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View Full Version : Depth Capabilities of subs/uboats


DigitalAura
10-09-09, 11:55 AM
One thing that strikes me about historical sub and uboat accounts is that American fleet boats report going as deep as 300 feet (Silent Running, Calvert) while German U-boats could submerge to 300 meters (Iron Coffins, Werner). That's almost 1000 feet!
Why the difference?
How deep can depth charges be known to go? I think I read that U-557 was able to evade charges because they could go deeper.

Freiwillige
10-09-09, 02:00 PM
nobody knows. The German VIIc\41 had a thicker pressure hull than most U-boats. Ive also heard of a balao class reaching 8 to 9 hundred feet and living to tell about it. But in the american navies the average test depth was 250 to 300 feet. In the U-boat it was 100 to 150 meters. Both American and German navies have out of necessity exceeded that figure by some margin and lived to tell about it.:arrgh!:

V.C. Sniper
10-09-09, 02:53 PM
A Balao class survived going to 1017 ft and back.

SteamWake
10-09-09, 03:04 PM
A depth charge will go as deep as you set the fuse to pop at.

What was the max depth on the fuse... dunno someone should fill it in.

But say that either you forgot to set the fuse or the fuse was defective therotically the DC would sink untill it hit bottom even if you dropped it in the Mairannas trench. :03:

It is known though that early in the war american crews underestmated the depth that german subs could attain and more often than not set there triggers too shallow.

Generally speaking German U boats could attempt depths much deeper than their allied counterparts.

A balo at over 1,000 feet ... wow thats some lucky SOB's

Ducimus
10-09-09, 03:46 PM
Fleet boats could go have gone deeper then many people (including the fans) think. You might find this thread interesting:

http://forum.kickinbak.com/viewtopic.php?f=42&t=414

Some good and interesting info there, but to summerize a few talking points:

- USS Salmon (salmon class, duh) went to 520 feet and was holding steady, though sinking slowly.

- USS Gurnard (gato class), is beleived to have passed 700 feet. To quote, "The depth gauge was well up against the limit pegs and the sea pressure gauges used to calculate depths beyond the depth gauges were only designed to calculate a depth of 650 feet."

- USS Tang (Balao) went to 620 feet in a test dive out of sea trials. Is reported to have gone to 700 when damaged, but came back up to 600.

- USS Chopper (Balao), out of control, depth exceeded 1000 feet as mentioned by VC sniper.

Now all that said, many areas of operation in the pacific were shallow, so if one were to draw comparisions to uboats, any depth advantage a uboat would have had is irrelevant in many places.

DigitalAura
10-13-09, 08:05 AM
Surely, with the content of the barrel under such extreme pressure, even a depth charge would have a limit to how deep they could go... are you telling me that they could still explode effectively at 1000 feet? :shifty:

SteamWake
10-13-09, 09:12 AM
Surely, with the content of the barrel under such extreme pressure, even a depth charge would have a limit to how deep they could go... are you telling me that they could still explode effectively at 1000 feet? :shifty:

Again I dont know what the deepest setting on a typical depth charge is. But if the fuse failed the charge would and did sink till it hit bottom. I may have been a crumpled mess of its former self but pressure would not cause it to detonate.

nikimcbee
10-13-09, 09:40 AM
Yeah, a gato/balao could go down to 600 ft. The question is, can the surface sonar track them that deep? Once the allies captured the U-570, they pretty much knew everything about them:dead:.

The japanese on the other hand, didn't have a clue:D.

Sailor Steve
10-13-09, 12:53 PM
Early war Allied depth charges were good to about 300 feet. By the end of the war the Mark X** could be set for as deep as 1500 feet.
http://www.navweaps.com/Weapons/WAMBR_ASW.htm

Japanese depth charges could be set for 25 or 50 metres - nothing in between. Later models could be set for 30, 60 or 90 metres, and nothing in between.
http://www.navweaps.com/Weapons/WAMJAP_ASW.htm

Airborne depth charges seem to have always been set for 25 feet (roughly 8 metres).

Ducimus
10-13-09, 01:36 PM
Airborne depth charges seem to have always been set for 25 feet (roughly 8 metres).

Tater kicked up an interregation report online somewhere, where the Japanese pilot said they carried two charges, one set at 20 meters, the other at 45. They'd drop one or the other depending on where they thought the boat was. Wish i could provide the link, i do recall reading it, but this was probably close to a year ago, so id be hard pressed to find that reference material now.

