Seawise Giant

TT Seawise Giant—earlier Oppama; later Happy Giant, Jahre Viking, Knock Nevis, and Mont—was a ULCC supertanker that was the longest self-propelled ship in history, built in 1974–1979 by Sumitomo Heavy Industries in Yokosuka, Kanagawa, Japan. She possessed the greatest deadweight tonnage ever recorded. Fully laden, her displacement was 657,019 tonnes.

Knock Nevis.jpg
TT Knock Nevis, formerly Seawise Giant, leaving the Dubai Drydocks
  • Seawise Giant (1979–1991)
  • Happy Giant (1991)
  • Jahre Viking (1991–2004)
  • Knock Nevis (2004–2009)
  • Mont (2009–2010)
  • Amber Development (2009–2010)
  • First Olsen Tankers Pte. (2004–2009)
  • Loki Stream AS (1991–2004)
OperatorPrayati Shipping (2009–2010)
Port of registryNorway (1980–2010)
Out of service2009
FateScrapped in 2010
General characteristics
TypeCrude oil tanker
  • 260,941 GT
  • 214,793 NT
  • 564,763 DWT
  • 81,879 long tons light load
  • 646,642 long tons full load
Length458.45 m (1,504.10 ft)
Beam68.6 m (225.07 ft)
Draft24.611 m (80.74 ft)
Depth29.8 m (97.77 ft)
Speed16.5 knots (30.6 km/h; 19.0 mph)
Capacity4.1 million barrels

The heaviest self-propelled ship of any kind, and with a laden draft of 24.6 m (81 ft), she was incapable of navigating the English Channel, the Suez Canal or the Panama Canal. Overall, she is generally considered the largest self-propelled ship ever built.[5][6] In 2013 her overall length was surpassed by 30 m by the Floating Liquified Natural Gas installation Shell Prelude (FLNG), a monohull barge design 488 m long and 600,000 tonnes displacement. Seawise Giant's engines were powered by Ljungström turbines.

She was sunk in 1988 during the Iran–Iraq War, but was later salvaged and restored to service.[7] The vessel was converted to a floating storage and offloading unit (FSO) in 2004, moored off the coast of Qatar in the Persian Gulf at the Al Shaheen Oil Field.[8]

The vessel was sold to Indian ship breakers, and renamed Mont for a final journey in December 2009. After clearing Indian customs, the ship sailed to Alang Ship Breaking Yard, Alang, Gujarat, where she was beached for scrapping. In 2010, scrapping of the ship was completed.[8][9]


Seawise Giant was ordered in 1974 and delivered in 1979 by Sumitomo Heavy Industries, Ltd. (S.H.I.) at her Oppama shipyard in Yokosuka, Kanagawa, Japan, as a 418,611-ton Ultra Large Crude Carrier (ULCC).[10] The vessel remained unnamed for a long time, and was identified by her hull number, 1016. During sea trials, 1016 exhibited severe vibration problems while going astern. The 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.[5]

Size comparison of some of the longest ships. From top to bottom: Knock Nevis (ex-Seawise Giant), Maersk Mc-Kinney Møller, Vale Brasil, Allure of the Seas, and USS Enterprise (CVN-65).

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.[5][11] "Seawise", a pun on "C.Y.'s", was used in the names of other ships owned by C.Y. Tung, including Seawise University.[12]

After the refit, the ship had a capacity of 564,763 tonnes deadweight (DWT), a length overall of 458.45 m (1,504.1 ft) and a draft of 24.611 m (80.74 ft). It had 46 tanks, and 31,541 m2 (339,500 sq ft) of deck space. When Seawise Giant was fully loaded its 25 meter/81 foot draft was too deep for the ship to safely navigate the relatively shallow waters of the English Channel.[5] The rudder weighed 230 tons, and the propeller weighed 50 tons.[13]

Seawise Giant was damaged and sunk in 1988[7] during the Iran–Iraq War by an Iraqi Air Force attack while anchored off Larak Island, Iran on 14 May 1988 and carrying Iranian crude oil. The ship was struck by parachute bombs.[14] Fires ignited aboard the ship and blazed out of control,[15] and it sank in the shallow waters off the coast.[16] The ship was declared a total loss and was written off.[17]

Shortly after the Iran–Iraq war ended, Norman International bought the shipwreck, salvaged and repaired her.[7] The ship was renamed Happy Giant after the repairs.[4] These repairs were done at the Keppel Corporation shipyard in Singapore after towing the vessel from the Persian Gulf. She entered service in October 1991 as Happy Giant.[17]

Jørgen Jahre bought the tanker in 1991 for US$39 million and renamed her Jahre Viking. From 1991 to 2004, she was owned by Loki Stream and flew the flag of Norway.[17]

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.[5][17]

