Napier Deltic

Deltic
Overview
ManufacturerD. Napier & Son
Layout
Configuration18 cylinder deltic
Displacement5384 cubic inches (88.3 litres)
Cylinder bore5.125 inches
Piston stroke7.25 inches
Compression ratio19.26 : 1
Combustion
Operating principle2-stroke
Fuel typediesel
Output
Power output2000 BHP at 2000 rpm

The Napier Deltic engine is a British opposed-piston valveless, supercharged uniflow scavenged, two-stroke diesel engine used in marine and locomotive applications, designed and produced by D. Napier & Son. Unusually, the cylinders were disposed in a three-bank triangle, with a crankshaft at each corner of the triangle.

Deltic (meaning "in the form of the Greek letter (capital) delta") is used to refer to both the Deltic E.130 opposed-piston, high-speed diesel engine and the locomotives produced by English Electric using these engines, including its demonstrator locomotive named DELTIC and the production version for British Railways, which designated these as the Class 55.

A single, half-sized, turbocharged Deltic power unit also featured in the English Electric-built Type 2 locomotive, designated as the Class 23. Both locomotive and engine became better known as the "Baby Deltic".