The M48 Severn Suspension Bridge is 50 in September this year...

...it is an extremely important structure as it was the world's first aerodynamic box girder suspension bridge and the first* of three with inclined hangars.

A number of large suspension bridge designs use the aerodynamic box girder design now and strides in technology have improved the performance further still.

So... anyone worked on it? Watched it being built? Any decent pictures of it? I've got a couple of very rare books from the opening of this bridge and they have some excellent photos as well as diagrams of the embryonic motorway system!

I feel the Audi A2 has much in common; aerodynamic; innovative and of course a world first.

Sadly I feel both are underrated.

* Bosporus 1 and Humber Bridge are the others!

I thought that this was announcement about a change in the speed limit on the bridge.

Great to see that it is 50 and I really appreciate engineering like this.

Steve B

It has has a few alterations made; largest trucks were 32 tonnes when it was built- and of course traffic loads are significantly higher! The strengthening works carried out in the 'eighties and nineties involved inserting many steel tubes through an inspection doorway in the towers to take the extra weight as well as changes to the deck and hanger clevis pins and sockets among other things!