mathematics

Seawise Giant

Seawise Giant is a mathematics topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Seawise Giant rather than just read about it. In short: TT Seawise Giant—formerly Oppama; later Happy Giant, Jahre Viking, Knock Nevis, and Mont—was a ULCC supertanker and the longest self-propelled ship ever built. It was constructed in 1974–1979 by Sumitomo Heavy Industries in Yokosuka, Kanagawa, Japan.

Key takeaways

Seawise Giant belongs to mathematics; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Seawise Giant to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Seawise Giant from memory before moving on to harder problems.

Reference excerpt

TT Seawise Giant—formerly Oppama; later Happy Giant, Jahre Viking, Knock Nevis, and Mont—was a ULCC supertanker and the longest self-propelled ship ever built. It was constructed in 1974–1979 by Sumitomo Heavy Industries in Yokosuka, Kanagawa, Japan. Seawise Giant's engines were powered by Ljungström turbines. The ship had the greatest deadweight tonnage ever recorded. Fully laden, she displaced 657,019 tonnes. When the ship was built, it was the heaviest self-propelled ship of any kind. With a laden draft of 24.6 m (81 ft) and a length of 458.45 m (1,504.1 ft), the ship 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 30 m (98 ft) by the floating liquefied natural gas (FLNG) installation Shell Prelude, a monohull barge design 488 m (1,601 ft) long with 600,000 tonnes displacement.. The ship 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 (FSO) 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. (S.H.I.) at Oppama shipyard in Yokosuka, Kanagawa, Japan, as a 418,611-ton Ultra Large Crude Carrier (ULCC). 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 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 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). She had 46 tanks, and 31,541 m2 (339,500 sq ft) 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 French-made Exocet missiles launched from Iraqi aircraft. 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's 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 Seawise Giant is now on public display in the newly opened Anchor Plaza outside piers 9 and 10 of the Central Ferry Pier.

Size record

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. Despite her 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. 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 captain Surrinder Kumar Mohan, the ship could reach up to 16.5 knots (30.6 km/h) in good weather. It took 9 km (5+1⁄2 miles) for the ship to stop from that speed, and the turning circle in clear weather was about 3 km (2 miles).

Gallery

See also List of longest ships TI-class supertanker Freedom Ship

References

Further reading Watt, Nick (4 January 2007). "Skipper Shortage: Supply Not Keeping Pace". ABC News Nightline. Retrieved 5 April 2008. Clarkson Research Studies Ltd. (1987). Tanker Register 1987. International Publication Service. ISBN 0-8002-4143-6.

External links

Video of Jahre Viking Video on YouTube Seawise Giant-launch in 1979 on YouTube The Jahre Viking

Illustrations

Worked examples

Example 1 — a first encounter with Seawise Giant

Start with the simplest possible case. Write down what Seawise Giant claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In mathematics, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Seawise Giant before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Seawise Giant ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Seawise Giant

In research: Seawise Giant appears in mathematics research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Seawise Giant in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Seawise Giant is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1979 ships, Construction records, Floating production storage and offloading vessels, so understanding it makes those chapters shorter.
In everyday life: Look for Seawise Giant outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Seawise Giant in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Seawise Giant means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Seawise Giant out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Seawise Giant in simple terms?

Why does Seawise Giant matter?

Because it connects several mathematics ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Seawise Giant?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Seawise Giant.