While reading Guy Gibson's 'Enemy coast ahead' I came across a word that I didn't understand nor could I find an explanation or translation anywhere (I'm Dutch). It is 'bumble motors'. What are they? They are mentioned on p. 203 in the 2007 reprint of the Goodall paperback:
"Then into another office to see the equipment officer. We would require ten aircraft to begin with, with all their gear. Later we would need
more. This was a big job; there were trestles, trolleys, spare wheels and bumble motors. (...). He promised that they would be delivered at Scampton tomorrow."
Someone suggested they'd be the special equipment for the bouncing bombs, but that seems unlikely to me since Gibson at that point had no idea about the purpose of this mission, let alone what to carry on that mission.
Hi, I think you will find that this referes to a trolley Ack or the small battery carts used for starting the engnes which were powered by a small charging engine which would make a noise a little like a bumble bee.