill trials, Felix observed: “Even today, everybody keeps talking about the speed which they achieved – 30mph (48km/h). But the real big achievement was that a locomotive could travel 112km in just one day and was reliable. It was range and reliability that made the fast development of railways possible. Stephenson discovered that his fears about adhesion were not realised. And as we now know, using adhesion and perhaps some sand, gradients of up to 1 in 8 can be managed.”

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The Elizabeth line (Crossrail) is a good example of a ‘System of Systems’.

What is a system of systems and what are emerging properties?

The complicated and complex cature of railways?

Following the history lesson, Felix moved to Systems of Systems (SoS), which he defined as “a set of large-scale integrated entities that are different from each other and they can operate independently of each other on their own. But when they are put together and networked, they have different characteristics than as individuals.” He used nature as an example of a system of systems, something worthy of a separate article.

He illustrated the challenges of SoS with the example of Crossrail (the Elizabeth Line) and its many interfaces. As examples of the challenges, Crossrail runs over the territory of three infrastructure managers and interfaces with two others, has three signalling systems and shares tracks with other services at either end of the line. This is a complex system with no one party in overall control.

Felix observed that many people think SoS are 21st century creations, but SoS is merely a new term for describing what has been in existence for a long time, and he compared SoS characteristics with early GB railways.

Felix said that railway systems are complex, complicated through being closely coupled, all of which he explained in brief.

Complicated systems are those that can be controlled by people with processes and rules, while complex systems are those that are not capable of being controlled easily by people (again with nature as an example).

The complication and complexity of railways were illustrated with a butterfly diagram, outlining the factors involved and how they are related. The 2018 timetable meltdown was an example of complexity. Close coupling contributes to the interdependency of sub-systems. Examples include wheel/ rail, pantograph/overhead conductor, and timetables, fleet and crew rosters.

Felix discussed the significantly complicating aspects of rail, including dispersion of organisations, people and equipment across the network, together with the diversity of components, assets and the skills and knowhow required. He illustrated this with an example of a railway with over 2,200 sets of point machines

Rail Engineer | Issue 186 | September/October 2020

FEATURE Generic SoS Characteristics

Characteristics of early GB Railways

Managerial, developmental, and operational independence

150 railways with separate owners and operators

Rapid requirements evolution

Rapid growth of network, services, passengers and performance

Multiple disparate stakeholders, often with conflicting needs and little incentive to work together

Passengers, cities, shareholders, govenmnet, suppliers all have different needs and aspirations

Emergence resulting from inter- and intrasystem interactions

Emergence of cross network travel opportunities required new rules

Systems of systems are often geographically dispersed and connected though a network

Trains spread across the whole country though he physical (rail) network

Characteristics of Systems of Systems compared with early railways in GB.

©: Rhianne Evans and Duncan Kemp

of 29 different types: all controlled through lists, databases, procedures and knowhow.

Whilst such diversity of equipment may not be desirable, it is quite normal on large established networks.

What makes railways difficult to manage When things go wrong in complicated and complex systems, there is often a management preoccupation with finding out what went wrong, and why. Felix suggested that ‘how?’ may be a more useful question than ‘why?’, as it elicits more information and that it is also productive to find out what works well and how organisations can ‘do the right things’ more often.

Based on the old railway adage ‘the railways would run a lot better if it weren’t for the passengers’, Felix observed that performance (delivery and punctuality) of the troublesome Deansgate corridor through Manchester has dramatically improved during the COVID-19 lockdown, when passenger numbers reduced by 90% or so. This experience provides lessons for operators – perhaps fewer longer trains might deliver better performance as passengers return?

Perrow’s ‘Normal Accident’ theory Felix also highlighted work by Charles Perrow, a sociologist at Yale and Stanford Universities, arguing that accidents in complex systems – as described here – are not completely avoidable, regardless of preventive effort. Perrow also suggested that technical solutions are not adequate mitigation because most incidents have organisational roots. Such systems have to respond to events and must adapt as the environment and other agents in the system change.

Part of this is caused by the fact that success and failure often have the same genesis. Felix discussed situations where normal work features degrees of non-compliance and workarounds, often because the real world diverges from the paper world. Most of the time, non-compliance and workarounds lead to success but, occasionally, they lead to failure. No one worries about the thousands of times where there was success,

but organisations always seek to prevent the rare failure. Unfortunately, the failure prevention actions may reduce the frequency of success.

Felix gave an example of a helicopter picking up injured people where the helicopter lands with its rotor skimming the top of the snow. People get rescued safely and nobody talks about it anymore.

