The FH70 was jointly developed by the British (Vickers) and the Germans (Rheinmetall GmbH) in the late 60's and early 70's at a development cost of £30 million with the first trials being in 1975 and finally going into full production in 1978.  Aproximately 500 were made and the British Army eventually took delivery of 71 at a cost of £300,000 each.  The gun was designed to be towed behind a purpose built Foden 6 by 6 gun tractor, but once on site it was too heavy to be manhandled into position.  It was therefore fitted with a Volkswagon 1800cc petrol engine and gearbox to allow it to be moved short distances.  The engine also powered the hydraulics which raised and lowered the transport wheels.  The gun could fire all standard NATO 155mm ammunition but special ammunition was developed which gave it a maximum range of 24,700metres.  It also had a sustained rate of fire of 120 rounds per hour.  The museums gun was first proof fired on 22/05/79.  The FH70 was phased out in 200 and the museums gun was last fired on 15/02/99.  The FH70 has now been replaced by the AS90 self propelled gun which uses the same 155mm system.