National Security & Defense

unhappycamper

(60,364 posts) Fri Apr 11, 2014, 09:27 AM Apr 2014

The loss of the Thresher: Why it should be remembered every year

http://www.latimes.com/business/hiltzik/la-fi-mh-thresher-20140410,0,7696563.column

The U.S. nuclear submarine Thresher, underway during early trials in 1961.

The loss of the Thresher: Why it should be remembered every year
By Michael Hiltzik
April 10, 2014, 10:17 a.m.

~snip~

On April 9, 1963, the Thresher cast off from Portsmouth. About 25 hours later, it began its test dives off the continental shelf, far deeper than could be reached by its escort's rescue equipment. At 8:53 a.m. on April 10, the Thresher radioed to the escort that it was proceeding to its test depth of 1,300 feet. Twenty minutes later a calm voice radioed, "Experiencing minor difficulties ... Attempting to blow" -- that is, to blow water from its ballast tanks with compressed air in an effort to surface.

The next few transmissions were garbled. Soon after that one of the radio operators heard a sound he thought he recognized -- the sound of a ship breaking up. Three and a half hours later, the Thresher was declared lost.

The Navy investigation concluded, on necessarily scant evidence, that an electrical failure possibly caused by a water leak had caused the Thresher's reactor to shut down. Its efforts to surface by blowing ballast were confounded by ice forming in its ballast valves at great depth, freezing the valves. When it sank to about 2,400 feet, its hull imploded in a split second.

But the real cause of the sinking was haste, which led the Navy to ignore accumulating problems in design, construction and operating procedures. Rickover lectured the investigative board that "the real lesson to be learned is that we must change our way of doing business to meet the requirements of present-day technology."