Just how bad were USN torpedoes?

[John Lansford]

The magnetic detonators tended to go off early as they reached a ship's magnetic field.  Coupled with the early war tactic for blind aiming by sonar bearings, this created a lot of 'false hits' that hid the actual problems.

The torpedoes also didn't run true; if they were set for shallow depth they would porpoise and reveal themselves, or dive under the ship.  If they went too deep, the magnetic detonator would never detect the field and not go off.

Finally, the contact detonators were flimsy; a right angle hit on a ship would crush the guides for the firing pins, keeping them from setting off the warhead.  Until this was fixed (but after it was discovered), sub captains were told to aim for angled hits, which wouldn't crush the guides.

As others have said, these three flaws tended to hide each other, and BuOrd refused to believe there were so many bugs in their wonder weapon.  It also didn't help that torpedo stocks were low in 1942, and captains were ordered to fire only one torpedo salvos at non-major warships, since only one would be needed for any ship smaller than a big cruiser.  Multiple torpedo salvos were frowned upon and considered evidence of less than aggressive captains.

[Panther Bait]

Besides the problems with the magnetic pistols, the backup mechanical pistol was too fragile.  The impact forces of a perpendicular 90-degree hit sometimes bent the pistol at the moment of impact causing the pin to miss the exploder.  Glancing blows were often strong enough to trip the pistol, but not to bend it as far and therefore exploded normally.  So a "perfect" shot was actually less likely to explode than a less perfect one.  Talk about punishing success.
 
Anyway, a pretty decent article on all the various issues can be found here: http://www.geocities.com/Pentagon/1592/ustorp2.htm

[wdolson]

The event that finally convinced the Navy that the contact exploder was bad was when a sub took off the propellers of an unescorted freighter with the first shot, then proceeded to fire every torpedo in the magazine from a perfect firing angle at the freighter only to have all of them hit and dud.  The sub captain kept one torpedo which he brought back to Pearl Harbor.  When they test fired it at a cliff, it went off, but the brass were willing to listen at that point and they found the firing pin on the contact exploder was too fragile and it shattered upon impact with  good hit.  The only time the firing pin would work would be with a glancing blow.

The story goes that the firing pins in the torpedo stock at Pearl Harbor were replaced with pins made from the propeller of a Zero shot down during the attack.  After that, US subs started doing a lot more damage.  The Navy later did an estimate on how much tonnage was left afloat due to that mess and the numbers were pretty staggering.

Not long after the firing pins were fixed, the sub fleet got torpedoes with torpex, which was a new explosive.  The standard explosive was mixed with powdered aluminum which gave the explosive up to a 50% boost in yield.  After torpex was introduced, one torpedo would usually sink most freighters.  For some reason torpex was never used with aerial or DD torpedoes. 

Bill

[Shark7]

ORIGINAL: Footslogger

Didn't john Wayne make a movie describeing the trouble with firing pin in the torpedo itself?

Operation Pacific released in 1951.

[LeeChard]

As I understand it torpedoes were so expensive that congress would not fund live tests. Most testing of components was done in labs. Not a single armed torpedo was ever fired to see if it actually worked as designed.

[Admiral Scott]

Politicians were idiots back then too.

[JohnDillworth]

The event that finally convinced the Navy that the contact exploder was bad was when a sub took off the propellers of an unescorted freighter with the first shot, then proceeded to fire every torpedo in the magazine from a perfect firing angle at the freighter only to have all of them hit and dud. The sub captain kept one torpedo which he brought back to Pearl Harbor. When they test fired it at a cliff, it went off, but the brass were willing to listen at that point and they found the firing pin on the contact exploder was too fragile and it shattered upon impact with good hit. The only time the firing pin would work would be with a glancing blow.

The story goes that the firing pins in the torpedo stock at Pearl Harbor were replaced with pins made from the propeller of a Zero shot down during the attack. After that, US subs started doing a lot more damage. The Navy later did an estimate on how much tonnage was left afloat due to that mess and the numbers were pretty staggering.

Not long after the firing pins were fixed, the sub fleet got torpedoes with torpex, which was a new explosive. The standard explosive was mixed with powdered aluminum which gave the explosive up to a 50% boost in yield. After torpex was introduced, one torpedo would usually sink most freighters. For some reason torpex was never used with aerial or DD torpedoes.

Part of the problem with the firing pin is that it was taken from the previous generation of torpedo. The previous generation had a smaller warhead and a slower speed. So the pin was not really up to the task. The real problem was lack of testing. Probably due to lack of funds during the pre-war years. The Ordinance bureau deployed a torpedo that was tested with a warhead that weighed less than the actual production warhead, with a firing pin from a previous generation, with a magnetic detonator that was only briefly tested in the Northern hemisphere that could not possibly work near the equator.

