The twin Wessex fuel consumption was not that much different between 2 engine ops & single engine. I was amongst the original Wessex pilots & we did several tests in both cold & hot weather to get some data. The result was the navy didn't do single engine cruise.
Another important point was that the combining gear box had only a 25 hour life on 1 engine. I would imagine that restriction must have been lifted by the time Bristows got the series 60.
