James Moore
ASTONE’S throw from the Tower of London, ignored by most tourists, is a small round, brick building. It is the entrance to a mysterious forgotten tunnel underneath the River Thames. Today the 7ft-wide iron passage is used merely for water mains pipes, but 150 years ago it was a wonder of the Victorian age – the site of the world’s first “tube railway”.
The pioneering venture would revolutionise travel underneath cities, allowing the tentacles of the London Underground to spread into the incredible 250-mile system we know today.
In 1863 the first steps had been taken to creating an “underground” when the Metropolitan Railway opened a stretch of brick tunnelling from Paddington to Farringdon serviced by steam trains. A trench was cut into a street and then roofed over. More miles were added as the decade went on, yet progress to burrow a transport network under the capital was slow.
But the opening of the 1340ft-long Tower Subway on August 2, 1870, heralded the great technological leap forward that would make London’s underground the envy of the world.
Having first descended in steam-powered lifts passengers entered an eight-wheeled, wooden rail car. It was then pulled through the tube – buried 22ft beneath the riverbed – on a steel cable hauled by stationary steam engines at either end. The single-track line could shuttle 12 people between north and south of the river in just 70 seconds for a penny.
What made the Tower Subway so special was the cylindrical, iron tunnelling shield that had been used to construct it over little more than a year.
Working like an apple corer its design was perfected by the project’s civil engineer James Henry Greathead and was superior to the rectangular kind that had helped build Marc Isambard Brunel’s pedestrian Thames Tunnel back in 1843.
The clay was excavated from the front of the shield by one set of workers using its protection, while others bolted pieces of the curved iron ring together behind it, forming a self-supporting structure.
The Tube was born… and the nickname for the burgeoning London Underground network would stick. The technology still forms the basis of the modern machines used to burrow tunnels worldwide today.
Soon Greathead, whose statue stands by Bank station, was helping to construct the first section of the City and South London Railway – today’s Northern Line – between Monument and Stockwell.
For this deep-level underground Tube – 60ft down – ground-breaking electric trains would be used – doing away with the need for dirty steam engines that proved troublesome to operate in confined spaces.
The line was opened in 1890 and formed