The Thornycroft company was a well-established and respected engineering company in 1927, producing commercial vehicles, ships and other engineering products. In many ways the firm’s progress in lorry design was far more impressive between 1927 and 1932 than it had been from 1919 to 1926. All Thornycroft’s lorries were powered by four-cylinder engines during the earlier period and had spark ignition. However, the need for more load capacity without loss of performance resulted in Thornycroft’s most powereful lorry engine having around double the output of the previous era’s best. The requirement for more power meant larger engines, leading to the introduction of six-cylinder units.
Mercedes Benz caused a stir when it exhibited a diesel lorry at the UK’s 1927 Commercial Motor Show, held at Olympia. Other manufacturers producing and marketing IC-engined lorries in the UK were then offering petrol vehicles. However, it was only a matter of time before they, too, had to introduce fuel-efficient diesel lorries in order to stay competitive. Thornycroft was not the first British manufacturer to offer diesels, and the firm seemed reluctant to do so for a while, waiting until 1931 to introduce a lorry diesel engine. However, once aboard the diesel bandwagon, Thornycroft demonstrated that it lagged behind no-one in applying the new (for lorries) diesel technology. Larger, six-wheeled, vehicles were introduced to cope with greater weights, and Thornycroft introduced vacuum servo-assisted brakes as well as all-wheel braking, superseding the rear wheel brakes fitted to an earlier generation of lorries. In summary, the 1927 to 1932 period was an era of more rapid technological advance in lorry design than before, both for Thornycroft and its competitors.
These pages provide a timeline history of the Thornycroft company's lorry-building activities during the period 1927 to 1932. In addition, data is given on Thornycroft's lorries for this period, in detail for nine selected models and in summary form for all the firm’s lorries. Also given are details of the Basingstoke factory and the production process. Road haulage expanded during the period covered in these pages, in some areas competing with railways for the carriage of freight, and the resulting social impact of road transport is examined in terms of goods distribution, lorry manufacturing, employment, etc. Thornycroft lorry sales news items are summarised, spread over a wide spread of operators both at home and overseas. Engineering developments and contemporary technical matters are discussed. Contemporary reference sources have been used, as well as archive photographs and current photographs of some of the HMS’s preserved vehicles.
Information for these pages comes from contemporary Thornycroft technical data and other sources, as well as contemporary copies of The Commercial Motor.