science

Long ton

Long ton 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 Long ton rather than just read about it. In short: The long ton, also known as the imperial ton, displacement ton, or British ton, is a measurement unit equal to 2,240 pounds (1,016.0 kg). It is the name for the unit called the "ton" in the avoirdupois system of weights or Imperial system of measurements.

Key takeaways

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

Reference excerpt

The long ton, also known as the imperial ton, displacement ton, or British ton, is a measurement unit equal to 2,240 pounds (1,016.0 kg). It is the name for the unit called the "ton" in the avoirdupois system of weights or Imperial system of measurements. It was standardised in the 13th century. It is used in the United States for bulk commodities. It is not to be confused with the short ton, a unit of weight equal to 2,000 pounds (907.2 kg) used in the United States, and Canada before metrication, also referred to simply as a "ton".

Unit definition A long ton is defined as exactly 2,240 pounds. The long ton arises from the traditional British measurement system: A long ton is 20 long hundredweight (cwt), each of which is 8 stone (1 stone = 14 pounds). Thus, a long ton is 20 × 8 × 14 lb = 2,240 lb.

Unit equivalences A long ton, also called the weight ton (W/T), imperial ton, or displacement ton, is equal to:

2,240 pounds (1,016.0 kilograms; 1.0160 metric tons) exactly 12% more than the 2,000 pounds of the North American short ton, 20 long hundredweight (112 lb) rather than 20 short hundredweight (100 lb) the mass of 35 cubic feet (0.991 m3) of salt water with a density of 64 pounds per cubic foot (1.03 g/cm3)

Usage around the world

United Kingdom To comply with the practices of the European Union, the British Imperial ton was explicitly excluded from use for trade by the United Kingdom's Weights and Measures Act of 1985. The measure used since then is the tonne, equal to 1,000 kilograms. If still used for measurement, then the word "ton" is taken to refer to an imperial or long ton.

United States In the United States, the long ton is commonly used in measuring the displacement of ships and the shipping of baled commodities and bulk goods like iron ore and elemental sulfur.

International The long ton was the unit prescribed for warships by the Washington Naval Treaty of 1922; for example, battleships were limited to a displacement of 35,000 long tons (35,560 t; 39,200 short tons). The long ton is traditionally used as the unit of weight in international contracts for many bulk goods and commodities.

See also Short ton, equal to 2,000 lb (907.2 kg). Ton Tonnage, volume measurement used in maritime shipping, originally based on 100 cubic feet (2.83 m3). Tonne, also known as a metric ton (t), equal to 1,000 kg (2,205 lb) or 1 Mg.

References

Worked examples

Example 1 — a first encounter with Long ton

Start with the simplest possible case. Write down what Long ton 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 Long ton 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 Long ton 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 Long ton

In research: Long ton 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 Long ton 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: Long ton is common in secondary-school and first-year university syllabi. It links to neighbouring topics Customary units of measurement in the United States, Imperial units, Units of mass, so understanding it makes those chapters shorter.
In everyday life: Look for Long ton 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 Long ton in 20 minutes

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

Frequently asked questions

What is Long ton in simple terms?

Why does Long ton 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 Long ton?

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 Long ton.