Simultaneous detonations

[Daniel Prates]

In the in-game experience, i've noticed that you can fire all your torps at praticaly the same time, and they will all explode upon contact (providing none are duds), even if they are shot, say, a fraction of a second from each other.

My point is: in real life, the detonation of the first torpedo could or could not induce a premature detonation on the second torpedo coming just behind it? Or damage its firing pistol, or wrecking it complete, or etc etc etc? My point is, torpedos were so delicate, that I often wonder if a skipper would wait a few seconds between torpedoes shots, just to avoid the first detonation causing any damage to the other torp following just behind.

What do you history buffs have to say about it? :yeah:

[Dogfish40]

Ahoy Daniel,
You have an interesting point. So far though, I have not read of any "domino" effect per say of one torpedo setting off another. This would have definitely been an issue looked upon early in the design faze of the torpedoes. There were a number of reasons for prematures. Prematures were most often a result of the magnetic exploder being set too fine resulting in the fish going off for any reason once it armed or got even near a ship much less under it. The firing pin issue was another problem in itself but unless a piece of shrapnel actually hit the pin, it probably wouldn't be set off by an explosion. I'll keep looking out for anything on the subject. I've also read of Skippers counting between firing, weather of not this was part of the reason, I don't know for sure. It might have been part of their firing solution.
D40 :salute:

[Armistead]

I use TMO, plus other mods, but have never had this issue, but I'm not sure what you mean by a fraction of time. Historically, torps couldn't be fired at the same time, most skippers ordered 6 second intervals, but a few more seconds would pass before the torp would launch, prolly around 10 seconds. The time intervals had more to do with correct spreads than worry about a premature causing problems for other torps, but in game due to the stop and start speeds of ships it's best to get them out as soon as you can based on your method. I often shoot by the wire, so I fire when the part of the ship I want to hit crosses the wire and that has more to do with the speed of the ship as far as timing when to fire.

In game, even the fastest you can shoot one after the other is about 3 seconds no matter how fast you click all the fire buttons together. Historically, you could fire one as soon as the other cleared and I'm sure it was done, but most waited some seconds. If you're say 6th torp is hitting a target within seconds of the first one you fired, something is amiss, there should be about a 9-12 second difference between 1 and 6 torp which can be seen using the redline on the watch.

Certainly historically a premature could disrupt another torp, but that would be rare due to timing and course, in game prematures do not effect other torps.

I agree the game is probably off some historically, they do hit close together if fired quickly one after the other, but when you say a fraction of time for all 6....I don't see that.

[TorpX]

In the in-game experience, i've noticed that you can fire all your torps at praticaly the same time, and they will all explode upon contact (providing none are duds), even if they are shot, say, a fraction of a second from each other.

My point is: in real life, the detonation of the first torpedo could or could not induce a premature detonation on the second torpedo coming just behind it? Or damage its firing pistol, or wrecking it complete, or etc etc etc? My point is, torpedos were so delicate, that I often wonder if a skipper would wait a few seconds between torpedoes shots, just to avoid the first detonation causing any damage to the other torp following just behind.

What do you history buffs have to say about it? :yeah:

You are right about torpedos being very delicate and complex. It didn't take much to cause malfunctions. Real skippers would never launch torpedos close together. Too many things could go wrong. Apart from the fractricide issue, they could interfere with each other. All it would take is one bumping the other and then, either an explosion or two erratic fish. Anyway, what would be the advantage? From what I've read they used 8 to 10 sec. intervals. US torps did have a "countermining" device designed to prevent shocks from prematurely setting them off, but I believe this was eliminated on later models. (I haven't read too much about this.) Perhaps it was considered unneccessary.


IDK about the game torps, they are probably borked like almost everything else. In SHCE you could have one torpedo overtake, impact and blow up another (by firing the first slow and the next fast).

[Platapus]

In some of the torpedo books there is mention of a counter-mining mechanism. That may be what you are talking about.

[Mescator]

I recall in Wahoo one of Mortons prematures either detonated or killed a couple of other torpedoes in the spread, but it's the only occasion i've heard of it.

[Daniel Prates]

In some of the torpedo books there is mention of a counter-mining mechanism. That may be what you are talking about.

No dude, what i'm talking about is a simple question: can the explosion of a torpedo interfere with another torpedo coming just behind it? Was that a historicaly documented concern for skippers?

