By the start of the 19th Century, the docklands in London had expanded rapidly, necessitating a new crossing of the Thames to connect the southern Rotherhithe docks to the northern Wapping docks. After several failed attempts to tunnel under the river, a remarkable engineer named Marc Isambard Brunel emerged with a groundbreaking invention.
Marc Brunel’s Revolutionary Invention
Marc Brunel, a French royalist exile, had made a fortune manufacturing pulleys for the Royal Navy during the Napoleonic Wars, but when the war finished he found himself bankrupt and imprisoned in the Southwark, Kings Bench Debtors Prison.
It was during his time there that he came up with a remarkable idea inspired by observing a wood-boring worm tunneling through ships’ timbers. This idea would prove to be the key to the successful construction of the Thames Tunnel.
His invention? A tunnelling shield, designed to support the structure of the tunnel as workers dug it out and paved the sides, that he patented in 1818.
When the Government heard of Brunel’s plans to emigrate to Russia and offer his skill to the Tzar, they quickly cleared his debt and released him, with the understanding he’d remain and work in the UK.
The Birth Of The Thames Tunnel: Challenges and Triumphs
Work started in 1825 with an access shaft being sunk down at Rotherhithe. The 80 ton cast iron shield was constructed below ground. It was designed to prevent the tunnel from collapsing and protect the men while they laboured.
It consisted of 34 individual compartments. In each, a man could stand, remove oak timber planks in front of him and then excavate four and a half inches of clay from the tunnel face and then reposition the planks. When all 36 men had finished the whole shield was jacked forward another four and a half inches using large screws, while teams of Bricklayers would follow behind lining the tunnel with arches.
The Thames Tunnel was a major engineering project that attracted widespread public interest. The Thames Tunnel Company, which was responsible for its construction, took advantage of this interest by selling a series of illustrated booklets chronicling the project. One of the most famous illustrations in these booklets shows the tunneling shield from the front.
Illustrations from ‘Sketches of the Works for the Tunnel Under the Thames’ – 1829
Later this innovation would go on to be adapted and improved by the Engineer James Henry Greathead who used it to construct most of the later deep level underground rail network. His work would give rise to the nickname of the London Underground network, “The Tube” As he used a round shape shield which would reduce the cost and time of the work.
Brunel’s invention was also the precursor to modern tunnel boring machines, such as those used to build Crossrail, the “Elizabeth Line”, opened in May 2022.
But let’s go back to Brunel’s 19th Century : Work was challenging, slow, dangerous and thwart with delay. Sewage from the polluted River Thames constantly surrounded the workers causing methane gas fires and sicknesses. When Marc Brunel became sick he handed the reigns over to his 20 year old son, engineer Isambard Kingdom Brunel, who went on to become one of Britain’s Greatest.
There were still many floods and deaths. On one occasion Isambard narrowly escaping with his life after a huge depression opened up in the river bed. This had to be plugged with bags of clay via a diving bell dangling from a boat in the Thames before the tunnel could be pumped clear of water so work could resume.
Opening And Legacy
Taking fifteen years to complete, the tunnel was finally opened by Queen Victoria in 1843. Marc Brunel would receive a knighthood but the Thames Watermen would fly black flags in protest of the new competition.
Watermen were the river taxis of the Thames, and they had suffered a lot recently from the advent of steam boats, from the building of the new London Bridge, easier to manoeuvre for said steamboats, and now this Thames tunnel…
At 400 meters long, 11 metres wide, 6 metres high and 23 metres below high tide mark, the Thames Tunnel was claimed to be the first tunnel in the world to be constructed for public traffic beneath a river. Although ancient historical records describe a tunnel built beneath the Euphrates River by the Babylonians in the second Millennia BC.
Initially intended to take horse drawn traffic this wasn’t possible as access approaches were never built through lack of funds. As a result it was never a financial success. Foot access was via staircases in the shafts at either end and it cost one penny to pass. 50,000 people passed through on the first day, but it quickly lost its popularity becoming a haunt for prostitutes, thieves and beggars.
In 1869 it was closed to pedestrians and sold to the East London Railway company and then became part of the underground rail network as the East London line. By this time the new Tower subway had opened as an alternative crossing. In 1995 it gained grade 2 listed status.
You can now visit the old boiler and engine house used for pumps during its construction. It stands at the Rotherhithe end and serves as the Brunel Museum. (Where you can find these delightful ‘Brunel socks’!)
Adam
