Always boring, never dull: Britain at cutting edge of tunnelling boom
As well as a surge in domestic demand that includes the 26-mile Crossrail project, tunnellers’ prospects are looking good around the world
The machines have finished, but the humans go on tunnelling. On Thursday, a landmark moment came when the final inches of Crossrail's train tunnels were dug by Victoria, one of eight 1,000-tonne monsters which spent the past three years reshaping London's underground pathways. But the completion of that massive, 26-mile dig is far from the end of a tunnelling boom in the capital and beyond.
For many in the industry, it’s a mark of pride that the construction work, metres under busy streets and houses, can pass unnoticed. A mile or two west of Farringdon, where the prime minister was underground to herald the tunnelling achievement, excavation continued in the heart of the West End. Below the shoppers of Oxford Street, weaving past the sovereign subsoil of the Tanzanian high commission and just above the ceiling of Central line trains, new tunnels linking the capital’s new and old subterranean train tracks are being gouged out of the earth.
This will be Bond Street’s expanded underground station, growing to meet the demand created by a more frequent Jubilee line even before the anticipated passenger boom when the £14.8bn Crossrail line connects here. Working in the city centre adds levels of complexity, and expense. Propertyinflates the bill massively: tens of millions of the £320m upgrade is spent on securing the space to do the work. To minimise the footprint, the building that will become a new station entrance doubles up as a five-floor storage and construction site, stacked with cranes, machinery and materials right up to the air conditioning system on the roof (pumping down air as fresh as can be found in the notoriously polluted Oxford Street).
“It’s a bit like threading the eye of a needle,” says Miles Ashley, London Underground’s programme director of Crossrail and stations. Work here goes on around the clock, with acoustic cladding to minimise noise nuisance for neighbours, who include African diplomats, flagship stores and high-end boutiques, and the great and good of the Oriental Club at the end of a short cul-de-sac where thousands of lorries have come to haul earth away.
Meanwhile, the tunnels must negotiate Bazalgette’s Victorian water mains and the mothballed Royal Mail underground railway line – not to mention a fully functioning tube station. After descending into the clay and adjusting to the subterranean world, dim and echoey between bouts of drilling, it is surreal to peek blinking into the light through an emergency door into the frenzy of rush hour escalators. That crowd is why they are digging: “There’s no point in having 36 trains an hour if you can’t get people off the platform before the next one,” says Ashley.
Where the state-of-the-art German-built tunnel boring machines made great drives forward on Crossrail’s long train paths, some methods used in the small confines here are in essence as old as the original underground. Most of the enlarged Bond Street (and the majority of the eight miles of service tunnels and walkways Crossrail has also built) uses a relatively new technique, called spray concrete lining, to form the walls of the tunnels. It is one of the skills taught at a training academy in east London developed to provide the workforce for Crossrail and beyond.
More than 8,000 people have been trained at the tunnelling and underground construction academy in Ilford, north-east London, since it opened in 2011. Valerie Todd, talent and resources director of Crossrail, says: “When we started we were in the midst of a recession and we had the opportunity to recruit from a broad market, but found there weren’t enough people with the right skills. That was the catalyst to build an academy to meet our own needs - but also to look ahead. Now the market is very much heating up, not only in major projects such as HS2, potentially Crossrail 2 or Thames Tideway, but the tube upgrades and road schemes.”
Those skills honed in the capital’s clay depths will be in demand for other projects. The £50bn HS2 high-speed rail network will build tunnels through much of London and the Chilterns, with more planned in Manchester for phase 2; the Northern line extension to Battersea has been given the go-ahead, while the proposed £4.2bn Thames Tideway super-sewer would see another 16 miles of tunnelling around the capital.
As well as the domestic boom, tunnellers’ prospects are good around the world: Bechtel is starting work in Riyadh on a metro project to dwarf Crossrail. Yet Miller sounds a warning note that Britain may end up missing out in a sector where it has traditionally been at the leading edge. Swaths of engineers are men on the verge of retirement; relatively few young people are entering the profession; and the proportion of women engineers (6%) in the UK is among the worst in Europe.
Miller says: “It pains me that young girls are not understanding what a great career they could have here.” There were women in all her tunnelling crews – labourers and engineers – she says, but admits: “It seems there are even fewer women in tunnelling – but the ones who are here find it meaningful, exciting and well-paid.”