A Giesl ejector is a suction draught system for steam locomotives that works on the same principle as a feedwater injector.
This ejector (German: Ejektor, Flachschornstein or Quetschesse) was invented in 1951 by the Austrian engineer, Dr. Adolph Giesl-Gieslingen.
The existing blastpipe in a locomotive is replaced by several, small, fan-shaped, diverging blast pipes, from which the diffuser gets its flat, long, drawn-out shape.
In the DR it was assessed that the Giesl ejectors would pay for themselves within a year, as a result of which they converted over 500 locomotives; primarily the Classes 38.10, 50, 52 and 65.10.
In 1962, Bulleid Battle of Britain class 4-6-2 34064 Fighter Command was fitted with a Giesl ejector on the grounds that a desired spark arrestor would "suffocate" an ordinary blastpipe.
It quickly became apparent, following some adjustment, that the ejector improved the locomotive design, and it was held in high regard by the crews.
[7] As a consequence of the experience with Fighter Command, and for the same reasons, during the 1980s the preserved Bulleid West Country class 4-6-2 34092 City of Wells was similarly fitted at the Keighley and Worth Valley Railway.