Knock Nevis, ex-Seawise Giant (in red) compared to large ships and buildings:
  The Pentagon, 1,414 feet, 431 m
  RMS Queen Mary 2, 1,132 feet, 345 m
  USS Enterprise, 1,123 feet, 342 m
  Hindenburg, 804 feet, 245 m
  Yamato, 863 feet, 263 m
  Empire State Building, 1,454 feet, 443 m
  Knock Nevis, ex-Seawise Giant, 1,503 feet, 458 m
  Apple Park, 1,522 feet, 464 m

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 Priyablue Industries. The vessel was beached on 22 December 2009.[3][9][18] Due to the length and the size of the vessel, scrapping only finished at the end of 2010. The ship's 36 tonne anchor was saved and donated to the Hong Kong Maritime Museum in 2010.[19] It was later moved to a Hong Kong Government Dockyard building on Stonecutters Island.[20]

Size recordEdit

Seawise Giant was the longest ship ever constructed, at 458.45 m (1,504.1 ft), longer than the height of many of the world's tallest buildings, including the 451.9 m (1,483 ft) Petronas Towers.[21]

Despite a great length, Seawise Giant was not the 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. It was the longest and largest by deadweight: 564,763 tonnes.[22][23]

Seawise Giant was featured on the BBC series Jeremy Clarkson's Extreme Machines while sailing as Jahre Viking. According to its captain, S. K. Mohan, the ship could reach up to 16.5 knots (30.6 km/h) in good weather. It took 9 km (5+12 mi) for the ship to stop from that speed, and the turning circle in clear weather was about 3 km (2 mi).[24]

See alsoEdit


  1. ^ "JAHRE VIKING (370263)". Port State Information Exchange. United States Coast Guard. Retrieved 16 October 2012.
  2. ^ "Knock Nevis (94118)".
  3. ^ a b "World's largest ship Knock Nevis to be scrapped". Bluepulz. 16 December 2009. Archived from the original on 8 July 2011. Retrieved 4 June 2010.
  4. ^ a b "20th Century Ships: Seawise Giant (Happy Giant) (Jahre Viking) (Knock Nevis) (Mont)". Relevant Search Scotland. 17 January 2010. Retrieved 4 June 2010.
  5. ^ a b c d e Baljit Singh (11 July 1999). "The world's biggest ship". The Tribune. Retrieved 4 June 2010.
  6. ^ Rich Galiano. "Artifacts & Shipwrecks: Tanker". Archived from the original on 2 July 2010. Retrieved 4 June 2010.
  7. ^ a b c Trex, Ethan (June 2011). "Seawise Giant: You Can't Keep A Good Ship Down".
  8. ^ a b "The world's largest ship to be scrapped". Bluepulz. 5 September 2009. Archived from the original on 17 March 2010. Retrieved 4 June 2010.
  9. ^ a b Bhavnagar (19 December 2009). "Crude oil carrier Mont awaits clearance to dock at Alang". The Indian Express. Retrieved 4 June 2010.
  10. ^ Clarkson Research Studies Ltd. (1987). Tanker Register 1987. International Publication Service. ISBN 0-8002-4143-6.
  11. ^ Sandra Burton (23 December 1996). "Beijing's Capitalist". Time Magazine. Archived from the original on 14 December 2007. Retrieved 4 June 2010.
  12. ^ "The Tung Dynasty". Far Eastern Economic Review. 116 (17): 76–78: 76. 23 April 1982. Like other "Seawise" ships in Tung's fleet, this vessel punned on C. Y.'s initials for its name.
  13. ^ Seawise Giant INC Alumni Association. Retrieved: 24 July 2010. Archived 18 November 2010 at the Wayback Machine
  14. ^ "Story of Seawise Giant (The Largest Ship Ever Sunk) -". Cruise Ups. 17 February 2019. Retrieved 3 August 2020.
  15. ^ "Iraq Hits 5 Ships in Persian Gulf".
  16. ^ "Largest Ship in the World".
  17. ^ a b c d John Pike (1 November 2006). "Knock Nevis / ex-Jahre Viking". Global Security. Retrieved 4 June 2010.
  18. ^ "World's Largest Ships: Supertanker – Knock Nevis". Maritime Connector. 2010. Archived from the original on 14 August 2008. Retrieved 4 June 2010.
  19. ^ "Main anchor of the Jahre Viking/Seawise Giant arrives in Hong Kong". Heavy Lift & Project Forwarding International. 30 June 2010.
  20. ^ Google (15 September 2020). "Seawise Giant Anchor Coordinates" (Map). Google Maps. Google. Retrieved 15 September 2020.
  21. ^ "Knock Nevis - The world's largest ship ever". Container Transportation. Retrieved 9 October 2020.
  22. ^ Shaw, John (May 2018), "Pioneering Spirit: Profile of the World's Biggest Ship", Ships Monthly: 33–37
  23. ^ "Pioneering Spirit".
  24. ^ Jeremy Clarkson (15 August 2008). "Powerrrrr!: Yara Viking Ship, Largest Man Made Moving Machine on the Planet!". Jeremy Clarkson's Extreme Machines. BBC. Retrieved 14 June 2010.

Further readingEdit

External linksEdit