Rail Engineer • April 2016 and distinguish it, from RIDC Tuxford (formerly High Marnham) which Network Rail set up in May 2009. Both facilities are used for railway vehicle testing, but Melton is particularly set up for testing trains while Tuxford is largely used for on-track machines, road-rail plant and infrastructure testing. On the day that Rail Engineer visited RIDC Melton, one of the new Hitachi IEP trains departed for North Pole depot in London. It had been testing on the longer, 21km Down line which is electrified with the new Series 1 overhead catenary, replicating that being installed on the Great Western. But parked next to the fence and the Old Dalby operations offices was the item of interest - a brand new S Stock train with zero in-service miles. It had completed its 500 fault-free kilometres of running, then been handed over to engineers from Thales to act as the test train for its new Seltrac signalling system for the Sub Surface Lines.
Grey boxes The contract to completely replace the signalling system on the four London Underground lines that make up the Sub Surface Railway (Metropolitan, District, Circle and Hammersmith & City) had been awarded to Thales in July 2015. It is to be a CBTC (Communications Based Train Control) system with almost no lineside signals - they will only be retained in areas shared with other trains such as the Chiltern line, the Richmond branch, the Piccadilly line between Uxbridge and Rayners lane and the Wimbledon branch. Instead, the train talks to the control room and instructions to the driver appear on the train’s control desk.
Although the contract was only placed nine months ago, Thales was in a good position to make an early start. A similar system has already been introduced on the Jubilee and Northern lines and is now working well. So the first implementation of the new SSR system is, not surprisingly, quite similar to that on the Northern line. Some of the equipment is one generation newer, and the software has been modified to account for some of the differences between the complex SSR and the comparatively uncomplicated Northern line, but the similarities are there to see. The main difference is communications - Northern line trains ‘talk’ to the control centre using an inductive loop system while the new SSR system uses radio. The similarities, however, were such that it gave the Thales engineering team the opportunity to make a quick start. Mobile office units were set up next to the Old Dalby car park, and filled with tall grey cabinets mysteriously labelled “SCS1”, “PDU Rack 2”, “COM Rack 3” and “VCC”. The latter is the Vehicle Control Centre, and it is the brains of the whole operation. Inside the cabinet are three large rack-mounted computers, all basically doing the same thing and controlling part of the network. The 4LM (4 Lines Modernisation) project will have 14 VCCs, overseen by the System Management Centre (SMC) which acts as the operator interface and controls the service according to LU’s timetable. Two of the three computers must agree at all times, otherwise the output will not go the rest of the system and the trains will come to a stop. The other cabinets control the systems at the various virtual stations that have been set up along the test route (SCS - Station Controller Substation), communications and uninterruptable power supplies for the whole system.
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Most of these cabinets are production items and will appear on the actual SSR installation, although the SCS ones will be located at stations and not at the control centre. The control room itself, however, was nothing like the final version. A row of desktop computers on office desks will be replaced with a bespoke, air-conditioned room with banks of video screens when it is installed in London.
On board Having looked behind the scenes, it was now time to board the train itself. First impressions were just how enormous the train is. It was one of the shorter ones, seven cars and 385 feet (117 metres) long, but when completely empty, and with wide gangways that allow views along the length of the train, it looked huge. Protective matting covered the floor and the only sign of life was at one table which had been erected just behind one cab, where a Thales engineer kept watch over the VOBC (Vehicle On-Board Controller) sitting next to him. Eventually, this will be built in to the space that awaits it in the cab itself. Various cables sprouted from the VOBC and were taped to the interior of the train, some going to the cab and others making their way outside to bits of kit under the floor. Doors were closed off using thin, red and white striped ‘safety’ tape from which hung signs reading “Warning - Doors May Open At Any Time”. After the doors had been closed, the train could make its way slowly out onto the test track. Once there, confirmed by radio and the new cab controls, the Serco driver pressed two buttons to engage the ATO (Automatic Train Operation) and we were off.