Prime Minister Boris Johnson has described the idea of a bridge from Scotland to Northern Ireland as a "very interesting idea", as government officials have stared working into the possibility.

Professor Wanda Lewis, a structural engineer from the School of Engineering at the University of Warwick analyses the possibility of the bridge becoming a reality.

The idea of creating a bridge between Scotland and Northern Ireland is more than a century old, so perhaps it is time for it to become reality.

Two possible routes have been proposed for the bridge: (i) the northern one, connecting Mull of Kintyre in Scotland to Torr in Northern Ireland, and (ii) the southern one, linking Portpatrick in Dumfries and Galloway to Larne in County Antrim. These routes have been suggested  proposed by a Scottish architect, Professor Alan Dunlop, and the indications are that, although 45 km long (20 km longer than the Kintyre-Torr route), the southern route is likely to be a preferred option, because it would not require a new road infrastructure to be built on land.

However, concerns have been raised over the southern route crossing the Beaufort’s Dyke - a natural trench 200 m -300 m deep, 35 km long, and 3.5 km wide; the trench became the largest offshore dump site for conventional and chemical munitions since the Second World War. There have also been suggestions that nuclear waste has been dumped into it.

The cost of the Beaufort’s Dyke risk mitigation could outweigh the cost of road building on land and, therefore, the shorter northern route would likely to be a cheaper and safer option, provided the environmental risk in that part of the Irish sea has been eliminated (at this stage, there is no clear picture emerging of the extent of the spread of the pollution).

Given the depth of the Irish Sea (between 100 m and 200 m) a tunnel under the sea bed would be prohibitively expensive, so the project presents an exciting construction challenge.

Professor Dunlop proposed a solution involving sections of conventional cable-supported bridges placed in shallower waters, and, in deeper waters, a cable-supported floating bridge connected to the sea bed by cables or a submerged tunnel (also anchored to the sea bed by cables). The design of floating bridge and tunnel solutions would draw on the expertise in construction of off-shore structures.

Indeed, these ideas (not new, but not tested before) are being currently evaluated in the Norway’s largest coastal highway project, involving joining a number of fiords along the 1100 km long, E39, route. The Norwegian structures, however, have to bridge a number of relatively short stretches of water, the longest being 4.5 km, unlike the 45 km span (or 25 km, if the safer, northern route is chosen) proposed for the bridge between Scotland and Northern Ireland.

There is no progress without conflict, and this project offers a number of advantages, in terms of bringing northern communities closer, providing a substantial stimulus to the construction sector in the UK, and research into innovative materials and methods of construction. All of these aspects would bring significant benefits to the economy.

ENDS

11 FEBRUARY 2020

FOR FURTHER INFORMATION PLEASE CONTACT:

Alice Scott
Media Relations Manager - Science
University of Warwick
Tel: +44 (0) 2476 574 255 or +44 (0) 7920 531 221
E-mail: alice.j.scott@warwick.ac.uk

FOR FURTHER INFORMATION PLEASE CONTACT:

Alice Scott
Media Relations Manager - Science
University of Warwick
Tel: +44 (0) 2476 574 255 or +44 (0) 7920 531 221
E-mail: alice.j.scott@warwick.ac.uk