Longest ship ever built

What to remember

Between 1974 and 1979, Sumitomo Heavy Industries built a supertanker at Yokosuka, Japan, that would go through a string of names: Oppama, Seawise Giant, Happy Giant, Jahre Viking, Knock Nevis and finally Mont. The ship did not start out at record size. It was originally smaller, and a jumboisation stretched it to 458.46 m overall.

That figure is the length overall, measured between the extreme points fore and aft. At that size the Seawise Giant also set the records for displacement, 657,019 tonnes fully laden, and for deadweight tonnage, 564,650 DWT. With a laden draft of 24.6 m, it could not use the English Channel, the Suez Canal or the Panama Canal. Its engines were powered by Ljungström turbines.

Only self-propelled ships count, which is why the 488 m Prelude FLNG floating structure is left out. The tanker was in service from 1979 to 2009 and was scrapped in India in 2010.