S.S. Petrokure was built by National Bulk Carriers, Kure Shipbuilding Division, Kure, Japan in 1952. All four of these large tankers were built there before the end of 1953, and were the first ships constructed by National Bulk Carriers in the Kure shipyard that Daniel K. Ludwig had leased in 1950 in order to move shipbuilding operations to a location capable of building mammoth ships. Apparently, they were just warming up. By the end of 1954, the yard had produced nine ships, all over 38,000 tons, including three 60,000 ton ore ships. Before 1960, a total of 31 ships would be built there, including the first 100,000 deadweight ton oil tankers in the world. The hull numbering scheme was carried over from the numbering scheme used in the company’s old shipyard in Norfolk, Welding Shipyards, Inc. Thus Petrokure was Hull Number 29, continuing from the last number issued by Welding Shipyards. Again, surplus engines were used in the construction of these ships. Ludwig was excruciatingly frugal, and used surplus and scrap materials whenever he could to reduce costs. Of couse, the equipment was refurbished before installation, and was maintained to a high standard to reduce repair and operating costs too. As may be noted below, these ships had quite an acceptable service life, one of them serving for over 25 years before being scrapped. Also note the thin stack, another trademark of the Ludwig ships.
| Ship | Hull# | Built | GRT | DWT | Length | Beam | Comments |
|---|---|---|---|---|---|---|---|
| Petrokure | 29 | 1952 | 21,262 | 38,021 | 673′ | 92’4″ | Again, largest tanker built when launched. Engine made 1945, fitted 1952. Renamed Gem Pet c.1965, Medusa c.1970. |
| Petroking | 30 | 1953 | 21,240 | 38,045 | 673′ | 92’4″ | Renamed Gem Star c.1970. Engine made 1944, fitted 1953. Scrapped 1975. |
| Petroqueen | 31 | 1953 | 21,240 | 38,073 | 673′ | 92’4″ | Engine made 1944, fitted 1953. Scrapped 1975. |
| Petroemperor | 32 | 1953 | 21,240 | 38,047 | 673′ | 92’4″ | Engine made 1944, fitted 1953. Renamed Gorgona 1967, Dorcas 1970, Burmah Lapis 1971. Probably scrapped in 1979/80. |