[magic452]

Well in the early war they were happy just to get them to go off at all. :damn:

It may have been a small concern but the methods use to fire pretty much eliminated any problem and I have never heard of any real concern by ships captains etc. In theory it could happen with a fast speed setting right behind a slow one or two torpedoes aimed very close to each other. Never heard of it happening though.

In the game it has no effect at all.

Magic

[TorpX]

No dude, what i'm talking about is a simple question: can the explosion of a torpedo interfere with another torpedo coming just behind it? Was that a historicaly documented concern for skippers?

If you use the historical 8 or 10 sec. interval, it should not be a problem. What would happen in-game if you fire them off close together, I don't know. You might have to figure this out yourself. I think in SH 3, one can use a salvo mode that fires them quickly, so apparently it is not an issue there.

[Daniel Prates]

If you use the historical 8 or 10 sec. interval, it should not be a problem. What would happen in-game if you fire them off close together, I don't know. You might have to figure this out yourself. I think in SH 3, one can use a salvo mode that fires them quickly, so apparently it is not an issue there.


Yeah, indeed in SH3 you can set a simultaneous salvo, which pretty much makes them run very close to each other.I know that in-game it makes no difference, but it seem to me that a torpedo exploding agains the hull of a ship would probably detonate or damage a torpedo close enough - say 20 or 30 feet, maybe even more, specially them being so delicate and flawed. So it seems strange that a skipper would choose to fire a simultaneous salvo such as SH3 permits.

I have gone ingame to stop guessing and see how that works (SH4, that is). Indeed, in all-stop and at periscope depth, even if you fire all 6 tubes as fast as you can (hitting 'fire' a fraction of a second from each other), the tubes will fire in order with several seconds (3-4) apart from each other.

Now I don't know why that is. I know that loading and firing a torpedo is a complex operation. But assuming all tubes are flooded and ready to fire, it should be possible to fire them all at once, and in such case they should leave their tubes also all at once.

That would be of course unwise - they could bump into eachother and cause a tragedy.

So this may explain why it was standard procedure to wait a few seconds between shots. Skippers would never do simultaneous shots even if the machinery allows it, because of the risk of two torpedoes colliding just in front of the sub.

Considering that, it puzzles me that SH3 has an 'all-out simultaneous salvo' firing mode.

[razark]

But assuming all tubes are flooded and ready to fire, it should be possible to fire them all at once, and in such case they should leave their tubes also all at once.

That would be of course unwise - they could bump into eachother and cause a tragedy.
Torpedoes bumping into each other would be a minor issue. You'd probably be to busy to even notice.

Imagine the weight of a single torpedo. Multiply by six. Now, suddenly remove that weight from one end of a carefully balanced lever. What happens?

As each torpedo is fired, the crew must work to keep the boat level, replacing the weight of the torpedo with an equivalent weight of water, redistributing the ballast water, etc. Even if the crew was fast enough and knew exactly how much when and where, I doubt the machinery would be able to handle it. You would end up with the boat's bow suddenly popping out of the water, which is not exactly the best thing when you're trying to be sneaky.

[Daniel Prates]

I see. Yet another reason not to fire them simultaneously.

[TorpX]

Torpedoes bumping into each other would be a minor issue. You'd probably be to busy to even notice.


It depends on what you consider a minor issue. Contact between torpedos would most likely result in an explosion or all the torps running erratic. You would not notice the bumping, but would notice that you missed your target.


Imagine the weight of a single torpedo. Multiply by six. Now, suddenly remove that weight from one end of a carefully balanced lever. What happens?

As each torpedo is fired, the crew must work to keep the boat level, replacing the weight of the torpedo with an equivalent weight of water, redistributing the ballast water, etc. Even if the crew was fast enough and knew exactly how much when and where, I doubt the machinery would be able to handle it. You would end up with the boat's bow suddenly popping out of the water, which is not exactly the best thing when you're trying to be sneaky.

When the torpedo is fired, as it leaves the tube, a poppet valve vents the air in the tube back into the boat. This is helpful in that there will be no big impulse bubble coming up to the surface to mark the position, and water will flood back into the tube to balance the weight lost (more or less). I suspect they could have fired torpedos rapidly, if there was some need to do so. (Evidently, there wasn't.) Most of the prep time would be getting the torpedo ready beforehand; i.e. flooding the tube, charging the compressed air impulse system, etc.


Yeah, indeed in SH3 you can set a simultaneous salvo, which pretty much makes them run very close to each other.I know that in-game it makes no difference, but it seem to me that a torpedo exploding agains the hull of a ship would probably detonate or damage a torpedo close enough - say 20 or 30 feet, maybe even more, specially them being so delicate and flawed. So it seems strange that a skipper would choose to fire a simultaneous salvo such as SH3 permits.

I have gone ingame to stop guessing and see how that works (SH4, that is). Indeed, in all-stop and at periscope depth, even if you fire all 6 tubes as fast as you can (hitting 'fire' a fraction of a second from each other), the tubes will fire in order with several seconds (3-4) apart from each other.

Yes, it's curious the differences here, but there are so many things in SH4 that were left in an unfinished state that I'm not surprised. Too bad they dumbed down the firing proceedure in this game. Firing a torpedo should be more complicated than firing a revolver. :haha:

[Daniel Prates]

Too bad they dumbed down the firing proceedure in this game. Firing a torpedo should be more complicated than firing a revolver. :haha:


You said it. Flooding, for instance. Even 'dangerous waters' depicts the problem of flooding prior to firing.

[Stealhead]

What do you mean by problem of flooding tubes before firing? I assume you mean the problem of keeping the sub balanced true it is a problem but in SH4 the crew just manages the balance.It would be nice if it was more detailed like having a consonance if you flooded too many tubes suddenly or fired several tubes at once.It would also be fun if they just simulated in trim and ballast and all that.

I notice that in books most crews spaced each fish around 6 seconds apart or more I'd imagine the main reason for this would be to allow the crew to keep the boat in the correct ballast.

[Mescator]

and water will flood back into the tube to balance the weight lost (more or less).


I'm curious if the water would actually be similar in weight. I don't think it is that clear cut, because i recall in a number of books having to reballast the boat was a recurring concern during and after firing.

[TorpX]

I'm curious if the water would actually be similar in weight. I don't think it is that clear cut, because i recall in a number of books having to reballast the boat was a recurring concern during and after firing.

The torpedos were slightly heavier than water. In other words, close to nuetral bouyancy. If one is fired and the propulsion fails, they sink. IMO, this was necessary. If they floated they would tend to be a hazard to the boat, and give away their position. If they were very heavy, they would tend to sink even if the motors worked correctly. Many of the references give the negative bouyancy of each model. Note that when they drain the tube to reload the water goes into the bilges, it is not pumped outside.

I imagine that they did have to do some adjusting to the trim between attacks, but even if launching 4 or 6 torpedos substantially affected the trim, how much could they adjust the trim in the 20 or 30 seconds between torps? I would say the diving officer had to have the skill to keep the boat under control. IIRC, on the Tang, they would have the boat trimmed with a slight downward angle and keep their speed a little higher to reduce the risk of broaching.

I think it is fair to say, that the trim and bouyancy were ongoing preoccupations of the crews. Even when not running submerged and making torpedo attacks, adjustments had to be made for fuel, food and water consumed/discharged. The temperature and salinity of the surrounding water also affected this to some extent.

[Daniel Prates]

What do you mean by problem of flooding tubes before firing? I assume you mean the problem of keeping the sub balanced true it is a problem but in SH4 the crew just manages the balance.It would be nice if it was more detailed like having a consonance if you flooded too many tubes suddenly or fired several tubes at once.It would also be fun if they just simulated in trim and ballast and all that.

I notice that in books most crews spaced each fish around 6 seconds apart or more I'd imagine the main reason for this would be to allow the crew to keep the boat in the correct ballast.

Sorry, not 'problem', i meant it in the sense of 'procedure'. The flooding procedure. I was only assessing that firing a tube requires a captain to order it loaded, flooded, opened and only then, fired. The flooding procedure is missing in SH4, that's what i was talking about.

[Dogfish40]

No dude, what i'm talking about is a simple question: can the explosion of a torpedo interfere with another torpedo coming just behind it? Was that a historicaly documented concern for skippers?

No. The answer is a simple no. As for being a concern for skippers, the effects of oneTorpedo on otherTorpedos fired in a salvo were not a concern as has been posted here below, the fastest torpedos could be fired was six to ten seconds, (not the verbal orders but the actual firing) by the time six seconds has gone by, the distance between the fish was too great to say, bump the next torpedo off course much less cause other fish to explode. I haven't read everything yet but I've read quite a lot and have never come across this as a worry for the Fleet boats.
Good Hunting Mate :salute:
D40

[Armistead]

The torpedos were slightly heavier than water. In other words, close to nuetral bouyancy. If one is fired and the propulsion fails, they sink. IMO, this was necessary. If they floated they would tend to be a hazard to the boat, and give away their position. If they were very heavy, they would tend to sink even if the motors worked correctly. Many of the references give the negative bouyancy of each model. Note that when they drain the tube to reload the water goes into the bilges, it is not pumped outside.

