And you thought you had a bad day

[Rab09]

July 24, 1943; easterly course from Palau to Truk.
The code braekers gave Daspit (Dan Daspit skipper of Tinosa) another juicy target: Tonan Maru III, the 19,000-ton whale factory on an easterly course from Palau to Truk. Daspit found her on the morning of July 24. He made an end around and submerged ahead. When he got a good look at her through the periscope, he saw she was heavily loaded, making about 13 knots.
Daspit attacked, firing four torpedoes. He believed that two hit; he saw large splashes of water forward. However, the ship did not appear to be damaged. She turned away, leaving Daspit in a poor firing position. However, he fired two more torpedoes. Both hit, one aft, causing smoke. The target stopped with a port list, settling by the stern, but showed no signs of sinking.
Daspit studied his prey carefully. He could see her deck guns. Men were running around dropping small depth charges over the side to intimidate him. There was still no sign of an escort, surface or air.

Daspit recorded what happened next in his patrol report:

1009. Having observed target carefully and found no evidence of a sinking, approached and fired one torpedo at starboard side. Hit, heard by sound to stop at same time I observed large splash. No apparent effect. Target had corrected list and was firing at periscope and at torpedo wakes with machine guns and one inch {gun}.
1011. Fired eighth torpedo. Hit. No apparent effect.
1014. Fired ninth torpedo. Hit. No apparent effect. Target firing at periscope, when exposed, and at wake when torpedoes were running.
1039. Fired tenth torpedo. Hit. No apparent effect.
1048. Fired eleventh torpedo. Hit. No effect. This torpedo hit well aft on the port side, made splash at the side of the ship and was then observed to have taken a right turn and to jump clear of the water about one hundred feert from the stern of the tanker. I find it hard to convince myself that I saw this.
1050. Fired twelth torpedo. Hit. No effect.
1100. Fired thirteenth torpedo. Hit . No effect. Circled again to fire at other side.
1122. Picked up high-speed screws.
1125. Sighted destroyer approaching from east....
1131. Fired fourteenth torpedo. Hit. No effect.
11321/2. Fired fifteenth torpedo. Started deep. Destroyer range 1,000 yards. Torpedo heard to hit tanker and stop running by sound. Periscope had gone under by this time. No explosion. Had already decided to retain one torpedo for examination by base.
In all, eleven of Daspit's torpedos, fired under almost perfect conditions, had been duds. When he returned to Pearl Harbor, the normally cool and unflappable skipper was in a rage.

Now THATS a bad day!!

[Syxx_Killer]

That must have been one LONG trip back to base for the crew.

[Jmack]

there where many of those ... read here

http://www.subsim.com/radioroom/showthread.php?t=96744

[Hyena]

I think this was the engagement that lead to the Navy shooting torpedo's into a cliff and dissecting the duds, to see what happened.

[bookworm_020]

I think it was. The testing was done in two parts. The first part had U.S.S Halibut fire torpedo after torpedo till a dud happend. It was the recovered by volunteers (the torpedo's were all warshots, so one mistake in recovery and it's all over)

A second test was hoisting aloft torpedoes with a crane and dropping them on to a steel plate set at different angles. They were fitted with a concrete warhead, but live detonators to see what was causing duds at different angles.

These tests revealed two problems with the impact detonator. One the rails the explosive caps travled to the warhead on buckled. They were made stronger.

Two the release pin for the caps were too heavy, and so didn't drop away. They were trimed down to make them lighter as a temporary measure, they were later replaced with new pins of a different metal. The best metal was found to come from the propellors of the japanese aircraft that had been shot down at Pearl Harbour

Testing was done at Fremantle, Australia about depth keeping. They used fishing nets that had been stung out and weighted. When a torpedo was fired at it, it punched a hole through the net. It was then a matter of measureing how deep the torpedo was set at to how far the hole was from the surface.

This revealed the depth keeping problem.

After this had happened, the number of sinkings climed, and fewer duds were reported.

The rest you know

[Driftwood]

This, as most of you already know, was one of THE great scandals of WWII in the Pacific. Naval Ordinance people maintained to the bitter end that it was human error that caused the malfunctions. It wasn't until the guys at Pearl figured it out on their own that something was done about the problem.