The Stalwart began as an Alvis Company private venture in the late 1950s. It utilised the cross country mobility of its Saladin armoured car, and the load carrying capacity of its Saracen APC. As developed, the vehicle was capable of carrying 5 tons of cargo over very rough ground and could also traverse rivers and lakes using its inbuilt Dowty water jet propulsion system.
In its role as an artillery ammunition vehicle an Atlas hydraulic crane was fitted. A similar variant made a suitable REME fitters vehicle for workshops supporting lightly equipped reconnaissance forces, where speed and stealth made the FV 434 less suitable.
The rapid transition in the 1980s towards an all diesel vehicle fleet left the Stalwart and similar Alvis vehicles with their Rolls Royce B series petrol engines somewhat outdated. Their load capacity too was uneconomical when trucks of not much greater dimensions could carry 8 tonnes. The gradual disposal of the Stalwarts in the 1980s and 1990s left greater fuel standardisation but no equivalent off road amphibious cargo carrier has replaced them.
The vehicle is an artillery ammunition carrier.
