Manufacturing activities of engineers John I Thornycroft & Co Ltd were carried out at factories in Basingstoke and Southampton. The firm's wide-ranging product line included commercial and military vehicles, high-grade cars, various types of boats and ships, marine engines, water-tube boilers and other items. The following history covers Thornycroft's activities from 1862 to 1912, and looks mainly at the company's cars. However, when helpful, the history covers wider aspects of Thornycroft's manufacturing activities to give context to the firm's car production.
The Thornycroft era started when John I Thornycroft (later Sir John) designed a steam road vehicle.
Thornycroft formed the Steam Carriage and Wagon Company, with works at Chiswick, London. However, the project was brought to a halt by over-zealous legislation for road vehicles. As a result, Thornycroft gave up road vehicles and turned, instead, to shipbuilding, also at Chiswick.
1864 to 1895
Although not part of the history of Thornycroft's vehicle manufacture, shipbuilding activities are covered below to account for the 31 year gap between 1864 and 1895, during which Thornycroft disengaged from road vehicles.
Thornycroft launched his 60ft (18.3m) steam launch Miranda in 1871, a vessel which was notable for its high speed of 18kts (33.3kph). John I Thornycroft & Co was set up the following year, and the firm became known for its small high-speed ships and launches. Thornycroft demonstrated his inventive skills by taking out numerous patents, the first in 1873, totalling 50 by 1924.
The firm built HMS Lightning in 1876, the Royal Navy's first torpedo boat, an 84ft (25.6m) steam craft which was manoeuvrable and, capable of over 21kts (38.9kph), fast for those pre-turbine days. Thornycroft recognised the potential of water-tube boilers, in comparison with traditional fire-tube boilers, and Thornycroft water tube boilers were first used in the Royal Navy in 1885. Two years later the Spanish Navy's Thornycroft-built torpedo boat destroyer Ariete exceeded the then-high speed of 25kts (46.3kph). In 1895, Thornycroft's torpedo boat destroyer HMS Desperate exceeded 30kts (55.6kph), a phenomenal speed for a ship with steam triple expansion piston engines.
John Thornycroft continued with his shipbuilding and marine engineering business, but he took up road vehicle work again and built his first steam vehicle at the Chiswick works.
The Thornycroft Steam Wagon Company of Chiswick became a producer of steam road vehicles, and demand for the firm's vehicles led to the setting up of a new factory at Basingstoke, Hampshire.
Thornycroft sold a steam lorry to the War Office, for experimental use by the Royal Engineers.
The above vehicle, with three or four others lent to the Army by the firm, performed well on trial at the autumn manoeuvres run by the Royal Engineers.
The original shipbuilding firm was registered as a limited liability company, becoming J I Thornycroft Co Ltd, and the works were transferred from Chiswick to Southampton in 1904. The firm absorbed the Thornycroft Steam Wagon Company in 1905.
Further steam lorries were ordered for the Army, and a Thornycroft vehicle won a War Office competition for the best type of military powered vehicle.
The War Office bought the winning vehicle and ordered more vehicles from Thornycroft.
London's first powered bus, a Thornycroft steam-driven double-decker, started to run between Oxford Circus and Shepherds Bush. A canopy was fitted to prevent cinders from falling on the passengers!
The first Thornycroft motor vehicle was introduced, a petrol-driven commercial vehicle with a 4 ton (4,064kg) load capacity.
Vehicles of similar design for 1.5 ton (1,524kg) and 2 ton (2,032kg) loads were introduced, and the firm went on to become a noted manufacturer of commercial motor vehicles, including buses.
Thornycroft entered the car market with a small 10hp two-cylinder model, starting nine years of production of upmarket cars, all at Basingstoke. Later on, the firm introduced a 20hp four-cylinder car.
Thornycroft continued the 10hp and 20hp cars for 1904, the only types produced that year. The firm recognised the value of successes in competition for publicising its cars, and a 20hp car won a gold medal in the 1904 Scottish Automobile Club Reliability Trials.
Thornycroft discontinued the 10hp for 1905 and introduced the 4,650cc 24hp and the 2,715cc 14hp. The latter was built for the Isle of Man TT Race and two 14hp cars were entered for the 1905 event, but there were no wins for Thornycroft that year. However, a 24hp car made the fastest time of any car entered in the 1905 Aston Hill Climb.
Thornycroft was favoured with an order for a 24hp Double Landaulette from HRH Princess Christian of Schleswig-Holstein, one of Queen Victoria's daughters and formerly Princess Helena before her marriage to Prince Christian.
The 20hp car was discontinued for 1906 and cars listed for the year comprised the 14hp and 24hp introduced the previous year, and the magnificent new six-cylinder 6,975cc 36hp. Tom Thornycroft drove a 14hp in the 1906 TT, but the car suffered from technical problems.
HRH Princess Christian was pleased with her 1905 24hp car, and Thornycroft's 1906 brochure proudly announced that their Royal Highnesses Prince and Princess Christian had given the firm a Royal Warrant of appointment as motor manufacturers.
Thornycroft continued producing its 1906 models for 1907, with the exception of the 4,650cc 24hp, which was replaced by the 5,213cc 30hp, another large "four" with the, by now, well-tried in-line, T-head layout. Thornycroft entered two cars for the 1907 Isle of Man TT Race, a 14hp and a 30hp. The 30hp competed in the heavy car event, but it ran out of petrol and so, according to the rules, was withdrawn. Not much is known of the 14hp's race performance, although it reportedly ran well.
Thornycroft enlarged its big "six" for this year to a massive 7,819cc, and called the car the 45hp. Other cars for 1908 comprised the 30hp, continued from last year, and the new 18hp. Thornycroft built three racing cars for the four-inch TT Race. The highest-placed Thornycroft car came fifth at 44.1mph (71kph) in the hands of Tom Thornycroft.
For this year, the company's three-car range included the 30hp and 45hp, and a revised 18hp with a larger engine. From this year forward, all Thornycroft cars had side valves, either L-head or T-head.
The 1909 range continued for both these years, but the 18hp was enlarged, yet again, from 3,258cc to 3,707cc for 1911. The London showrooms in Albemarle Street were closed in 1910.
Thornycroft discontinued the big 45hp six-cylinder cars for this year, and retained the 18hp and 30hp cars. However, Thornycroft stopped car production later that year to concentrate resources on its best-selling commercial vehicles.
The 1903 10hp Thornycroft has taken part in the London-Brighton event, four up.
The quiet-running 1907 30hp Thornycroft is displayed at Milestones Living History Museum
Photo Nick Corrie