Page 102 - Built Expressions - Online Construction Magazine - November 2014 Issue

Connectivity Set Free the project have the ability to operate Eurotunnel was between January and September 1986 when the proposed Channel link once the 10 construction companies and fve banks negotiated among the project was completed and the proposed link must be able to endure themselves two of the key contracts, namely the Construction for at least 120 years. Contract and the detailed term sheet for the credit facilities. Ten proposals were submitted, including various tunnels and bridges plans. Some of the proposals were so outlandish in design that they were Connecting the Tunnels and weighed over 15,000 tons. They easily dismissed; others would be so One of the most diffcult tasks on the could cut through the chalk at a rate of expensive that they were unlikely to Channel Tunnel project was making about 15 feet per hour. In total 11 TBMs ever be completed. The proposal that sure that both the British side of the were needed to build the Channel was accepted was the plan for the tunnel and the French side actually Tunnel. Channel Tunnel, submitted by the met up in the middle. Special lasers Balfour Beatty Construction Company and surveying equipment was used The Design for the Channel (Now it is known as a Transmanche however with such a large project, no Tunnels Link) is an international infrastructure one was sure it would actually work. The project was frst estimated at $3.6 group that delivers world class Since the service tunnel was the billion but it reached over budget at services essential to the development, frst to be dug. It was the joining of the $15 billion. The Channel Tunnel was creation and care of infrastructure two sides of the tunnel caused the most to be made up of two parallel railway assets. It might be from fnance and fanfare. In 1990, the meeting of the tunnels dug under the English Channel. development through design and two sides was offcially celebrated. Two These two railway tunnels would run project management to construction workers, one British (Graham Fagg) a third, smaller tunnel that would and maintenance either alone or in and one French (Philippe Cozette), be used for maintenance, including partnership and by integrating local were chosen by lottery to be the frst drainage pipes, communication cables, supply chains. to shake hands through the opening. drainage pipes, etc. Each of the trains Later hundreds of workers crossed to that would run through the Chunnel Building the Channel Tunnel the other side in celebration of this would be able to hold cars and trucks. The digging of the Channel Tunnel amazing achievement. For the frst These enable personal vehicles to go began simultaneously from the British time in history, Great Britain and through the Channel Tunnel without and the French coasts with the fnished France were connected. having individual drivers face such a tunnel meeting in the middle. On the Each TBM or tunnel boring long, underground drive. Over 13,000 British side the digging began near machine used during construction of skilled and unskilled workers was Shakespeare Cliff outside of Dover the Channel Tunnel was 750 feet long hired to build the Channel Tunnel. and at French side began near the village of Sangatte. The digging was done by huge tunnel boring machines known as TBMs. It cut through the chalk, atkinsglobal.com collected the debris and transported the debris behind it using conveyor belts. The debris known as spoil be hauled up to the surface via railroad wagons (British side) or mixed with water and pumped out through a pipeline (French side). As the TBMs bore through the chalk, the sides of the newly dug tunnel had to be lined with concrete. This concrete lining was to help the tunnel withstand the intense pressure from above as well as to help waterproof the tunnel. PG 102 Built Expressions Vol: 3 Issue: 11 November 2014