Hull difference....german, american - Page 2

Bulkhead · 01-28-08, 06:35 PM

Ok ok ok.... so the pressure is the same, nothing to do with the pressure because its the same for each boat at the same depth, and its not about the size either, or surface for the pressure to work on. But its about the supporting structure inside all of the surface plating. Lets call it "the sub sceleton".... The gato needs a stronger and alot heavier sceleton to face the pressure than a type-VII. If the size is twise it may need twise the number of framework to stand the same depth i dont know.
The basic question was whats the difference between the two subs, witch after all the reading ive done in this thread (BTW, thanks for all the input) i guess it narrows down to structure, construction and building techniqs.

Please continue with all stuff you can find.

Thanks

Palidian · 01-28-08, 10:31 PM

However if the hull is close to being round, size should not matter. Try smashing an egg with your hand.

http://www.wonderquest.com/egg-pressure.htm

Quote:

Originally Posted by Penelope_Grey

Quote:

Originally Posted by jazman

Size has nothing to do with the pressure found at a depth. You put a Gato or a Type VII at 300 feet, they face the same pressure.

Semi-True, however the Gato has a larger surface area, therefore the total area of pressure is greater than that of a U-Boat. as in.... Pressure per square inch is the same, but a Gato has a lot more inches than a U-Boat does. So will naturally not be able to go as deep due to being larger.

scrag · 01-29-08, 12:59 PM

The size of the ship has very little to do with it at the depths we are talking about in regards to Sea Preasure - the same argument can be stated with the overall water depth - the Pacific is deeper so the water mass is different or the salinity content is different and that will disapate the blast effect differently. While the size of the ship may contribute to how much hull is exposed to the blast - water preasuure (44 ib per sq inches for every 100 feet) treats the preasure hull the same equal way. There is a lot more to sub construction - bulkhead thickness, water tight compartment integrity, framing arrangement (external or internal frames), fixtures exposed to sea preasure i.e. trim and drain system and the pumps of the system, main induction valve and diesel exhaust - you get the idea. One thing the game leaves out (seemingly) is the improved Gato depth capabilities seen in Mid WWII to the end allowing US boats to operate 500 plus feet. The Germans also had better depth capabilities too but faced the same issues. Very often, failure of a valve or other system than the preasure hull resulted in a loss of the boat at deep depths.
To answer the question about ballast tanks water dispating a blast - nope - water does not compress so it will (practically) transmit any force equally, so the effect on a submerged U Boat would transmit the effect directly to the preassure hull. Yes you would get rippling and distortion of the metal structure but the presure hull had to restrain the additional effect of the preasure wave moving through the water. Remember the string going across the engine compartment being taught on the surface but having slack at depth - that is a practical example of the effect.

01-28-08, 06:35 PM	#1
Bulkhead 中国水兵 Join Date: Sep 2007 Location: Norway, Hordaland Posts: 279 Downloads: 153 Uploads: 0	Ok ok ok.... so the pressure is the same, nothing to do with the pressure because its the same for each boat at the same depth, and its not about the size either, or surface for the pressure to work on. But its about the supporting structure inside all of the surface plating. Lets call it "the sub sceleton".... The gato needs a stronger and alot heavier sceleton to face the pressure than a type-VII. If the size is twise it may need twise the number of framework to stand the same depth i dont know. The basic question was whats the difference between the two subs, witch after all the reading ive done in this thread (BTW, thanks for all the input) i guess it narrows down to structure, construction and building techniqs. Please continue with all stuff you can find. Thanks __________________ KHJ

01-29-08, 12:59 PM	#3
scrag Medic Join Date: Dec 2006 Location: Pearl Harbor, Hawaii Posts: 161 Downloads: 6 Uploads: 0	There is a lot more than size The size of the ship has very little to do with it at the depths we are talking about in regards to Sea Preasure - the same argument can be stated with the overall water depth - the Pacific is deeper so the water mass is different or the salinity content is different and that will disapate the blast effect differently. While the size of the ship may contribute to how much hull is exposed to the blast - water preasuure (44 ib per sq inches for every 100 feet) treats the preasure hull the same equal way. There is a lot more to sub construction - bulkhead thickness, water tight compartment integrity, framing arrangement (external or internal frames), fixtures exposed to sea preasure i.e. trim and drain system and the pumps of the system, main induction valve and diesel exhaust - you get the idea. One thing the game leaves out (seemingly) is the improved Gato depth capabilities seen in Mid WWII to the end allowing US boats to operate 500 plus feet. The Germans also had better depth capabilities too but faced the same issues. Very often, failure of a valve or other system than the preasure hull resulted in a loss of the boat at deep depths. To answer the question about ballast tanks water dispating a blast - nope - water does not compress so it will (practically) transmit any force equally, so the effect on a submerged U Boat would transmit the effect directly to the preassure hull. Yes you would get rippling and distortion of the metal structure but the presure hull had to restrain the additional effect of the preasure wave moving through the water. Remember the string going across the engine compartment being taught on the surface but having slack at depth - that is a practical example of the effect. __________________ Last edited by scrag; 01-29-08 at 01:24 PM.