Gin gang

A gin gang, wheelhouse, roundhouse or horse−engine house, is a structure built to enclose a horse mill, usually circular but sometimes square or octagonal, attached to a threshing barn. Most were built in England in the late 18th and early 19th centuries. The threshing barn held a small threshing machine which was connected to the gin gang via wooden gears, drive shafts and drive belt, and was powered by a horse which walked round and round inside the gin gang.

The gin (short for "engine") was the horse mill driving a small threshing machine, and the horse did the gang, or going. The gin gang was always attached to the main threshing barn, where the gin was situated. It was almost always of one storey and it could be circular, polygonal or square. There was a hole for a drive−shaft or drive−belt, linking it with the threshing barn. The gin was connected by cogs to a vertical spindle. The spindle was connected to a horizontal arrangement including a shaft attached to a horse, which turned the spindle and powered the machine by ganging or walking round and round the cogs and vertical spindle inside the walls of the gin gang. This arrangement was necessary in locations where there was no power for a water wheel, hence in Wales and Ireland there is evidence of fewer gin gangs.

Gin gangs were not usually thatched but were stone−flagged, tiled or pantiled, possibly because the gin damaged potential thatching straw. Its structure tended to reflect locally available materials and hence local vernacular building style, because railways had not generally distributed brick and slate. Building materials include thatch in Sussex, pantiles in North Yorkshire, stone tiles and sandstone in Northumberland, granite pillars in Devon, wooden poles and flint in Norfolk, weatherboarding in Berkshire, brick in the East Riding of Yorkshire, white magnesian limestone in West Yorkshire, ironstone in Bedfordshire, and one instance of hexagonal ashlar pillars salvaged from Finchale Priory in Finchale, County Durham. Gin gangs were required to shelter the wooden gears, and not to protect the horse; hence in some places there is evidence of horse−walks or open−air horse−powered threshing machines instead. The horse in the gin gang could also power machinery outdoors.

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