Marc Brunel's Thames Tunnel: engineering innovation beneath London

Thames Tunnel was originally created as a means of connecting Wapping and Rotherbridge beneath London's River Thames. Each of those areas was located on the southern and the northern portions of the river; locals desired a direct connection between these two locations to accommodate the burgeoning docks on each side. The earliest efforts to create a tunnel of this sort can be traced back to the close of the 18th century, when Ralph Dodd was unsuccessful in making a tunnel between Tilbury and Gravesend. The initial financial investors in the creation of the Thames Tunnel were known as the Thames Tunnel Company, which was formed in 1824 and included the likes of investors such as the Duke of Wellington -- who once helped free Thames Tunnel engineer Marc Brunel from prison (Pudney 57). The original plans for the tunnel were largely conceived of by Marc Brunel (No author), who worked with Thomas Cochrane to create the technology that would make the building of the tunnel possible. Originally, the tunnel was designed to accommodate horse drawn carriages. Although there were certainly pragmatic reasons regarding trade and commerce that were instrumental in the tunnel's creation, of equal importance was the degree of hubris on the part of Brunel in particular to build and underground (and underwater) tunnel for the sake of novelty.

1.2 Design

The Thames Tunnel was constructed approximately 23 meters below the River Thames. It is 396 meters long, with a width of 11 meters and a height of six meters. Near the completion of its construction, the tunnel was adorned with spiral staircases and suitable lighting along its roadways. Beneath the bank of the side closest to Rotherhithe, an engine house was built in order to quarter machinery used to drain the tunnel. Although Cochrane and Brunel were widely credited for innovating the technology that paved the way for the tunnel's completion, there was previous inspiration for a design of such a construct known as the Thames Archway (Aaseng 28), which was attempted by a group of Cornish miners between 1805 and 1809. The project eventually dissolved due to flooding, which would prove to be an ominous portent for the construction of the Thames Tunnel.

The principle technological innovation devised by Cochrane and Brunel that was instrumental for the completion of the Thames Tunnel was called the tunneling shield, a protective structure that serves as a support while builders tunnel beneath the ground. The tunnel shield is particularly useful when digging beneath soil that is soft, loose, or unstable -- which was one of the problems that the builders of the Thames Archway encountered approximately 10 years prior to Cochrane and Brunel patenting this technology in 1818.

1.4 Significance

The Thames Tunnel will always be remembered as the first tunnel that was built beneath a river that was used for transportation purposes. It represents an immense triumph for architecture and for man's steady struggle to exert his will against his natural surroundings. The length of time it took to build and the numerous setbacks endured only attest to the importance of the triumph. Moreover, the tunnel served as a watershed of sorts, particularly in light of the fact that after its completion -- which was facilitated by the technological innovation of Cochrane and Brunel's tunneling shield -- a host of underwater tunnel were completed in the United Kingdom in the subsequent years including London's Tower Subway, the Mersey Railway Tunnel and the Severn Tunnel. Most significant of all, nearly all of these ensuing structures were completed using variations of the tunneling shield.