DHN999J is a Dennis Heavy Recovery Fire Appliance based on the Dennis Maxim 30 ton chassis. It is fitted with a Holmes 750 recovery crane. This appliance was supplied new to Durham County Fire Brigade in 1970 and was only withdrawn from service in 1995. It was based at Darlington during its operational life, with most incidents being vehicle accidents on the A1(M) which cuts through County Durham.
It is powered by a Perkins V8 640 engine and is fitted with 2 PTO's, one for the crane and the second for a compressor which works the air cutting equipment. It is still kept busy recovering broken down preserved Leyland Cub Fire Engines!