Bluebell Railway Release Update on Q Class Steam Locomotive #30541

The Bluebell Railway have issued their latest report of Maunsell Q Class 0-6-0 No. 30541 at their locomotive workshops in Sheffield Park.

The examination of pistons and valves on steam locomotives is a routine procedure which is regularly undertaken. The process is usually done from 20,000 miles upwards.

An indication that a review is due may be indicated by a lack of potency; problems with drain valves such as blockage; and the valves failing to close, which could be due to broken piston rings.

To remove the pistons and valves, it is often necessary to dismantle some of the structures in front of the cylinders. It is also often necessary to remove the piston and the valve covers themselves.

Cylinder bore for 541. Credit: John Fry

After extracting the pistons and valves, the segments of these components are examined and measurements are taken of the diameter along the bore of the piston and valve. Any change in diameter can be corrected by reboring the piston or valve, a process which was undertaken on #30541.

The drilling equipment used was from Eastleigh Works. It consists of an electrically driven worm gear driving a shaft with an attached cutting head. Center alignment is achieved by a front mounted cage bolted to the studs used to hold the cylinder cover as seen in the photo below.

New steam lines for 541
New steam lines for 541. Credit: John Fry

Once the bore diameter is consistent throughout, new pistons and valve heads can be machined and new rings ordered.

The 30541 move has been removed and the re-erection now begins, with the slide bars already in place. In addition to this work, it was necessary to construct new main steam lines. New ones have been made and can be seen in the following photo.

Jose P. Rogers