[REL] Dark Waters

[Bubblehead1980]

Originally Posted by KaleunMarco

yes, their G7a was essentially the same fish as our Mk14.
not sure who stole what from whom but, after all was said and done, it was like Spy v Spy in the old Mad magazine.
i do not think that the G7a/Mk14 were circle runners as much as the Mk18, but you could see them coming and they ran deep and they failed to explode.
it could be that an over-enthusiastic Ubi designer added it to the German side out of enthusiasm.

Yes, in my research I noticed there was some cross over, more than would be possible by simple coincidence, so likely some spying going on. Well MK 14 had bit of circle runner problems earlier in war...Grunion is believed to have been damage by MK 14 circle run exploded close to her when submerged. Tulibee was lost to a MK 14 circle run in March 1944. but yes MK 18, especially the MK 18-1 had among depth keeping and battery issues, circle run issues.

Interesting enough, sure you know, the MK 18 design was based on a German TII G7e electric torpedo which did not explode and ran up on the beach when was fired close to shore. G7e had depth control issues until Spring 1942. So the design flawed carried over from captured torpedo into the MK 18. No exploder issues with MK 18 because it used the simple MK 8 exploder, contact only, with the new firing pins that solved the dud issue.


All research thus far, have not read about U Boat's suffering circle run. I mean its possible and may have happened, but figured it would be mentioned. I did not remove it from the torpedo.sim file since such a small chance, when reworked them to match history .

[propbeanie]

In my opinion, the dangerous part of the Mark 14 and the Mark 18 was the failure to have vane limiters for the rudders. Cost saving... Spend all that money on a weapon, and especially the 18, the vane could lock full-over, especially if shooting with a higher angle.

[Bubblehead1980]

Originally Posted by propbeanie

In my opinion, the dangerous part of the Mark 14 and the Mark 18 was the failure to have vane limiters for the rudders. Cost saving... Spend all that money on a weapon, and especially the 18, the vane could lock full-over, especially if shooting with a higher angle.

That is what caused the circle runs yes? Rudder locked hard over..


Quite infuriating to think how many lost their lives and the boats lost due to the torpedo issues...especially circle runs. We know of two for sure (Tang, Tullibee) and appears Grunion was lost to a circle run as well. Likely some of those unexplained losses were due to circle runs. Then all the close calls.


One that always sticks out to me is from the book "The Luck of the Draw", USS Pollack in 1943. Night surface attack on a convoy...this was before magnetic features were disabled. They fired MK 14's are convoy, one (unobserved) circled back and exploded directly below Pollack. Knocked her systems offline, she went dead in water. Only thing saved her is torpedo ran deeper than set, so they do not catch the full power of the explosion. However, this explosion alerted a nearby escort, which promptly spotted Pollack and began closing at high speed, while Pollack's engine and maneuvering rooms worked to get things back on line, which they did, barely in time. Two failures, but one actually saved the one (running deep).

[propbeanie]

I almost forgot that there was also mention of the material used on the Mark 18 for vane pivots... or maybe the friction bearing? I cannot remember... but due to the environment on a submarine, submerged in the saltwater and humidity of the ocean over time, the pivot points had a tendency to corrode, contributing to the stuck condition of the vanes, in that the gyro could not "pull" the vane back once it went over, so whereas the Mark 14 would run erratically, the Mark 18 just turned into a circle runner...