ton#ton of TNT

The ton is derived from the tun, the term applied to a cask of the largest capacity. This could contain a volume between {{convert|175|and|213|impgal|USgal l|lk=on}}, which could weigh around {{convert|2,000|lb|kg|lk=on}}, and occupy some {{convert|60|cuft|m3|lk=on}} of cargo space.{{cite web |url=http://ntl.bts.gov/DOCS/narmain/narmain.html |title=Naval Architecture for All |publisher=United States Bureau of Transportation Statistics |access-date=October 13, 2008 |url-status=dead |archive-url=https://web.archive.org/web/20081010071508/http://ntl.bts.gov/DOCS/narmain/narmain.html |archive-date=October 10, 2008 }}. "Historically, a very important and standard cargo for European sailing vessels was wine, stored and shipped in casks called tuns. These tuns of wine, because of their uniform size and their universal demand, became a standard by which a ship's capacity could be measured. A tun of wine weighed approximately 2,240 pounds, and occupied nearly 60 cubic feet." (Gillmer, Thomas (1975). Modern Ship Design. United States Naval Institute.) "Today the ship designers standard of weight is the long ton which is equal to 2,240 pounds." This is the weight of 35 cubic feet of Sea Water at a specific gravity of 1.025, compared to Fresh Water, specific gravity of 1.000 usually measured at 60 degrees F. Handy numbers: 35, 36, 37, number of Cubic Feet per Salt Water, Fresh Water and Lube Oil.

There are several similar units of mass or volume called the ton:

{{notelist|}}

The difference between the short ton and the other common forms ("long" and "metric") is about 10%, while the metric and long tons differ by less than 2%.

The metric tonne is usually distinguished by its spelling when written, but in the United States and United Kingdom, it is pronounced the same as ton, hence is often spoken as "metric ton" when it is necessary to make the distinction. In the United Kingdom the final "e" of "tonne" can also be pronounced ({{IPAc-en|ˈ|t|ʌ|n|i}}).{{cite OED|tonne}} In Australia, it is pronounced {{IPAc-en|t|ɒ|n}}.

In Ireland and most members of the Commonwealth of Nations, a ton is defined as {{convert|2,240|lb|kg|5}}.{{efn|The "pound" used in this article is the avoirdupois pound. Its mass is defined as exactly 0.45359237 kg }}{{cite web| url = http://www.opsi.gov.uk/acts/acts1985/pdf/ukpga_19850072_en.pdf| title = Weights and Measures Act 1985| access-date = 2010-02-03| date = 1985-10-30| publisher = Her Majesty's Stationery Office| url-status = live| archive-url = https://web.archive.org/web/20091208083258/http://www.opsi.gov.uk/acts/acts1985/pdf/ukpga_19850072_en.pdf| archive-date = 2009-12-08}}

In the United States and Canada,{{cite web|url=http://laws-lois.justice.gc.ca/eng/acts/W-6/page-10.html#docCont|title=Weights and Measures Act: Canadian units of measure, Schedule II (Section 4)|publisher=Department of Justice|access-date=2011-07-06|url-status=live|archive-url=https://web.archive.org/web/20110811094412/http://laws-lois.justice.gc.ca/eng/acts/W-6/page-10.html#docCont|archive-date=2011-08-11}} a ton is defined as {{convert|2000|lb|kg|5}}.

• Deadweight ton (abbreviation 'DWT' or 'dwt') is a measure of a ship's carrying capacity, including bunker oil, fresh water, ballast water, crew, and provisions. It is expressed in tonnes ({{convert|1,000|kg|lb|0}}) or long tons ({{convert|2,240|lb|kg|0}}). This measurement is also used in the U.S. tonnage of naval ships.
• Increasingly, tonnes are being used rather than long tons in measuring the displacement of ships.
• Harbour ton, used in South Africa in the 20th century, was equivalent to ({{convert|2,000|lb|kg|0}}) or 1 short ton.

{{anchor|Assay ton}}

Assay ton (abbreviation 'AT') is not a unit of measurement but a standard quantity used in assaying ores of precious metals. A short assay ton is approximately {{convert|29.16666|g|abbr=on|adj=ri2|3}} and a long assay ton is approximately {{convert|32.66666|g|abbr=on|adj=ri2|3}}.{{Cite book |last=Fenna |first=Donald |title=A Dictionary of Weights, Measures, and Units |publisher=Oxford University Press |year=2002 |isbn=9780198605225 |location=Oxford |at=assay ton}}{{citation needed|reason=though the different US/UK values are attested, the terms "short" and "long" with "assay ton" seem only to be found in Wikipedia/Wiktionary and derivative online convertors|date=August 2023}} These amounts bear the same ratio to a milligram as a short or long ton bears to a troy ounce. Therefore, the number of milligrams of a particular metal found in a sample weighing one assay ton gives the number of troy ounces of metal contained in a ton of ore.

