DIESEL TRACTION GROUP
Welcome to westernchampion.co.uk home of the Diesel Traction Group (DTG) online with details about D1015's mainline railtours plus news, updates and information on all our locomotives.
Welcome to westernchampion.co.uk home of the Diesel Traction Group (DTG) online with details about D1015's mainline railtours plus news, updates and information on all our locomotives.
January 2022
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 and 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 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.
A replacement, overhauled engine was recently fitted and is currently being reconnected.
Many thanks for your continued support.
Happy New Year to all our supporters.
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 and 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 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.
A replacement, overhauled engine was recently fitted and is currently being reconnected.
Many thanks for your continued support.
Dont forget to order your DTG 2022 Calendar, which is now available! Full colour archive photos throughout featuring all the DTG locos. More details here
| DTG Locomotives are based at the Severn Valley Railway and Chinnor & Princes Risborough Railway and operate in conjunction with Pathfinder Tours & Vintage Trains |
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