Latest Project update

Our new dragbox has completed fabrication where all of the plates are welded together. Non destructive testing is complete. The next stage is for the dragbox to go through heat treatment. Post weld heat treatment is required due to the residual stresses and micro-structural changes that occur after welding has been completed. The next stage will be to machine, the side, back and bottom faces. When machining the bottom face, we will also drill and ream the bolt holes for the pony truck centring pin. Once we receive the completed dragbox we will be able to complete the activities that will finish off frame assembly phazse 1 and 2. This involves

 

• Fitting the dragbox, hind beam, gussets and pony truck bolsters

• Welding manganese steel liners to the hind beam rubbing plates

• Modifying the hind beam intermediate rubbing block to the new dragbox design

• Tightening a couple of difficult to access bolts on the firebox support stretcher

• Drilling the rivet holes for the trailing spring hanger brackets

• Fitting the final horizontal stretcher packing plate

• Riveting the front horizontal stretcher sides, the hind beam and the trailing spring hanger brackets

Virtually all of the bogie components are in stock. By the time you receive this update we should have shrunk fit the bush in the bogie centre slide and the pivot pin spring pads in the top of the cannon axleboxes - this is scheduled for 6 November using dry ice to shrink the components before fitting. Countersunk bolts are on order which allow us to complete the fastening of the frame plates to the central stretcher. We then have the critical job of fitting the axlebox guides and liners. The cannon box have manganese steel liners welded to the rubbing faces. Manganese Steel is very hard wearing once it has initially work hardened. Fitting will involve

 

• Manufacture of the axlebox guide steel liners and welding manganese steel liners to them

• Temporarily bolting the liners to the axlebox guides then drilling and reaming the bolt holes ( 3 per guide)

• Bolting the axlebox guides to the bogie frame (fitted bolts)

• Careful measuring of the distance between the opposing faces of the manganese liners for each pair of guides

• From this we will be able to work out what machining is required on the steel face of the axlebox liner, i.e. the face against the axlebox guide

• We need 10 to 17 thou inch clearance between the manganese steel face of the liner and the manganese steel face of the cannon box

 

Once this work is complete, we will be able to the rest of the, relatively minor, work to complete the bogie

For the Pony Truck, a lot of the drawings are now complete and we can start ordering components as funds allow. A request for quotation has been placed for the pivot pin and a quotation will be sought shortly for the pony truck wheels. We will be seeking a budgetary estimate for the triangular radial arm so that we can raise funds for it.

 

For the Driving Wheels, we are in the process of initial research into producing the driving wheel wheelsets. If we can complete all of the above we will have a rolling chassis.