Skip to main content
Part of complete coverage on

Meet the midnight 'tunnel moles' of world's longest undersea structure

From Atika Shubert, CNN and Eoghan Macguire, for CNN
September 20, 2013 -- Updated 1352 GMT (2152 HKT)
STORY HIGHLIGHTS
  • Every night, engineers and maintenance workers descend to the darkest depths of the Channel Tunnel
  • Teams of workers clean and make essential repairs so that train services can run as planned during the day
  • On some shifts workers are expected to cover more than 100 kilometers in just a few hours

(CNN) -- It's approaching midnight at the bottom of the English Channel and a team of eager "tunnel moles" stands poised for a busy night's work.

Employing a mix of hi-tech tools and no little elbow grease, the 70-strong crew of engineers and maintenance staff will carry out essential repairs on the Channel Tunnel rail link that connects southern England and northern France.

At 50-kilometers (31 miles) long and buried more than 100 meters beneath the surface at its deepest point, the "Chunnel" -- which consists of two rail traffic tunnels split by one service passageway -- is the longest undersea structure in the world.

Making sure this engineering wonder runs smoothly is a detailed and complex task. Enter site operator Eurotunnel and their beavering band of "tunnel moles."

See also: Navigating world's busiest shipping lane

Outside of good design (the most important thing is) lots of maintenance
Paul Bushell, maintenance engineer

"Outside of good design (the most important thing is) lots of maintenance," explained lead maintenance engineer Paul Bushell.

"You've got the ventilation supply, you've got the drainage supply, you've got the main power supply, the water supply and you got the cooling supply. All of these things are vital for the day-to-day running of the tunnel," he added.

Keeping track

Since opening in 1994, more than 320 million people -- the equivalent of almost 5 times the population of the United Kingdom -- have traveled through the Channel Tunnel, according to Eurotunnel. The route is also estimated to carry 550,000 tonnes of cargo every day.

Engineers work through the night in the Channel Tunnel

It's no surprise then that rail tracks here wear out far quicker than those on conventional networks. After just 16 years of operations, all of the tunnel's rails have already been changed twice.

Trains also bring in immense amounts of dirt and dust that, if left to fester, can cause long-term damage to equipment and infrastructure.

Inside world's longest undersea tunnel
How 'blue motorway' stays afloat

See also: Inside world's longest undersea tunnel

"The job of our technicians is more like being a traveling service engineer," Bushell said.

"The service tunnel is 50 kilometers (31 miles) long and we've got plant rooms and control rooms all along that length. So quite often our technicians can cover 100 to 150 kilometers (62 to 92 miles) in an hour shift where they visit different sites," he continued.

Strict timetable

Covering such lengthy distances makes the Channel Tunnel one of the longest workshops in the world meaning repairs must be carried out at a breakneck pace.

Engineers generally begin late at night and must have all jobs completed before early morning services begin. During the daytime hours a team of trouble-shooters ensure a prompt response to any emergencies.

According to UK work site manager, Dave Bennet, these procedures require close co-operation with both English and French based engineering and planning teams.

"We're all one big company," said Bennet in the spirit of cross-border tunnel bonhomie.

"(Generally) English teams do work on their own (and) French teams do work on their own but we also all work together. Language isn't really a barrier. Most of us are bilingual and that works both ways so it's not a problem for us," he added.

Quite often our technicians can cover 100 to 150 kilometers (62 to 92 miles) in an hour shift
Dave Bennet, Eurotunnel

See also: Silk road railways link Asia and Europe

Some long-serving engineers have been working in the tunnel since it was first opened in 1994. Others were even involved in the construction process itself, ensuring they know the deepest darkest recesses of the structure.

Given the tight timescales involved, this detailed knowledge is an invaluable operational asset. As the service of the tunnel expands, this expertise is likely to become even more important.

Future expansion

Eurostar -- which currently operates services between London and Paris through the tunnel -- has already invested heavily in extending the capacity of their fleet.

