science

Tokai Maru

Tokai Maru is a science 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 Tokai Maru rather than just read about it. In short: Tokai Maru was a Japanese passenger-cargo ship built by the Mitsubishi Heavy Industries shipyard that was sunk in Apra Harbor, Guam, in 1943, during World War II. It had served as a fast ship service between New York City and Japan for Osaka Shosen Co. before World War II; during the war it was used as a military transport ship for the Imperial Japanese Navy.

Key takeaways

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

Reference excerpt

Tokai Maru was a Japanese passenger-cargo ship built by the Mitsubishi Heavy Industries shipyard that was sunk in Apra Harbor, Guam, in 1943, during World War II. It had served as a fast ship service between New York City and Japan for Osaka Shosen Co. before World War II; during the war it was used as a military transport ship for the Imperial Japanese Navy.

History Construction by Mitsubishi Heavy Industries began in 1929, the ship was launched on May 16, 1930, construction was completed on August 14, 1930. Osaka Shosen Co., now Mitsui O.S.K. Lines, used her as a fast luxury freighter for Tokyo-New York City service through the Panama Canal. In July 1941, the United States closed the Panama Canal to Japanese shipping in retaliation for the Japanese invasion of French Indochina. Tokai Maru, on the eastern side of the Canal, was forced to sail back to Japan through the Strait of Magellan. The ship was then requisitioned as a war-time transport freighter, a class of ships known as ‘Ippan Choyosen’ that were not officially part of the Imperial Japanese Navy and had civilian crews. The ship went under contract to the Japanese Navy at the Kure Naval Arsenal on October 17, 1941. She was tasked with transporting men and material throughout the Pacific. She would have been armed with two 12 cm guns, two twin 25 mm guns, and two single 25 mm guns. On January 24, 1943, USS Flying Fish spotted Tokai Maru in Apra Harbor, Guam, a U.S. territory then occupied by Japan. After waiting for three days for Tokai Maru to leave the harbor, Flying Fish fired two torpedoes at Tokai, running at 15-foot (4.6 m) depth. One ran aground but the other struck Tokai, inflicting significant damage, but did not sink her. Seven months later, in August 1943, USS Snapper spotted Tokai Maru and another vessel moored in the northeast corner of Apra Harbor. She waited seven days for the Japanese ships to leave before sailing to the north of the harbor on August 27, 1943, and firing three torpedoes at the first target and one at the second. One torpedo hit Tokai's port side #3 cargo hold, sinking her directly on top of the wreck of SMS Cormoran, a World War I German merchant raider.

Wrecksite The Tokai Maru shipwreck, 120 feet (37 m) under water, is listed on the U.S. National Register of Historic Places, as is the shipwreck of SMS Cormoran, which it lies beside. It is one of the few places where divers can explore a World War I shipwreck next to a ship from World War II. In 1988 the wreck was placed on the National Register of Historic Places because of its association with World War II.

See also Media related to Tokai Maru at Wikimedia Commons Foreign commerce and shipping of Empire of Japan Underwater diving on Guam

References

Illustrations

Worked examples

Example 1 — a first encounter with Tokai Maru

Start with the simplest possible case. Write down what Tokai Maru claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, 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 Tokai Maru 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 Tokai Maru 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 Tokai Maru

In research: Tokai Maru appears in science 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 Tokai Maru 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: Tokai Maru is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1930 ships, Apra Harbor, Auxiliary ships of the Imperial Japanese Navy, so understanding it makes those chapters shorter.
In everyday life: Look for Tokai Maru 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 Tokai Maru in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Tokai Maru 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 Tokai Maru out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Tokai Maru in simple terms?

Why does Tokai Maru matter?

Because it connects several science 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 Tokai Maru?

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 Tokai Maru.