Eurotunnel's Channel Tunnel concession provides for a second fixed link. Such a project would signal a £3 billion construction bonanza - but contractors should not build their hopes up. Isabel Pitman reports
EUROTUNNEL has unveiled a proposal for what would be the world's longest road tunnel - if it is ever built.
The Channel Tunnel operator put forward the plan to the French and English governments as part of a £1 million feasibility study for a second fixed link.
The study outlines two schemes, one for road, and an alternative for rail, both of which would exploit recent technical developments in large single-bored tunnels and take nine years to construct. Eurotunnel stresses that it has no intention of going ahead with either plan at present, describing the study as 'illustrative'.
In fact the proposals were submitted to fulfil a contractual obligation in the Channel Tunnel concession, signed by Eurotunnel and French and British governments in 1986. This required Eurotunnel to carry out a study for a second link and deliver a proposal before the Millennium.
Patrick Ponsolle, executive chairman of Eurotunnel, says: 'The option of adding a second fixed link to the existing tunnel is a long-term issue. Eurotunnel would only embark on such a venture if it would enhance the profitability of the company and if it were in the interests of shareholders.'
So, no action will be taken until demand for the present tunnel reaches full capacity.
Eurotunnel presently runs four rail services: Eurostar, passenger shuttles, freight shuttles (belonging to Eurotunnel) and international freight. Growth has been steady, with 11 million cars or coaches and 42 million passengers being carried on the shuttle alone since 1994. But full capacity is not predicted for a further 25 years.
Although the terms of the concession only stipulated a proposal for a road scheme as a second link, Eurotunnel has provided an alternative scheme for rail. John Noulton, the firm's director of public affairs, says this is in recognition of therecent shift in public transport policy, which now places greater emphasis on rail.
The feasibility study for the second link was launched in November 1998, with the appointment of two independent consultants, Maunsell in the UK and Scetauroute in France. In all, 10 designs were put forward, including those that had been considered back in 1986 for the present tunnel. The consultants rejected options such as bridges and immersed structures, thought to present insuperable technical difficulties, and limited their final selection to bored tunnels.
The road tunnel version is for cars and light vans only. The design proposes a large, single-bored tunnel, of 15 m external diameter, housing two separate, uni-directional roadways, one on top of the other. Each would carry a two-lane motorway plus a hard shoulder.
Safety is clearly a key issue, with all concerned mindful of the Mont Blanc road tunnel disaster last March.
Second link project manager Patrick de Montigny stresses that lessons have been learnt from the Mont Blanc accident. He highlights the importance of emergency access, which would be available in the road tunnel in the form of 'safe havens' of stairwells at 400 m intervals along the tunnel's length and a separate technical gallery. Additional protection would be provided by a fire-resistant lining, an automatic fire detector system and two undersea emergency stations.
The rail option has the same safety safeguards as the existing Channel Tunnel, with access stairs to a service gallery and cross-passages every 400 m.
But it differs in configuration, housing two-way traffic in a single tube, compared with the existing two single-lane tunnels. The structure would be housed in a 14.8 m external diameter single bored tunnel with an internal separator beween two uni-directional rail tracks.
The new rail link would be for exclusive use by Eurostar trains, international freight trains and, possibly, 'piggyback' unaccompanied road trailers. Under the proposal, the present tunnel would carry freight and coach passenger shuttles only.
The scheme would entail expansion at the rail terminals in Coquelles and Folkstone from 8 platforms to 16.
If the road option were to go ahead, car traffic would be restricted to the road tunnel and would no longer run on the passenger shuttle service.
Alain Bertrand, Eurotunnel deputy managing director, says: 'We have focused our attention on the capacity made available to freight traffic, as we believe moving freight from road to rail is going to be a critical issue for Europe in the next century.'
While the rail link option would allow the passage of up to 20 times per annum the freight volume predicted for the year 2000, the road option would also have a large impact on freight traffic. M Bertrand explains that a combination of the road tunnel and the existing tunnel would free up the space currently used for the passenger shuttle and allow 13 times per annum the expected freight load for this year.
He said: 'The road option, if ever built, would actually allow a massive transfer of freight cargo from road to rail, probably exceeding what the governments of Europe would be able to switch because of other bottlenecks inland.'
But what may be good news for freight may not be so appealing to car passengers. Some simply may not want to drive 50 km below the sea bed. A road tunnel of such length is unprecedented and the unknown fear factor could spell commercial failure for the operators.
Surveys of driver attitudes and behaviour have already been carried out at existing road tunnels in Norway and France, which would be used to inform the design of a second Chunnel road link.
Technical issues aside, the project would face a great financial hurdle, even if Eurotunnel were willing to press ahead with it. With the cost of the road option at today's prices estimated at £2.7 billion and the rail option at £3 billion, shareholders are unlikely to come running.
Eurotunnel is still saddled with a £7 billion debt from the first tunnel, on which costs more than doubled over the original estimate. Under the terms of its agreement with the UK and French governments, Eurotunnel has until 2010 to decide whether it wishes to go ahead. After that they will be free to invite other promoters to come forward with schemes.
But the message from Eurotunnel is not encouraging. M Bertrand says: 'There is no intention on our part to start spending or preparing for the construction of a detailed design for the second link. It is a proposal. It shall remain as it is.'