The Loss of USS Scorpion
(Well, worth the read)
May 22, 2011 marks 43 years since the tragic loss of USS Scorpion, the second of two U.S. nuclear submarine losses. To date, many theories have been put forth, but the Navy has never provided a definitive cause for Scorpion's loss. So, what did happen?
USS Scorpion, SSN 589, fifth ship of the Skipjack class was lost with all hands on May 22, 1968 while enroute back to her home port in Norfolk Virginia. Scorpion was due to arrive in Norfolk on 27 May. For hours after the scheduled time of arrival, anxious family members, friends and Navy officials awaited in the driving rain and wind for any appearance of the overdue ship. Gradually they all drifted home; word came out later that the sub was missing and on 5 June, after searching for nine days, the Navy declared the ship lost and its crew all dead.
The wreckage of the ship was located on 28 October, 1968, approximately 400 nautical miles south west of the Azores in water deeper than 10,000 feet. Initial photographs of the wreckage showed that the torpedo room, while largely intact, was sheared off from the rest of the ship; the operations compartment had disintegrated; fifty feet of the stern had telescoped into the pressure hull and the sail had been sheared off.
A Court of Inquiry COI was convened to attempt to determine what had caused the loss of Scorpion but failed to come to a definitive conclusion.
Over the years, beginning with testimony before the COI many theories have been expounded as to cause of the loss. An early theory, promoted by Dr. John P. Craven, then Chief Scientist for the Navy's Special Projects Office, was that Scorpion was lost due to explosion of one of its own MK37 torpedoes. The COI, in fact, although it did not draw any conclusion as to loss of Scorpion, did state as an opinion that a large explosion occurred external to the hull and was recorded as acoustic event number one. (More about the acoustic events later.) Dr. Craven has in later years distanced himself from the theory of a torpedo explosion causing loss of the ship.
There have been at least two books written postulating loss of Scorpion being caused by a Soviet torpedo either submarine launched or dropped from a helicopter.
There is even one far out theory which postulates that the propeller threw a blade while the ship was operating at high speed; the imbalance of the shaft due to loss of the propeller blade then causing catastrophic failure of the propulsion clutch and shearing of the shaft and then the ejection of the shaft from the ship. Finally the resulting flooding through the shaft penetration caused the ship to sink.
All of these theories have been debunked either through lack of credible evidence for their support or by analysis of available photographic evidence and acoustic recordings which points in other directions.
So, what did happen? Mr. Bruce Rule of Louisville KY believes he knows the answer and has produced some documentation to validate his claim. As to his bona fides, Mr. Rule was, for over 40 years, lead acoustic analyst for the Office of Naval Intelligence. Please note, ONI was not involved in any of this analysis, rather Mr. Rule has performed detailed analysis pro bono of acoustic recordings that have been available in the public domain for over 40 years.
This article will present results and some discussion of his work without going into excessive technical detail. All of his notes are available in the Submarine Force Library for anyone who wishes to study further.
Mr. Rule bases his conclusion on analysis of Scorpion acoustic data and associated Navy documents over about a two year period of time. Included in this analysis were original Columbia University Hydroacoustic Station Canaries (CUHSC) and Sound Surveillance System (SOSUS) array 3141 detections of acoustic signals associated with the loss of Scorpion. According to Mr. Rule, exploitation of these recordings has provided important new information on the cause of the event and what did not cause the event.
According to Mr Rule's analysis the initiating events that resulted in the loss of Scorpion were two low order explosions contained within the pressure hull within a half second period at 18:20:44Z on 22 May 1968. He concludes based upon reanalysis of acoustic signals detected by multiple seafloor sensors on both sides of the Atlantic that the following occurred:
- "The initiating events responsible for loss of Scorpion were two explosions that occurred about 0.5 seconds apart at 18:20:44Z on 22 May and were contained within the pressure hull."
- "These explosive events prevented the crew from maintaining depth control. Scorpion sank to a depth of 1530 feet at which depth the pressure hull and all internal bulkheads collapsed at 18:42:34Z in 0.1 seconds with a force equal to the explosion of 13,200 lbs. of TNT."
- "During the 111.6 second period when it was conjectured in 1968 that Scorpion had reversed course to deactivate a MK-37 torpedo that had become active in its launch tube, the already-fragmented hulk was sinking at about 12 knots with a displacement of no more than 100 feet from the vertical."
- "During the 200 second period following pressure-hull collapse, 17 additional acoustic events were detected. These events were produced by small, more pressure resistant structures that survived within the wreckage to collapse at greater depth. Six of these events were produced by the collapse of the Scorpion torpedo tubes at depths between 3400 and 4600 feet."
Mr. Rule also concludes there were no explosions external to the pressure hull from any source.
Mr. Rule attributes the initiating events discussed above to explosions in the ship's TLX-53-A main storage battery. Said assessment is based upon "examination and microscopic, spectrographic and X-ray diffraction analyses of recovered Scorpion battery material that confirm an explosion occurred" and "July 2008 reanalysis of the Scorpion "precursor" acoustic signals that identified these signals as explosions contained within the Scorpion pressure hull."
Detailed analysis of the recovered battery components showed that the battery explosions occurred before the battery well was flooded and therefore before hull implosion.
Therefore, Mr. Rule concludes that the initiating event resulting in loss of Scorpion was one, likely two, nearly simultaneous explosions in the ship's main storage battery. This resulted in loss of capability to maintain depth control and the ship slowly sinking until it reached a depth of 1530 feet, at which depth the hull imploded destroying the ship and instantly killing all hands onboard. No conspiracies, no Soviet attack, no torpedo hot run, but a tragic accident.
Mr. Rule has requested, in writing to CNO Admiral Gary Roughead in May 2010, that the Navy take action to declassify and release material related to loss of Scorpion so that this information may be available to the public. To date the material still has not been released.
