The two tilt hammers

The two tilt hammers, camshaft, gearing and drum from Holbeam Hammer Mill Devon

This machinery, which is thought to date from the eighteenth century, was removed from Holbeam Mill, near Newton Abbot, Devon, where it was in use until 1942.

The two tilt hammers were operated by a pitchback water wheel, 1 2 feet in diameter and just visible through the small door, which received water from the River Lemon through an open leat and wooden launder. The axle is a rough-hewn oak trunk, on which are wedged two cast-iron cam-rings, the cams of which raise the hammers by pressing down their ironshod tails. On disengagement the hammers fall back on the anvils.

This mill was used for the manufacture of thatchers' sickles, hedging hooks and grass sickles ; and there is a tradition that in the days of sailing fishermens' knives and fishing hooks were made for export to Newfoundland.

In images taken in the mill while it was working, the smith is seen at work at the forging hammer while the lighter hammer, used for finishing, is propped up in order to disengage it from the cams. The frequency of the hammer blows was controlled by adjusting the opening of the sluice over the water wheel, which is connected by levers with the linked rods, which end in a perforated plate. This was secured to whichever hammer head was not in use, by a peg. A second water wheel was used to drive the bellows of the forge.

The bevel-gear ring between the cam rings and the water wheel drove a bevel pinion. This gave motion through spur gearing, which is not shown, to a large drum, which was used to drive through belting the woodturning lathe for making the handles of the tools.

Water-driven hammer mills were widely used from the Middle Ages until the advent of the steam hammer in the mid nineteenth century, but very few of them now survive.