Self-Cleaning Smokebox

76084 and Self-Cleaning – the SC Plate

Often mistaken for indicating a connection with the Scottish Region of British Railways the ‘SC’ plate shown in the adjacent image under the Shedcode actually stands for Self-Cleaning.
British Railways Standard Classes of steam locomotives used a simple technology, where a robust mesh grille was incorporated into the smokebox, forming a filter between the front tubeplate and the exhaust. Any large pieces of ‘char’ passing through the boiler tubes would tend to be broken up on impact with the mesh, creating finer particles that would be swept up the chimney instead of accumulating in the bottom of the smokebox. This did not negate the need to clean out the smokebox but reduced the amount of work that had to be done. In the best case, smokebox cleaning could be avoided between boiler washouts, typically at intervals of two weeks.

The fitting of such a mesh was performed at the end of 76084’s 2016 Winter Maintenance and running experience on the North Norfolk Railway since shows the system to be working with fine particles floating out of the chimney at station stops and larger particles when working hard.

The ‘SC’ plate was placed on the smokebox door in British Railways days to inform cleaning staff that less work was required on the locomotive. Just a half dozen shovels-full of ash need removing after several days work.

Now that 76084 has self cleaning kit fitted we have put an ‘SC’ plate on the smokebox door as in British Railways days. The fitting of self cleaning equipment is a pre-requisite for working on Network Rail often referred to as the ‘mainline’.

76084 IS now ready for the challenges of secondary routes on Network Rail.