The Hughes Mining Barge, or HMB-1, is a submersible barge about 99 m (324 ft) long, 32 m (106 ft) wide, and more than 27 m (90 ft) tall. The HMB-1 was originally developed as part of Project Azorian (more widely, but erroneously, known as "Project Jennifer"), the top-secret effort mounted by the Central Intelligence Agency to salvage the remains of the Soviet submarine K-129 from the ocean floor. The HMB-1 was designed to be submerged under the Glomar Explorer to conceal any salvaged remains from Soviet observers.[1]
After the conclusion of Project Azorian, the HMB-1 was mothballed at the Todd Shipyard in San Francisco, California until November, 1982. At that time, the United States Navy towed the huge barge to a Lockheed Martin facility in Redwood City, California, where it became a floating drydock for the construction and sea trials of the Sea Shadow, an experimental stealth ship being tested by the Navy. Sea trials of the Sea Shadow continued until 1986.[1][2]
The HMB-1 currently sits along with the Sea Shadow - which is still docked inside the vessel - in the National Defense Reserve Fleet at Suisun Bay, California.