Real Submarine Technology & History Q&A

[MonTana_Prussian]

Just want to say,this is a great thread guys! Lots of real good stuff,keep it comming!

[Hitman]

I arrive a little late for the periscope colour filters question that Arclight posed some time ago, but if it's still of some help, I'd like to point out that german WW2 submarines had two exchangable colour filters in the oculars: Deep neutral and orange. Orange was used to allow looking at a target against sunset/sunrise, as the orange blocked the intense orange sun rays, while the deep neutral (Looking like fog, soft grey) was used specifically to eliminate the disturbing small light reflexes in the peak of the waves in bright sunny days.


As for moving torpedoes from the stern to the bow torpedo room, I have no idea if someone actually did it, but if I had to (And I find it highly impractical, since it's easier caluclating a solution for a stern shot than taking the pains of moving the torpedoes around) I would do somethings more simple:

1.- Eject the torpedo from the stern torpedo tube into the water, ensuring it is set to float
2.- Tow it along the hull forward and
3.- Submerge the boat until the bow torpedo tube aligns with water level
4.- Push it backwards in

No really, I know this won't work in real life, but it feels cool to have found a solution

[Nisgeis]

As theories go, it's a nice one. I'm no expert, but I think I read that only the practice torpedoes float and that's because they have a cannister in them that expels the water in the dummy warhead after the fuel is spent and the run complete and they bob to the surface. Live torpedoes float in the water just like bricks don't (sorry Douglas).

[DaveyJ576]

I would like to take this opportunity to once again strongly encourage everyone who plays and enjoys SHIV to visit one of the many submarine museums throughout the country. There is nothing like being in the boat to provide you with the perspective necessary to truly understand how things worked and what the submarine sailors went through on patrol. A lot of this left field stuff we talk about in this thread will make sense if you can see it in person and put your hands on it.

Some of the boats had post war Guppy mods and some (like the Albacore, Blueback, and Nautilus) are "modern" post war designs. But all of them will provide the basics necessary for understanding the fine points of submarine design and history. Some of the boats are in mint condition, and some are showing the ravages of time. All of them desperately need your support in order to keep operating.

The following link: www.hnsa.org, will direct you to the Historic Naval Ships Association website. There you will find a comprehensive list of all the boats on display. Obviously most of them are on the coasts, but for those who live inland, don't despair! There are boats in unusual places like Michigan, Arkansas, Oklahoma, Pennsylvania, Wisconsin, and upstate New York! For those of you in other countries, several submarines from other navies are on display around the world and these boats are listed as well.

All of the boats are worth visiting (I myself have been to six of them), but for the true experience I recommend the USS Cod (SS-224), located in Cleveland, Ohio. She is the only boat that has not been altered for ease of access. You have to go up and down the vertical ladders and through the trunks just like the real crew did. She is in great shape and even has a fully functional TDC.

If you live near one of the boats, they are always looking for volunteers to help with maintenance and cleaning. They would be happy to get your help.

Please visit one of the boats. It is a great time and you won't regret it!

[MonTana_Prussian]

being from the SF Bay Area originally,I have visited USS Pampanito SS-383 on several occasions. Very cool,and if you are in the area,you might want to take a hop over to the former NAS Alameda and vist USS Hornet CV-12.

[DaveyJ576]

Originally Posted by Hitman

1.- Eject the torpedo from the stern torpedo tube into the water, ensuring it is set to float
2.- Tow it along the hull forward and
3.- Submerge the boat until the bow torpedo tube aligns with water level
4.- Push it backwards in

Actually, Hitman's procedure, even though totally and utterly impractical (sorry!), is technically doable. It just needs a little massaging. Torpedoes are designed to be neutrally buoyant, so you don't have to worry to much about them sinking, just very carefull. So, a modified procedure would look something like this:

1. Flood the tube and open the outer door. Attach a line to the nose of the weapon and pull it out of the tube. If you eject it it will go a long way, even if the engine doesn't start, then you would have to run it down. Pulling it out of the tube at sea will be a problem, though. Even though neutrally buoyant, it still has about 2000 pounds of mass, making it hard to move.

