A low camera angle clearly shows the Giesl ejector fitted to Class BB No 34064 ‘Fighter Command’ seen at Basingstoke in the 1960s. The Giesl was put on in an attempt to reduce spark throwing on the LSWR main line which was causing problems at the time. It remained a unique experiment. (Did it work?)
Robert Waterman answers " Yes, the Giesl Ejector was effective in increasing smokebox vacuum and reducing cylinder exhaust back pressure. The vacuum increase more than compensated for the loss created by a spark arrestor mesh and the cylinder back pressure reduction would have resulted a power increase. Anecdotal evidence suggests this loco was regarded as being almost as good as a Merchant Navy. Also I believe there was an exhaust velocity increase at the chimney exit which reduced drifting exhaust enabling the driver 'to see where he was going', as phrased by the late Bert Hooker."

Copyright David P Williams Archive / Rail-Online