Crossrail is on track and now 63.4% complete, with the line in a critical ‘transition’ stage where it moves from being a civil engineering and tunneling project to an ‘end to end railway’.
So said Crossrail programme director Simon Wright this morning when he addressed a packed event at NLA on the new line, its construction challenges and the archaeology that has been newly revealed.
‘It’s not all about tunnelling’, said Wright. ‘We have started to lay the tracks’ There will be 10 new ‘enticing’ stations, most of which are now well advanced and feature over site development, while the 66 ‘large, comfortable’ surface-type trains will be 200m long, have nine carriages and hold up to 1500 passengers each. 12,000 people work on Crossrail, with 140 contractors, and the central stage opens at the end of 2018. But alongside innovations such as creating Custom House station off-site, the key lessons from Crossrail, Wright said, should be carried forward to future projects. ‘Knowledge sharing is key’ he said. ‘We’re trying to leave a legacy of knowledge and lessons learnt to make it available for all future programmes.’
Part of that will be a recommendation for Crossrail 2 to similarly retain an arms-length team that is focused on the project, to learn lessons from other countries, and, if possible put in place a ‘more succinct build process’ whilst still protecting those who might be impacted.As a city that is resilient and tolerant of new infrastructure, London will adapt to the increased footfall that comes with Crossrail, added Wright, but its 10% total capacity improvements will be absorbed quite quickly.
The conference also heard from Alison Norrish, Arup director, Andy Alder, project manager, Western Tunnels, Crossrail and Nick Elsden, project manager at MOLA. Norrish said the line had presented difficulties in weaving a route through existing infrastructure and buildings and her team adopted a ‘risk-based approach’ to look at impacting structures including 3,5000 buildings, 12,000 utilities, and live underground routes, which it crossed 12 times. Alder revealed that tunneling went at 1km a week at its best rate but was extremely tight at places like Tottenham Court Road, where there was little separating 1000 tonne, 7.5m diameter Tunnel Boring Machines and existing, operating underground tunnels which only moved by 3mm as a result. Finally, Elsden said that excavations had revealed important discoveries, including dense burials of 2500 skeletons at over 6 skeletons per cubic metre of ground at Liverpool Street Station, arising from the plague.
David Taylor, Editor, New London Quarterly