In documents that predate 1960 the word ton is sometimes spelled tonne,{{citation needed|reason=No entry for tonne in SOED|date=June 2018}} but in more recent documents tonne refers exclusively to the metric ton.

In nuclear power plants tHM and MTHM mean tonnes of heavy metals, and MTU means tonnes of uranium. In the steel industry, the abbreviation THM means 'tons/tonnes hot metal', which refers to the amount of liquid iron or steel that is produced, particularly in the context of blast furnace production or specific consumption.

{{vanchor|Dry ton|Dry tonne|Wet ton|Wet tonne|text=A dry ton or dry tonne has the same mass value, but the material (sludge, slurries, compost, and similar mixtures in which solid material is soaked with or suspended in water) has been dried to a relatively low, consistent moisture level (dry weight). If the material is in its natural, wet state, it is called a wet ton or wet tonne.}}

Both the UK definition of long ton and US definition of short ton have similar underlying bases. Each is equivalent to 20 hundredweight; however, they are long {{convert|112|lb|kg|order=flip}} or short hundredweight {{convert|100|lb|kg|order=flip}}, respectively.

Before the 20th century there were several definitions. Prior to the 15th century in England, the ton was 20 hundredweight, each of 108 lb, giving a ton of {{convert|2160|lb|kg}}.{{Citation needed|date=October 2009}} In the 19th century in different parts of Britain, definitions of 2,240, or 2,352, or 2,400 lb were used, with 2,000 lb for explosives; the legal ton was usually 2,240 lb.Definitions of 2,000, 2,240, 2,352, and 2,400 lb are included in citations listed in the Oxford English Dictionary, 2nd ed. OED cites an 1858 dictionary of trade products "the legal ton by weight is usually 20 cwt".

In the United Kingdom, Canada, Australia, and other areas that had used the imperial system, the tonne is the form of ton legal in trade.

{{See also|Tonnage}}

The displacement, essentially the weight, of a ship is traditionally expressed in long tons.{{Cite web|last=DesVergers|first=Jake|title=Rules of the Road: Tricky tonnage measurement not about weight|url=https://www.the-triton.com/2017/10/rules-of-the-road-tricky-tonnage-measurement-not-about-weight/|access-date=2021-04-23|website=The Triton|language=en-US}} To simplify measurement it is determined by measuring the volume, rather than weight, of water displaced, and calculating the weight from the volume and density.[https://books.google.com/books?id=vylCkqTg7H0C&pg=PA249 Displacement ton] Dictionary of international trade retrieved 22July2010

For practical purposes the displacement ton (DT) is a unit of volume, {{convert|35|cuft|sigfig=4}}, the approximate volume occupied by one ton of seawater (the actual volume varies with salinity and temperature).[http://www.oxfordreference.com/views/ENTRY.html?entry=t135.e351&srn=1&ssid=351170645#FIRSTHIT A Dictionary of Weights, Measures, and Units, Donald Fenna, 2002] {{ISBN|0-19-860522-6}} It is slightly less than the 224 imperial gallons (1.018 m³) of the water ton (based on distilled water).

