[caldrail]

Seems that the Brits liked their counter-rotating props.

They liked the idea. It took more efficient advantage of available power and erased gyroscopic forces on takeoff and landing. It wasn't however a lightweight or simple device, and the issues of reliability and maintenance under service conditions was a factor acting against it. Contra-props were, in other words, a technological advance and advantage that needed development before the service use was authorised. In fact, some designs might have been taken more seriously if conventional props had been substituted. Faster development, off the peg parts, and the mechanical skill in the field would have already been present.