AN ENGINEERING MASTERPIECE
THE ENGINEERING MISSION
TML was responsible for the design of the transport system according to its contract with Eurotunnel. TML carried out all the engineering studies for the Channel Tunnel.
The transport system was designed to meet the performance set by the Concession agreement, including:
- 35-minutes crossing time between terminals
- 4-minutes between trains (the system allows 2 minutes, like a subway)
- Track designed for 200 km/h
- Evacuation of passengers in less than 90 minutes in the event of an incident.
THE DESIGN PHASES
The studies took place in several phases:
- 16 development studies on fundamental topics, such as geology, cross overs, railways, concrete durability, drainage, rolling stock, safety…
- Many preliminary designs (APS) and outline designs (APD) to select the best solutions
- The detailed design studies, for all components of the transport system.
The 110,000 engineering documents were used to define:
- The work performed by TML with its means
- Subcontracts managed by TML (metal constructions, electromechanics, equipment rolling…)
HOW WAS THE ENGINEERING ORGANIZED?
The Tunnel and Terminal engineering departments were organized by type of work, as were the Construction Departments.
The « Electromechanical » and « Rolling Equipment » engineering departments were organized by « elementary system » such as the Electromechanical and Rolling Stock (TSE) Branches.
The System, Operation and Safety engineering department ensured the consistency of the transportation system.
The Engineering Departments for ‘Tunnel France’ and ‘Terminal France’ comprised:
- the design offices set up with personnel provided by the TML parent companies (BETU, BETER),
- Specialists (BRGM, Simecsol, Mécasol, Terrasol, Jaillet Rouby, Coyne and Bellier…),
- Architectural agencies (Paris and Paul Andreu Airports, Larrivière, Noyon, Landscape Signs, Agency Provost…)
From the summer of 1986 studies were launched simultaneously, in all disciplines, in a coordinated and iterative way, to ensure the coherence and performance of the transport system.
The civil engineering works were designed according to
- Ground characteristics
- Construction methods designed by the Technical Services of the Construction Departments,
- Volumes needed for safety (circulation for the evacuation of people), for the Electromechanical equipment and for the trains and vehicles.
SOME SIGNIFICANT FACTS
As early as October 1986, aerodynamic calculations showed that the diameter of the railway tunnels planned by the Concession had to be increased from 7.30 m to 7.60 m, to allow for the lateral movement of the trains.
These decisions were crucial to ordering the TBMs, and to design the concrete segments and the prefabrication plant.
The tunnel layout follows the blue chalk layer, complying with a minimum radius of 4200 m with maximum slopes of 1.1% needed for a railway with 200 km/h design speed, avoiding unplugged old offshore drilling and minimizing the number of pumping stations.