Maintenance for a Smart Tunnel

Reliability, safety, availability

It is a daily challenge to ensure the faultless maintenance of an infrastructure as complex as the Channel Tunnel and of rolling stock handling the world’s highest density of traffic, while minimising costs and downtimes. It also represents a wonderful incentive to invent and digitalise new processes and tools: a sophisticated transport system and the world’s number one road-rail link, the cross-Channel Fixed Link is still at the cutting edge of technology, 30 years after construction began.

tunnel-ferroviaire
Eurotunnel tracks are amongst
the most heavily used in the world


As well as being the world’s longest undersea railway tunnel, the Eurotunnel network is also setting records in terms of its operations. 350 trains run each day through the Tunnel, representing one train every 3 minutes at peak times. The Truck Shuttles carry up to 32 heavy goods vehicles of 44 tonnes, some of the shuttles can weigh up to 2,500 tonnes. The Passenger Shuttles can transport up to 120 cars and 12 coaches. These 800-metre long trains run at 140 kph; 160 kph for Eurostar.

Such an activity requires a major equipment maintenance effort. Keeping the infrastructure and facilities in excellent condition to meet the highest reliability and safety standards, at a cost respecting the company’s profitability targets, represents a challenge not only at a technological and economic level, but also in terms of organisation.

The main goal is to optimise the availability of facilities and equipment, anticipating breakdowns and devising solutions so that the infrastructures can be maintained with minimal disruption to traffic.



A recognised expertise and innovation

With the built-up experience and the implementation of many innovations, the group has become a globally recognized in railway maintenance. Many rail infrastructure managers and operators, as well as professionals from other business sectors, regularly visit our workshops. Eurotunnel willingly shares its know-how in this area.

Eurotunnel is also member of the i-trans competitive pole and and cooperates with various industrial and scientific organizations in the region (Corus, RailTech, Sculfort, Outreau Technologies, RFF, Ecole des Mines de Douai, INSA-Lyon) on 4 different topics: the future materials and geometries for extending rail life; new welding; and the tracks of tomorrow. In July 2018, Eurotunnel renewed its Chair in “Railway transport Science” with the French Grand Ecole, the Ecole des Ponts ParisTech, which has already led to innovation and the patenting of an exceptional engineering equipment for the track maintenance in the Channel Tunnel (+ info: COBRA robot video).

A predictive approach to maintenance

Stringent monitoring of wear and tear on wheels

In Coquelles, when the trains are brought in to be serviced in the world’s longest workshop (825m), each wheel is scanned by the Wheel Measurement System (WMS), which takes a series of measurements. The accuracy and frequency of these measurements make it possible to anticipate maintenance needs. In this way, the under-floor lathe for wheel reprofiling can be scheduled, ensuring that this does not affect the equipment’s availability for commercial services. In addition, this forward-looking approach makes it possible to extend the lifespan of the rolling stock and by extension, the lifespan of the rails. WMS are also installed on the Tunnel lanes in order to examine the condition of the wheels in operation, in particular on the trains of the other railway operators, in order to ask them to carry out repairs which make it possible to avoid early wear of the rails.

Connected objects to monitor track circuits

All data recorded on track circuits is being input into a big database, with a view to updating the guidelines that will allow parts to be replaced in advance and thereby preempt breakdowns.

The Vectoor measurement train

Eurotunnel is getting a new measurement train Vectoor. As part of a major development to reduce railway infrastructure maintenance to just one night per week instead of two, the Vectoor measurement train is a two-wagon set that will bring together all the equipment needed for inspections of the railway tunnels.

Information collected will be used to create big data models capable of evaluating the lifespan of equipment, anticipating breakdowns and developing a predictive approach to maintenance, to further increase the availability of the Tunnel.

The first Vectoor module hosts one of the very first systems in the world capable of checking rail integrity via ultrasound at a standard speed between 100km/h and 140km/h, rather than 70km/h currently. The second contains all the equipment already used for inspecting, measuring and analysing track, catenary, GSM networks, track circuits, sleeper blocks, apron, tunnel lining, etc.

A drone for maintenance of terminals

A drone with a high-definition camera now enables us to perform these inspections more effectively with no disruption to traffic. For example, by flying beneath bridges and access ramps it captures detailed images that allow their condition to be assessed, while avoiding the need for scaffolding to be erected.

A power supply to anticipate growth in traffic

The continuous growth in traffic and the entry into service of the new Eurostar distributed power trains require the power supply to the catenary lines to be upgraded. A major piece of equipment used to regulate the electricity network, the SVC (Static VAR Compensator), will be replaced by a more recent device. Electrical capacity will also be better distributed and upgraded, with 25,000-volt cables being laid through the service tunnel, to the central intervals of the railway tunnels.