“Metal, as you probably know, tends to be quite heavy and quite useless as a flotation device. ”

… which is why it is never used for things like aluminum canoes or steel aircraft carriers.

You should take a look at the publication..
‘The Cockleshell Canoes’ (google it)..
you will be surprised.

regards
Q

If you want to read about some unknown secrets of WW2 you will enjoy this book esp. if anyone is an engineer or into British Military Maritime History.

“Metal, as you probably know, tends to be quite heavy and quite useless as a flotation device. ”

… which is why it is never used for things like aluminum canoes or steel aircraft carriers.

You should take a look at the publication..
‘The Cockleshell Canoes’ (google it)..
you will be surprised.

regards
Q

quoting from my favorite acoustic expert:
Executive summary: It’s garbage.

As WW II began, the US established a set of defense-oriented laboratories: MIT got radar (and set up the Radiation Laboratory); the University of California got nuclear weaponry (and set up Los Alamos); Columbia University got sonar and set up the Underwater Sound Laboratory in New London CT. USL’s director was named Horton; he wrote quite a bit about his experience, and in particular he described how right at the start he went down to Key West where the Navy ran a training program. He was encouraged by the results of his first morning’s observations – he was aboard a destroyer that was working with a sub – but then after a lunch break, there was no longer any sign of the target. He asked for an explanation and was told that it was an everyday occurrence, known as “the afternoon effect”. And that turned out to be all that was “known”!! It didn’t take Horton long to recognize that what was going on was the increase in refraction caused by the sun warming the water, and that insight was seen as a revelation.

The point of that anecdote is that during WW II we didn’t know enough about undersea acoustics to be aware of the deep sound channel. And we didn’t have apparatus to put sensors down there. And nobody would have dreamed of cabling those (non-existent) sensors ashore. And the depth of the channel is latitude dependent (also not known in WW II).

It’s true that an imploding vessel makes a helluva bang (of course you gotta be sure that the apparatus is negatively buoyant): a light bulb is a good choice. I one had a two-foot diameter “float” implode on me (at about 2,000 feet): the sound was audible on the decks of the ships nearby.

But on retrospect, clumsy is better than misleading (esp when it comes to science based posts) – I’ll change it a little.

… which is why it is never used for things like aluminum canoes or steel aircraft carriers.

(Just think your ironic wording was a little misplaced.)

Chill!:

WW2 engineers and physics professionals were well aware of the thermoclines. These were used extensively in submarine warfare. Subs that shot torpedoes would dive below the thermocline, which would deflect the sonar pings from ships seeking them.

I doubt they gained this knowledge from studying whales, and more likely obtained in from physics experimentation with sonar devices.