Duration of asdic searches?

Fidd · 12-06-19, 10:26 AM

Ok, I completely buy that as an explanation which squares anecdotal evidence (accounts) with some sound physics.

Out of curiosity, does anyone know the time intervals at different depths, for the main ballast tanks to be blown or flooded?

The reason I ask is that again working from anecdotal accounts, a loss of vertical control was not that unusual, with u-boats being "blown to the surface". This suggests that in attempting to recover from great depths, the main ballast tanks were blown at least partially, but that reflooding them either not be achieved quickly enough to prevent broaching to the surface, or, that once a rapid upwards movement began, it could not be arrested despite the main ballasts being reflooded at depth.

I suspect the latter, which might indicate that the inertia of our boats is a little off, as in the ordinary way we can always (air permitting) blow the mains at depth and arrest that ascent before broaching...

It might also mean that our planes are rather too "fast-acting" in altering the pitch of the boat?

12-06-19, 10:26 AM	#12
Fidd XO Join Date: Apr 2005 Location: Blighty! Posts: 439 Downloads: 10 Uploads: 0	Ok, I completely buy that as an explanation which squares anecdotal evidence (accounts) with some sound physics. Out of curiosity, does anyone know the time intervals at different depths, for the main ballast tanks to be blown or flooded? The reason I ask is that again working from anecdotal accounts, a loss of vertical control was not that unusual, with u-boats being "blown to the surface". This suggests that in attempting to recover from great depths, the main ballast tanks were blown at least partially, but that reflooding them either not be achieved quickly enough to prevent broaching to the surface, or, that once a rapid upwards movement began, it could not be arrested despite the main ballasts being reflooded at depth. I suspect the latter, which might indicate that the inertia of our boats is a little off, as in the ordinary way we can always (air permitting) blow the mains at depth and arrest that ascent before broaching... It might also mean that our planes are rather too "fast-acting" in altering the pitch of the boat?