Comment - a fixed link to France

From time-to-time the suggestion is made that there should be a tunnel or bridge connecting Jersey to France. This note provides a high-level review of the issue.

The shortest distance from Jersey to the Normandy coast is 23 kilometres. However, bridges and tunnels can't just run from shore to shore. A fixed link would probably need to be at least 25 kilometres. The issues that need to be considered are practicality, viability, demand, implications for the ferry service, whether France wants a fixed link and perhaps the most politically difficult issue - the landing area for the fixed link.

The practicality issue is simple. It would be a difficult engineering task given the nature of the water between Jersey and Normandy, but perfectly feasible.

Viability depends on cost and demand. Some basic desk research reveals a surprisingly wide range of costs for tunnels and bridges, broadly speaking a range from £80m to £800 million per km.

In 2020 there was discussion in Guernsey about rail tunnels between the islands and to France. A rail tunnel between Jersey and France was estimated to cost £3 billion and a bridge £3.5 billion. This article from Construction News on 6 February covered the concept –

A rail tunnel between Guernsey and France via Jersey would cost around £5.6bn and take up to 10 years to build, according to a tunnelling engineer.

The idea of a rail link is being driven by local entrepreneur and former Guernsey Chamber of Commerce president Martyn Dorey. Dorey took inspiration from the tunnels that link the Faroe Islands and has claimed that such a fixed connection could help the Channel Islands double their GDP in a decade.

Ramboll head of tunnels Stephen Whitham told Construction News that the governments of both Guernsey and Jersey have resolved to support the exploration of the idea, though they have so far said this would be funded privately, with Ramboll providing technical input.

Whitham's proposals connect Guernsey and Jersey in one phase, with a second phase continuing the connection to Normandy in northern France.

The consultant said that his initial findings, produced after two years of work, have shown that a 28-kilometre rail tunnel connecting Guernsey and Jersey will cost around £2.6bn. A bridge between the islands is “physically impossible”, he added, because the excessive water depth meant that foundations would be too expensive.

A second phase, consisting of a 32-kilometre rail tunnel from Jersey to France, will cost around £3bn, according to Whitham. The consultant estimates that the rail journey on both stretches will be around 15 minutes. Since the water between Jersey and France is shallower, a bridge for this section would be a possibility, though he estimated it would be more expensive at £3.5bn.

Whitham said that he was in the closing stages of reaching a deal with a consortium of private sector investors to fund full feasibility studies for the project, adding that Jersey is “very keen on pursuing this as a post-Brexit option for the country's development”.

He added that a link between Guernsey and Jersey could be beneficial due to the ageing demographic: “We've come at this from a sustainability agenda. If Guernsey and Jersey want to have a post-Brexit economy, there needs to be a commuting population to service old people’s homes, hospitals, service lines.”

There seems to be no formal report and little more has been heard about the concept.

Following are other examples, some of actual costs and some of estimates –

• A 31 km undersea road tunnel linking two Japanese islands was costed at £5.6 billion.
• The 16 km link between Copenhagen to Malmo cost £1.5 billion in the late 1990s so about £2.7 billion in today’s prices.
• The 3 km Stonehenge tunnel will cost £1.6 billion.
• A link between the Isle of Wight and Hampshire - much shorter than Jersey-France – has been costed at £2 billion. It is being promoted by a campaign group.
• There is a network of tunnels in the Faroe Islands that have been constructed at costs well below the costs of tunnels in England. This Wikipedia article gives key information and sources of detailed information.
• A 15 km tunnel is Scotland was costed at £1.6 - £2.1 billion. A detailed technical note gives valuable information on the cost of tunnels generally.
• A detailed feasibility study (which cost £900,000) for a fixed link between Scotland and Northern Ireland (one of Boris Johnson’s fantasy projects) concluded that the cost would be £209 billion for a tunnel and £335 billion for a bridge, a special factor here being a deep trench.

There is a huge disparity in costs between the Faroes and the UK. A Faroes tunnel apparently costs £12 million per km, the Stonehenge tunnel 44 times more at £533 million per km and the Solent tunnel a broadly similar figure. Two points explain some, but not all, of the reasons for the disparity. The tunnels connect parts of the same jurisdiction and that jurisdiction is very sparsely populated so reducing construction costs, particularly for landing points.

Taking all these estimates together a minimum cost seems likely to be between £1 billion and £2 billion, but with a range of perhaps £500 million to £5 billion. A more detailed desk study could quickly narrow the range. £1 billion would require interest and debt repayments costs of £70 million a year or about £200,000 a day with an interest rate of 5%. The lower the charge the more crossing would be needed to make the crossing viable. A charge of £100 a crossing would require 2,000 crossings a day just to pay the capital costs.

Would there be demand at this level? This would require some market research together with an analysis of existing traffic on the ferries. This raises the question of the implications for the ferry service. Clearly there would be implications, which could range from very modest to quite substantial. Jersey absolutely needs a ferry service; a fixed link to France could only supplement, not replace, the service, but it would make the service less viable.

It is important for Jersey to have good connections with France but less important for France to have connections to Jersey. There could be no fixed link between Jersey and France without not only the support but the active cooperation of the relevant authorities in France.

In practice a key issue in addition to viability would be the landing point in Jersey. A bridge or tunnel cannot just emerge in 50 metres but rather requires a lengthy landing area at either side. The landing area has to accommodate customs and immigration facilities and be well connected to the road network. The Royal Jersey golf course is probably the ideal landing area but this would mean huge opposition, as probably would anywhere else. A bridge would be more difficult as it well it might be a thing of beauty viewed from afar but not when viewed from 100 yards away. St Catherine's breakwater and the La Rocque area are possible landing areas. The La Collette area would have obvious advantages but at the expense of lengthening the bridge and running into problems with shipping lanes.

Clearly a fixed link between Jersey and France would face huge challenges in respect of viability and the substantial area that would be needed in Jersey at the entry point. The project would also be risky, given the tendency for large infrastructure projects to exceed initial budgets, often substantially so.