Boris bridge spanning English Channel ‘doable but costly’, experts claim
The Foreign Secretary raised the prospect of a second crossing following a top-level summit on Thursday.
Boris Johnson’s idea of a bridge spanning the English Channel has split opinion but is technically possible, experts have said.
Dr Kostas Tsavdaridis, associate professor in Structural Engineering at the University of Leeds, said constructing such a bridge was “doable” so long as issues including waves, water flow and depth, wind strength and soil condition were properly planned for first.
However issues including the weather, shipping and the financial implications could make the concept a less-than-practical reality.
It is thought that a bridge could be challenging for vessels crossing one of the busiest shipping channels in the world, sometimes with limited visibility.
Dr Tsavdaridis said he would use such a bridge “but only on the good days of the year”, as conditions could be harsh.
He said any seismic action in the area would not have a significant effect on the structure, and it was being mooted for the narrowest and shallowest stretch of the channel.
At 20-plus miles, it would be one of the longest bridges, but “it has been done in the past”, he said.
The world’s longest bridge is the Danyang–Kunshan Grand Bridge in China, which spans just over 100 miles.
He said: “If you are asking me just as an engineer I will say: Yes, it’s something that can be done, provided that very meticulous investigations take place.
“All that is doable. The problem, it comes usually from the economic and financial perspective – whether it is worth it to go for something like this.”
Expert estimates put the cost of such a project at more than £100 billion, according to the Times.
Alan Dunlop, who teaches architecture at the University of Liverpool, told the paper: “I’d say at least £120 billion for a Channel bridge and that’s a conservative estimate.
“It would really be cheaper to mover France closer.”
At the @V_and_A last night @EmmanuelMacron and I were proud to celebrate the extraordinary values and the talented people who link our countries. More than a century on from the “entente cordiale” let us celebrate our own “entente chaleureuse”. #UKFRsummit pic.twitter.com/X6jUQ8IC3r— Theresa May (@theresa_may) January 19, 2018
Bridge designer Ian Firth, a former president of the Institution of Structural Engineers, said the idea was “entirely feasible”.
He tweeted: “It was a serious contender to the tunnel back then and is even mor (sic) feasible now. Costly, yes, but so was the tunnel.”
Before construction on the Channel Tunnel began in 1988 there were four rival bids, including one with offshore islands.
The idea for a bridge was separately floated in 1981 when a formal submission was made to the then transport secretary.
The bridge would have been built along the lines of the Severn Bridge that links South Wales and England at an estimated cost of £3 billion, said engineering group LinktoEurope.
It was envisioned that motorists would pay a toll charge to drive the 21 mile route, 220ft above the water.
The group admitted that the pylons that would support the structure could cause navigation difficulties for vessels.
They dismissed the idea of tunnelling under the water as “impractical”.