Dutch newspapers published in September 1975 a small news item including an illustration dealing with a design made by the Norwegian shipyard Aker for an arctic tanker. The news items however differs. She had a knife shaped bow with the intention to plough through ice with a thickness of 3,5 metres. The major part of the cigar shaped hull was submerged. There were two main structures. The one at the bow included bridge and accommodation facilities for the crew. The one at the stern the propulsion. She was to be used on the oil transport line between Alaska and the USA via the Northern Sea. Cargo capacity was 230.000 ton crude oil. Permanent she was ballasted with 40.000 ton to preserve her stability. To become semi submersible was another 60.000 ton water stored. The NRC Handelsblad mentioned a tanker icebreaker of 250.000 tons with a push-break power of at least 40.000 tons far more stronger than any existing ice breaker. The type was called a SSIT with a double keel sharp like knives. The building costs however were twice of the conventional tanker namely 126 against 51 million US dollars. The designer however received until none orders for building such design.
On a website dealing with projects never realized was also an item published about this design, partly based on the Aviation&Marine magazine of April 1976. There were not just one but three designs made by the shipyard, one for a conventional and two semi-submerged. The abbreviation SSIT stands for Semi-Submarine Icebreaking Tanker. With a deadweight of 150.000 tons, light ship weight 1110.000 tons and maximum displacement 420.000 tons were her dimensions 300 (between perpendiculars)-360 (over all)x x 54 (moulded) x 42.5 (moulded depth) x 37,5 (maximum draught) metres. The wetted surface was 43.600 metres. Horsepower 125.000 shp. The design dated however from the period 1970-1971. In the 1970s were more designs made of ice breaking tankers for instance one of Robert Melling Stephens, patent dated 30 October 1973 for one with s.s. Manhatan proportions.
Note
1.The ss Manhattan was built as a conventional tanker by the Fore River Yard in 1962 but fitted out with an icebreaker bow in 1968-1969 to be used in Arctic waters in the Northwest Passage. The conversion was a result of a co-operation between Esso and Wärtsilä.
Sources
Dutch newspaper Algemeen Dagblad dated 25 September 1975
Dutch newspaper NRC Handelsblad dated 23 September 1975
Dutch newspaper Leeuwarder courant dated 12 September 1975
websites
Secretprojects
Aker Arctic
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