Seawise Giant
TT Seawise Giant—formerly Oppama; later Happy Giant, Jahre Viking, Knock Nevis, and Mont—was a ULCC supertanker and one of the longest self-propelled ships in history, with only the Prelude FLNG surpassing her. She was built in 1974–1979 by Sumitomo Heavy Industries in Yokosuka, Kanagawa, Japan. The ship possessed the greatest deadweight tonnage ever recorded. Fully laden, her displacement was 657,019 tonnes.
At the time she was built, she was the heaviest self-propelled ship of any kind. With a laden draft of and a length of, she was incapable of navigating the English Channel, the Suez Canal or the Panama Canal. She is generally considered the largest self-propelled ship ever built. In 2013, her overall length was surpassed by by the floating liquefied natural gas installation Shell Prelude, a monohull barge design long with 600,000 tonnes displacement. Seawise Giant's engines were powered by Ljungström turbines.
She was damaged in an airstrike in 1988 during the Iran–Iraq War but later repaired and restored to service. The vessel was moored off the coast of Qatar in the Persian Gulf at the Al Shaheen Oil Field in 2004 and converted to a floating storage and offloading unit.
Seawise Giant was sold to Indian ship breakers and renamed Mont for her final journey in December 2009. After clearing Indian customs, the ship sailed to Alang [Ship Breaking Yard] in Alang, Gujarat and beached for scrapping, which was completed in 2010.
History
Seawise Giant was ordered in 1974 and delivered in 1979 by Sumitomo Heavy Industries, Ltd. at Oppama shipyard in Yokosuka, Kanagawa, Japan, as a 418,611-ton Ultra Large Crude Carrier. The vessel remained unnamed for a long time, and was identified by its hull number, 1016. During sea trials, 1016 exhibited severe vibration problems while going astern. The unknown Greek owner refused to take delivery and the vessel was subject to a lengthy arbitration proceeding. Following settlement, the vessel was sold and named Oppama by S.H.I.The shipyard exercised its right to sell the vessel and a deal was brokered with Hong Kong Orient Overseas Container Line founder C. Y. Tung to lengthen the ship by several metres and add 146,152 tonnes of cargo capacity through jumboisation. Two years later the ship was relaunched as Seawise Giant. "Seawise", a pun on "C.Y.'s", was used in the names of other ships owned by C.Y. Tung, including Seawise University.
After the refit, the ship had a capacity of, a length overall of and a draft of. She had 46 tanks, and of deck space. When Seawise Giant was fully loaded, her 25 meter/81 foot draft was too deep to safely navigate the relatively shallow English Channel. The rudder weighed 230 tons, and the propeller weighed 50 tons.
Seawise Giant was damaged in 1988 during the Iran–Iraq War by an Iraqi Air Force attack while anchored off Larak Island, Iran on 14 May 1988 while carrying Iranian crude oil. The ship was struck by two 1,000 kg bombs dropped from planes. Fires ignited aboard the ship, spreading to the oil leaked into the surrounding water and blazing out of control. Contrary to some later internet reports the vessel did not sink; images of the burnt-out but still afloat vessel have been published online.
After the fires were extinguished, the remaining cargo was discharged to other tankers. The ship was declared a constructive total loss, meaning she was intact but so damaged that she would not be economical to repair.
Shortly after the Iran–Iraq war ended, a Norwegian investment firm managed by Finanshuset bought the damaged vessel, which had by then been towed to a lay-up location off Labuan. The manager was Norman International AS, a Norwegian ship manager that was subsequently dissolved in 1992. The vessel was then towed from Labuan to Singapore and repaired at the Keppel Corporation. She was renamed Happy Giant, in line with Norman International's tradition of naming tankers with the prefix «Happy» and bulkers with the prefix «Norman». She re-entered service in October 1991.
Jørgen Jahre bought the tanker in 1991 for US$39 million and renamed her Jahre Viking. From 1991 to 2004, she was owned by various Norwegian investment firms and flew the flag of Norway.
In 2004, the tanker was purchased by First Olsen Tankers, renamed Knock Nevis, and converted into a permanently moored storage tanker in the Qatar Al Shaheen Oil Field in the Persian Gulf.
Knock Nevis was renamed Mont and reflagged to Sierra Leone by new owners Amber Development for a final voyage to India where she was scrapped by Priya Blue Industries at Alang. The vessel was beached on 22 December 2009. Due to the vessel extreme size, scrapping took until the end of 2010. The ship's 36 tonne anchor was saved and donated to the Hong Kong Maritime Museum in 2010. It was later moved to a Hong Kong Government Dockyard building on Stonecutters Island.
As of 20 November 2025, the anchor of the Seawise Giant is now on public display in the newly opened Anchor Plaza outside piers 9 and 10 of Central Ferry Pier.
Size record
Seawise Giant was the longest ship ever constructed, at, longer than the height of many of the world's tallest buildings, including the Petronas Towers.Despite her length, Seawise Giant was not the List of [largest ships by gross tonnage|largest ship] by gross tonnage, ranking sixth at 260,941 GT, behind the crane ship Pioneering Spirit and the four 274,838 to 275,276 GT Batillus-class supertankers. She was the longest and largest by deadweight at 564,763 tonnes.
Seawise Giant was featured on the BBC series Jeremy Clarkson's Extreme Machines while sailing as Jahre Viking. According to the captain Surrinder Kumar Mohan, the ship could reach up to in good weather. It took for the ship to stop from that speed, and the turning circle in clear weather was about.