Amazing Engineering – Channel Tunnel

Amazing Engineering is an introduction to the Seven Wonders of the Modern World, a list of modern engineering marvels compiled by the American Society of Engineers (ASCE):

By now, you may be familiar with our previous pages on the subject. In the first installment, we learned a little bit about the Golden Gate Bridge in San Francisco, California. In part two, we traveled out of the United States to northwestern Europe to learn about the Netherlands North Sea Protection Works. After that, we headed to South America where we learned about the Itaipu Dam on the borders of Brazil and Paraguay. Last time, we learned about the CN Tower in Toronto, Ontario. Today, we hope you read along with us as we learn about the Channel Tunnel connecting England and France.

472px-Course_Channeltunnel_en.svgThe Channel Tunnel, often referred to as the “Chunnel,” is a 31.4-mile rail tunnel connecting the United Kingdom with northern France. What makes this tunnel worthy of being named a “modern marvel?” Of the entire length, 23.5 miles of the tunnel runs undersea, under the English Channel!

Leading up to the completion of the Channel Tunnel in 1994, finding a way to travel between England and France other than by water had been a dream of many engineers. In fact, design plans for some type of tunnel connecting the two countries can be traced all the way back to 1802.

Over the years, the Channel Tunnel has faced many ups and downs. Prior to completion, for example, workers faced hazardous working conditions, as well as strict project requirements, and new technology had to be invented just to get through the construction phase. After the project was completed, the tunnel served as an easy way for travelers and goods to pass between the two countries, but problems such as fires and illegal immigration issues required immediate and special care.

The Beginning

The Channel Tunnel was a project in the making for more than 100 years. To learn more about the history of tunnel proposals prior to the official Channel Tunnel construction, please see the end of this article for resource links.

Before construction began, engineers had to decide how they would cut through the layers of earth—in this case, chalk marl—under the English Channel. At the time, machinery did not exist that would be able to withstand the immense pressure under the Channel’s seabed. The solution was to create 11 special boring machines. The machines would be able to cut through the chalk marl to construct what in the end would be three separate tunnels (two rail tunnels and a service tunnel). The two machines would start their work at either end of the tunnel. When they were ready to meet in the middle, the English boring machine burrowed down into the earth and the French machine completed the connection above it.

595px-Eurotunnel_schema_(empty_service).svgOver the course of the project, more than 13,000 people worked on the Channel Tunnel. Ten workers lost their lives during construction, the first being a 19 year-old worker who was hit by a locomotive in the marine service tunnel in January 1989. Numerous unsafe working practices cases were brought against the five United Kingdom-based companies that funded most of the Channel Tunnel project.

By the time the two ends of the tunnel were ready to meet in the middle, the alignment was only off by 50 centimeters—well within the range allowed for the project to be successful.

To celebrate the completion of the project, Britain’s Queen Elizabeth II and France’s President Mitterrand officially opened the tunnel by each traveling from their respective country and their trains meeting nose-to-nose in the middle.

Channel Tunnel Today

Today, it takes roughly 35 minutes to complete the journey from terminal to terminal. According to Eurotunnel, which operates the train terminals, more than four times the population of the United Kingdom has crossed through the tunnel.

1280px-Chargement_voiture_EurotunnelThe trains are equipped to handle cargo and personal vehicles, and since 2000 it is estimated that more than 1 million dogs and cats have made the journey.

Each shuttle is 755 meters long, which is roughly the length of eight soccer fields. Since opening, there have been three fires and multiple train failures for various reasons.

Another issue that has been a problem for the two countries is the number of would-be asylum seekers trying to cross borders via the trains, or even by attempting to travel by foot within the tunnel itself. It is estimated that over the span of two days in the summer of 2015, more than 3,500 immigrants attempted to cross the border into the United Kingdom via the Channel Tunnel. Both French and English authorities are reported to be working together with Channel Tunnel personnel to intervene in these situations.

More Facts About the “Chunnel”

Via Telegraph and About:

  • At the height of construction, 13,000 people were employed. Ten workers – eight of them British – were killed building the tunnel.
  • They didn’t quite meet in the middle – the English side tunneled the greater distance.
  • There are actually three tunnels down there – two for trains and a smaller service tunnel that can be used in emergencies.
  • 11 boring machines were used to dig the tunnel. Together they weighed a total of 12,000 tons (more than the Eiffel Tower), while each was as long as two [soccer fields]. One from the British side remains buried under the channel.
  • The lining of the tunnel is designed to last for 120 years.
  • It takes a total of 35 minutes to travel across the Channel Tunnel, from terminal to terminal.
  • The northern tunnel carries passengers from England to France. The southern running tunnel carries passengers from France to England.
  • One of the biggest fears about the Channel Tunnel was held by the British … Since Great Britain had been rabies-free since 1902, they worried that infected animals could come through the tunnel and reintroduce the disease to the island.

Other Links of Interest

Eurotunnel Infographic (PDF)

Super Structures: Eurotunnel Part 1 – YouTube

Eurotunnel Le Shuttle – Facebook

Eurotunnel Le Shuttle – Blog

Channel Tunnel – Wikipedia

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