Forth rail tunnel is ‘no pipe dream’

Construction experts have claimed a new Firth of Forth tunnel crossing is not just a pipe dream but entirely feasible and doable in just five to seven years.

Eyebrows were raised earlier this month when the Scottish Green Party unveiled costed plans for a nine-mile long twin bore rail tunnel under the estuary which would stretch from a point between Kirkcaldy and Seafield on the Fife side through to Leith on the Edinburgh side.

The Greens’ Rail for All plan described the project, which would come with an estimated £4-6 billion price tag, as a “gamechanger” that would vastly reduce travel times, improve punctuality and release capacity over the Forth Bridge that could be used for extra services to Dunfermline, west Fife and Alloa.

Sceptics have already dismissed the plans as unworkable, and sources close to the Scottish Government suggest it is unlikely to feature as an investment priority when it publishes its Strategic Transport Projects Review, setting out major projects for the next 20 years.

However, the chairman of one of the country’s tunnelling specialists has told The Courier people should not be too quick to dismiss the initiative.

Martin Knights, chairman of London Bridge Associates – which has been involved in several high-profile projects including the Channel Tunnel Rail Link, upgrades to the London Underground and the second Dublin Area Rapid Transit Underground scheme – believes further work should be done to quantify the project’s feasibility in terms of cost, programme, delivery and risk.

“While not without hydrographical and geological risks, dykes, faults and varying profile of sea bed and rockhead, recent subaqueous tunnelling projects in the UK and Nordic countries have demonstrated that tunnelling of this nature is entirely feasible,” he said.

“This is demonstrated by the spectacular advances in tunnel boring machine and blasting technology for hard rock and variable ground conditions.

“These advances... make it possible to consider undersea transit crossings such as the UK Government’s Union Connectivity initiative, chaired by Sir Peter Hendy, between Northern Ireland and Scotland.”

Mr Knights also pointed to work in Norway and Japan for how advances in tunnelling capability are already delivering deep sea tunnel schemes.

His comments were echoed by Dr Sauer and Partners, an independent consultancy which provides construction management services for tunnels, shafts and caverns.

The company’s managing director, Brian Lyons, said the Forth’s challenges could be managed by “modern bored tunnelling techniques” and added: “The UK tunnelling industry has the skills and capacity to deliver this project within a timeline of five to seven years.”

Deltix Transport Consulting, which was commissioned by the Greens to produce the report, also suggested there has been a long history of boring under the Forth for coal mining, noting that railway tunnels “much longer than this” have become relatively common in mainland Europe.

A spokesperson for the Scottish Government said: “Aspirational projects, such as the Firth of Forth tunnel, would be subject to the same scrutiny from the earliest stages to ensure they merited any serious consideration.”