Building a bridge to Havana

Let’s assume for the moment that in the near future Cuba and the US are best buds and everything is hunky dory.

What are the engineering considerations of building a 100 mile long causeway over open water?
What other things need to consider?

Off the top of my head:

Weather: Of cause hurricanes, tropical storms, tropical depressions but also isolated thunderstorms could wreak havoc with traffic.

Accidents: Help could be up to an hour away, and a serious accident could cause a backup for most of the length of the causeway if there is no way to turn traffic around.

Border crossing: Even if we’re best buds we would still need a border crossing like we have with Canada & Mexico. Where do we build this? US side, Cuba side, or in the middle?
Assuming we can answer all the engineering and other questions, is there any reasons NOT to do this? It seems like one of those cool mega-projects.

Well, for border crossing, I’d say both. The Cubans would have one on their end, and we’d have on ours.

I guess you could swap that, so that people either side doesn’t want to admit don’t have to drive all the back.

Who would want to pay such an exorbitant amount of money for such a bridge?

There’s a occasionally-discussed topic of building a bridge between Djibouti and Yemen, which is an 18-mile bridge. The estimated cost is $20 billion (yeah, right). Why anyone things that Yemen and Djibouti need to be linked by road is a total puzzle to me.

There’s also always talk of connecting Sicily with the Italian mainland, usually with a single, very large, suspension bridge.

Back to the original topic - you also have to consider the fact that either you would block all shipping traffic trying to pass through that gap, or you would need to raise the roadway high enough to allow ships to go underneath - but doesn’t a bridge involve anchorages, in whch case, where would you put them? Is a standalone cantilever span feasible in the middle of the ocean?

No need to put the whole thing above water, you know.

Ferries.

What is this strange technology that allows carriages to traverse the seas as a barrow travels over the earth? It is the most commonest of sense that chattel may not suspend itself by its own accord above a watery tomb. It is only through logick that we know to cross a channel we must build the soil up to above the tides, for no mystickal vehicle can remain on the surface with no firmament below it – so thou has proposed WITCHCRAFT!

Why, no, 'tis a Christian device, which by the Grace of God doth provide us to drive witches in carriages out to the water which Our Lord trod upon, fling them out, and should they float, they be guilty of WITCHCRAFT, and in the unlikely event they be innocent and sink, to drive a Man of God upon the water near in a carriage to give them the Last Rites.

'Tis a Win-Win thing, Milord.

I think that only works if a Cuban weighs the same as a duck.

The Florida Strait is fairly deep, too. Take a look at the soundings on this chart (measured in fathoms.) The depth of the water at the narrowest point of the strait looks to be over a mile deep (900 fathoms.) Even if you went further east instead, you’d still be stuck with waters over 4000’ deep. For comparison, the deepest bridge foundation (that I found in a few minutes of Googling) is the Tejo (Tagus) River bridge, whose deepest foundation is at a depth of 260 feet.

ETA: for another comparison, the Deepwater Horizon was drilling in waters about 5000’ deep when it had its blowout. Given how much difficulty there was in getting that plugged, I have trouble envisioning creating a bridge pier at that depth.

By the Grace of Our Most Holy Lord, and His Holy Mother, Mary of 142nd Street, all things be possible.

Hovercraft? Or Blessed as thine might need be, Holy Hovercraft?

I thought that was finally under construction? Although Googling for it, I’m finding lots of news sites saying “work is finally going ahead next year”, dated 2009, 2010, 2011… :dubious:

I find it slightly worrying that, if it does go ahead, the two longest suspension bridges in the world will be in active earthquake zones. I foresee some rather exciting but ultimately messy car journeys in the not too distant future…

Floating supports tethered to suction piles or whatever other deepwater foundation system you want.

My Holy Hovercraft is full of Gefilte fish.

Is it possible for floating supports to be compatible with shipping traffic? You would almost certainly need to have a raised section to let shipping traffic through; my impression is that the Florida Strait is a major shipping channel. Currents in the strait are pretty strong too.

It’s to help get Djibouti on the dance floor, baby.

Sorry, mine’s full of eels. Also, there’s going to be a big problem with Americans going over and then refusing to buy Cuban records because they are scratched.

Or if he’s made of wood.

The bridge would be littered with dead '47 Studebakers and '55 Hudsons.