Case Studies

Our specialist heritage locomotive boiler repair and rebuild services were recently called into action again as we welcomed Locomotive No. 1296 to our workshop. Built by Andrew Barclay in 1912, it was used by the National Coal Board and carried the number NCB 8 at its workplace of Polkemmet Colliery, to the south of Stirling and Bannockburn in Scotland.

After it was decommissioned as coal was fading out, No. 1296 found its way to the Scottish Industrial Railway Centre, an industrial heritage museum operated by the Ayrshire Railway Preservation Group. The centre owns several standard gauge steam locomotives as well as diesel-powered engines.

Unfortunately, during its stay there, the cab, bunker, tanks and side rods were stolen but the frames, wheels, cylinders and boiler survived. Ownership then transferred to a private owner and in 2020 the remains were relocated to the North East. With a plan to restore the locomotive to full working order in place, we were commissioned to rebuild the boiler.

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The original undertaking involved new crown stays and several side stay repairs. Crown and side stays are used to brace the metal walls, known as sheets, which separate the water in the boiler and the firebox which heats the water and turns it to steam. The top (crown) and side stays brace the walls against distortion due to the pressures created by the extreme heat within the firebox. 

We were also commissioned to perform a full retubing. The fire tubes, or smoke tubes as they are sometimes known, are housed within the boiler cylinder and carry the hot gasses from the firebox to the smokebox, where they are ejected through the chimney as smoke.

With any project of this nature, a full non-destructive test (NDT) must be carried out to uncover any defects that would affect operation. A thorough NDT survey and inspection by a leading insurance company was carried out and several extensive defects were uncovered, which is not surprising given the age and history of the locomotive.

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As a result of the inspection, the scope of the restoration increased significantly. Sections of the outer firebox required replacing, and both the firebox and the smokebox needed new tubeplates, which support the fire tubes between the two boxes, connecting them at each end. Furthermore, plate work needed reclaiming and re-studding.

So far, we have completed welding the sections of the outer firebox and fitted a new ring on the front of the barrel. Our extensive knowledge of traditional boiler systems and our ability to combine original techniques with modern technology allows us to restore these machines to full working order, keeping Britain’s proud railway heritage alive and well!