If you build it, they will come... - underground vision

Materials World magazine
30 Apr 2013

Politicians and economists can be a contrary bunch, but one thing they tend to agree on is that capital investment in transport and infrastructure is one of the most effective ways to kick start an ailing economy. In addition to the direct jobs created by such projects is the trickledown effect on the service and supply chain, in particular the construction materials supply chain. But it is the ‘if you build it, they will come’ effect that more often than not leads to long term economic growth and prosperity.

Take the London Underground, for example, which earlier this year marked 150 years since the first six kilometre stretch of Metropolitan line opened for business. The idea of an underground railway, the first of its kind anywhere in the world, was the brainchild of Charles Pearson, a City of London solicitor and reforming campaigner who first proposed the idea in 1845 and campaigned for it until a Parliamentary Bill was passed in 1853 to build a subterranean railway between Paddington and Farringdon. Actually, Pearson’s plan was driven by practical rather than economic necessity, since a Royal Commission of 1846 prevented mainline railways from terminating in Central London, so a method of linking Paddington, Euston and King’s Cross stations was urgently required to alleviate overcrowding on the roads above.

The Metropolitan railway was an immediate success, with more than 30,000 passengers on its first day and nearly 12 million passengers in the first year – four times the population of London at the time. Some of those to benefit most were the low-paid workers who were able to move out from the overcrowded centre of London into cheaper and more spacious accommodation further afield, a trend continued to this day by the millions of Londoners who use the Underground for their daily commute.

The District and Circle lines that soon followed were built by the cut and cover method, whereby the road along the route was dug up, tracks laid and then covered by a brick lining before being backfilled. Although quick and relatively cheap, not least because property owners did not have to be paid compensation, this method of construction created as many problems as it was designed to solve, including the congestion during construction, and it was abandoned towards the end of the 19th Century in favour of proper tunnels. Fortunately, much of London is underlain by an ideal tunnelling material – the London Clay. This stiff, fissured, heavily over-consolidated, silty clay is perfect for digging tunnels through, being soft enough to cut with relative ease but sufficiently strong and impermeable to remain open long enough for a retaining lining to be fitted. Today, approximately 45% of the 402km London Underground network is in tunnels.

Pearson’s vision for an efficient mass transit system is continued in the 21st Century by the Crossrail project. Although on a much larger scale, Crossrail shares much of the original Metropolitan Railway’s vision and purpose. The 118km network will link Berkshire and Buckinghamshire in the west via Heathrow and Central London to Essex in the east, and is currently Europe’s largest civil engineering project.

Of course, quantifying the economic benefits is not an exact science, especially as the first trains are not due to run until 2018. According to the Mayor of London’s office, the £14.5bln project has a benefit-to-cost ratio of 1.97–2.76, depending on how value of time is calculated (Transport for London and the Department of Transport use different assumptions for this). Well, I suppose those economists have to disagree about something.