Puncheon

An 84-gallon wide-bellied traditional bulk shipping cask used for rum and wine storage.

Eighty-four gallons, and the cask of the long-haul spirit trade. Its distinguishing feature is its shape: wide-bellied and relatively short, which lowers the centre of gravity and makes it markedly more stable in a rolling hold than a taller cask of the same capacity. West Indian rum came to Britain in puncheons, and so did a good deal of wine and molasses. The size is a compromise between two opposing pressures, the economics of shipping favouring larger vessels and the physical limits of what dockers could move favouring smaller ones. A full puncheon weighs the better part of half a tonne, which is at the outer edge of what can be rolled and winched by hand, and that is almost certainly why the cask hierarchy stops climbing shortly above it.