Increasing crush depth to a theoritical value

beartooth91 · 12-22-07, 04:06 PM

Based on my experience (USS Pintado SSN-672) and my WW2 Submarine book collection; I believe "collapse depth" to be the minimum depth at which you're in danger of losing the submarine. Its historically been specified to be 1.5 x Test Depth. On Pintado, "collapse depth" was listed as 1.5x test depth in the boat's manual.
Based on some of my books regarding WW2 fleet boats, I believe a true crush depth to be around 1.9x to 2x of the test depth.
The Silent Victory account of the Balao is data point #1.
There is another account, also in Silent Victory, of the USS Salmon losing depth control in the midst of a depth charge attack and dropping down to 500 ft before the crew regained control of the boat. She obviously survived, but, was leaking heavily during the ordeal.
In "Find 'Em, Chase 'Em, Sink 'Em" (a newer book about the USS Gudgeon - and the best researched WW2 submarine book I've ever read); the boat went too deep while evading an attack by a Q-ship on her 2nd war patrol in the East China Sea. The patrol report listed the max depth as 350 ft. Some of the crew members interviewed said the boat went as deep as 513 ft during this episode. Her skipper, Joe Grenfell, admitted - after the war - she reached 425 ft during this event. Whether it was 425 or 513, she was still seaworthy after the event with no flooding reported.
The account of the USS Chopper (a Balao or Tench) surviving 1011 ft is another data point.
During Tang's sea trials, O'Kane took her to 612 ft.
I need to find some data on some of the Gatos with regard to the deepest recorded - or admitted - dives.
Its pretty clear the 1.5x number is on the conservative side.
However, I know of no submarine intentionally exceeding the 1.5x number. Many of the skippers were afraid to even go near the 1.5x number. Fluckey's normal evade depth in Barb (a Gato), was 375 ft. I believe once, he may have taken her to 415 or 425 ft. My impressions are that he was afraid to push her much deeper than 375.

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12-22-07, 04:06 PM	#1
beartooth91 Loader Join Date: Nov 2007 Posts: 82 Downloads: 21 Uploads: 0	Some Data Based on my experience (USS Pintado SSN-672) and my WW2 Submarine book collection; I believe "collapse depth" to be the minimum depth at which you're in danger of losing the submarine. Its historically been specified to be 1.5 x Test Depth. On Pintado, "collapse depth" was listed as 1.5x test depth in the boat's manual. Based on some of my books regarding WW2 fleet boats, I believe a true crush depth to be around 1.9x to 2x of the test depth. The Silent Victory account of the Balao is data point #1. There is another account, also in Silent Victory, of the USS Salmon losing depth control in the midst of a depth charge attack and dropping down to 500 ft before the crew regained control of the boat. She obviously survived, but, was leaking heavily during the ordeal. In "Find 'Em, Chase 'Em, Sink 'Em" (a newer book about the USS Gudgeon - and the best researched WW2 submarine book I've ever read); the boat went too deep while evading an attack by a Q-ship on her 2nd war patrol in the East China Sea. The patrol report listed the max depth as 350 ft. Some of the crew members interviewed said the boat went as deep as 513 ft during this episode. Her skipper, Joe Grenfell, admitted - after the war - she reached 425 ft during this event. Whether it was 425 or 513, she was still seaworthy after the event with no flooding reported. The account of the USS Chopper (a Balao or Tench) surviving 1011 ft is another data point. During Tang's sea trials, O'Kane took her to 612 ft. I need to find some data on some of the Gatos with regard to the deepest recorded - or admitted - dives. Its pretty clear the 1.5x number is on the conservative side. However, I know of no submarine intentionally exceeding the 1.5x number. Many of the skippers were afraid to even go near the 1.5x number. Fluckey's normal evade depth in Barb (a Gato), was 375 ft. I believe once, he may have taken her to 415 or 425 ft. My impressions are that he was afraid to push her much deeper than 375.