Is it conceivable to nuke a usable canal into existence?

This PDF file is a very interesting summary of the various sub-projects in Operation Plowshare, few of which were ever put into practice.

Only today I found out about a similar project in the UK, about 40 miles from where I live. Kudos to Tom Scott for his detective work.

Not necessarily. There are, as far as I know, only 5 ocean-to-ocean canals in use for freight traffic. Two of them do not have locks: Suez and Cape Cod. The Panama Canal has locks, of course, although that’s mainly because it’s not a sea-level canal. But if it were a sea-level canal it would likely need locks anyway. The Kiel Canal has locks for the reason you state. The White Sea-Baltic Canal is not a sea-level canal, so it also has locks.

That ship has sailed, so to speak. The U.S. detonated 1,021 nuclear bombs in Nevada in the 50’s and early 60’s. 100 of them were air bursts.

You can see why people thought they could be used for other purposes, with an average of 100 nukes per year being detonated in the U.S. already during that time.

It also shows that a nuclear detonation does not have to be as devastating as people think. Still, digging canals with nukes is a bad idea.

Do you have a cite for this? Having lived within a kilometer of the Nagasaki bomb site, and having visited Hiroshima Peace Park with the Atomic Bomb Dome which was about 150 m horizontially from center of the blast, as well as having read extensively about the bombing, I’ve never read about a crater.

Numerous cites say that there was no crater.

Trinity was conducted on a 100-foot tower and did create a crater.

I’ve read various numbers for the size of that crater, but there doesn’t seem to be any doubts that there was one. However, I haven’t seen any numbers that are anywhere as deep as you suggest for the Hiroshima bomb.