The Stalwart, formally classified by the British Army as Truck, High Mobility Load Carrier (HMLC), 5 Ton, 6 x 6, Alvis Stalwart and informally known by servicemen as the Stolly, and by former RCT as the Stally,[1] is a highly mobile amphibious military truck.

Alvis then used the same suspension and drive methods to develop the FV601 Saladin armoured car, and the Salamander airfield crash tender.

[4] Following the success of those vehicles, Alvis then decided to start a private venture of an off-road truck, capable of carrying 5 tons and being highly mobile.

Camion is commonly known by its chassis number of PV 1 (Project Vehicle 1), and as "The Beast" by staff at Alvis.

PV 2 was put through a number of trials and tests both in the UK and Sweden, and received various facelifts to the cab roof and body sides along the way.

The Stalwart was adopted and entered service with the British Army in 1964 as a general transport truck in preference to the FV431, the load carrier variant of the FV430 series.

The high mobility and amphibious capabilities were considered ideal for resupplying units in the field, particularly those of the British Army of the Rhine.

The engine is situated under the load deck in the rear of the hull and the gearbox with transfer box and differential forward of this.

[6][better source needed] In the water it can be driven at about 6 knots by vectored thrust water-jet propulsion units.

The Stalwart's over-terrain capabilities come from the fact that the six-wheel-drive system lacks differentials, using simple bevel gears to transmit drive.

However, this system causes "wind up" in the transmission (inter-component stress) as all the wheels are forced to rotate at the same speed, which during cornering is impossible.

This problem is of special concern for modern-day Stalwart owners – to get a vehicle to a show requires moving it by low-loader or driving it on the road, risking damage to the transmission.

Alternatively, the front and rear driveshafts can be removed, eliminating wind-up at the expense of off-road capability.

It consisted of an Alvis Salamander hull and cab, with the radiator still located in front of the rear mounted engine.

YouTube - PV2 showing it paces in Devon during 1961 A Pathé News film from 1962 of PV2 in the original configuration, with the full-length single-skin side boards.

The Mk 1 was used for troop movement in Aden, but the Stalwart was more regularly used for carrying packed fuel, over 300 Jerry cans, or ammunition as alternatives to the five tonnes of cargo in the UK and Germany.

When swimming on deep water when fording operations are expected, i.e. the vehicle will be subjected to full floatation, it is important that the maximum load be restricted to 3 tons 10 cwt.

[20] This modified crane was more stable (and safer) for lifting and holding engine, transmission, and other heavy equipment whilst manoeuvring them into position.

When swimming on deep water when fording operations are expected, i.e. the vehicle will be subjected to full floatation, it is important that the maximum load be restricted to 3 tons 10 cwt.