Built by Sun Shipbuilding and Dry Dock Company in Chester, Pennsylvania, for Global Marine and launched in 1972, the 51,000-ton Glomar Explorer was purportedly constructed as a deep-sea mining vessel to recover manganese nodules from the ocean floor. It had a large interior well to house Hughes Mining Barge 1. Commonly known as HMB-1, this was a submersible barge designed to carry the large claw for the recovery effort and also to house and hide the submarine when recovered. The cost of all this came to some $200 million.
The Glomar Explorer displaced 50,500 tons and was some 619 feet in length with a beam of nearly 116 feet. The large center well or moon pool provided access to the sea and accommodated the robotic claw. The vessel incorporated technological innovations, including both thrusters and a heave compensator to limit the motion of the ship during salvage operations.
The ship went to sea in late June 1974 and began operations on 4 July. It soon located the sunken submaine. The Soviets watched the operation during the next month but did not attempt to interfere. Accounts differ sharply as to jennifer's success. Some hold that only the forward 38 feet of the submarine was actually recovered, with two nuclear-tipped torpedoes, encoding equipment, and the bodies of eight Soviet seamen (which were then buried at sea). Other reports dispute even this success. Efforts to secure information regarding CIA involvement in the salvage operation have been denied under Freedom of Information Act restrictions.
In any case, the operation was blown in 1975 when the news media learned of it. The Glomar Explorer was transferred to the navy and designated AG-193. It was then laid up at Suisun Bay, California. The government tried to sell the ship without success, and it remained in mothballs until 1996 when Global Marine leased the vessel for a thirty-year period, converting it to drill for oil off the West African coast at a maximum depth of 7,800 feet. MMB-1 was also laid up but was converted in the 1990s from a submersible barge into a covered floating dry dock to serve as the mother ship for the stealth ship Sea Shadow.
Spencer C. Tucker
Varner, Roy. A Matter of Risk: The Incredible Inside Story of the Mission to Raise a Russian Submarine. New York: Random House, 1978.