Napier Deltic Marine Diesel Engine

Like the petrol-powered Sabre aero engine, the Napier Deltic was a remarkably high power-to-weight ratio engine with highly original features and layout to work in mainline express rail locomotives, minesweepers, and high output fire pumps.

A valveless 2-stroke diesel engine with pistons in opposed cylinders, the 3000+ horsepower arrangement found within the Class 55 locomotive with a total of 36 cylinders and 72 pistons across 6 crankshafts is remarkable – see more information in this video:

Within the marine arena, the Deltic marine diesel engines were historically used in Royal Navy minesweepers like HMS Ledbury, these were replaced by CAT C32 4 stroke diesel engine, which, to be fair, being a conventional 32 litre V12 4-stroke engine has likely been a lot more reliable!

Historically a Deltic engine was installed in a captured German E-Boat to replace the Mercedes Benz diesel unit and provided much more power at a fifth of the weight.

A technical marvel, the Deltic marine diesel engine also saw service in the US Navy during the Vietnam conflict, but these days is only found in heritage railway Class 55 examples.

Recommended Posts