The tun (Old English: tunne, Latin: tunellus, Medieval Latin: tunna) is an English unit of liquid volume (not weight), used for measuring wine, oil or honey. Typically a large vat or vessel, most often holding 252wine gallons, but occasionally other sizes (e.g. 256, 240 and 208gallons) were also used. The modern tun is about 954 litres.
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 (1016kg). The spellings "tun" and "ton" were sometimes used interchangeably.
History
Originally, the tun was defined as 256 wine gallons; this is the basis for the name of the quarter of 64corn gallons. At some time before the 15th century, it was reduced to 252 wine gallons, so as to be evenly divisible by other small integers, including seven.
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.
—Untitled manuscript, consisting of a list of various customs duties, dated 15 July 1507
Translation:
He that is a gauger ought to understand that there is in a tunne 60sesters, and every sester is 4gallons, be it wine or oil.
With the adoption of the Queen Anne wine gallon of 231 cubic inches in 1706, the tun approximated the volume of a cylinder with both diameter and height of 42 inches. These were adopted as the standard U.S. liquid gallon and tun.
When the imperial system was introduced in 1824, the tun was redefined in the UK and its colonies as 210 imperial gallons. The imperial tun remained evenly divisible by small integers. There was also little change in the actual value of the tun.
Standard tuns of wine came to serve as a measure of a ship's capacity.
comparisons
historically
imperial definitions
US definitions
measure
tuns
butts
puncheons
hogsheads
tierces
barrels
rundlets
litres
gallons
litres
gallons
litres
tun
1
1/2
1/3
1/4
1/6
1/8
1/14
950–960
210
954.6789
252
953.923769568
butt
2
1
2/3
1/2
1/3
1/4
1/7
475–480
105
477.33945
126
476.961884784
puncheon
3
1+1/2
1
3/4
1/2
3/8
3/14
316–320
70
318.2263
84
317.974589856
hogshead
4
2
1+1/3
1
2/3
1/2
2/7
237–240
52+1/2
238.669725
63
238.480942392
tierce
6
3
2
1+1/2
1
3/4
3/7
158–160
35
159.11315
42
158.987294928
barrel
8
4
2+2/3
2
1+1/3
1
4/7
118–120
26+1/4
119.3348625
31+1/2
119.240471196
rundlet
14
7
4+2/3
3+1/2
2+1/3
1+3/4
1
68–69
15
68.19135
18
68.137412112
Definitions
In the US customary system, the tun (symbol: US tu) is defined as 252 US fluid gallons, or exactly 953.923769568 litres.
In the imperial system, the tun is defined as 210 imperial gallons, or exactly 954.6789 litres.
Conversions
Both the imperial and US tuns are subdivided into smaller units as follows.
↑"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."
