World's Deepest-Diving Unmanned Submarine Lost

XenonOfArcticus writes "Kaiko, the world's deepest-diving submarine was lost in in late May off Japan, after it snapped its tether as a typhoon approached. Kaiko entered the record books in 1995 by diving 36,008 feet to the bottom of the Challenger Deep - the ocean's deepest point."

Comments

Nitpick

[crashnbur]

I know this is a tedious point, but there are four oceans, and not everyone knows where Challenger Deep is. Also, it wouldn't hurt to let everyone know that Challenger Deep is allowed to be confused with the Marianas Trench, since Challenger Deep is the distinct section of the trench that reaches the deepest below the surface, almost seven miles.

An interesting article about how to calculate the ocean's depth was put together by Nathan Becker, a student at the University of Hawaii when the report was written in 2001.

Re:hmmm

[anubi]

I just read the article.. and it sure looks like there is a bug in there somewhere. The article claimed exactly the design you describe.

"Kaiko is designed to float to the surface and emit a tracking signal if its tether is broken. Although searchers briefly detected the beacon, they were unable to locate the probe and suspected it has either drifted off site or sunk to the bottom."

I would assume the sub has local batteries, albeit rechargeable via the tether, for cacheing energy. As you noted, in the event the sub detected its tether being broken ( I would probably try to sense a loss of power feed ), use the cached energy in the battery to blow the ballast tanks.. or maybe have some sort of fire extinguishing system using liquid CO2 that could be routed into the ballast tanks to insure floatation in failsafe mode.

I am not privy to the design plans, but somehow this whole episode reeks of a malfunction of some failsafe system. I find it difficult to conceive of some design engineer not hedging his bets against something as inevitable as a severed tether.

Another poster noted RF being lossy underwater. My guess would been to place piezoelectric sonar transducers on the hull and ping them in the event the sub considered itself lost. It wouldn't take that much energy, but if you knew what kind of racket you were listening for, it would stand out from the normal oceanic noises.. kinda like those old war sub stories of marooned submariners taking a wrench and tapping out the morse code for SOS on the steel hull of the submarine.