HTN 21 - Sandstone’s Sentinel S4 Lorry

Sandstone Heritage Trust - News

Heavy trucks are a commonplace sight on the roads today. As most people know they are diesel powered and capable of carrying heavy loads. In fact South Africa has some of the largest payloads in the world, a fact testified by the damage to our road system. Of course it was not always so. In the days of South African Railways (SAR) most large consignments were moved by rail and hauled by steam powered locomotives.

Most people imagine that steam was only a motive power on the railways but in earlier days steam was a power source for road vehicles. We are all aware of traction engines and road rollers powered by steam, some examples of which are in the Sandstone collection. What is not well known is that steam also powered trucks.
The most famous of these were made by Sentinel in the UK. Originally manufactured by Alley & MacLellan in Polmadie, in Glasgow, the company moved to Shrewsbury in 1915 and became the Sentinel Wagon Works in 1920.
Their first model was the Super series from which was developed the DG4 series. Their main competition in the steamer market was Foden but new legislation in the 1930s saw demands for lighter vehicles and Sentinel survived the longest. In 1934 they defied the odds and produced the S type with a single acting 4 cylinder underfloor engine with a longtitudinal crankshaft suited to cardan shaft drive to an overhead worm-drive rear axle.
The S series was much lighter than previous models and featured a modernised cab with a set back vertical boiler.
Built in four, six and eight wheeled form designated S4,S6 & S8 they were quite sophisticated but could not ultimately compete with diesel powered trucks for ease of operation and payload capacity and production was phased out in the late 1930s. However the company did go on to build another 100 steam powered wagons for Argentina in 1950. Ultimately Sentinel went into the production of diesel trucks using their own engines. The company finally ceased production in 1956 and the factory was sold to Rolls Royce.
Sandstone has in its collection a Sentinel Steam lorry , serial number 9178, built in 1934 This was acquired from the James Hall Museum of Transport in Johannesburg and is currently at Stevens Mechanical in Howick, KZN, undergoing restoration.
The machine has been completely rebuilt and the boiler refurbished. Although it came complete with cab this has had to be replaced and a new one is being fabricated by Keith Stevens.
New tyres were acquired from Dunlop in Durban and although a non standard size they were found ex stock. The Sentinel S4 has been fired up in chassis form and given a brief test drive by Keith and found to be perfect. The rear body has been restored and pending completion of the cab the unit will be returned to Sandstone in the near future.
Interestingly a numberplate, TS 3718, was found on the vehicle indicating registration in Springs under the old Transvaal numbering system.

Does this ring a bell with anyone?
A similar Sentinel S4 in fully restored condition in the UK
The S4 as delivered to Sandstone
The S4 chassis
Rear axle detail
The vertical boiler in position after rebuild