Boscastle Locomotive Limited
18th July 2012
The view below shows the right hand suspension link fitted into position. This is part of the valve gear and transfers movement from the radius rod to the piston valve.
The bearings (bushes) in this item were very badly worn and have been replaced. It is important not to have worn components on the valve gear, if each link in a set of valve gear is worn then the cumulative wear will affect the distance the piston valves travel and cause the cylinder to be less efficient.
The photo above shows new bronze bearings for the expansion links which have been machined by one of our volunteers. The bearings will be pressed into the steel housings (to the left of them) and will then have the internal bores machined to the final size. The old bearings are sitting on top of the housings.
The expansion links are a fundamental part of the valve gear, which allows the locomotive to be put into forward or reverse and also allows the piston valve settings to be altered to improve the efficiency of the cylinders.