Tun (unit)

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The tun (Old English: tunne, Latin: tunellus, Middle Latin: tunna) is an English unit of liquid volume (not weight), used for measuring wine,[1] oil or honey. Typically a large vat or vessel, most often holding 252 wine gallons, but occasionally other sizes (e.g. 256, 240 and 208 gallons) were also used.[2]

In one example from 1507, a tun is defined as 240 gallons.

Early Modern English: "He that ys a gawner owght to understonde there ys in a tunne lx systerns and every systern ys iiii galons be yt wyne or oylle."
Translation: "He that is a gauger ought to understand that there is in a tunne 60 sesters, and every sester is 4 gallons, be it wine or oil."

— Untitled manuscript, consisting of a list of various customs duties, dated 15 July 1507[2][3][4]

The word tun is etymologically related to the word ton for the unit of mass, the mass of a tun of wine being approximately one long ton, which is 2240 pounds (1016 kg).

History[edit]

Originally, the tun was defined as 256 wine gallons;[nb 1] this is the basis for the name of the quarter of 64 corn gallons. At some time before the 15th century, it was reduced to 252 gallons, so as to be evenly divisible by other small integers, including seven.[nb 2]

With the adoption of the Queen Anne wine gallon of 231 cubic inches the tun approximated the volume of a cylinder with both diameter and height of 42 inches.[nb 3] These were adopted as the standard US liquid gallon and tun.

When the imperial system was introduced the tun was redefined in the UK and colonies as 210 imperial gallons. The imperial tun remained evenly divisible by small integers.[nb 4] There was also little change in the actual value of the tun.[nb 5]

Standard tuns of wine came to serve as a measure of a ship's weight capacity.[5]

 
measure
tun
butt
puncheon
hogshead
tierce
barrel
rundlet
comparisons
tuns butts puncheons hogsheads tierces barrels rundlets
1    2    3    4    6    8    14   
12 1    1 12 2    3    4    7   
13 23 1    1 13 2    2 23 4 23
14 12 34 1    1 12 2    3 12
16 13 12 23 1    1 13 2 13
18 14 38 12 34 1    1 34
114 17 314 27 37 47 1   
historically
litres[nb 6]
950–960
475–480
316–320
237–240
158–160
118–120
68– 69
imperial definitions
gallons litres[nb 7]
210     954.6789
105    477.33945
70    318.2263
52 12 238.669725
35    159.11315
26 14 119.3348625
15    68.19135
US definitions
gallons litres[nb 8]
252     953.923769568
126    476.961884784
84    317.974589856
63    238.480942392
42    158.987294928
31 12 118.29411825
18    68.137412112

Definitions[edit]

In the US customary system, the tun (symbol: US tu[6]) is defined as 252 US fluid gallons.[6]

In the imperial system, the tun is defined as 210 imperial gallons.

Conversions[edit]

Both the imperial and US tuns were subdivided into smaller units as follows.

1 tun  ≡  2 butts or pipes
3 puncheons or tertians
4 wine hogsheads[6]
6 tierces
8 wine barrels
14 rundlets
 
Conversions of the imperial tun are as follows.
1 imperial tun  ≡  210 imperial gallons
1680 imperial pints
954.6789 litres[nb 7]
0.9546789 cubic metres[nb 7]
69910 cubic inches
40.4570 cubic feet
252.199484 US fluid gallons
2017.595875 US fluid pints
 
Conversions of the US tun are as follows.
1 US tun  ≡  252 US fluid gallons[6]
2016 US fluid pints[6]
953.9237769568 litres[nb 8]
0.953923769568 cubic metres[nb 8]
58212 cubic inches
33.6875 cubic feet
209.833895 imperial gallons
1678.671156 imperial pints
Seven barrels, each of a different size.
English wine cask units[7]
gallon rundlet barrel tierce hogshead puncheon, tertian pipe, butt tun
1 tun
1 2 pipes, butts
1 1 12 3 puncheons, tertians
1 1 13 2 4 hogsheads
1 1 12 2 3 6 tierces
1 1 13 2 2 23 4 8 barrels
1 1 34 2 13 3 12 4 23 7 14 rundlets
1 18 31 12 42 63 84 126 252 gallons (wine)
3.785 68.14 119.24 158.99 238.48 317.97 476.96 953.92 litres
1 15 26 14 35 52 12 70 105 210 gallons (imperial)
4.546 68.19 119.3 159.1 238.7 318.2 477.3 954.7 litres

Notes[edit]

  1. ^ 256=28
  2. ^ 252 = 22×32×7
  3. ^ The volume, V, of this cylinder may be approximated from the height, h, and the radius, r, as follows.
    V  = πr2h
    227×(21 in)2×42 in   since π ≈ 227
    = (22×32×7)×(3×7×11) cu in
    = 252×231 cu in
  4. ^ 210 = 2×3×5×7
  5. ^ The imperial tun is only about 0.0792% larger than the US tun assuming current definitions. Note that 5 imp gal ≈ 6 US gal.
  6. ^ The conversion to litres is approximate and given as a range to reflect the varying definitions of the gallon and the tun in terms of the gallon.
  7. ^ a b c The conversion to litres is exact assuming the current 4.54609-litre definition of the imperial gallon.
  8. ^ a b c The conversion to litres is exact assuming the current 25.4-millimetre definition of the international inch.

References[edit]

  1. ^ Cardarelli, F. (2003). Encyclopaedia of Scientific Units, Weights and Measures. Their SI Equivalences and Origins. London: Springer. p. 49. ISBN 978-1-4471-1122-1. 
  2. ^ a b Zupko, Ronald E. (1985). "A Dictionary of Weights and Measures for the British Isles: The Middle Ages to the Twentieth Century, Volume 168". Memoirs of the American Philosophical Society. American Philosophical Society. 168. ISBN 9780871691682. Quoting Gras (1918), p. 706 
  3. ^ Gras, Norman S.B. (1918). Early English Customs Systems. Cambridge. p. 706. Quoting Forgon (1507) 
  4. ^ Forgon, T. (15 July 1507). Untitled manuscript, consisting of a list of various customs duties. Reproduced at sizes.com. 
  5. ^ "Naval Architecture for All". United States Bureau of Transportation Statistics. Retrieved October 13, 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."
  6. ^ a b c d e Cardarelli, F. (2003). Encyclopaedia of Scientific Units, Weights and Measures. Their SI Equivalences and Origins. London: Springer. p. 43. ISBN 978-1-4471-1122-1. 
  7. ^ http://www.sizes.com/units/barrel_wine.htm