Thames Tunnel

Location: London, England
Completion Date: 1843
Length: 1,200 feet
Purpose: Pedestrian/Subway
Setting: Underwater
Materials: Brick
Engineer: Sir Marc Isambard Brunel

By the early 19th century, London, England was a prospering city. Several bridges crossed the Thames River but more were needed. The British decided to construct a new structure: a tunnel under the Thames River. Unfortunately, the tools of the day (explosives and power drills) were no help for building tunnels through soft, watery ground at the bottom of the river. Several attempts had been made to dig a tunnel beneath the Thames River, but they were all unsuccessful. It was until 1825 when a French engineer named Marc Isambard Brunel finally found a way to do it.

Brunel invented the tunnel shield, a giant iron box that could be pushed forward through soft soil. Diggers worked from 36 individual cells in the box and faced a wall of removable wooden planks. Each digger removed one plank at a time, scooped out about four inches of muck, and then quickly replaced the board. The shield was pushed forward by hydraulic jacks, and the whole process was repeated. While the iron shield held up the soft soil, workers lined the tunnel walls with brick. But the wooden planks were too weak to support the soft, watery soil, and the entire tunnel flooded five times. Methane and other pollutants in the soil caused unexpected explosions and deaths in the tunnel. Finally, 18 years after construction began; Brunel’s tunnel shield emerged on the other side of the Thames, proving for the first time that it is possible to carve a tunnel underwater. By 1965, the Thames Tunnel was converted to railway use. Today, the Thames Tunnel is part of the London Underground, also called “The Tube.”

1.22. Robert Hulse, director of the Brunel Museum, takes us on a tour of the Thames tunnel. He describes many interesting facts about the Thames Tunnel which is considered to be the eighth wonder of the world. Listen to him and try to catch some new facts for you.

Click here to watch the video: http://www.guardian.co.uk/culture/video/2010/mar/12/thames-tunnel-rotherhithe-robert-hulse

1.23. Click here to watch the video: http://www.youtube.com/watch?v=cp5xzmTP-CA&feature=related

While watching the video, try to comment every picture.

Дата добавления: 2015-10-31