Engineering Castings

The Duke of Gloucester Restoration Project

The 71000 Duke of Gloucester locomotive uses a class "K" large exhaust steam injector. This exhaust steam injector is a system of using waste steam from the boiler, converting and transferring this back to the boiler to increase the power and efficiency of the locomotive.

The Duke of Gloucester Trust employed Brass Founders Sheffield to produce an injector body for this locomotive, a type which had not been manufactured since the late 1950's of which the original drawings had been destroyed in a fire in 1962. A drawing was then put together by the discovery of an incorrectly produced drawing which had been discarded but kept in the files of Davies & Metcalfe, the original manufacturer. With dimensions taken from a similar injector body presently operating in Italy, along with our own design and modification, a complete drawing was produced.

We then manufactured the pattern equipment by creating an outside model of the body. To create the internal shape it was necessary to manufacture a series of complex core boxes all linked together with prints and change pieces to form chambers within chambers which would then house the many valves and components needed to operate the injector system.

BS1400 LG2 Bronze was the chosen material for the casting of the injector body with the approximate weight of the casting being 95kg. Once cast and cleaned, the casting was pressure tested to 150psi, with the normal operating requirements being 50psi. After all tests were completed, the casting went to our machine shop where our engineers were set the task of machining the complex internal housings within the chambers.

This was achieved by setting up the casting to its true centre in order to machine a true horizontal and vertical datum. From this, multiple datum's could be machined to facilitate the positions required to rotate the casting for the many machining operations including milling, boring, counter boring, drilling and thread cutting, all necessary for the fitting of the various components. Once assembled, the injector body was mounted and connected to the locomotive.

Test trials were conducted with great success enabling the 71000 Duke of Gloucester Class "K" locomotive to run successfully. It is presently nearing the end of its refit and overhaul at Bury and will soon be seen on our rail systems.