2. Tow it along the hull forward. Pretty good, but you got to be careful not to bang it around.

3. Submerge the boat until the bow torpedo tube aligns with water level. Oops. Remember, the forward tubes on a fleet boat are underwater at normal trim. Therefore, you would have to raise the bow to get the tube to surface level. On the surface all main ballast tanks are already dry, so it is hard to raise the bow. You would have to flood down the stern and pump dry the forward trim tank, and then probably move a lotta stuff aft to trim up the bow enough. It would be far easier to push the fish downward (remember, the fish is neutrally buoyant) until it lined up with the tube, flood down the tube, open the outer door, then...

4. Push it backwards in. Perfect.

In 1985 on the Darter, we were in Pearl Harbor and had to unload some Mk 37 warshots to storage. The way our after torpedo room was arranged, it was a lot easier to just float them out of the tubes and hoist them to the pier with a crane. So with a couple of divers in the water we did just that. It took about a quarter of the time. We were alongside the pier at the submarine base, though and not at sea.

I have to say one more time that while the procedure described above is completely impractical and unnecessary, it is technically feasible.

[Hitman]

You mean it actually could work on that variant you explained? LOL not bad for someone who studied humanities and not sciences - I'm a jurist, but Gene McKinney and a few more also were and didn't fare bad at all

Torpedoes are designed to be neutrally buoyant, so you don't have to worry to much about them sinking, just very carefull

Yes, that I knew, hence the idea

Oops. Remember, the forward tubes on a fleet boat are underwater at normal trim. Therefore, you would have to raise the bow to get the tube to surface level.

Ahhhh my bad, in the U-Boats a pair of the tubes are above the water
, so I didn't think in the US boats it wouldn't. Well come to think of it, actually in the boats equipped with external firing tubes they certainly are

I have a nice photo of USS Permit showing them just below the deck level, and also look at my signature , so in those it would work out I suppose. Or in the other boats you could put the torpedo on the deck and surface the boat having it aligned with the hatch for torpedo loading

I have to say one more time that while the procedure described above is completely impractical and unnecessary, it is technically feasible.

Cheers As I already said, a stern shot is always the best option.

I also wanted to add that it is a HONOUR and a PLEASURE to be able to talk with submarine and surface ship veterans like you or Steve and be able to learn so much and enjoy your comments. I love subsim.com

[Sniper31]

I am REALLY enjoying this thread! It's chock full of great information and history. I am a career US Army Infantryman, so not much real world experience with ships and such, other than some Zodiac small boat ops
That said, I keep learning more and more from this thread with every post. Thanks guys, and keep it coming.

[Nisgeis]

Hmmm, I'm not convinced the larger torpedoes floated. I think they are a couple of hundred pound heavier than the water they displace according to my highly accurate napkin and pencil calculations .

Originally Posted by DaveyJ576

In 1985 on the Darter, we were in Pearl Harbor and had to unload some Mk 37 warshots to storage. The way our after torpedo room was arranged, it was a lot easier to just float them out of the tubes and hoist them to the pier with a crane.

OK, so the Mk. 37 is a 19" swim out torpedo, like the cutie? There'd be no suction holding it in the tube, like there would be for a 21" torpedo. Would it still be possible with a 21" torpedo? Would you have to have the flood or vent valves open to let air or water in behind the torpedo, or you'd have a bit of a job on your hands?

[DaveyJ576]

Originally Posted by Nisgeis

Hmmm, I'm not convinced the larger torpedoes floated. I think they are a couple of hundred pound heavier than the water they displace according to my highly accurate napkin and pencil calculations .

Sigh...Folks, the operative word here is feasible... I knew I was going to get in trouble with that post!

Originally Posted by Nisgeis

OK, so the Mk. 37 is a 19" swim out torpedo, like the cutie? There'd be no suction holding it in the tube, like there would be for a 21" torpedo. Would it still be possible with a 21" torpedo? Would you have to have the flood or vent valves open to let air or water in behind the torpedo, or you'd have a bit of a job on your hands?

