The cost of building prime minister Boris Johnson\u2019s mooted transport link between Northern Ireland and Scotland is \u201cimpossible to justify\u201d an official review has found.<\/p>\n
An investigation by professors Douglas Oakervee and Gordon Masterton, with support from consultants Jacobs and COWI, commissioned by the government<\/a>, has concluded that building either a bridge or tunnel is theoretically possible, but should not proceed until technology can bring costs down.<\/p>\n The study<\/a> found that a suspension-bridge crossing would cost \u00a3335bn, while a tunnel would be cheaper at \u00a3209bn. Either a bridge or underseas-tunnel option would be the longest of their kind ever constructed.<\/p>\n Planning, design, parliamentary and legal processes, and construction would take 30 years before the crossing could become operational, assuming it had a smooth passage of securing funding and winning permission.<\/p>\n The study, released as part of the Union Connectivity Review<\/a>, carried out by Sir Peter Hendy, recommends against the scheme going ahead and suggests no more work should be done to plan for it.<\/p>\n In a foreword to the study, Sir Peter said: \u201cWhilst the economic and social effects would be transformational, the costs would be impossible to justify, given the government\u2019s already very significant commitment to long-term transport infrastructure improvement for levelling up, and the further likely significant expenditure that would result from the further studies I am suggesting in my main report.\u201d<\/p>\n As an alternative, the main review recommends the more modest plan of upgrading the A75 road in Dumfries and Galloway to improve the port of Cairnryan and boost sea crossings between Great Britain and Northern Ireland.<\/p>\n Several issues raised previously about the Irish Sea link, including the extreme depth of the water at Beaufort\u2019s Dyke creating engineering challenges, as well as unexploded ordinance dumped in the area are noted in the report. There would also need to be significant upgrades to rail and road links at either side of the link, it highlighted.<\/p>\n The carbon emissions associated with the build would also be significant, the consultants found. The least carbon-intensive option, a lean tunnel, would generate an estimated 4.5 million tonnes of carbon dioxide, while the biggest bridge option would generate 18.4 million tonnes. If building the link diverted a significant number of people away from flying, it would take between 42-61 years to offset the construction impact for a bridge, although only 15-24 for building a tunnel.<\/p>\n The scheme is one of several ambitious infrastructure projects put forward by Johnson that have not come to fruition. While mayor of London, he advocated plans for the abandoned Garden Bridge project, which cost \u00a353.5m<\/a>, despite no construction work ever commencing. He also repeatedly backed plans for a\u00a0Thames Estuary Airport<\/a> \u2013 dubbed \u2018Boris Island\u2019 \u2013 which ultimately fell through.<\/p>\n