Rail Engineer • November 2015 bridge, the system achieved savings of £864,000 and 21 programme days, providing greatly increased assurance and resulting in further savings in document management. In addition to the survey cost and time savings, the use of BIMXtra also resulted in a faster turnaround on design solutions and technical clarifications. Assurance was much improved with clear, consistent repair details reducing the risk of non-conformance while human error was virtually eliminated with no re-work required. The availability of centralised, accurate and robust data, shared across the two organisations, allowed the team to conduct real-time desktop reviews and audits of progress and assurance. This was especially valuable given the challenging logistics for managers visiting every part of the structure. So what did BIMXtra add to this project? Colin described it as “a 3D model of the bridge, enabling every one of its 9,000 components, its condition, designs of any repairs, progress and assurance, all to be simply and accurately identified, recorded and shared by our engineers using iPads”. At the start of the contract, the team had available the original but unreliable construction drawings and a 2D survey carried out by rope-access engineers back in 2000. From this, the 3D model known as the ‘Backbone’ was constructed, a data rich 3D CAD model that provided locational reference for later survey and repair activities. Details were recorded for every element, ranging from whole girders to small brackets. The engineers had real-time access to the model from the bridge, using Wi-Fi or 3G-linked iPads. They took photographs of every element, pinned to the relevant
location on their screen. The engineer then selected, from a standard list, the details of any observed defects such as cracks, reduced sections or corrosion, failed or missing bolts or rivets, and added text to further describe specific problems. The data entered by the engineer on site was instantly synchronised back to the BIMXtra database and used to automatically generate a survey sheet, allowing the designer to promptly produce a work sheet including repair instructions, standard repair details and sketches if necessary. Each defect repair proposal was colour coded to aid the authorisers’ understanding. Red - critical to stability and structural integrity, requiring individual designs, Amber standard minor repairs such as missing bolts, knife-edging
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The successful repair of around 10,000 defects has ensured that this 150 yearold iconic structure is now in excellent condition and ready for another 25 years of intensive use.
Kier is a leading property, residential, construction and services group, which invests in, builds, maintains and renews the places where we live, work and play. With a network of 88 UK offices, we have the technical expertise to undertake some of the most significant construction, civil engineering and service contracts anywhere in the country. Our strengths in the rail sector include: • In-house multi-disciplinary design team • Civils construction and design & build • Signalling design, installation and test of mechanical, RRI and SSI • Major projects including Crossrail, King’s Cross, HS2, Solum, National Footbridge Level Crossing Replacement Framework, W&W Renewals CP5 Framework, Type C Signalling Framework • BIM Xtra
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