The inside diameter of a Mk 32 torpedo tube on a fleet boat is actually 21.125", which is slightly larger than the diameter of a Mk 14 torpedo. Spread out along the bottom of the tube are four rollers that the fish actually rests on. With the tube vented to sea pressure, any suction effect would be minimized.

However, with almost 2000 pounds of mass and using nothing but Armstrong Engineering to get it out of the tube, just getting it moving and then controlling it once you are moving is a tall order.

Once again guys...feasible, not practical or realistic.

[Nisgeis]

Great stuff, something else for the memory bank . I never knew there was a slight gap. This thread is great.

[U-boat luver]

wow, what a thread this is! I can't play SH3 due to loss of computer so I haven't come here often.

My questions are: How would a sub (German or American) pump water in the sub to the outside. For example when taking on water from an explosion.

Also when a destroyer pings for a sub wouldn't the first thing the ping hits underwater come back? How would the radio man at the helm know if it is a sub or not?

[DaveyJ576]

Originally Posted by U-boat luver

How would a sub (German or American) pump water in the sub to the outside. For example when taking on water from an explosion.

Water can accumulate inside a submarine for a variety of reasons, only one of which is battle damage. The propeller shaft seals may leak (fairly common), condensate water drains from the refrigeration and A/C plants, water drains from the access trunks after surfacing, etc. All this water goes into the bilges in the lowest levels of each compartment. Let it accumulate long enough and it interferes with the operation of equipment and of course it will effect the buoyancy of the boat.

In the appropriately named Pump Room underneath the Control Room, is the Drain Pump. This is a very large and powerful reciprocating type pump (sorry, the specs and capacities are escaping me right now). It is powered by an electric motor. It is connected to a drain line that runs all the way to the forward torpedo room, and one that runs all the way to the aft torpedo room. Along the way, attached to this drain line are various suction valves, at least one in every compartment. The pump operator will contact the compartment that needs to be pumped, have someone open the appropriate bilge suction valve, start the pump, and pump the water overboard through a discharge valve.

There are many times in which the water being pumped overboard will be contaminated with oil or fuel. If this is the case, and the enemy is topside, the drain pump operator has the option of pumping the bilge to a holding tank. This will prevent oil from creating a sheen on the surface and giving away the boats' location. The holding tank will be pumped at a later time.

The drain pump is powerful enough to pump any bilge on the boat overboard, all the way down to test depth. That is a lot of water pressure to overcome.

Originally Posted by U-boat luver

Also when a destroyer pings for a sub wouldn't the first thing the ping hits underwater come back? How would the radio man at the helm know if it is a sub or not?

The ocean is really pretty empty, when you stop to consider the vast size. There really aren't too may things the sonar beam is going to bounce off of other than the submarine the tin-can is hunting. Trained sonar operators can easily tell the difference between a bottom bounce and a submarine and any whale or other marine life that might be in the area are easily scared off by the activity. Their soft flesh also makes for a lousy and mushy return.

Since the boats' radiomen had the best electronics training of anyone on the boat, they sometimes doubled as sonar operators. As the war progressed, specially trained sonar operators replaced them. Helmsman drove the boat and usually did not operate the sonar or the radio.

[LukeFF]

Originally Posted by DaveyJ576

Since the boats' radiomen had the best electronics training of anyone on the boat, they sometimes doubled as sonar operators. As the war progressed, specially trained sonar operators replaced them. Helmsman drove the boat and usually did not operate the sonar or the radio.

To add to this: the Navy created the rating of Soundman in 1942 and was merged with Sonarman in 1943. However, these ratings were almost always found on surface ships and only very rarely on submarines, as the Radioman rating was also used for operating the sonar on submarines (I've found only one submarine that had a Sonarman-rated man on board). Correct me if I'm wrong on this, Dave, but that's my understanding of how it worked.

[LukeFF]

Now another question for you, Dave: the early patrol reports mention the use of "open sights" on the 3"/50 as an alternative to using the scope when engaging targets (such as when the lens was damaged or fogged up). Are there any pics out there that show what those "open sights" looked like?