Barrel (unit)

A barrel is one of several units of volume applied in various contexts; there are dry barrels, fluid barrels (such as the UK beer barrel and US beer barrel), oil barrels and so on. For historical reasons the volumes of some barrel units are roughly double the volumes of others; volumes in common usage range from about 100 litres (22 imp gal; 26 US gal) to 200 litres (44 imp gal; 53 US gal). In many connections the term "drum" is used almost interchangeably with "barrel".

Since medieval times the term barrel as a unit of measure has had various meanings throughout Europe, ranging from about 100 litres to 1000 litres, or more in special cases. The name was derived in medieval times from the French baril, of unknown origin, but still in use, both in French and as derivations in many other languages such as Italian, Polish and Spanish. In most countries such usage is obsolescent, increasingly superseded by SI units. As a result, the meaning of corresponding words and related concepts (vat, cask, keg etc.) in other languages often refers to a physical container rather than a known measure.

Barrel

A barrel, cask, or tun is a hollow cylindrical container, traditionally made of wooden staves bound by wooden or metal hoops. Traditionally, the barrel was a standard size of measure referring to a set capacity or weight of a given commodity. For example, in the UK a barrel of beer refers to a quantity of 36 imperial gallons (160 L; 43 US gal). Wine was shipped in barrels of 119 litres (31 US gal; 26 imp gal).

Modern wooden barrels for wine-making are either made of French common oak (Quercus robur) and white oak (Quercus petraea) or from American white oak (Quercus alba) and have typically these standard sizes: "Bordeaux type" 225 litres (59 US gal; 49 imp gal), "Burgundy type" 228 litres (60 US gal; 50 imp gal) and "Cognac type" 300 litres (79 US gal; 66 imp gal). Modern barrels and casks can also be made of aluminum, stainless steel, and different types of plastic, such as HDPE.

Someone who makes barrels is called a "barrel maker" or cooper. Barrels are only one type of cooperage. Other types include, but are not limited to: buckets, tubs, butter churns, hogsheads, firkins, kegs, kilderkins, tierces, rundlets, puncheons, pipes, tuns, butts, pins, and breakers.

Barrel (disambiguation)

A barrel is a cylindrical container.

Barrel may also refer to:

See also

Gun barrel

A gun barrel is the tube, usually metal, through which a deflagration or rapid expansion of gases are released in order to propel a projectile out of the end at a high velocity. Barrels are part of firearms and artillery pieces.

The first firearms were made at a time where metallurgy was not advanced enough to cast tubes able to withstand the explosive forces of early cannon, so the pipe (often actually built from staves of metal) needed to be braced periodically along its length, producing an appearance somewhat reminiscent of a storage barrel.

Construction

A gun barrel must be able to hold in the expanding gas produced by the propellants to ensure that optimum muzzle velocity is attained by the projectile as it is being pushed out by the expanding gas(es). Modern small arms barrels are made of materials known and tested to withstand the pressures involved. Artillery pieces are made by various techniques providing reliably sufficient strength.

Early firearms were muzzle-loading, with powder, and then shot loaded from the muzzle, capable of only a low rate of fire. Breech loading provided a higher rate of fire, but early breech-loading guns lacked an effective way of sealing the escaping gases that leaked from the back end of the barrel, reducing the available muzzle velocity. During the 19th century effective mechanical locks were invented that sealed a breech-loading weapon against the escape of propellant gases.