February 1, 2017


While you’re travelling the easy 35-minute journey between Folkestone and Calais, our Infrastructure Division is working tirelessly to make sure that your trip is as smooth as can be. To show you just how this is achieved, we’re going to have an interactive piece of equipment outside our terminals during the February Half Term, called the STTS (Service Tunnel Transport System).

With several different Infrastructure teams working together as one dedicated division, such as Planning, Signalling, Track, Power Supply, Catenary (OCS), Mechanical & Engineering, Civil Engineering, Works Train and Telecommunications, all of our workers are following the same clear objective: to maintain the Eurotunnel Infrastructure to the highest level of safety, reliability and availability for our customers and employees. Achieving exceptional customer service while running the longest undersea tunnels in the world is no mean feat – read on to find out about some of our individual teams and what they do for you.

Mechanical and Electrical

Simply put, the Mechanical and Electrical (M&E) department is focused on many different tunnel systems - including ventilation, firefighting, cooling and drainage. On our terminals M&E are also responsible for equipment including building services, access control, traffic management and security systems. It is the job of highly skilled M&E Technicians to find faults, keep on top of maintenance and repair anything that’s gone wrong, and working on the most varied types of bespoke equipment means there’s always something to be done!

Just a few of the kinds of equipment the M&E team work on include: two, 90-tonne cross-over doors, 270 cross passage doors, 400 kilometres of pipe, 3000 valves (for cooling and firefighting) and 200 customer information system screens, 240 traffic lights – and that’s far from all of them!

Works Train


Our fantastic Works Train team members include all kinds of professions, from electricians and mechanics, to Train Drivers and Support Staff. Their focus is on safety, performance and reliability, and of course, they’re always looking to improve embracing new technologies. Among other things, the Works Train team maintain all road service vehicles and buses and deliver road and rail based maintenance equipment, which allows the infrastructure teams to carry out their planned maintenance activities. This means they have to be on-hand in no time if something goes wrong (they’re never more than 15 minutes away!) so they’re always on call to respond to any issue.  Be it a technical infrastructure fault or a failed train anywhere between Calais and London St Pancras, the Works Train team working side by side with all infrastructure teams remain highly committed to fast intervention, correction and prevention of any fault leading to a fast return to normal service for our customers.

Works Train equipment includes: 9 Krupp DE6400 Diesel locomotives each fitted with a state of the art depollution exhaust filtration system, 12 Schoma worksite locomotives, a vacuum train, a tunnel cleaning train, a drainage train, catenary access platforms, rail lifting modules and a measuring train allowing infrastrure teams to continuously measure and monitor systems predicted and fixing faults before they occur.  

Road based vehicles include fork trucks, cranes, telehandlers, over 100 cars and vans 14 buses and a fleet of 24 bespoke STTS vehicles totally unique considering they are bi-directional.


Civil Engineering

When it comes to the maintenance of terminal structures and infrastructure, it’s down to the folks in the Civil Engineering department. They look after all three tunnels (two rail tunnels and one maintenance service tunnel) as well as the Sea Wall at Samphire Hoe. Safety inspection is incredibly important, so there are plenty of structures and systems for them to look over. Some of these within the terminals include:

  • 20 major concrete structures, including platforms, ramps and underpasses  
  • Metal structures, including wind fencing 
  • Reinforced earth structures 
  • 103 different buildings, including 55,161 square-metres of main buildings!

Keeping an eye on two rail tunnels and a maintenance tunnel means checking structures such as:

  • 93,313 reinforced concrete rings 
  • 100 kilometres of track concrete 
  • 148 electrical rooms



The 25kV AC Overhead Catenary System (OCS) is equipment that distributes an electric current to each shuttle locomotive and Eurostar locomotive, using pantographs – these are the metal frames you see above electric trains and trams, which collect power through contact with the wire. The specialist works protection and OCS teams apply strict protection procedures to safely isolate the equipment prior to any work commencing. The OCS is divided into sections by switches known as SELS, which are kept separate from other adjacent lines. The current travels down the catenary wire into each locomotive - electricity is also generated by locomotives when travelling downhill which is returned back into the catenary and to the substation.

Power Supply

Working closely with the OCS team, Power Supply Technicians are highly skilled in maintaining the high and low voltage electricity supply required to operate all systems and buildings on the UK Terminal, 2 running tunnels and service tunnel and at Samphire Hoe.

The main electricity intake substation is 132kV which is then cleverly distributed through a large number of substations and transformers providing 25kV to the catenary system and 21kV to the UK Terminal. Our Power Supply Technicians remain ready on standby 24/7 ensuring our operations run smoothly.

Track and Signalling


Infrastructures Track and Signalling teams work side by side maintaining our track and associated equipment ensuring our passengers a smooth uninterrupted journey. Our Track team is responsible for over 150km of track and over 120 turnouts (points) and are regularly working at night inspecting rails with ultra-sonic and geometry measuring equipment. With the highest tonnage of rail traffic in the world our dedicated Track teams work hard ensuring the track remains in top condition at all times.

Our Signalling teams specialise in all track control systems which allow the Rail Control Centre Operators to control track equipment including turnouts from many km away, Signalling teams also manage and maintain track circuits which allow the Rail Control Centre to know the location of each shuttle and to provide speed indication to each shuttle allowing it to proceed between our terminals.

Telecommunications (TCS)   

Infrastructures TCS Team amongst their responsibilities ensure Eurotunnel passengers and teams are able to communicate. From the hundreds of CCTV cameras, specialist operational systems, the mobile phone network, terminal information displays to Wifi this dedicated Infrastructure team work hard keeping our passengers informed and connected.   

Fun Facts about the Channel Tunnel 

Did you know?  

  • The Cross-Channel Fixed Link is the only way to cross the water between Great Britain and continental Europe in total safety, 24 hours a day, 365 days a year. 
  •  Since it’s opened, more than 380 million passengers and 75 million vehicles have already used the Tunnel. 
  •  All three tunnels are 40 metres below the Channel seabed, with 38 kilometres of tunnel below the sea! 
  •  Our service tunnel links to the rail tunnels every 375 metres.


Eurotunnel Le Shuttle transports cars, coaches, camper vans, motorcycles and all their passengers in just 35 minutes from Folkestone to Calais, platform to platform. Look out for our interactive STTS at terminals during February Half Term!

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