BTW, the Germans and Brits disabled their magnetic detonator. This was a bureaucratic disaster.
Let's start the real discussion. How many days would the war have been shortened if the torpedos worked from day 1? It is a damn shame that there is not a pacific war simulation that could model the entire war with an option to model the effeft of functioning torpedos...........
hold on....

crap, this soap box is looking pretty high right now, sorry

[DuckofTindalos]

The lack of live-fire testing was nothing to do with lack of fund (the Two-Ocean Navy Act put plenty of money into the Navy), but because of security concerns over the Super-Duper Magnetic Exploder(TM).

Doesn't mean the politicos weren't idiots, but BUORD was far more to blame.

[Kull]

ORIGINAL: JohnDillworth
It is a damn shame that there is not a pacific war simulation that could model the entire war with an option to model the effeft of functioning torpedos...........

Ummm. There's a toggle switch that will do exactly that in AE (and WitP before it).

[Tone]

Failing torpedoes made early japanese war effort possible. as a convoy system was not working till the fall of 1943.

The convoy system then didnot work. as there was not enough escorts.

Convoy system just put all targets in one place. for good working now usa torpedos. [:(]

[skrewball]

Here's my favorite example of how bad the Mark 14 was (Taken from Wikipedia)...

"At 12:53, a damaged aircraft carrier with two escorts was sighted. The carrier was identified as Soryu, but later research suggests it was probably Kaga. An hour later, Nautilus had moved into attack position. Between 13:59 and 14:05, after the battle was largely over, Nautilus launched four torpedoes at the carrier from less than 3,000 yards (2,700 m). One failed to run, two ran erratically, and the fourth was a dud (a familiar problem for the Mark 14), impacting amidships and breaking in half.Nautilus reported flames appeared along the length of the ship as the first hit, and the skeleton crew which had been aboard (survivors of which reported no torpedo hit) began going over the side, with the air bottle of the dud torpedo acting as a life preserver for Japanese sailors."

[DuckofTindalos]

ORIGINAL: Kull

ORIGINAL: JohnDillworth
It is a damn shame that there is not a pacific war simulation that could model the entire war with an option to model the effeft of functioning torpedos...........

Ummm. There's a toggle switch that will do exactly that in AE (and WitP before it).

He was being sarcastic.

[RevRick]

ORIGINAL: Terminus

Correct. The Mk 14 had those three big problems, which conspired for 18 months to make it somewhat less than useful.

I hereby nominate this post for the "Understatement of the Decade" Award.

[philabos]

In my current game I became accustomed to sub torpdoeos acting like B17's bombing BB's - a sure miss or dud. Lots of marus with dents in their hulls.
Imagine my surprise when SPEARFISH fired three at ZUIHO - Jan 42 in the Celebes Sea - BOOM! She went down like a brick. Didn't feel so bad about missing those marus now!

[Shark7]

ORIGINAL: warrenup

In my current game I became accustomed to sub torpdoeos acting like B17's bombing BB's - a sure miss or dud. Lots of marus with dents in their hulls.
Imagine my surprise when SPEARFISH fired three at ZUIHO - Jan 42 in the Celebes Sea - BOOM! She went down like a brick. Didn't feel so bad about missing those marus now!

Of course in strategic terms 1 Maru is worth about 10 Zuihos. I've noticed this as well, the torpedo's miss or dud on the ships that would be the most damaging, but manage to sink ships that don't matter so much in the end game.

[JohnDillworth]

Ummm. There's a toggle switch that will do exactly that in AE (and WitP before it).

I was trying to be sarcastic. about once a year I learn that sarcasm does not translate into print well

[DuckofTindalos]

That bit translated just fine.

[Kull]

ORIGINAL: JohnDillworth

I was trying to be sarcastic. about once a year I learn that sarcasm does not translate into print well

Understood. However, I've seen odder things asked in here, so I opted to point it out, just in case you hadn't noticed the toggle. In the future, you should use some kind of smiley to indicate mood when using sarcasm, especially if it's not immediately obvious (and this time it wasn't). As you note, "all-text" communication has it's pluses, but conveying underlying meaning isn't one of them.

[JohnDillworth]

It is interesting to speculate what if the torpedoes worked from day 1. Subs hit alot of ships, including many warships. Japanese would probably have to start trying to convoy early in the war. Therefore destroyers would not have been as available for use carrying troops and what not. Everything I read, and many of the games I have played indicted the Japanese were very short of destroyers. They certainly made the most of them when they had them though.
It is ironic that the only time allied torpedoes worked well is when they sunk the HMAS Canberra

[DuckofTindalos]

Those weren't Mk 14's.