"So Far as Any Present Use is Concerned, The Tunnel is an Entire Failure.” Or: Marc Brunel's Thames Tunnel:

In the 1800’s, London was the busiest city in the world. Trade brought goods from all over the globe, and they all came by ship down the Thames, to be unloaded in the various docks and wharves that lined the river.

The city itself was becoming busier too, as these newly arrived goods needed to be distributed from wharves to places of business. With London spreading ever outwards, a new crossing was required to the east of the city, but with so many ships with tall masts and sails coming down the Thames from the sea, a bridge would have to be extremely tall and steep, it seemed impossible. Was there any way a river could be crossed by thousands of people, horses and carts, without building a ship-impeding bridge?

In 1808, Richard Trevithick; inventor and mining engineer, attempted to construct a tunnel running underneath the River Thames in London, connecting the south bank to the north. The project was delayed after a sudden inrush of water flooded the tunnel, and a month after this flood, and a more serious inrush occurred. The tunnel was flooded again, and Trevithick was nearly drowned. Clay was dumped on the river bed to seal the hole and the tunnel was drained but mining was now more difficult.

Marc Brunel

The problem that Trevithick had encountered was the soft ground next to the river, which was soft and sandy and had no cohesion. Unlike more solid, clay-like land, this ground could not support itself when tunneled into, and subsequently was hugely prone to collapsing and vulnerable to seepage of water. With a thousand disastrous and potentially dangerous feet of tunnel having been completed, the general consensus was that a tunnel under the Thames was at best, impractical, and at worst impossible. Civil engineer William Jessop was an influential voice expressing this opinion, and the project was abandoned.

Ten years later, in 1818, engineer Marc Isambard Brunel patented a tunneling device, known as a tunneling shield. This shield was a large, rectangular structure, with three horizontal lines of twelve ‘spaces’ across the width of it, making thirty six ‘spaces’ roughly the size of a wardrobe inside each of which a man would stand with a small shovel, a candle and the minimum of elbow room. In front of each worker there were a series of horizontal boards. The worker unscrewed the top board to expose the earth at the face of the shield. He would dig away at this small portion of earth, and then replace the board, screwing it tightly into the empty space he had just dug away. The worker would then repeat the process with the boards below until he reached the bottom board. Once he had got to the bottom board he would start from the top again. The second time he finished at the bottom board his whole digging position would be jacked forward by around two inches using screw jacks. As the shield moved forward, bricklayers followed, lining the walls, and the process would be started again. Written down, this sounds awfully complicated. The picture helps:

The Thames Tunnel was dug using this process, meaning these workers dug a 1,200 ft tunnel two inches at a time for 1,200 feet across the River Thames. It is thought – whether true or not, I don’t think anyone knows – that Brunel modeled his tunneling shield on the shipworm; a creature that eats through the wooden timbers of ships with its head protected by a hard shell.

The prospect of testing his tunneling shield by constructing a tunnel under the Thames led Brunel to write to as many influential people he could think of who may be able to help him.
Subsequently, in February 1824, an impressive 2,128 people bought shares for £50 each in Brunel’s idea. Four months later the Thames Tunnel Company was formed.

The first stage of the build was to create an entrance to the tunnel. There was not enough space to build long, gentle-gradient ramps in and out of the tunnel for horses, so a vertical brick shaft was built on the soft Rotherhithe bank, and as the shaft became taller and heavier, the ground beneath gave way, leading the shaft to sink down to the depth where the tunnel entrance was planned to be built. This vertical shaft was completed in November 1825, and the tunnelling shield, which had been manufactured at Lambeth by Henry Maudslay's company, was then assembled at the bottom. but despite the tunneling shield, the process was still dangerous and difficult due to the soft ground around the Thames. The ground, though, was not the only problem the project would encounter. The sewers of Joseph Bazalgette were still almost forty years away, and so the Thames was a virtual open sewer surrounding the workers. The tunnel, not being particularly water-tight, seeped the sewage and became damp with it. The air quality underground naturally suffered, with workers feinting, coughing, and having to be pulled from their work and up to ground level to recover in fresh air. There was a more menacing danger to the presence of the sewage too; it gave off methane gas, which, in an environment full of men working by candle-light led to the odd fire-based accident.

Brunel Lowering the Diving Bell

These incidents, however, paled in comparison to some of the more serious dangerous occurrences during the construction.

