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 Author  Topic: Question for Al Ross
David Buck

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Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of David Buck   Send Email To David Buck Posted on: Feb 12, 2012 - 4:37am
Thanks Jeff and Ted

The photo in this instanct does show that there is no form of fixing of the tube to the deck, I say that because in looking at the damage to the lower support of the mount some of the turntable is damaged were as if there had been a more permernant attachment of the tube to the turntable support the lower turntable plate would have been torn away from the deck strengthener and there is clearly no damage to the plate bolted to the deck.

This is what I asked Al to clarify as his drawing does not show any form of connection and this photo tends to bear out the fact that the only thing that held the tubes down onto the turntable was the weight of the tube and a faily close fit of the turntable ,such as most larger turrets are held down only by there weight.

Something to think about, as the Bismark sank she turned turtle and all her turrets fell off and then she righted herself and landed upright on the bottom many fathoms below.

Something to think about !

Al You may find somethine differant if you do I would greatly appeciate your view.

D.buck

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Jeff D

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Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of Jeff D   Send Email To Jeff D Posted on: Feb 12, 2012 - 6:43am
Hopefully Al can help. No man on earth knows PT boats better than he. But in the meantime, I'll stick with thinking they were held down. The "turntable base" drawing seems to show 4 slots in the side view and in detail AA, and the damaged base photo seems to show them also. The "turntable and details" drawing looks like it shows corresponding retaining pin bosses on the moving part of the turntable. I may be wrong but the more I'm looking at the drawings the more I'd bet money on it.



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alross2

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Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of alross2   Send Email To alross2 Posted on: Feb 12, 2012 - 1:58pm
After looking at the photos and drawings, I think I agree with Jeff - there had to have been a mechanical holddown of some sort. Here's my thoughts (remembering I have no engineering background...)



There are four slots in the turntable base vertical tube. The saddle tube fits down over the turntable base tube and has four bosses on it. Each boss has a large diameter hole and a small diameter hole. I didn't see any text about threads on the drawing, but would guess that a plate with a large diameter pin welded to it would be attached to the boss with a bolt through the smaller hole after the saddle tube was placed over the turntable tube. The pin would be long enough to pass through the slot, acting as a stop for vertical movement. The interior gussets in way of the slot may have had a corresponding slot milled in their edge where they met the tube, but that wouldn't be much of a problem. The elongated slots would allow the tube to pivot (only 12 degrees needed) and would act as a mechanical stop (pin hitting the end of the slot) to prevent an overzealous torpedoman from cranking the tube too far.

Plausible??

Al






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David Buck

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Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of David Buck   Send Email To David Buck Posted on: Feb 12, 2012 - 6:49pm
Hi Al,

Quite plausible I think as in the closeup shot three of the four damaged areas appear to have what would have been the bottom of the slot visible with the top section torn away.

(when there is damage to a metal item you generaly do not end up with nice straight lines with rounded ends arla a slot cut with an end mill)

I wonder if the base was a cast item pos. alloy not fabricated from steel as the top section has torn off with very little damage to the lower section and base?

See Al They are right You are the one we ask all those hard questions of ,Thankyou !

D.buck

Total Posts: 332 | Joined: May 4, 2008 - 2:59am | IP Logged

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