The Thames Tunnel

The Thames Tunnel

When it opened in 1843 the Thames Tunnel was described as the Eighth Wonder of the World. People came from far and wide to see the first tunnel under a river.

On the first day, fifty thousand people descended the staircase and paid a penny to walk through the tunnel. By the end of the first three months there were a million people, or half the population of London. This was the most successful visitor attraction in the world.

In the age of sail and horse-drawn coaches, people came from all over the world and bought souvenirs and listened to the entertainment in the cross-tunnel arches.

The idea, of course, was not entertainment but to move cargo and turn a profit. So what happened?

The Need For A Tunnel

The trade of the world came up the Thames, and there were three thousand tall masted ships in the river everyday. A tunnel was the only to get cargo across the river without stopping the  tall masted ships, but no-one had tunnelled under a river before.

Brunel invented the Miners’ Cage, or tunnelling shield. Miners would dig inside a protective frame, and bricklayers would build the wall as they advanced. Horses would pull loaded carts down huge double helix ramps down into the tunnel and across to the other side.


Work started in 1825 but conditions were appalling. Inside each cage, the miner would carefully dig out the wall in front, but in strips four inches wide. When he was done, and the man above and below as well, the whole row would be pushed forwards using screw jacks. Bricklayers working behind them made everything secure and the process began again. The Thames was tunnelled in four inch strips by miners using short handled spades.

As they worked, the miners showered in raw sewage and dodged flames from ignited methane gas. It was the worst job in the world, but the men only worked four hour shifts. They collapsed after four hours, and were replaced by men who were still breathing, and they worked until they fell over and were replaced in their turn…

The Tunnel flooded five times, and in the worst flood six men drowned and Isambard Kingdom Brunel barely escaped with his life.


The tunnel finally opened eighteen years later in 1843, but only for pedestrians. They ran out of money and could not afford to build the ramps to get cargo into the cargo tunnel. The tunnel opened as a visitor attraction.

Even under construction, the Tunnel was a tourist attraction, and when complete millions of people came to pay a penny to walk through the ‘Eighth Wonder of the World’


The East London Railway company bought the tunnel in 1865 with the intention of digging new tunnels to link up from the North and South to link the Thames Tunnel to the national railway network. Four years later, in 1869, trains started to run through the tunnel meant  for horses and carts. For the first time the tunnel was doing what it was intended to do – carrying freight across the river.

In 1869 electric trains had not yet appeared on the national network, so the trains running through the tunnel were hauled by steam engines. Entering the tunnel the trains would go downhill towards the low point at mid-river before starting the hard climb back up to the surface. The harder a steam engine works the more smoke it produces. In railway tunnels on land there are frequent shafts to allow the smoke to escape to the surface. No ventilation shafts could be built in the river so The Thames Tunnel was full of smoke making life very unpleasant for the steam engine drivers and firemen.

In 1913 the railway was electrified and incorporated into the London Underground as the East London Line, making the Thames Tunnel the oldest tunnel in the oldest underground system in the world. This is the birthplace of the tube!

London Overground

A hundred years later, the line was closed as part of an ambitious scheme to build an orbital railway for London. The Thames Tunnel is now part of the London Overground,  reducing journey times and congestion in the centre of the city. This very busy and successful railway is the latest addition to the capital’s transport system, incorporating The Brunels’ Tunnel, oldest river tunnel in the world…