Update on steam locomotive 35011 General Steam Navigation’s trailing truck
The General Steam Navigation (GSN) Locomotive Restoration Society has released the latest update on progress to restore the trailing truck of Bulleid Pacific No.
35011 General Steam Navigation. The truck has been delivered to the North Norfolk Railway (NNR) where it has been fully dismantled, and a detailed examination and testing undertaken. Visual and Non Destructive Testing (NDT) of the axle showed no defects.
Although one end of the axle has some pitting, most of the axle is at its original size. NNR is awaiting confirmation from GSN’s certification body, Ricardo, that it can appoint its preferred subcontractor for tyre turning and profiling to be done.
35011’s trailing truck. Credit: General Steam Navigation Locomotive Restoration Society.
A new set of springs that was purchased as part of an order with the 35006 Locomotive Society all have the same deflection under load, so setting up the height of the Trailing Truck will be easier.
The left-hand axlebox has visible cracks in three places, one of which extends at least two inches down the side. It will need grinding out to near the top of the arch before attempting a welding fix. As this is made of gunmetal, it could be difficult toshowe that it has been adequately done.
The right-hand axlebox has no visible cracks. Both axleboxes are bent at the bottom, probably from the truck being jacked up at some stage. The LH axlebox is far worse than the RH and could fracture if an attempt is made to try to return it to shape.
The RH axlebox might be in a suitable condition to be returned to shape. Penetrative dye will be used on both axleboxes to look for further cracks, but it is likely that the LH axlebox will need to be replaced. There is a pattern available for the axleboxes, as these are the same as for the tender.
To reduce costs, the society may consider ordering all eight, including the RH axlebox. The swan necks at the front of the truck, especially the RH one, are in poor condition. The best long-term solution is to cut them out completely and replaced them.
That will enable NNR to examine the rear of the frame and the condition around where the necks are connected. There is a small crack in the right rear of the frame which should be repairable. NNR is to arrange for NDT to be carried out around the crack, the location on the LHS of the frame, and around all other weld areas as well to determine how much material is there and how sound the welds are.
The next step is for NNR to create full CAD drawings of the trailing truck, to understand how the truck went together originally, and for obtaining replacement parts.