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Re: German/American Torpedo failures
Posted by: ROBERT M. ()
Date: February 19, 2008 06:55AM


Nickolay Nedelchev's article titled: "The US Silent Service in Early WWII: A Story of Failure." contains a few errors.....

The First error appears near the bottom of the 5th paragraph: "The two main components of the US submarine arsenal were the Mark XIV-steam-driven and the Mark VI torpedoes."

The Mark VI torpedo was 17.7" in diameter, and built by Bliss & Leavitt in 1911. If any of these existed in 1942, they still could not be launched from 21" torpedo tubes in submarines.

Next sentence, same paragraph:

"The Mark XIV relied on magnetic pistols to detonate the warhead."

The Mark XIV torpedo relied on a Mark VI magnetic-influence and a Mark V contact exploder mechanisms, mounted on the same baseplate.

"......and the Mark V! was armed with impact detonators."

Sorry, but there never was such an arrangement.......The U.S. Navy does not use
the word "pistol" in describing their exploder mechanisms. However, the term is
used for depth charges.

The Mark V Exploder mechanism is a contact-type, containing a mechanical arming
mechanism, a 65-grain Fulminate of Mercury detonator, and a Tetryl booster housed
in the warhead.

The Mark VI magnetic-influence exploder mechanism consists of a large pick-up coil and pickup rod, an electronic circuit. An 8 mfd condenser (capacitor) is charged by a DC generator, and triggered by a Thyratron tube when the magnetic influence of the target is the strongest. This action, through a solenoid strikes the firing ring of the Mark V contact exploder mechanism, and detonates the detonator, booster and main charge in the warhead.

Same paragraph:

"The former exhibited two kinds of failures: premature detonation and vertical deviation from the course set, while the latter simply armed on impact."

The magnetic-influence portion of the Mark VI exploder mechanism did experience
premature detonations. The vertical deviation was caused by an incorrectly installed seawater inlet (sensor) to the depth (Uhlan) gear and this was corrected as described below. The Mark V contact-type exploder mechanism did jam on contact with the target, because the firing pin block assembly was made of
steel and the four 1/2" diameter brass supports (legs) collapsed upon impact.
This was corrected by the personnel at the torpedo shop in Pearl Harbor. The
firing pin block assembly was now made of aluminum and the four brass supports were re-configured.

Paragraph 10:

"The depth control device of the Mark XIV was also found to be defective, which explained why the fish often plunged towards the bottom in stead of steering straight at the target."

The fish never plunged towards the bottom. The torpedoes were all running 11 feet deeper than set. The correction was to relocate the seawater (sensor) inlet for the depth (Uhlan) gear to the midships section of the torpedo. The steering
(azimuth) was controlled by its (Mark 12) gyro and gyro mechanism.

Same paragraph, next sentence:

"As for the Mark VI, the impact detonator was replaced with an improved one."

Again, you must be referring to the Mark VI torpedo. Later in the war, a simple
contact switch was installed in the warhead, just above the Mark VI exploder mechanism.

It consisted of a 1" diameter brass ball set to close the electrical contacts upon being displaced when striking a target. The magnetic-influence portion of the Mark VI exploder mechanism was disabled when the new switch was installed, by removing the pick-up rod from the warhead.

Paragraph 13:

"Shipyards in California churned out boats for the Pacific much faster than the
Japanese could sink them."

When Pearl Harbor was bombed. the U.S. only had 111 operational submarines in commission. At war's end in mid-August 1945, thanks in part to Mare Island Shipyard (California), the navy had a force of 260 submarines in commission. All in all, twenty-two Mare Island-built subs got into the shooting war, and they alone accounted for the sinking of 252 ships for a total of 357 tons of shipping.
Portsmouth (New Hampshire) Shipyard built 70, Cramp (Philadelphia) Shipyard built 14, Manitowoc (Wisconsin) Shipyard built 28 and Electric Boat (Groton. CT) Shipyard built 78 submarines in WWII.

I had notified Gummi about these errors, but nothing was changed.



Options: ReplyQuote

Subject Written By Posted
German/American Torpodes failures PF 02/18/2008 02:17PM
Re: German/American Torpodes failures ROBERT M. 02/18/2008 06:03PM
Re: German/American Torpodes failures schalke 02/18/2008 07:50PM
Re: German/American Torpodes failures Rainer 02/18/2008 08:22PM
Re: German/American Torpodes failures PatW 02/18/2008 10:57PM
Re: German/American Torpedo failures ROBERT M. 02/19/2008 06:55AM
Re: German/American Torpedo failures PF 02/24/2008 02:52AM
Re: German/American Torpedo failures Victor 06/27/2008 12:15AM
Re: German/American Torpedo failures ThomasHorton 06/27/2008 02:02PM

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