Semi trailer

A Leland of 1919 vintage. Rated as a 5/6 tonner, it is here shown drawing a semi trailer with an outsize container body.

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115 S. Spring Valley Road, Spring Valley, Wilmington, Delaware 19807.

The following article is reprinted with permission from a 1955 issue of Commercial Motor Magazine, Quadrant House, The Quadrant, Sutton, Surrey, England SM2 5AS.

In 1906 there were 24 prominent makes of steamer in Britain. These included Foden, Leyland, Thorny croft and Sentinel, whose internal combustion engined vehicles stand in the front rank today.

Excluding an order for 112 steamers built by Sentinel in 1950 for the Argentine Government, this type of vehicle was not produced in this country much after 1933. The main reason for its demise was the restriction of gross laden weights.

There were two principal classes of steamer, known respectively as the overtype and under type, the former having its engine on top of the boiler and the latter with its engine under the boiler. Boilers, too, were classified as being either of the vertical type or locomotive pattern and throughout the years the subject of boilers was keenly debated.

It, one of a famous line of steamers, this Yorkshire 5 tonner, whilst not a thing of beauty, was notable for its consistent performance. The design of the boiler was one of its outstanding features, being a double-ended locomotive type.

This Foden model attained great popularity in 1926. It was followed by the Foden Speed Six fitted with giant pneumatic tires. It sold well up to 1931.

The last models to be produced by both Foden and Sentinel were of the under type with vertical boilers, although up to 1927 these makers, along with numerous others, had adopted the overtype engine with locomotive or horizontal boiler. Although the locomotive type boiler was a good steamer, it suffered from the disadvantage, when used in a road vehicle, that in climbing or descending a steep gradient the fire tubes would temporarily be above water level.

This drawback did not apply to the vertical boiler or to the special type of steam generator fitted to the Yorkshire steamer. This was of the double ended locomotive type and, being mounted transversely, was not affected by road gradient.

One of a batch of 112 Sentinel steam vehicles built for the Argentine Government in 1950. A road-test report of this model was published in The Commercial Motor on January 6, 1950. The payload was 13 tons.

One of the most famous makes of steamer was the Yorkshire, and this is a typical 5 ton model of the 1905 era. It ran on cast-steel wheels, and because its gross weight was over 8 tons it was restricted to a maximum speed of 5 mph. All Yorkshire steam wagons had a double-ended, fire tube boiler placed transversely across the frame, and this particular vehicle had twin cylinders, one on each side of the frame underneath the body floor.

The all British motorbus made news in 1905 because of the large number of German built chassis in use at that time. Although bearing a Birmingham registration plate, this Thorny croft 24 HP bus was owned by the London Motor Omnibus Co., Ltd., and leased by them to the Birmingham Motor Express Co., Ltd. The total passenger capacity was 36, including two alongside the driver, and the bus, which had a top speed of 12 mph, cost 900, with tires and body.

A novel feature of this 1905 Maudslay double decker was that the 40 HP engine had mechanically operated inlet and exhaust valves, an overhead camshaft being employed. The bus was built for the Scottish Motor Traction Co., Ltd., and carried 16 passengers in the saloon and 18 on top. Ventilation was stated to have been 'carefully considered,' but upper-deck passengers are likely to have called this an understatement. The radiator cowl was neat for this period and the mud guarding was thought to be particularly comprehensive.

Specialized transport for the Army; a 1905 ambulance built for the Royal Army Medical Corps. The chassis was a Straker Squire and was similar to the bus chassis, but had a shorter wheelbase. The sides, roof and floor were lined with 1 inch felt, presumably to deaden the noise of the vehicle in motion, and a slight form of.

It was not until the later years in the life of the steamer that attempts were made by some manufacturers to tidy them up. For example, the Foden Speed 12, produced in 1930, was similar in appearance to a modern oil engined six-wheeler. The boiler was behind the driver, so that it was not difficult to bring the frontal styling into line with that of current combustion engined vehicles.

Apart from Government policy, driver recruitment presented difficulties, as the driver of a steamer had to be of an entirely different calibre from those who had started out on petrol engined vehicles. The fire had to be carefully watched, as did the water level in the boiler if the correct head of steam for all emergencies was to be available.

In the Clarkson steam vehicle, which was produced both for passenger and goods work, a water tube boiler was employed. On bus work this was oil fired, but in 1914 a coke fired version was introduced on a goods chassis. The coke was preheated and fed to the boiler automatically.

Although a steam driven vehicle is ideal in many ways, there is little chance of its revival unless improvements can be made in steam generation.