Work has started on the refurbishment of the valve gear components. The two photo's show the right hand radius rod having the worn end faces ground flat and parallel to one another. Bronze blocks called 'die blocks' slide between these faces and allow the rod to be lifted or lowered into different positions. This in turn determines the direction in which the locomotive will move and allows adjustment of the amount of steam admitted to the cylinders.
The middle and left hand radius rods have been similarly treated, this will enable the new die blocks to be machined and fitted to the correct tolerances.
This operation is being performed on a vertical milling machine, which has with a simple adaptation been temporarily turned into a grinding machine.
Our thanks go to Great Central engineer, Mick Carr for coming up with this clever solution !