Donkeyman? Merchant Navy

[cupoflife]

A 'donkey-man' took care of the 'donkey-engine' a small steam powered engine.

https://en.m.wikipedia.org/wiki/Steam_donkey
"Steam donkey, or donkey engine, is the common nickname for a steam-powered winch, or logging engine, widely used in past logging operations, though not limited to logging. They were also found in the mining, maritime, and nearly any other industry that needed a powered winch."

[Lucy2]

Scroll down to Photo No. 7 at following link :

http://horowhenua.kete.net.nz/en/site/topics/2683-mangahao-dams-diagrams-and-photos

... photo shows the temporary steam and compressor plant building.

*  Didn't one of your posts Betty, mention that Robert W. STEVENS worked on a "temporary power house building"  ??

    ~   Lu

[Mean_genie]

DD:

If he spent most of his life in Hull, that suggests merchant navy rather than Royal Navy. That isn't proof in itself, of course, but lacking any other evidence I would look in merchant navy sources first if you want to find out more about his service.