One measurement ton or freight ton is equal to {{convert|40|cuft|sigfig=4}}, but historically it has had several different definitions. It is used to determine the amount of money to be charged in loading, unloading, or carrying different sorts of cargo. In general if a cargo is heavier than salt water, the actual weight is used. If it is lighter than salt water, e.g. feathers, freight is calculated in measurement tons of 40 cubic feet.{{cite web |url=http://www.msc.navy.mil/annualreport/2003/financial.htm |title=MSC 2003 in Review - Financial and Statistical Review |publisher=Msc.navy.mil |date=2003-09-30 |access-date=2010-07-31 |url-status=dead |archive-url=https://web.archive.org/web/20110722195701/http://www.msc.navy.mil/annualreport/2003/financial.htm |archive-date=2011-07-22 }}{{cite web|url = https://www.ustranscom.mil/dbw/docs/FY18_Liner_Breakbulk_and_Container_Rates_and_Guidance.pdf|publisher = Military Surface Deployment and Distribution Command|title = Liner Ocean Transportation Program Stabilized Breakbulk/Dry Cargo and Container Billing Rates|date = 2018}}{{cite web |url=http://bulk.resource.org/courts.gov/c/F2/182/182.F2d.916.235.21638.html |title=182 F.2d 916 |publisher=Bulk.resource.org |access-date=2010-07-31 |url-status=dead |archive-url=https://web.archive.org/web/20110727214911/http://bulk.resource.org/courts.gov/c/F2/182/182.F2d.916.235.21638.html |archive-date=2011-07-27 }}{{cite web |url=http://www.stocktonport.com/TERMINAL%20TARIFF/POS%20DEFINITIONS%20GENERAL%20RULES%20AND%20REGULATIONS%20ttariffI.htm |title=Pos Ttariff General Definitions |publisher=Stocktonport.com |access-date=2010-07-31 |url-status=live |archive-url=https://web.archive.org/web/20110716144906/http://www.stocktonport.com/TERMINAL%20TARIFF/POS%20DEFINITIONS%20GENERAL%20RULES%20AND%20REGULATIONS%20ttariffI.htm |archive-date= 2011-07-16 }}

Gross tonnage and net tonnage are volumetric measures of the cargo-carrying capacity of a ship.

The Panama Canal/Universal Measurement System (PC/UMS) is based on net tonnage, modified for Panama Canal billing purposes. PC/UMS is based on a mathematical formula to calculate a vessel's total volume; a PC/UMS net ton is equivalent to 100 cubic feet of capacity.[http://www.pancanal.com/eng/general/peajes-en-el-canal.html Panama Canal Tolls] {{webarchive|url=https://web.archive.org/web/20080916113752/http://www.pancanal.com/eng/general/peajes-en-el-canal.html |date=2008-09-16 }}, Panama Canal Authority. Retrieved 10 May 2006.

The water ton is used chiefly in Great Britain, in statistics dealing with petroleum products, and is defined as {{convert|224|impgal|cuft m3|sigfig=4}},{{cite web|url=https://www.nist.gov/pml/wmd/pubs/upload/AppB-12-hb44-final.docx|title=NIST: Units and Systems of Measurement Their Origin, Development, and Present Status|website=nist.gov|access-date=1 May 2018|url-status=live|archive-url=https://web.archive.org/web/20160616205300/http://www.nist.gov/pml/wmd/pubs/upload/AppB-12-hb44-final.docx|archive-date=16 June 2016}} the volume occupied by {{convert|1|long ton|lb kg|0}} of water under the conditions that define the imperial gallon.

• Ton is also used informally, often as slang, to mean a large amount of something.Merriam-Webster's English Dictionary defines ton as: "a great quantity". [https://www.merriam-webster.com/dictionary/ton]
• In Britain, a ton is colloquially used to refer to 100 of a given unit. Ton can thus refer to a speed of 100 miles per hour, and is prefixed by an indefinite article, e.g. "Lee was doing a ton down the motorway"; to money e.g. "How much did you pay for that?" "A ton" (£100); to 100 points in a game e.g. "Eric just threw a ton in our darts game" (in some games, e.g. cricket, more commonly called a century); or to a hundred of any other countable figure.Colin R. Chapman, Weights, Money and Other Measures Used by our Ancestors, p.93, Genealogical Publishing Com, 1996 {{ISBN|0-8063-1501-6}}.{{cite book|first = John|last = MacRae-Hall |title =A Deniable Asset|page = 85|publisher = iUniverse|date = 2011|isbn= 9781450280808|url =https://books.google.com/books?id=_MaEhEXt2W8C&pg=PA85}}The Oxford English Dictionary 2nd ed. lists colloquial use of "ton" from 1946 for £100, and later 100 mph, and for 100 in general.

{{Wiktionary|ton}}

{{Div col}}

• Conversion of units

• English units
• Gross ton mile
• Imperial units
• Systems of measurement
• TNT equivalent
• Ton of refrigeration
• truck classification
• unit of energy
• United States customary units

{{colend}}

{{Notelist}}

{{Reflist}}

{{Imperial units}}

{{United States Customary Units}}

Category:Units of mass

Category:Units of volume

Category:Customary units of measurement in the United States

Category:Imperial units

de:Tonne (Einheit)

no:Megagram

nn:Megagram

te:టన్