Trains from German operator, Deutsche Bahn, meanwhile will be gracing the line come 2015, opening up services from London to Amsterdam, Frankfurt and beyond.

A Eurostar train exits the Channel Tunnel (Image: Getty/AFP/Denis Charlet)

An extra three to four million passengers are expected to pass through the tunnel each year as a result of these developments, while increased trade between the UK and countries on mainland Europe will also likely be further facilitated.

See also: Introducing the world's biggest ship

According to UK civil engineers team leader, Philip Edwards, this means rapid maintenance work will likely take on an even greater importance. How it is carried out will remain broadly similar though.

"The (work) will adapt to the frequency of the trains going through the tunnel (but) we'll still have the same tasks and inspections," Edwards explained.

"The maintenance is always evolving and as things get older it has to adapt to it ... (Exactly) how that will happen though (as time progresses), I have absolutely no idea," he added.

Either way, he concluded, "more trains can only be good for Eurotunnel" and their fast-moving team of tunnel moles.

Find out more about The Gateway and when you can watch the show on CNN here

ADVERTISEMENT
Part of complete coverage on
September 18, 2014 -- Updated 1054 GMT (1854 HKT)
What will the airport of the tomorrow look like? We've compiled some of the most exciting projects in an interactive feature.
November 20, 2013 -- Updated 1205 GMT (2005 HKT)
In the sleepy seaside town of Mariel, northwest Cuba, a hulking monument to the communist islands' evolving economy is taking shape.
November 26, 2013 -- Updated 1353 GMT (2153 HKT)
Meet Russian Tugboat captain, Viktor Nikolsky, who has sailed the world's seas and survived being hijacked by Somali pirates.
November 8, 2013 -- Updated 1039 GMT (1839 HKT)
A high exposure photograph of a drawbridge in St Petersburg, Russia.
Meet Sergey Matveev and family, St Petersburg's "First Family" of drawbridge operators.
October 31, 2013 -- Updated 1159 GMT (1959 HKT)
Where are the world's most dangerous waters? Hint; they're not off the coast of Somalia.
October 17, 2013 -- Updated 1122 GMT (1922 HKT)
Train and metro stations have become unlikely havens for some of the most exquisite architecture and design. We profile some of the best.
October 9, 2013 -- Updated 1239 GMT (2039 HKT)
Rubber ducks float upon the Suchitlan lake in Suchitoto, 47kms east from San Salvador in October, 2007.
What have 29,000 plastic toys that fell overboard a cargo ship in 1992 been doing for the last 21 years?
October 4, 2013 -- Updated 1340 GMT (2140 HKT)
A yacht sails behind a giant Maersk cargo ship at the port of Felixstowe, England.
How are ports adapting to cope with the new generation of giant cargo ships?
September 27, 2013 -- Updated 1152 GMT (1952 HKT)
London, Beijing or somewhere in the United States: Where is the world's busiest airport? Find out in our detailed infographic.
September 18, 2014 -- Updated 1054 GMT (1854 HKT)
A ropeway hangs above the Brazilian city of Rio de Janeiro.
Urban gondolas are offering cheap and effective methods of mass-transportation in some of South America's biggest cities.
June 27, 2013 -- Updated 0923 GMT (1723 HKT)
The Silk Road was once a series of dusty trails forged by traders traveling between Asia and Europe. Today it takes the form of a bustling railway.
June 26, 2013 -- Updated 1249 GMT (2049 HKT)
An all new class of container ship, the Triple E is a quarter-of-a-mile long and built from enough steel to construct 8 Eiffel Towers.
June 18, 2013 -- Updated 1136 GMT (1936 HKT)
Crossrail construction workers stand near to one of the 1,000 tonne tunnel boring machines during a photocall to mark the breakthrough into the Canary Wharf station box in London's docklands area on May 31, 2013.
Take a peek at some of the most exciting travel infrastructure projects currently in the works around the world.
ADVERTISEMENT