23 April 2007
Gibraltar bridge?
Brian Micklethwait

Michael Jennings often emails me with links to things he doesn’t have time to blog about himself, or maybe isn’t sure anyone else cares about other than me.  I don’t always respond so these suggestions, but they are always welcome.  Others who do the same thing, but somewhat less often, are likewise much welcomed.

Anyway, rather longer ago than is strictly dignified for me now to blog about but never mind, knowing that I do love bridges, Michael sent me this link, to an article about a possible tunnel, linking Spain (i.e. Western Europe) to Africa, and had this to say about the idea:

There is no economic case for it so it would be a huge white elephant, so I can’t actually imagine it being built soon. (The observations about its usefulness for freight are grasping at straws of justification - ships are fine for freight).

However, the more interesting thought comes from this statement:

“The Strait of Gibraltar, formed millions of years ago when land masses split to form what are now Europe and Africa, is only 14 kilometres wide at its narrowest point. But the water is so deep there a rail tunnel would be like a roller coaster slope, so steep as to be out of the question.

“So engineers have chosen a longer but shallower path spanning about 40 kilometres. Even there, however, the water is about 300 metres deep, five to six times deeper than the water in the English Channel where the channel runs.

“Then there is the messy terrain at the bottom of the Strait. ‘It is chaotic. The word is chaotic,’ said Sebastian Sanchez, an engineer overseeing the tunnel test site in Tarifa.”

There is an obvious word that comes from this (both the fact that the narrowest point is too deep for a tunnel and that the terrain on the bottom of the Mediterranean is complex) and that word is “bridge”.  Imagine huge towers each a kilometre or two from the shore and a single suspension span of more than 10km. We don’t quite have the materials for this yet, but in twenty years we probably shall. Then this is potentially the most mindboggling structure on Earth.

And there’s also this:

The other reason why the Spanish at the moment aren’t talking about bridges is because the obvious place to land the bridge on the European side is actually British territory.

Indeed.  The thing about these emails from Michael is that he has no time to do a proper blog posting, so he just emails me instead, but ends up doing a proper blog posting.


  1. Likewise, a tunnel ‘neath the Bering Strait!

    Posted by Blognor Regis on  23 April 2007 at 03:02 am

  2. A bridge there would have to be high enough to allow the biggest ships anyone can possibly conceive of to get under it, too, as that route from Europe through the Straits of Gibraltar, the Suez Canal and the Straits of Malacca to China and Japan is might be the world’s most important shipping route. Of course, if a bridge is 14km long, it doesn’t have to be very steep to be very high indeed.

    Posted by Michael Jennings on  23 April 2007 at 07:00 pm

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