Torpedoes again

Brian W

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"Following a series of failed attacks and premature detonations, including point blank attacks on Ark Royal and the heavy cruiser Norfolk, an angry Dönitz orders magnetic exploders deactivated on all submarine torpedoes. "

It took the German Navy six weeks after the war started to figure out that magnetic exploders weren't working. The US Navy would stick with them for 18 months after Pearl Harbor; three years after the Germans. Whether we knew if the Germans decision or not is unknown. Hard to believe it wasn't known after three years.
 

jrv

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The American torpedo had a number of problems. The first problem was that it ran too deep. That was fixed in the first six months. Having fixed a major problem the Navy found it hard to accept that there was a second problem. Also the problem was not encountered consistently. The official position was that 2% of torpedos exploded prematurely, while skippers estimated that around 10% did. There is also the difficulty that attacking ships with torpedos from submarines is inherently chancy. If the attack fails, there could be a thousand different reasons why. It's not easy to determine from the effect what the cause might be. https://en.wikipedia.org/wiki/Mark_14_torpedo#Magnetic_influence_exploder_and_premature_explosions.

The problem with the premature detonation of the Mark XIV proved the subtlest of all. A magnetic detonator is usually set to explode beneath the ship, with the trigger being the ship's magnetic filed. The shape of the magnetic field, however, depends on the ship's position on the surface of the Earth. Therefore, the shape of the field at Newport, Rhode Island, where the magnetic detonators were originally developed, was quite different from that in the Southwest Pacific. The failure to note this subtle, yet crucial difference explains many of the disappointments that submarine skippers experienced in the first half of the war.
https://www.uboat.net/allies/technical/torpedo_problems.htm

The Germans also had problems with depth in addition to the magnetic exploder. Although they deactivated the magnetic exploder, they don't seem to have fixed all their problems until 1942. https://www.uboat.net/articles/index.html?article=23

It is easy to say with 20-20 hindsight that the Navy should have recognized and fixed the problem the first day of the war, but if you look at the details I think it is at least a little understandable why it was not so simple at the time.

JR
 

Brian W

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It is easy to say with 20-20 hindsight that the Navy should have recognized and fixed the problem the first day of the war, but if you look at the details I think it is at least a little understandable why it was not so simple at the time.
Having real world tests within six months would have made it much more forgivable. Although even then, the world has been at war for the last two years and you're getting into it, albeit slowly, not conducting real world tests is nearly criminal negligence.

Seriously, JR. You spent more time in real world test with ROAR than BuOrd did with their torpedoes.

"Here's 24 bullets. They worked great in the lab so if you come back without a kill, we're going to rotate you out of command with the stink of LMF. And no complaints about failures; that's what they all claim."
 

Brian W

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Monday morning QBs are undefeated
Yes, it's always easier to complain about getting substandard product than it is to make substandard product.
 

Chas

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I was being funny.

I am interested to hear statistics on effectiveness or lack thereof of early war US torpedoes.
 

bendizoid

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I was being funny.

I am interested to hear statistics on effectiveness or lack thereof of early war US torpedoes.
They found that a 45 degree attack was best, the Torpedo would detonate. 90 degree strikes tended to bounce and fizzle.
 

jrv

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Having real world tests within six months would have made it much more forgivable. Although even then, the world has been at war for the last two years and you're getting into it, albeit slowly, not conducting real world tests is nearly criminal negligence.
The failure to note the defect earlier was due to the BO's reluctance to test the torpedoes in peacetime. Fish cost $10,000 apiece, and it was considered prodigious to expend them on target practice. In comparison, a similar German torpedo cost RM 25,000-but the Germans never shied away from such "peacetime expenditures."
https://www.uboat.net/allies/technical/torpedo_problems.htm

Perhaps it was criminal, but the cause probably lay more in the realm of budget rather than the commitment of the Navy to trials.

JR
 

Brian W

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80 years ago today.

On learning that Dönitz had ordered the deactivation of the magnetic exploder, the torpedo directorate informs him that the G7 torpedoes are running two meters deeper than set. They hadn't previously informed BdU of the flaw since they assumed it wouldn't matter with the magnetic exploder detonating the warhead underneath the target's hull.
 

Brian W

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They found that a 45 degree attack was best, the Torpedo would detonate. 90 degree strikes tended to bounce and fizzle.
Once some real world tests were made, they found the firing pin would bind if struck too hard. That meant torps set at high speed that were "perfect" hits would fail most often. Firing at oblique angles risked not hitting the pin hard enough, or failing to hit it at all. However, duds dropped in half once that solution became common.
 

Brian W

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One of the reasons this is so egregious to me is that Germany and Great Britain both had similar problems at the start of the war, and both were proactive in fixing those problems. And the US Navy knew that, yet failed to ensure they would not have the same problems all the while headed into war.

Subs with good torps at January-42 would have significantly reduced allied casualties during the war, and perhaps shortened the war by months. And some good captains would not have been beached because they were given blanks to go into battle with.
 
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