Station HYPO

Celebrating the Past, Present and Future of Navy Cryptology


April 2021

Honoring Cryptologic Limited Duty Officer, Past and Present

It is hard to say when the Cryptologic Limited Duty Officer (LDO) was first established, but to give you an idea of the history, the first LDO promoted to Captain was Albert Ross. He received his LDO commission in 1970 – 51 years ago.

On April 6, 2021, the cryptologic LDO program was officially terminated.  Because of the huge influence LDOs contributed to the navy and the cryptologic community throughout the years, it is only right to recognize these officers who served or is serving “Up from the Ranks” as an LDO (644X/681X).

Honor these cryptologic LDOs you served with in the comments below.

Remembering USS Thresher (SSN 593)

On April 10, 1963, the USS Thresher (SSN 593) sank during deep-diving tests about 220 miles (350 km) east of Boston, Massachusetts, killing all 129 crew and shipyard personnel aboard. Her loss was a watershed for the U.S. Navy, leading to the implementation of a rigorous submarine safety program known as SUBSAFE. The first nuclear submarine lost at sea, Thresher was also the first of only two submarines that killed more than 100 people aboard; the other was the Russian Kursk, which sank with 118 aboard in 2000.

After hearing about the disaster, the young son of skipper CDR John Harvey made this crayon drawing of the sub lying on the ocean floor. The drawing is now in the collection of the U.S. Navy Museum in Washington, D.C.

http://1963 USS Thresher Investigation: Rickover Testimony

Source: U.S. Naval Institute

USS Northampton (CLC 1) Decommissioned, April 8, 1970

In April 8, 1970, the “Doomsday Ship” USS Northampton (CLC 1) was decommissioned. Laid down as a heavy cruiser in 1944, the Northampton was converted into a command ship that would serve as the “Floating White House” to direct a retaliatory strike in the event of a nuclear attack. The Northampton alternated deployments with the Saipan-class carrier USS Wright which also had been converted into a strikeback command ship.

Continue reading “USS Northampton (CLC 1) Decommissioned, April 8, 1970”

Remembering the crew of PB4Y-2 Privateer

71 years ago today, 10 crewmen of PB4Y-2 Privateer 59645 were the first to be MIA during the Cold War.  It is the official position of the United States Government that all or some of these men were captured and held in the Soviet Gulag. 

Continue reading “Remembering the crew of PB4Y-2 Privateer”

Thanks to SIGINT Japanese Battleship was Sunk

On April 7, 1945 the Yamato, a Japanese battleship, sunk off Okinawa, largely due to SIGINT tipoffs. Yamato was the lead ship of the Yamato class of Imperial Japanese Navy World War II battleships.

Continue reading “Thanks to SIGINT Japanese Battleship was Sunk”


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