SCORPION’s story and the necessity of security classification have fueled an unending speculation on the true causes of her loss. I was delighted to see Mr. Rule’s letter shed light on the definitive engineering analysis of the evidence found by Trieste from the disaster site. If I may, I would like to add some more facts and conjecture to the story.
From 1977 to 1980, I had the privilege of serving at Naval Reactors as an assistant to Mr. William Wegner. Curious, I reviewed the wreck photos from SCORPION’s and THRESHER’s gravesites that were routinely made as part of a continuing monitoring program. In 1983 after my XO tour on NATHANAEL GREENE, I received orders to USS SHARK. Needless to say the cause of SCORPION’s loss became more than idle curiosity and I read the Structural Analysis Group’s report while at NR PCO School.
Later, while in command, I noticed some characteristics of SHARK that I am sure SCORPION shared. First, her battery ventilation air flow was significantly below what I was used to on 637 class submarines, to the point that a detailed ventilation survey of the battery well had been conducted in order to raise the maximum hydrogen specification to 2.0% rather than what I thought was sacrosanct at 1.5%. The equalizing charge procedure allowing for the charge to be suspended and recommenced in one hour had seemed irrelevant to me, but on SHARK, we were rarely if ever able to complete one without suspending the charge, preparing to ventilate, ventilating for about 20 minutes, redoing the ventilation lineup and restarting the charge within that hour.
Something I saw on GREENE where over time the pressure in the boat would rise to significant levels led to speculation on the following scenario: Returning from deployment SCORPION probably was accomplishing the routine maintenance that had been difficult while in the Med. One item, the test discharge is a significant controller of dedicated time. Starting with an equalizing charge, the test and followed by another charge, I am certain that during the first charge her hydrogen concentration reached the 2% limit. On a transit with an SOA to maintain, particularly going home, the Captain and crew would be loath to spend more time at periscope depth than absolutely necessary, likely relying on oxygen candles and scrubbers for atmosphere control. If the pressure in the boat had risen, during the first equalizing charge, when SCORPION commenced ventilating or snorkeling, the pressure in the boat likely would immediately drop and the highly concentrated hydrogen inside the top of the battery cells would rush out of the flash arrestors. Many factors would need to combine to reach the 8% for an explosive concentration to be set off by the DC battery exhaust fan, but the plastisol evidence supports that it did. Though there are other explanations, the fact that SCORPION’s detached sail was photographed with masts and antennas raised, is consistent.
The Structural Analysis Group report goes on to detail the effects of the explosion (insufficient to breach the hull) on the lower level operations compartment deck and the attached negative tank flood valve actuator that would leave a 10 inch unisolable hole for sea water to quickly reach the destroyed battery cells. Burned mattress ticking recovered at the site supports the horror her crew faced: explosion directly under where the majority of the crew slept, attendant injuries, fire, unisolable flooding and high concentrations of toxic chlorine gas in the same compartment as the ship control station and radio. The casualty simply overwhelmed the crew and the sounds of her hull imploding about 22 minutes after the first recorded explosion gives testament to the gallant fight her remaining crew waged trying to save her.
On a personal note, one of the individuals I had the pleasure to serve with twice was the last man to leave SCORPION when she stopped in Gibraltar on the way out of the Med. An electrician’s mate, he never failed to impress me.
George W. Jackson