What is expected to be the biggest project in the northern hemisphere is expected to get under way in three years time, after chancellor Alistair Darling confirmed the funding package for the project on Tuesday.
The announcement was the signal for engineering teams to get cracking on enabling work and detailed designs, before tunnelling for the central section between Paddington and east London begins.
At the same time, the Crossrail Bill that will enable the project to go ahead is making its way through the final stages of the parliamentary process, and is expected to gain Royal Assent next summer. The deal became a reality last Thursday after the City of London Corporation agreed to stump up £350M to plug a gap in the funding package.
Since the resolution of the split between private and public finance, there has been much support for the project, and few, if any, Labour MPs dare risk their careers opposing the bill.
Taylor Woodrow is now poised to start the enabling works programme in 2009, a year before the major civils work begins. Events have shifted the dates back by about a year, but the timetable for the start of the main works is still a firm 2010.
The sheer complexity and scope of the project cannot be underestimated. Planning is everything if the construction programme is to come in on time and to budget. The vast, highly challenging project involves building 16km of twin bore running tunnels up to 40m below ground, as well as eight underground stations. The tunnels will cross eight Underground lines, the Thames, the Blackwall Tunnel, as well as passing beneath densely built central London.
Transport secretary Ruth Kelly said it would be the largest infrastructure project in the northern hemisphere. It is a struggle to think of larger projects in the southern hemisphere.
To make project management easier, the project has been split into four work packages, each steered by a multidisciplinary consultancy. These consultants will in turn be coordinated by Bechtel.
The overland sections to the east and west of the central tunnelled section are to be handed over to Network Rail, and it is likely existing Crossrail designer for the overground sections Scott Wilson will be novated to Network Rail for the duration. The tunnelled sections are split into three. An Arup/Atkins consortium will manage the section from Royal Oak, just west of Paddington through the West End to Farringdon at the edge of the City. This will present particular logistical challenges as access to station sites and the tunnels will go through some of the busiest urban streets in the world. The tunnels themselves also snake above and below Tube tunnels and other obstructions.
Mott MacDonald is the consultant taking the section east from Farringdon to the edge of the 2012 Olympic park at Pudding Mill, where the tunnels resurface.
Halcrow is consultant for the tunnels running south and east of Liverpool Street, which surface just before the station at Woolwich after passing under the Thames and the busy Blackwall tunnel.
Oakervee also sees a "cascade" of workers moving from the Olympics to Crossrail post-2012.
But the real test for Crossrail will be to deliver on time and on budget. Oakervee is adamant that Crossrail will join a growing series of British mega-projects completed to order, from the Emirates stadium, to HS1 to Heathrow’s Terminal 5.
This will be done by setting the work in stone before the work starts. "The government and the delivery agent, which is us, have frozen the scope of work before we start," says Oakervee.
The companies working on the tunnelled section are likely to be encouraged to form a single team, as happened in the Rail Link Engineering (RLE) consortium for the £5.8bn High Speed 1. In fact, a fair proportion of the existing Crossrail protagonists were part of the RLE team – namely Arup, Halcrow and Bechtel.
Resourcing is one problem that will have to be tackled. Many of the engineers involved with the HS1 design have moved on. "They could be laying pipes in Alaska or playing golf in Dubai," according to one HS1 insider.
While HS1 opens next month, much of the tunnelling work was completed in 2005. Work on Crossrail will not begin in earnest until 2010 – a gap of five years. Many of the 14,000 staff Crossrail needs could be anywhere as skilled tunnelling engineers are always in demand.
A HS1 spokesperson said: “We made huge advances in tunnelling knowledge, which would be very valuable to Crossrail. Tunnelling is probably the least transferable skill.
"But, HS1 is built in the minds of the executives, and a lot of people have already transferred from HS1 to Crossrail, especially in planning and finance.
"I could speculate that there could be problems if you didn’t make sure there is a good transfer. The advantage you have got is a ready-made facilitator to transfer that knowledge in Bechtel," he said.
Oakervee has been canny in spotting opportunities. Linking the project to HS1 is one example. Another is that “many of the people who will be involved [in building Crossrail] are still at school” says Oakervee. A programme of engagement with 900 schools will tap into this as-yet-unused resource. Promoting engineering and technology will keep the government happy, and will also raise the industry’s profile in the minds of school children.
£16bN The cost of the scheme that will revolutionise transport in London.
16km The amount of twin bore running tunnel to be excavated 40m beneath the capital.
14,000 The number of people needed to build the scheme - many of which will move on to the job from the Olympics.
2017 Completion date for a project for which many of the staff are still at school.