The naval oceanographic research ship USNS H. H. Hess T-AGS-38 was originally built as the general cargo ship Canada Mail for the American Mail Line in 1965. The ship, a MARAD design type C4-S-1a hull, was built by the National Steel and Shipbuilding Company in San Diego for the Maritime administration as MA hull 154, and launched on May 30, 1964. The Canada Mail was the fifth of a series of vessels built to replace the line’s World War II-era tonnage.  It was placed into service in March 1965. American Mail Line operated between the Pacific Northwest and ports in Japan, Korea, Taiwan, Okinawa, the Philippines, Hong Kong, and Vietnam.  Cargoes bound for the East Asia were usually loaded in Vancouver, British Columbia; Seattle, Tacoma, and Longview, Washington; and Portland, Oregon.  The Canada Mail was built as the containerization revolution was still getting underway.  Aside from possible stowage on deck, no provision was made in its design for the transport of standardized cargo containers, and it remained a purely break-bulk cargo ship while in commercial service.  SS Canada Mail also had provisions for a small number of passengers. (1,2,3)

In December 1973 the ship was briefly chartered by the Navy’s Military Sealift Command (MSC).  In 1974 it was “traded in” to the Maritime Administration and placed in the Reserve Fleet in Suisun Bay, California.   Two years later the Canada Mail was acquired by MSC for conversion to an oceanographic research ship.  Hess was intended to replace USNS Michelson T-AGS-23, which was declared unfit for sea by the USCG ca. 1975 while in port in Japan.  Much of Michelson's oceanographic research equipment was transferred to Hess. Oceanographic Unit Three, previously embarked aboard USNS Michelson, was transferred to Hess. Alterations resulting from the conversion were largely internal and below the waterline.  Outwardly, the vessel appeared little changed.  It was renamed  USNS H. H. Hess in honor of the geologist Harry Hammond Hess(6) and designated T-AGS-38. The ship’s new role was deep ocean research.  It was expected to stay at sea for as long as 34 days, charting the ocean’s topography and other features using multi-beam sonar.    Much of this work was done in support of the Fleet Ballistic Missile Submarine Program.  The Hess served the Navy for nearly 20 years.  In 1992, Hess was removed from service and placed in the Suisun Bay Reserve Fleet.  The ship was declared non-retention in 1994.  In February of 2011, USNS Hess began towing from Suisun Bay, California to Brownsville, TX for disposal.  (1)

Displacement: 13,521 Tons (light)
Length Overall: 563'-6"
Beam: 76 ft.
Draft: 27 ft.
Speed: 20 kts.
Propulsion: Steam turbine, single shaft.
19,250 shaft hp 


(1)  Modified from: