The three ships President Polk , President Monroe and President Harrison of the US shipping company American President Lines were fundamentally rebuilt twice during their service life. They were built in 1965/66 and were given the MARAD designation C4-S-1qa . The shipping company gave them the name Master Mariners (German roughly: captain on a long voyage), which at the same time indicated their origin and further development of the Mariner class . After the first conversion to semi-container ships, they were given the abbreviation C6-S-1qc . In the third part of their career, they still serve the Military Sealift Command of the United States Navy as auxiliary crane ships of the Keystone State class with the MARAD designation C6-S-MA1qd .
The three turbine general cargo ships were originally built in 1965/66 at the National Steel and Shipbuilding Company in San Diego. Soon after it was put into service, the future importance of the container in merchant shipping became obvious, whereupon the trio of ships was sent to the Todd Shipyards in Seattle, Washington in 1972/73, where they were extended by around 32 meters and to semi-container ships of the MARAD type C6-S -1qc were rebuilt. In the period from September 1972 to February 1973, the ships came back into service. In the period from April 1979 to October 1982, the shipping company returned the ships to the United States Maritime Administration (MARAD) under the terms of the Merchant Marine Act of 1936 , which assigned them to the Suisun Bay Reserve Fleet between May 1980 and July 1982. In 1986/87 the USNavy took over the ships and had them converted to auxiliary crane ships of the Marad Design C6-S-MA1qd type at the Defoe Shipbuilding yard in Bay City, Michigan. Today the three ships are part of the Ready Reserve Fleet and are under the Military Sealift Command.
technology
The C-4-S-1qa design represented a contemporary general cargo ship design with a slightly streamlined bridge house just behind the center of the ship, a heavily protruding stem with a bulbous bow and a cruiser stern.
The layout of the holds was that of a conventional general cargo ship, but in many ways had modern details. The hatch covers with a large degree of deck opening on the main deck, in conjunction with the large hydraulic tween deck hatches, were intended to ensure problem-free vertical access to the cargo. The transhipment facilities consisted of contemporary loading trees. The ships had five holds, some of which were designed for refrigerated cargo, and deep tanks for liquid cargoes. The superstructures were completely air-conditioned. The type of ship reached speeds of a good 20 knots thanks to its geared steam turbine drive.
After the first conversion to a semi-container ship, which was carried out by installing a 32-meter-long central ship section, the ships could again be described as contemporary for a limited period of time.
The last conversion on behalf of the US Navy changed the ships one more time. In the mid-1980s, the units were adapted to the new military requirements, among other things by installing six powerful 30-tonne ship cranes with a large outrigger and 60-tonne lifting capacity in the Gemini operation. With the new loading gear , it was now possible to handle heavy loads, such as tanks, or the cargo handling of other ships without their own loading gear.
Overview
Master Mariners
Commissioning
Shipyard / construction number
Building name
Renaming and whereabouts
1965
National Steel and Shipbuilding Company / 338
President Polk
1972/73 converted to a semi-container ship, 1984 → Grand Canyon State , 1986 → conversion to the auxiliary crane ship Grand Canyon State (T-ACS 3) of the MSC / RRF
1966
National Steel and Shipbuilding Company / 339
President Monroe
1972/73 converted to a semi-container ship, 1984 → Gem State , 1986 → conversion to the auxiliary crane ship Gem State (T-ACS 2) of the MSC / RRF
1966
National Steel and Shipbuilding Company / 340
President Harrison
Converted to a semi-container ship in 1973, launched NDRF in 1982, 1984 → Keystone State , 1987 1984 → converted to the auxiliary crane ship Keystone State (T-ACS 1) of the MSC / RRF