I imagine that they did have to do some adjusting to the trim between attacks, but even if launching 4 or 6 torpedos substantially affected the trim, how much could they adjust the trim in the 20 or 30 seconds between torps? I would say the diving officer had to have the skill to keep the boat under control. IIRC, on the Tang, they would have the boat trimmed with a slight downward angle and keep their speed a little higher to reduce the risk of broaching.

I think it is fair to say, that the trim and bouyancy were ongoing preoccupations of the crews. Even when not running submerged and making torpedo attacks, adjustments had to be made for fuel, food and water consumed/discharged. The temperature and salinity of the surrounding water also affected this to some extent.




When a torp leaves the tube, the compressed air is shut off and the outer door remains open allowing water to fill the space. This would offset the lost weight of the torpedo keeping the sub in trim, although some minor adjustments may be needed, but almost always after torps were fired.

[TorpX]

When a torp leaves the tube, the compressed air is shut off and the outer door remains open allowing water to fill the space. This would offset the lost weight of the torpedo keeping the sub in trim, although some minor adjustments may be needed, but almost always after torps were fired.

This is pretty much what I said [read post #13, paragraph 2].

No. The answer is a simple no. As for being a concern for skippers, the effects of oneTorpedo on otherTorpedos fired in a salvo were not a concern as has been posted here below, the fastest torpedos could be fired was six to ten seconds, (not the verbal orders but the actual firing) by the time six seconds has gone by, the distance between the fish was too great to say, bump the next torpedo off course much less cause other fish to explode. I haven't read everything yet but I've read quite a lot and have never come across this as a worry for the Fleet boats.


I think the original question was in regard to torpedos being fired close together. It would not be a problem with 8 or 10 sec. intervals, but might be a problem with 2 or 4 sec. intervals. I believe this is exactly why they spaced them out. I've never come accross anything that said they couldn't fire salvos close together.

[Anthony W.]

With magnetic detonators being so fine, if you fired 2 simultaneously in theory the trailing torpedo would be set off by the metal in the first, or, with a fast running eel, be thrown off course by a matter of precious degrees due to the wake.

[Daniel Prates]

I think the original question was in regard to torpedos being fired close together. It would not be a problem with 8 or 10 sec. intervals, but might be a problem with 2 or 4 sec. intervals. I believe this is exactly why they spaced them out. I've never come accross anything that said they couldn't fire salvos close together.




My point exactely.

[commandosolo2009]

Yeah, indeed in SH3 you can set a simultaneous salvo, which pretty much makes them run very close to each other.I know that in-game it makes no difference, but it seem to me that a torpedo exploding agains the hull of a ship would probably detonate or damage a torpedo close enough - say 20 or 30 feet, maybe even more, specially them being so delicate and flawed. So it seems strange that a skipper would choose to fire a simultaneous salvo such as SH3 permits.

I have gone ingame to stop guessing and see how that works (SH4, that is). Indeed, in all-stop and at periscope depth, even if you fire all 6 tubes as fast as you can (hitting 'fire' a fraction of a second from each other), the tubes will fire in order with several seconds (3-4) apart from each other.

Now I don't know why that is. I know that loading and firing a torpedo is a complex operation. But assuming all tubes are flooded and ready to fire, it should be possible to fire them all at once, and in such case they should leave their tubes also all at once.

That would be of course unwise - they could bump into eachother and cause a tragedy.

So this may explain why it was standard procedure to wait a few seconds between shots. Skippers would never do simultaneous shots even if the machinery allows it, because of the risk of two torpedoes colliding just in front of the sub.

Considering that, it puzzles me that SH3 has an 'all-out simultaneous salvo' firing mode.

Realism dictated that firing torpedoes was on the move with practically 2-3 degrees down bubble on the fore plane to counter rise by impulse pressure. That is not depicted in U571 (since firing all tubes was possible, but a hell of a rise could expose the bow on surface, hence the down angle on the nose. In game however, a time taken to fire 2 torpedoes to simultaneously impact together target ships hull, is doable. A mix of slow and fast is in order. So if a target is 1000 meters on firing bearing, 1000 m/ 25m\s and 1000 m/ 12.5m/s is the answer. Subtract fast from slow, then subtract 3 for actual run.