General Discussions
This is the place to discuss general issues related to the U-boat war or the war at sea in WWII.
Re: U-boats attacked by allied submarines
Posted by:
ROBERT M.
()
Date: February 23, 2005 05:28AM
J.T., Rainer, et al:
I located the info on the steel plate used on the BALAO-class
fleet boats. "Another change in the BALAO-class was the change in the material used for (pressure) hulls. High tensile steel was a
chronium-vanadium alloy with a maximum tensile strength of
50,000 psi with 20% elongation. When the composition was changed to titanium-manganese alloy, because of wartime shortages, the strength dropped to 45,000 psi. The thick-skinned came along in 11942 with test depth of 412 feet. These boats had
the same 7/8ths-inch thick hull as SALMON-classs, but the quality of the hull steel ie., high tensile steel had significantly improved.
The "crush depth" of these boats was estimated to be around 450 feet."
I posted this information in General Discussions on 11/04/04 12:12
addressed to Rainer, and provided the following URL:
[www.submarineresearch.com]
Explanation of the 412-foot maximum operating depth of the BALAO-class follows: "Test Depth" or maximum allowable operating depth was 412 feet. Actual test depth for the hull was 400 feet - figured at the center of the pressure hull. The pressure hull was 16 feet in diameter. To 1/2 of the hull diameter was added the distaance from the pressure hull to the bottom of the keel beneath the tanks. That was about 4 feet. So, to 400 feet was added 8 feet + 4feet = 412 feet keel depth which was what was
read on the depth guages at the diving station in the Control Room."
The 4-page document I refer you to above explains more than I have mentioned here; ckeck it out, OK?
And have a great day,
ROBERT M.
I located the info on the steel plate used on the BALAO-class
fleet boats. "Another change in the BALAO-class was the change in the material used for (pressure) hulls. High tensile steel was a
chronium-vanadium alloy with a maximum tensile strength of
50,000 psi with 20% elongation. When the composition was changed to titanium-manganese alloy, because of wartime shortages, the strength dropped to 45,000 psi. The thick-skinned came along in 11942 with test depth of 412 feet. These boats had
the same 7/8ths-inch thick hull as SALMON-classs, but the quality of the hull steel ie., high tensile steel had significantly improved.
The "crush depth" of these boats was estimated to be around 450 feet."
I posted this information in General Discussions on 11/04/04 12:12
addressed to Rainer, and provided the following URL:
[www.submarineresearch.com]
Explanation of the 412-foot maximum operating depth of the BALAO-class follows: "Test Depth" or maximum allowable operating depth was 412 feet. Actual test depth for the hull was 400 feet - figured at the center of the pressure hull. The pressure hull was 16 feet in diameter. To 1/2 of the hull diameter was added the distaance from the pressure hull to the bottom of the keel beneath the tanks. That was about 4 feet. So, to 400 feet was added 8 feet + 4feet = 412 feet keel depth which was what was
read on the depth guages at the diving station in the Control Room."
The 4-page document I refer you to above explains more than I have mentioned here; ckeck it out, OK?
And have a great day,
ROBERT M.