If the same helicopter’s rotor had dug into the snow leading to an accident, there would have been a big investigation with the conclusion that the root cause was a reckless pilot despite having relied upon the same apparent recklessness to successfully rescue many injured mountaineers or skiers.

The system lifecycle Vee model for the railway With all the challenges of complication and complexity, Felix suggested that there were no certain solutions available but there were techniques which organisations might employ to minimise the inevitable challenges. He explained the CENELEC system Vee life cycle which he teaches to all his students, but he had added three opportunities.

Firstly, during the Concept, System Definition and Application Conditions, and System Requirements stages, there is the opportunity to address complexity.

Secondly, during System Requirements, Apportionment of System Requirements, and Design and Implementation stages there is the opportunity to address complication.

CENELEC system lifecycle Vee model.

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Complex Systems Adaptive Cycle.

And thirdly, during System Acceptance and Operation and Maintenance stages there is a further opportunity to address complexity.

He also added that anything planned at the concept stage for Operations and Maintenance and Decommissioning Disposal is unlikely to be what actually happens. For example, no one who designed the old New York ‘Redbird’ subway cars would ever have imagined that they would be sunk in the ocean to become reefs for sea life.

The Complex Systems Adaptive Cycle, ‘Resilience and Scale’.

In any large railway, there are probably hundreds if not thousands of system Vee cycles in operation at any one time and, irrespective of how well they are applied, they do not prevent unintended consequences or undesired emergent properties.

Felix described other approaches which had been presented by an Australian colleague, Alexandra McGrath. This is the Complex Systems Adaptive Cycle, originated by Brian Walker and David Salt in 2006. This is illustrated by four phases with rail examples in brackets: Rapid Growth - often accompanied by an investment boom (pioneering railways), Conservation - where assets procedures and control are standardised or consolidated (railway grouping 1923, British Railways 1948), Shock internal or external events trigger fundamental change (arguably the spate of rail crashes in the late 1990s/early 2000s), and Reorganisation experimentation focus with novel and creative ways to move forward (perhaps this is the way forward from Covid-19).

Reducing complication works well during Rapid Growth, ideally leading to standard and repeatable solutions. However, Conservation can result in excessive control and in entrenchment and non-compliance. Following a shock (Release phase), swift intervention is necessary to put in place the building blocks for the next cycle, which usually leads to Reorganisation and some fundamental engineering research and innovation. Felix added that resilience, or lack thereof, is often demonstrated at the System Release phase, but the best place to put resilience in place is when systems are being designed.

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Felix illustrated the Adaptive Cycle through the Hatfield derailment on 17 October 2000, where an inter-city train derailed whilst travelling at 120mph. Sadly, four people died and 70 were injured. Well-ordered processes had been disrupted, probably unknowingly, during privatisation.

Previously, one organisation was responsible for track maintenance and planning, but there were now at least four (the train operator with a say in access arrangements, Railtrack with overall responsibility for the track, the track maintenance contractor and the track renewals contractor) with multiple hierarchies, different technical disciplines and with sometimes conflicting incentives. In this close coupled system, it was not possible to gain access to inspect the rail, communications channels were long and therefore rolling contact fatigue was not recognised until it was very severe. It was too hard to arrange rapid replacement and no one put mitigation measures in place.

Following the accident, widespread rolling contact fatigue was found and emergency speed restrictions were imposed across the whole network; a network wide crisis.

Resulting from this derailment, Railtrack became Network Rail, track maintenance was brought in-house and a great deal of research led to fundamental changes in how the rail industry managed rolling contact fatigue.

Concluding remarks Felix concluded his talk with some blatant advertising for the IMechE Railway Division’s Annual Luncheon which will be held virtually for the first time on 5 March 2021. He encouraged organisations to set up lunch in a room for their teams and guests with an online video link so they can connect with friends and colleagues whilst listening to the Railway Division update and a stimulating guest speaker. Whilst intended as a one-off, it could be the biggest Railway Division event yet.

And finally...

This report has omitted many interesting points made by Felix. If you want to hear about the Turkish, the Chinese and the porridge, the purple signal aspect, the Railway Children charity or Paddy, it might not be too late to tune into one of his later addresses – one firm date is on 11 November hosted by the Railway Division Midlands Centre; booking though the IMechE website, events section.

Thanks to Professor Felix Schmid for his support and assistance in preparing this report and to his colleague Alexandra McGrath for permission to publish some of her illustrations.

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