Tuesday, December 11, 2007

Curious Facts from the Submarine's Political and Physical Operating Environments

UPDATE: January 1, 2008 - Ship safety - As a retired submarine officer, it is my experience that all piping systems (many of which are subject to sea pressure) follow well-established procedures and testing, with no exceptions. None! - T.J. Smith, Williamsburg

Since US submarines spend 95 percent of their time operating in waters deeper than their hull crush depths, escape or rescue prospects have been largely a 5% fiction for the comfort of wives and mothers.
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The pressure on a submarine's hull increases with depth, by 44.45 pounds per square inch for every 100 feet of additional depth in salt water. Submarine designers define safety margins (150% US, 175% UK, and 200% German) for key depth benchmarks: Test Depth and Crush Depth. Obviously, it is well to stay within these envelopes, if possible.

Most military submarine hulls are constructed of special steel alloys (titanium has also been used, notably by Russia). Prior to 1936, (SS-182) U.S. submarines has riveted hull plates. So did the 1860's Hunley. Soviet Alfa submarines, constructed of titanium, reportedly had an operating depth of nearly 4,000 feet, according to Global Security.

The bitterness of poor quality lingers long after the sweetness of meeting a schedule is forgotten. - CAPT (s) S.E. Iwanowicz, USN, Director of Submarine Safety & Quality Assurance, Naval Sea Systems Command.
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December 11, 2007 - Problems discovered with submarine welds
The wrong filler materials [ed. undermatched welding] were used during welding, sparking an investigation into all Virginia-class subs. ... inadequate processes at the Newport News shipyard allowed the improper use of a weld material that could lead to cracking of joints and result in leaks, according to a Navy statement. The SUBSAFE program is still in force.

August, 2006 - Los Angeles class attack subs (most of present fleet) -maximum straight line walking distance aboard: 15 feet. Human density: 1.6 per linear foot. Installed: 1,500 miles of electric cables; 150 miles of piping.

April 23, 2006 - Undermatched welding for HY 100 pressure hull applications had been approved. Future testing would still be necessary before HSLA 100 could be approved. What "undermatched" welding means. The SUBSAFE program is still in force.

February, 2005 - MOA between NASA and NAVSEA for NASA Benchmarking of NAVY SUBSAFE

February 1, 2003 - The Space Shuttle Columbia disintegrated during re-entry over Texas, on its 28th mission (7 crew members perished).

January 28, 1986 - Breakup during launch of the Space Shuttle Challenger (7 souls perish).

February, 1980 - My decision to register women confirms what is already obvious throughout our society-that women are now providing all types of skills in every profession. The military should be no exception. - Jimmy Carter, 39th (and only submariner) US President

May 22, 1968 - USS Scorpion (SSN-589) lost with all hands (99 men). The SUBSAFE program is still in force.

February, 1967 - Scorpion entered the Norfolk Naval Shipyard for another extended overhaul. The cost of that last overhaul was only one-seventh of those given other nuclear submarines at the time. She got only emergency repairs to get her back on duty as soon as possible, not the Submarine Safety Program requirements implemented after the loss of USS Thresher. The SUBSAFE program is still in force.

December, 1963 - Initial Submarine Safety Certification Criteria (SUB SAFE) promulgated. Among many other quality improvements SUBSAFE was intended to provide maximum reasonable assurance of hull integrity and operability of critical systems to control and permit recovery from a flooding casualty. SUBSAFE intensified structural inspections -- particularly hull welding inspections using ultrasonic testing. From 1915 to 1963, the United States Navy had lost 16 submarines to non-combat related causes. From the beginning of the SUBSAFE program in 1963, only USS Scorpion (SSN-589), has been lost (May, 1968). USS Scorpion had NOT been SUBSAFE certified.

April 10, 1963 - USS Thresher SSN-593 lost (129 men) - Catastrophic flooding of the engine room; loss of propulsion and electrical control; unable to blow ballast tanks.

October, 1928 - Free speech does not live many hours after free industry and free commerce die. -Herbert Hoover, 31st (and only engineer) US President



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