Many workers, including Brunel himself, soon fell ill from the poor air quality. Resident engineer William Armstrong took ill in April 1826, leaving the engineering team a man down. Marc drafted in his twenty year old son, Isambard Kingdom Brunel, who took Armstrong’s place.

In May 1827 the tunnel suffered a flood when the miners breached the tunnel wall. Isambard lowered a diving bell from a boat to repair the hole at the bottom of the river, throwing bags filled with clay into the hole in the tunnel's roof. Once the tunnel had been repaired and drained, dignitaries were invited to a banquet inside it.

The Banquet in the Tunnel

The tunnel flooded again in January 1828, in a disaster in which six men died and many others, including Isambard, were almost drowned. To recuperate, he was sent to Clifton in Bristol, where he put himself forward to be the engineer to build a bridge there, amidst much competition. He won the contract, and today we have the Clifton Suspension Bridge.

Meanwhile, back in London, the tunnel was facing financial difficulties after the second flood. The resources Marc Brunel had acquired for the Thames Tunnel Company were spent, and despite his efforts to raise more money with tours of the tunnel, but these were fruitless. The tunnel was sealed up just behind the shield in August 1828. Marc Brunel resigned from his position and offered his help to Isambard in designing the Clifton Suspension Bridge.

The tunnel remained abandoned and sealed for seven years until Marc Brunel raised enough money for the work to continue. The project was plagued by the same floods, gas leaks and sick workers as before, which continued to set work back.

Because of the slow process of the build, the tunnel would not be completed until 1842, seven years after the re-start.

The Thames Tunnel, building of which commenced in January 1825, was finally completed in 1842.

The main reason the tunnel had been created was to allow trade vehicles – namely, horses and carts – to cross the river at this hugely busy point, without the need for a bridge. A bridge was completely impractical, as the thousands of ships that sailed in and out of the port of London – the busiest port in the world at the time – all had tall sails, and would be unable to pass a bridge, hence, the reason for crossing beneath the river, and not over it.

The original plan for the tunnel entrances was to use two large shafts with spiraling ramps running at a very gradual gradient that horses could pull carts down into the tunnel, then up to street level again at the other side.

However, because the project had taken so long to complete, and had taken so much money, there were no funds available to build these ramps, and so the only way in and out of the tunnel was via the spiral staircases in the entrance and exit shafts shown in the pencil drawing on the right. This clearly meant that horses and carts – the very passengers the tunnel was designed and created for – could not use the tunnel. Below is a cross sectional cut-away picture of the entrance shaft and part of the tunnel. Definitely not horse and cart friendly:

Despite this, it opened to the public on 25th March 1843. On 7 November 1842 Brunel suffered a stroke that paralysed his right side for a time, but despite ill health he still took part in the opening ceremony.
On the first day of opening fifty thousand people paid a penny each to walk though the new tunnel. Within the first ten weeks a million people had passed under the river via the new tunnel. With tourists coming from Europe it was deemed a worthy enterprise to set up souvenir stalls inside the tunnel. Shops were set up in the arches and entertainment was put on for pedestrians crossing the river. The tunnel was declared ‘The 8th Wonder of the World’. The novelty of the tunnel, though, soon wore off. After a short amount of time it became populated by hawkers of tatty wares who tried to sell to the pedestrians. It also earned a reputation as a place of business for prostitutes seeking work. This was a blow for the tunnel, with American novelist Nathaniel Hawthorne writing of it:

“It (the tunnel) consisted of an arched corridor of apparently interminable length, gloomily lighted with jets of gas at regular intervals ... There are people who spend their lives there, seldom or never, I presume, seeing any daylight, except perhaps a little in the morning. All along the extent of this corridor, in little alcoves, there are stalls of shops, kept principally by women, who, as you approach, are seen through the dusk offering for sale ... multifarious trumpery ... So far as any present use is concerned, the tunnel is an entire failure.”

The Shaft Today - Note the Scarring Where the Stairs Once Were

The East London Railway took over the tunnel in 1865. They wanted to dig new tunnels to link the Thames Tunnel to the national railway network. In 1869 trains did start to run through tunnels where horses and carts should originally have traipsed. 

Twenty six years after the tunnel opened, it was finally carrying out the function it was designed for – carrying goods from north to south beneath the river, albeit by train and not horse and cart.

The tunnel remains in use today as part of the London Underground’s East London Line. Occasionally, the Brunel Museum, located in the old engine room to the tunnel, put on a guided walk through the museum. Keep checking their website here for any future walks.

Modern Photo of entrance shaft taken by David Flett, used with permission. See more of David’s work on FlickR here