Navy Releases Latest Round of USS Thresher Documents

February 4, 2021 10:39 AM - Updated: February 4, 2021 1:12 PM

This week, the Navy released the fifth set of documents related to the April 10, 1963 loss of USS Thresher (SSN-593) and its crew of 129 sailors off the coast of New England.

A freedom of information lawsuit from retired Navy Capt. James Bryant, a former Thresher-class submarine commander, compelled the Navy to release the documents on a rolling basis.

The following is the fifth release from the Navy related to the FOIA suit. While the prior releases were proceedings of the 1963 court of inquiry following the 1963 loss of the attack boat, this release is the previously unclassified 1978 two-volume history, Sea-Based Airborne Antisubmarine Warfare 1940-1977. The document was part of Bryant’s original FOIA request. The so-called Cross report was declassified in 1990 and mentioned the original test depth of Thresher in passing as part of a short history of U.S. and Soviet 1960s era nuclear submarine programs.

The passage was referenced in Norman Friedman’s book, U.S. Submarines Since 1945, Revised Edition: An Illustrated Design History published by the Naval Institute.

“The shift to 1,300 feet in the THRESHER class has been widely publicized. An official declassified reference is R. F. Cross Assoc. Ltd., Sea-Based Anti-Submarine Warfare 1940 – 1977, 2:11 (report prepared for OP-95; originally Secret but declassified 31 December 1990),” reads a reference in Friedman’s book.

While unclassified in 1990, the Cross report could not be located by Bryant and was included in the FOIA lawsuit, he told USNI News on Thursday. In the latest release, the passage that mentioned the test depth was one of two redacted portions.

The other documents can be found here.

From the report

U.S. and Soviet Submarine Programs

During the very early sixties, the U.S. Navy introduced not only the hydrodynamically advanced Skipjack, but the Navy’s smallest nuclear powered ASW submarine, the 2,300-ton prototype Tullibee (SSN 597), carrying the first version of the BQQ-2 sonar system. The improvement in passive detection which this represented was incorporated in the larger Thresher (SSN 593) class which followed immediately.

Redacted portion of the unclassified Cross Report that included the test depth of Thresher during its 1963 loss.

From a strategic point of view, the five Fleet Ballistic Missile submarines of the George Washington class (SSBN 598) were followed immediately by the improved Ethan Allen (SSBN 608) class. The success of the nationally oriented, strategic deterrent Polaris program led to the first U.S . SSBNs going on patrol by mid-1960. The need for Polaris submarines in the North Atlantic and Mediterranean, where their relatively short range A-1 missiles could be effective, delayed Polaris deployment in the Pacific until the Daniel Boone (SSBN 628) made her first patrol in December 1964.

While the United States had terminated its cruise missile submarine construction programs along with the Regulus II missile development, the Soviets elected to continue development in this area. Early Soviet designs were very short range–under then current U.S. intelligence projections. The cruise missile carried by the Juliett and Echo classes, for example, was able to reach only 220 miles, while the range of the SS-N-4 ballistic missiles was a mere 350 nautical miles, this being extended in 1963 with the introduction of the 700 mile SS-N-5. This limitation forced Soviet operation close to the United States, increasing emphasis on the close-in SOSUS shallow water system then under development. In short, Soviet missile technology during this period lagged behind that of the U.S., all Russian missile systems requiring surface launch while the Polaris A-1 missiles, able to reach 1,300 nautical miles, could be fired from a submerged submarine.

USNI News has uploaded two versions of the document. One is the original scan of the pages provided by the Navy, the second is a word-searchable document. Processing the searchable document has left some difficult to read pages blank which can be seen in the original version.

Download the original version here.
Download the word-searchable document here.

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