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View Full Version : Another oddball question: How deep can the subs in SH3 be and safely fire a torpedo?


zygoma
04-01-12, 09:05 PM
I can see where at least two factors would come into play: one is the "crush depth" for the torpodo, and the other is the amount of pressure the inner torpedo door can withstand at depth.
Since I could theoretically manually come up with a solution for firing a torpedo at a threat (ideally a Type IV or V acoustic with settings for depth and heading), how deep could I be and not have the torpedo imploded by the water pressure when I flood the tube? And if the torpedo is robust enough to withstand the pressure at depth, would the inner torpedo door (into the torpedo room) exceed the rating of the door and its hardware?
As it is, I'm not even sure of where the pressure hull is in relation to the outer skin, so I've got no idea if the outer torpedo door is baically just a sheet metal cover for the torpedo tube, designed to help streamline the outer skin of the sub, or if it plays a part in helping purge water from the tube following a shot.
<sigh> I've only been on two submarines in my life. First one was a diesel boat at the Brooklyn Navy Yard around 1965, while iI was with the Boy Scouts. The other is an ex-Soviet diesel-electric fast attack boat tied up next to the Queen Mary in Long Beach Harbor. For the first one, I was too young to know what to ask the retired Chiefs who were the caretakers. On the second, the Russian ex-communications Commander who was part of the boat's ownership group seemed delighted to have someone who understood radio communications systems to talk with, so we never got to questions about weapons systems. It was mid-week, there were only two other tourists like me, so the Commander took me through on a personal tour, taking time to explain the almost-silent electric drive they could run on, and opened a few hatches to spaces that weren't typically manned but had to be accessible, and such. Turns out he's a ham, too, so we got to chat some about common ground.
But his English wasn't perfect, and I never quite go the distinction between the pressure hull and the.....what, outer skin?
But I still wonder if I should be able in SH3 to fire an acoustic fish from 100m down as long as I give it a bearing go steer to, or whether we're all likely to get a bit moist.
Thanks,
Zygoma, still wet behind the ears (and everyplace else Bernard could hit from the top of the sail hatch....)
_________________________________________________
May the total of all your submarine's surface operations exceed the number of dives by exactly one at the end of your career.

Sailor Steve
04-01-12, 10:46 PM
There are three doors - the rear (inner) door, the cap (outer door) and the shutter. The shutter is the door on the outer hull, which conforms to the streamlined shape. The terms are all British, and I don't know what the German terms are.
http://www.uboatarchive.net/U-570BritishReport.htm Page 16.

This will tell you more about torpedo tubes than you ever wanted to know.
http://www.maritime.org/fleetsub/tubes/index.htm

postalbyke
04-06-12, 12:17 PM
Zygoma:

Word. I'm an ex-submariner myself, served in the USN for five years, four on a sub.

So all the factors leading into torpedo launch depth are basically as follows:
1. "failure" depth of the: torpedo tube (to the inside of the boat), breech door (inner door to the inside of the boat), the torpedo itself.
2. The amount of pressure your torpedo launch system can generate (versus water pressure on the outside of the boat). If you can't overcome sea pressure, you can't "launch" a torpedo, it would have to find its own way out. AFAIK, WWII u-boats didn't have "swim-out" torpedos, they had to be launched.

For condition #1, the torpedo tubes on these boats were made of brass, I think, which would not give it superior resistance to excessive water pressure. They were not made to launch deeper than periscope depth based on their (then) current combat doctrine.
(oops,correction: made of bronze)

http://www.ubootwaffe.pl/component/option,com_flexicontent/Itemid,76/cid,66/id,337/view,items

At the end it mentions specifically the breech doors being the weakest link as far as pressure.

Sailor Steve
04-06-12, 03:26 PM
Alright postalbyke! :rock:

New information is always great to have! Any time I've wanted to describe torpedo tubes I've had to refer the American Fleet Sub website. Now we have an actual explanation of the u-boat tubes!

Thanks for the link. :sunny:

u crank
04-06-12, 04:01 PM
But I still wonder if I should be able in SH3 to fire an acoustic fish from 100m down as long as I give it a bearing go steer to...

I just did a check in my current career. Below twenty metres weapons officer tells you "too deep to launch torpedoes, Sir.", when you ask him to open outer doors.

That is a great link postalbyke. Lots of good reading there and cool pics.:salute:

zygoma
04-06-12, 05:45 PM
Steve, Postal, and Crank --
Many thanks to you all. The links were great, and just having the in-game give the "too deep" warning at such a shallow depth is a great indication. I know I've been unable to fire at depth in the past, but I always figure I've just done something wrong in the the process, skipped a step etc.
What a wonderful resource the folks who make up this forum are. A terrific mix of "real world sailors" and serious gamers: the best of both worlds.
Again, thanks.
-- Zygoma --
__________________________________________________ ____
May your number of surface activities exceed your dives by exactly one at the end of your career.

Sailor Steve
04-06-12, 08:04 PM
I'll tell you something weird. In SH3 you can use the switches to open all the doors, and I've done so on many ocassions. More than once I've only fired a couple of torpedoes then gone deep. The game doesn't care if the doors are open, but I do. So I'm deeper than 25 meters and start flipping switches to close the doors that were still open only to be told "Too deep to fire torpedoes, Herr Kaleun!"

So you not only can't open the doors if you're too deep, you can't close them again either! :dead:
:rotfl2:

TorpX
04-06-12, 10:20 PM
I paged through some of the USN manual provided by SS. Interesting stuff. I noted that it was possible for at least some types of torpedos to be launched down to 200 ft. keel depth. They had to increase the impulse tank pressure to accomplish this. (Check pp 131-132.)

I think one of the reasons both the KM and USN favored impulse luanching of torpedos is that you would have to have the torpedo smaller in diameter, than the tube, or else it would not be able to swim out. The USN did this with the "cutie", but AFAIK, it was the only one.



So you not only can't open the doors if you're too deep, you can't close them again either! :dead:

I'm guessing that the game closes the tubes automaticly at a certain depth. I think this happens in SH 4.