I think this one will even beat "Johnson Dumper."
Has anyone got a decent pic. of the rare Muir Hill 20B dumper
It had a 5 yard skip and payload of 8/9 tons.
Unlike it's smaller more usual 10B & 14B stable mates it had fully sprung suspension and four wheel braking. The gear box gave 3 speeds traveling skip first and 4 speeds the other way and power was provided by an AEC 7.7 litre engine which produced 96 hp.
It was in production circa 1950 and was fitted with the usual Muir Hill swivel seat and controls.
I don't know how many were made, but apparently some were exported to Eastern Europe.
Below is a very poor pic. (The only one I've been able to find).
Fred