Question please, I have often wondered why locos in America only have one cab whereas most European countries go for two cabs (except on switchers).
In the UK our class 20 locos only have one cab and usually work in pairs like this;
Photograph © Bob Avery
A similar situation exists with the class 121 in Ireland (sadly only two left in service now)
Photograph © Ian Leech
But these are actually GM products which CIE bought to "try out" in the early 1960's. Having decided that they liked them, they then ordered a further batch but specified a two cab version (and for all subsequent GM types for Ireland)
Photograph © Mark Bearton