DigitalAura
10-14-09, 06:32 PM
Japanese depth charges could be set for 25 or 50 metres - nothing in between. Later models could be set for 30, 60 or 90 metres, and nothing in between.
http://www.navweaps.com/Weapons/WAMJAP_ASW.htm

hmm...so the Americans only had to go beyond 250 feet to be safe, even from the deepest Jap charges??
Is this reflected in game?

Sailor Steve
10-14-09, 06:39 PM
Tater kicked up an interregation report online somewhere, where the Japanese pilot said they carried two charges, one set at 20 meters, the other at 45. They'd drop one or the other depending on where they thought the boat was. Wish i could provide the link, i do recall reading it, but this was probably close to a year ago, so id be hard pressed to find that reference material now.
Yeah, sure, tell me now that you can't find it...:rotfl2:

No, really, that's some pretty interesting info.

hmm...so the Americans only had to go beyond 250 feet to be safe, even from the deepest Jap charges??
Is this reflected in game?
Probably not. Nor should it be, as the Americans didn't know this at the time. I'm realism's biggest booster, but sometimes being technically accurate just gives the player an opportunity to cheat.

Ducimus
10-14-09, 06:45 PM
hmm...so the Americans only had to go beyond 250 feet to be safe, even from the deepest Jap charges??
Is this reflected in game?

Ehhh... no on two counts.

Count 1:
You know that old saying, "loose lips sink ships?" I give you, Congressman Andrew J May who opened his big mouth. The japanese adjusted accordingly.
http://en.wikipedia.org/wiki/Andrew_J._May#The_May_Incident

Count 2:
Limiting depth on depth charges has been on the list of, "I wish i could get this working" for modders since the earliest days of Sh3. Sh4 inherits legacy issues from SH3, one of those is that depth charges cannot be limited in depth.

Ducimus
10-14-09, 07:08 PM
Here you go Sailor steve, found the reference:
http://ibiblio.org/hyperwar/AAF/USSBS/IJO/IJO-63.html


Interrogation of: Lieutenant Commander OKAMOTO, T.; Staff Officer of First Escort Fleet Air Squadron and (general Headquarters, Grand Escort Fleet.

Interrogated by: Commander T.H. Moorer, U.S.N

Q. What size of depth bombs did your aircraft use?
A. 250 kg.

Q. Did you use any other airborne weapon besides depth bombs?
A. We had nothing besides bombs. The bomb was a standard 250 kg bomb with a modified flat nose attachment and a special tail, a nose and tail fuse was used.

Q. What depth setting did you use?
A. We used 25 and 45 meters. If the submarine was discovered near a convoy at periscope depth and immediately submerged, we dropped the 25 meter; if time passed and gave the submarine time to go to a lower depth, we would drop the 45 meter bomb.

Torplexed
10-14-09, 08:22 PM
Q. Did pilots object to anti-submarine duty?
A. The pilots objected and much preferred active combat. This quote is a powerful insight into Japan's attack-minded philosophy which was such a handicap to their overall war effort. Just like so many of the destroyer captains, the pilots detested ASW duty.

Ducimus
10-14-09, 08:25 PM
That whole site is really informative. Been doing some additional reading there. I wish i had kept this reference bookmarked and handy all these months. Reading it, there's a ton of adjustments id like to make, but i simply don't have the time now. :cry:

SteamWake
10-14-09, 09:59 PM
Ehhh... no on two counts.

Count 1:
You know that old saying, "loose lips sink ships?" I give you, Congressman Andrew J May who opened his big mouth. The japanese adjusted accordingly.
http://en.wikipedia.org/wiki/Andrew_J._May#The_May_Incident

Count 2:
Limiting depth on depth charges has been on the list of, "I wish i could get this working" for modders since the earliest days of Sh3. Sh4 inherits legacy issues from SH3, one of those is that depth charges cannot be limited in depth.


Nice had forgot about that bit... !

Pacific_Ace
10-15-09, 01:48 AM
"Nor should it be, as the Americans didn't know this at the time."

I'm confused. Obviously we had to have known, or May couldn't have revealed it in 1943. It had to have been known for some time in order for such a secret to have percolated to his ears.

Sailor Steve
10-15-09, 02:29 PM
"Nor should it be, as the Americans didn't know this at the time."

I'm confused. Obviously we had to have known, or May couldn't have revealed it in 1943. It had to have been known for some time in order for such a secret to have percolated to his ears.
It's been my impression that they didn't know right away, or know the specifics. It began to be recognized that the Japanese were constantly "setting their charges too shallow", and this began to be reported, hence the admonition "Run silent, run deep".

Of course I might be wrong.

And of course I might just be covering my tracks...

DigitalAura
10-16-09, 11:28 AM
Of course I might be wrong.

And of course I might just be covering my tracks...

heheh :D