The engineers at Harry F Rochat Ltd not only are capable of fully manufacturing our own machinery but take pleasure in manufacturing bespoke heritage items and enjoy the challenges they present.
We have undertaken many projects over the years from extrusion rolls for the plastics industry to smaller heritage items such as the objects below. Below / side, are images of the Gudgeon pin assembly made specifically for a local railway society, who are painstakingly rebuilding GWR 7200. The original assembly was incomplete and heavily worn, so there were no pattern parts to copy. These items were remade by measuring the existing body of the crossheads, which were heavily worn, along with the bores, which were no longer round due to extensive use on the train during it’s working life and then working out what was required from a selection of old parts and drawings, none of which were accurate or consistent.
Each part was reviewed on paper before machining started to ensure all the parts would fit together into the crosshead to the tight tolerances and tapers called for. Jigs had to be made for the crossheads to enable the bores to be lapped by hand, until the bores were in line and as round as possible. Specific specialist material was then chosen for each part and machining commenced. Once the parts were made, they were sent off to the hardeners for hardening and then the parts were machined in our works to size, using specialist CBN tooling. Castle nuts were made and the parts were then fitted to the crosshead bodies in our works. These parts have now been collected from our works and are waiting to be fitted to the train. Further details of this restoration project can be found on the Trust’s web site www.7200trust.org.uk