Welcome to the Alvis Stalwart 6x6 Load Carrier section of the website. Below is a brief overveiw of the Stalwart 6x6 amphibious truck. The following pages go into greater depth, with evidence, as well as dealing with myths, workshop manuals, and more.

The driver sits, unusually, in the middle, with one passenger seat on the left. Some models had a passenger seat on the right as well. There are no doors, only the roof hatches, however the rear side window on each side will slide up and down, and can be locked in any mid position – and is big enough to be an escape hatch.. 

It is very much a "forward control" vehicle, the driver sitting ahead of the leading wheels. With all that weight and 3 pairs of wheels behind you, it can be a very strange sensation to reach to top of a steep climb only to continue skywards, the nose becoming nicely "airborne".

For such a large beast the Stalwart is a formidable cross-country vehicle. Approach and depart angles are good, maximum speed on land is 40mph, and trenches up to five feet wide can be tackled with impunity. Before taking to the water the operator must undertake a veritable plethora of tasks, chores, and checks, including switching on the bilge pumps! Manoeuvrability in water is good, steering being achieved by a combination of vectored thrust from the PTO driven twin Dowty water-jet propulsion units, and the road wheels. Speed through water is said to be about 6 knots.

So how does it all work? I'm glad you asked me that. The "chassis" is, in fact, the hull, and is made from steel, of frameless construction. Suspension is independent all round, utilising torsion bars with parallel links. There are a total of 12 telescopic hydraulic Bump and rebound dampers, and 10 shock absorbers – the middle wheels only having one shock absorber. The engine is mounted at the rear, under the load deck, access being gained via lift-off hatches. Drive is taken forward through a 12 inch Borg and Beck clutch, to the 5-speed primary gearbox, which incorporates PTO's for winch and marine drive. Forward again to the transfer box, which incorporates the Forward and Reverse, and a "No-Spin" “Detroit Locker” differential, the purpose of which is to limit the slippage between left and right wheel sets – whilst allowing the vehicle to happily go around corners. This differential will lock automatically when it detects one side slipping, to fix all six wheels as one solid unit. From here drive is taken out sideways to the centre wheel bevel boxes, then, by using Bevel boxes, on to the front and rear wheel pairs by further side mounted drive-shafts. Each wheel station consists of axle half shafts to join bevel boxes to reduction gears in the hubs. Because of the wishbone suspension, each wheel station is fitted with two Tracta CV joints between each bevel box and hub.

Complicated, isn't it ? Yes, it is, and many will, by now, have spotted the reason why private Stalwart ownership could be the stuff of nightmares if not maintained and serviced correctly.  All three wheels on each side are locked as one mechanical unit. If driven on hard surfaces when empty and for long distances, the amount of transmission wind-up generated can be self-destructive. As the Army were quick to find out, the bevel boxes bear the brunt if untrained drivers were sent on garrison duties. One of the Driver’s duties after a set distance of milage had been covered, was to measure and rotate the tyres. Any system with multiple axles being driver, will suffer from the rear wheels trying to overtake the front wheels. The wheel rotation was to ensure that the largest circumference was at the front, and the smallest at the rear.

Not put off by that ? There's more ....... A full tank of 100 gallons can reasonably be expected to take you just over 400 miles. Yes, that's 4 mpg, driven lustily. There are 5 gallons of oil in the engine, 3 more in the gearbox, 15 in total of hydraulic fluid. There are countless more fluids and lubricants required all over the place. There are seals, unions, hoses, joints, gaskets and such, in more places than you can shake a stick at. Go swimming and all those fluids may, nay probably will, need replacing.

So there you have it. Stalwart by name, but not necessarily by nature. One thing is clear; in order to keep one of these wonderful machines running, you need more than a domestic garage and a socket set. Ideally, you will have access to a serious engineering shop, a second donor vehicle would be a good idea, and a generously proportioned low-loader is a must, to cart the thing around. Obviously, you'll have a class 1 heavy goods vehicle licence for the low-loader, and it goes without saying that you'll need a very healthy bank balance. Where to play ? Might I suggest purchasing 10,000 acres of Scotland, preferably with a small loch or two thrown in for good measure ?

We do have a selection of other files, trade reviews, articles, etc on the HMLC Stalwart Facebook group.

We would enjoy seeing you there, especially if you have any photos or articles of the Alvis Stalwart in service, in any country.

www.facebook.com/groups/alvis.hmlc.6.x.6.stalwart.group