This in-depth, evidence-based assessment has concluded that cutting-edge, twenty-first century civil engineering technology would make it possible to construct either a bridge or a tunnel between Great Britain and Northern Ireland. A bridge crossing, however, would be the longest span bridge built to date. A tunnel would be the longest undersea tunnel ever built given the limited gradients on which trains can operate, the route it would need to take and the depths it would need to reach. In addition, based on today’s technology and safety considerations, a tunnel crossing could only be constructed for railway use …
The consequence of these parameters for either a tunnel or a bridge is that they are expensive. The indicative cost estimate for the full route, including optimism bias (at P95), is £335bn for a bridge crossing and £209bn for a tunnel crossing. The bridge or tunnel, and the associated very significant works on either side for a railway and possibly for roads would take a very long time. Planning, design, parliamentary and legal processes, and construction would take nearly 30 years before the crossing could become operational, even given a smooth passage of funding and authority to proceed.
Whilst the economic and social effects would be transformational, the costs would be impossible to justify, given the government’s already very significant commitment to long term transport infrastructure improvement for levelling up, and the further likely significant expenditure which would result from the further studies I am suggesting in my main UCR report.
