Somewhere in the shops a diesel prime mover rests on a dolly, at an unknown stage in its rebuilding process. Never having developed an interest in diesel engines I have no further details to offer, but perhaps diesel aficionados will be able to identify this unit. One thing I did learn during this shop tour was that heavy metal parts such as couplers still require periodic maintenance in the form of annealing, or heating to a high temperature to allow the molecules to rearrange themselves. This helps to prevent fracture through crystallization. We were shown some parts that were undergoing this process.