How many ways can a torpedo be a dud?

[Otto Heinzmeir]

My duds seem to go in cycles. I have none for 10 to 12 shots and then 2 in a row. I recently learned that some of the 'duds' may not be a true dud. What I mean is if you fire a torpedo at 3.5m depth in 8' waves. The torpedo can break the surface when the waves dip and then the torp breeches the surface, crashing into the next wave and detonating prematurely. Since I fire 95% of the time from a 90AOB, usually with a TDC angle of no more than + or - 10 degrees, I eliminate most of the duds from impacts that bounce off the hull.

I still don't use the external camera to help set up an attack but I started to use it after I fire to see just what happens sometimes when a torp doesn't hit the target from 600m. I saw in one case the torpedo traveled 580m and just 30m before hitting the ship, it changed direction about 30 degrees and exploded. I believe this was the result of popping out of the waves and impacted on the next wave. So not a true dud. In heavy seas, the kind where the wind is 15mps, this seems to happen about 20% of the time. Perhaps even higher when I set depth to 3.5m, as I didn't realize what was happening so wasn't documentting it.

I was wondering what other ways can a torpedo malfunction in game. An impact can bounce off and not detonate. The magnetics can just sail underneath and not trigger. Are there cases where the torpedo will just run haywire and not track its course?

I have had much better luck in heavy seas with magnetics than impacts. I'm trying to determine the minimum depth you can set in real heavy seas without it detonateing prematurely. I think 7.5m may be near the depth where the torp is not likely to breech a wave.

The last ship I sunk was in the heavy seas with 15mps winds and rain. I fired two torpedos at 7.5m and one torp and 6.5 It was in a convoy in a the narrow channel north of Ireland and wanted to be certain that at least 2 hit and sank the ship as I wouldn't be able to shadow it. It was so dark I couldn't see the fish trails but i did watch and time the 3 shots. Both of the torps set to 7.5 hit the ship. Once again I heard an explosion after about 25 seconds for the one set at 6.5m but it didn't appear the hit the ship. Probably impacted a wave and pre-detonated again. Though I didn't have the lxery to check with the external camera as I needed to dive. Good news is the ship sank as I heard it moaning on the hydro. What an sad sound that is.


The real bugger of this is since a fair amount of DD's only have a draft of 2m. In heavy seas firing a torp at 2m has too high a degree of failure to waste a shot at them. Then the plus side is your sub is hard for them to detect in heavy seas as well.

[GoldenRivet]

1. simple dud (ie bad fuse, trigger or warhead / factory defect)

2. Magnetic Detonation prematurely (usually in far northern latitudes)

3. Failure to detonate magnetically (if depth set too deep, the magnetic trigger never detects the ship overhead)

3. Torpedo breaches the surface and hits the next wave, triggers the detonator and the torpedo explodes prematurely

4. Torpedo strikes the target at too shallow of an impact angle and the trigger is not engaged as a result (torpedo was good, it was just a bad shot)

[Otto Heinzmeir]

Thanks for that! Simple to understand.

[Lt.Fillipidis]

Originally Posted by GoldenRivet

4. Torpedo strikes the target at too shallow of an impact angle and the trigger is not engaged as a result (torpedo was good, it was just a bad shot)

@ GR
But when that happened in WW2, the torpedo bounced off and sank or had its course and probably the depth changed?
Cause if No2 happened then the torpedo still had a chance to hit something.

[GoldenRivet]

if the torpedo was set too deep for one ship... It might be the right depth for another ship. However, you would have to be very very lucky to miss one and hit another.

But that's happened before.

And in real life a failed impact could result in the torpedo being deflected in another direction but it may also result in the torpedo being damaged badly enough that it would simply sink.

You have to think that a torpedo set to "fast" is running along at about 40kts which is about 45 mph. That's a pretty tough impact when you think about it.

[ozzysoldier]

5 torpedo hits dos not explode runs straight through the ship holes both sides

[Bosje]

there was a vid on youtube of a harbour raid where the torpedo bounced off some crappy hull and went on to sink something else which was initially blocked from view/torpedo track.
it was either SH3 or SH4 and it was apparently just incidental (not actually aimed) but it looked dead cool

anyway... on topic: you can actually set depth to run under the smaller outer column ships to hit the bigger inner column ships etc, but I'm not sure if they actually would have tried that in real life.

[Oneshot/Onekill]

Originally Posted by ozzysoldier

5 torpedo hits dos not explode runs straight through the ship holes both sides

You must be using those top secret Armor piercing torpedos. They were supposed to still be in the testing phase.

[Pepe le Moko]

I don't know but i think we're lucky in SHIII because the real U-Boats experienced between 25 and 45% duds at the begining of the war.
During the invasion of Norway it was even worse, more like 90% of all the torpedos missed their intended targets.

Not sure if the depth problem is modeled in SHIII. I have had a few torpedos go too deep under the keel of the ships i was firing at but i can't tell if it was me setting the wrong depth, caused by the state of the sea and the waves or a dud.

The only time i know i got a dud is when the torpedo hits and there is a big splash of water but no explosion and that doesn't happen very often at all.

[Otto Heinzmeir]

I get duds about 2 to 3 per 14 or about 17% of the time. I count the ones that go under the ship as a dud. However in GWX in 15mps winds with waves over your conning tower. If you fire at 3.5m depth probably close to half will breech the surface and detonate early. At 4.5m a fair amount still will breech. Magnetics become unreliable as well from the ships pitching. Technically these wouldn't be true duds, but amount to the same thing. Setting the depth to 5 to 6m can eliminate the breeching torps but then you have a good chance of the torp deflecting off the rounded part of the hull. Thus its possible to get close to 30% torpedo failure in 15mps winds. I used to have 2 week periods of these high winds in game.

I wonder if turing duds off eliminates breeching torpedos as well as actual duds? The NYGM mod trys to get the dud ratio more realistic by having all torpedoes use the magnetic arming system and limits the depth the torpedo can be set to 3m or deeper. I think the 3m limit is a good idea since many DD's have a 2m draft so the torp has to be magnetic and in moderate to heavy seas makes it less likely to detonate. I always cringe whenever I read posts where someone takes out the 4 escorts then sinks the entire convoy at their leasure with theie deck gun. NYGM fixes that pretty well.