enginehistory.org

[rinkol]

The ill-fated airship, R101, used the Beardmore Tornado engines with 8 inline cylinders, each having dimensions of 8.25 inches bore and 12 inches stroke.

These engines seem to have cotributed several weaknesses to the R101. The five engines weighed 17 tones overall, five more than had been planned for. Also, the maximum power had to be reduced from 700 hp at 1000 rpm to 585 hp at 900 rpm due to torsional vibration. The R101 ended up overweight and underpowered.

I'm curious as to why a straight eight layout ws used - the long crankcase and crankshaft would involve a significant weight penalty. Presumably this was done for reasons of convenience - the Wikipedia article on the R101 states that the engines were developed by combining a pair of four cylinder railway diesels. According to http://www.oldengine.org , plans for an aluminum crankcase had to be abandoned due to excessive flexibility.

Is any further information available? Would this engine have been better designed as an inline six or V8? Was the stroke excessive? Interestingly, the later DB 602 used in the Hindenburg and Graf Zeppelins was a V16.

Robert