Engineering: Oresund Bridge

[Buenchico]

Back in the days when the plans for the new Channel crossing were first being drawn up, comedians used to joke that the problems would come when the engineers had to work out how to link up the French Channel Tunnel with the English Channel Bridge. It seemed obvious, then, that having a tunnnel at one end and a bridge at the other end was a daft idea.

Earlier this week, however, when I crossed between Malmo, Sweden and Copenhagen, Denmark I found that this is exactly what the Scandinavians have done! At the Swedish end there's a bridge and at the Danish end there's a tunnel! (They're linked on a man-made island in mid-stream). I'm sure that there are sound engineering reasons for doing it this way but does anyone know what they are?

[sddsddean]

There are several bridge/tunnels around the world. The basic reason is to stop shipping hitting the bridge. It is easier to give them a nice 1 mile wide channel with no obstructions, rather than a channel with bridge piers in it every couple of hundred yards. Here is a picture of the Chesapeake Bay Tunnel/Bridge. It is much cheaper to build a bridge with short spans, but of course you can't get an aircraft carrier under them!! http://www.budowle.pl/budowle/grafika/ameryka_polnocna/chesapeake_bay_bridge-tunnel_2.jpg

[kaktus]

you can read about the bridge  here. It's a pdf document. I only skimmed it, but it seems that sddsddean is right.