- Boris Johnson believes the government should “seriously” consider a proposal by a Liverpool architect to build a £15 billion bridge between Scotland and Northern Ireland.
- A vast, undersea military weapons dump sits in the way.
- Bombs cached there still explode, occasionally.
- Apart from that, it is totally doable.
LONDON – UK Foreign Minister Boris Johnson thinks the government should look “seriously” at the idea of building a 28-mile,£15 billion bridge over the Irish Sea to connect Scotland and Northern Ireland.
There are only a couple of problems with the proposal: The sea there is up to three times as deep as the English Channel (which separates Britain and France) and part of it includes a 1 million tonne underwater weapons dump.
Johnson has proposed speculative bridges before.
In January, he said Britain and France should be joined by a 22-mile bridge because it was “ridiculous” that two of the world’s greatest economies are linked only by a single railway. Prior to that, when he was Mayor of London, he proposed a new “Garden Bridge” across the Thames River. After £46 million was spent on research and planning, the bridge was cancelled by his successor, Sadiq Khan.
This time around, Johnson thinks the 26-mile gap between Larne (near Belfast, Northern Ireland) and Portpatrick (Scotland) is doable.
“Boris thinks this is an interesting idea which should be looked at more seriously – as politicians in both Scotland and Northern Ireland have already said,” The Telegraph reported. “It’s the kind of ambitious project we need to make a success of [post-Brexit] Global Britain.”
- Local sea depths:
- Irish Sea: 160 metres
- English Channel: 45 metres
At first glance, it looks as if a bridge might be a good idea. The Irish Sea reaches its narrowest point between the two nations in the north, and a bridge there would provide a straight-shot connection between Belfast, Glasgow and Edinburgh of just a few hours’ journey. Currently, the gap is served by a ferry that takes about two hours each way.
But there are problems.
Crossing one of the narrowest parts would land the bridge near Campbeltown in Scotland, which is a two-and-a-half hour, 138-mile drive to Glasgow, because there are no other bridges over the intervening lochs. The other route, via Portpatrick, is only 93 miles, but still takes 2 hours and 20 minutes to Glasgow, by car.
Either way, within that narrow gap is “Beaufort Dyke,” an especially deep trench in the sea that the British military began using as a safe place to dump chemical and conventional munitions after the Second World War.
There are up to 1 millions tonnes of unexploded, rotting ordnance sitting in the 300-metre deep hollow. Decaying weapons still occasionally wash up on shore from it. There have been 186 sudden explosions linked to the dump, according to this study of seismic activity in the area.
The largest explosion was also the most recent one, in 2004, the study’s authors note. Here is a seismograph of the blast:
Even the architect who first proposed the bridge, Professor Alan Dunlop of Liverpool University, says the weaponry poses a daunting challenge:
While Alan believes this is the most beneficial route, it also poses a number of challenges. The distance between Portpatrick and Larne spans around 26 miles and the bridge would need to accommodate Beaufort’s Dyke, a 300-metre deep trench off the west coast of Scotland, which was used as a munitions dump after the Second World War.
“How you would build a bridge across that was a challenging thing to actually do,” Alan admitted.
“I looked into the prospect of how that might be done and I found out, for instance, in Norway they’re prototyping floating bridges and they’re building bridges that are spanning across trenches that are 500 metres deep.”
A bridge is architecturally possible. China has at least three bridges that are more than 100 miles long.
But there are also economics to think about. A Northern Ireland-Scotland bridge would seek to replicate the success of the Øresund bridge linking Copenhagen in Denmark and Malmo in Sweden. Both those two countries have much larger populations and therefore a much greater potential level of trade. Northern Ireland and Scotland are, combined, half the size:
- Market populations:
- N. Ireland: 1.8 million
- Scotland: 5.3 million (Total: 7.1 million)
- Sweden: 10 million
- Denmark: 5.7 million (Total: 15.7 million)
No doubt building such a bridge would increase the amount of trade between Scotland and Northern Ireland. But it would still be a market that has half the number of consumers that benefit from the Øresund span.
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