Tuns

Tuns are large casks historically used for storing and transporting liquids, especially wine, and by extension they came to denote a unit of volume based on the capacity of such a vessel. The term derives from the Old English tun, meaning a large container or cask.

In English wine measures, a tun was standardized as 252 gallons, approximately 954 liters. This size is four hogsheads, since a hogshead was commonly defined as 63 gallons. The exact capacity of a tun could vary by time and region, but the 252-gallon reference served as the conventional standard in medieval and early modern England. In maritime and mercantile contexts, a tun also functioned as a unit of cargo capacity, reflecting the volume of liquid a vessel could carry and influencing provisioning and trade.

Today, the tun is largely obsolete as a measurement, surviving mainly in historical texts and discussions of traditional wine and beer casks. Modern standards use liters or cubic meters, and the term is largely confined to historical or literary contexts. The concept remains part of historical vocabulary and is encountered in descriptions of old taverns, inns, and ship provisioning, where the tun is referenced as a symbol of bulk storage and commerce.