B12 Update April 2016

The crack in the bogie frame has been gouged out and welded . The bogie horn guides have been removed progressively Set up on the milling machine to have their slide faces milled true and flat once again. Once this has been completed then they can be refitted and the slots in the frames heated and jacked back to parallel.

The bogie transverse slide faces are being plated to recover the effects of years of wear and tear and to restore the slides thickness. New bronze slipper plates will be finally fitted to the bogie stretcher once the steel plating work has been completed on the centre slide block.

Both sets of bogie wheels have had their tyres turned and profiles machined.

The work to overhaul the expansion link and fit new die blocks has been presented with some challenges following the heat treatment process to re-case harden the links. Due to the exact metallurgy of the steel not being known it was not possible to harden them by the nitrating process so conventional higher temperature methods had to be used which has caused some slight distortion. This is measured in tens of thousandths of an inch, but has meant that further visits have had to be made to Bedestone Engineering Works to discuss and agree the optimum setup for the final grinding, all of which has added time to the job.

New piston rings are on order following the valve and piston exam.