DTG reveals findings of D1015 engine failure investigation
Traction Group has released more information about what it has discovered following an investigation into the engine failure suffered by D1015 Western Champion
during a main line loaded test run. The Class 52 diesel-hydraulic locomotive’s B end engine suffered a seizure shortly after starting the run, operated in conjunction with GB Railfreight between Avonmouth and Penyffordd Cement Works on September 17 last year.
The run was organised in preparation for Pathfinder Tours charter ‘The Champion Torbay Express’ that the ‘Western’ had been due to work on September 25.
Following the engine failure, the tour was operated using the Class 50 Alliance’s 50007 Hercules and 50049 Defiance.
A statement posted on the DTG’S website states: “The failed B end engine from D1015 has now been stripped and inspected by DTG engineers and analysis has shown that one big-end bearing has ‘picked up’. “This is the bearing at the bottom of the connecting rod which runs on the crank pins of the crankshaft. On the MD series engine, this bearing consists of two semi-circular shells consisting of a steel backing shell, which then has a running surface of a bronze style alloy overlaid.
“It is the oil film between this overlay and the surface of the crankpin that keeps the bearing free.
“The term ‘picked up’ means that there has been metal-to-metal contact through the oil film. The subsequent friction has created heat and the running surface bronze of the shell has effectively melted onto the crank pin, thereby seizing the bearing.
“The disruption to the oil film can be through many reasons. The engine had very good oil pressure, so it is likely that either a metal fragment was passed through the oil or that the running clearance at some point across the bearing surface was too tight to allow the oil film to flow across the entirety of the bearing surface. From the nature of the damage it seems likely that it is the latter cause.
“This could be due to slight imperfections in the machining of the bearing shell, bearing in mind the extremely tight tolerances involved.” The DTG has already prepared a replacement engine for its main line-registered Class 52 and this was fitted into the locomotive on December 29. Work on returning the locomotive to service on both engines will now continue, prior to testing both on the Severn Valley Railway and then on the main line.
More information about the DTG and their fleet of locomotives – which also includes Class 17 D8568, Class 35 D7029 and Class 42 D821 Greyhound – can be found at westernchampion. co.uk