Armstrong Siddeley was a British engineering group that operated during the first half of the 20th century. It was formed in 1919 and is best known for the production of luxury motor cars and aircraft engines.
Armstrong Siddeley manufactured luxury cars, and later, aircraft engines. In 1935, J. D. Siddeley's interests were purchased by Hawker Aircraft to form Hawker Siddeley, a famous name in British aircraft production. Armstrong Whitworth Aircraft became a subsidiary of Hawker. The aviation pioneer Thomas Octave Murdoch - Tommy, later Sir Thomas, Sopwith - became chairman of Armstrong Siddeley Motors, a Hawker Siddeley subsidiary.
Armstrong Siddeley produced their last cars in 1960 and the aircraft engine business was merged with that of Bristol Aero Engines to form Bristol Siddeley as part of an ongoing rationalisation of the British aerospace sector. Bristol Siddeley and Rolls-Royce merged in 1966, the latter name subsuming the former.
The first car produced from the union was a fairly massive machine, a 5-litre 30 hp; a smaller 18 appeared in 1922 and a 2-litre 14 hp was introduced in 1923. 1928 saw the company's first 15 hp six; 1929 saw the introduction of a 12 hp vehicle. This was a pioneering year for the marque, during which it first offered the Wilson preselector gearbox as an optional extra; it became standard issue on all cars from 1933. In 1930 the company marketed four models, of 12, 15, 20, and 30 hp, the latter costing £1450.
The company's rather staid image was endorsed during the 1930s by the introduction of a range of six-cylinder cars with ohv engines, though a four-cylinder 12 hp was kept in production until 1936. In 1933 the 5-litre six-cylinder Siddeley Special was announced, featuring a Hiduminium (aluminum alloy) engine; this model cost £950. Car production continued at a reduced rate throughout 1940, and a few were assembled in 1941.
The week that World War II ended in Europe, Armstrong Siddeley introduced its first post-war models; these were the Lancaster four-door saloon and the Hurricane drophead coupe. The names of these models echoed the names of aircraft produced by the Hawker Siddeley Group (the name adopted by the company in 1935) during the war. These cars all used a 2-litre six-cylinder engines, increased to 2.3-litre engines in 1949. From 1953 the company produced the Sapphire, with a 3.4 litre six-cylinder engine.
In 1956 the model range was expanded with the addition of the 234 (a 2.3-litre four cylinder) and the 236 (with the older 2.3 litre six-cylinder engine). The Sapphire 346 sported a bonnet mascot in the shape of a Sphinx with namesake Armstrong Siddeley Sapphire jet engines attached. The 234 and 236 Sapphires were a radical departure from the traditional Armstrong Siddeley appearance. This, coming in a time of conservative auto design, was not well received by the marque's loyal customers. Hence, the "baby Sapphire" brought about the beginning of the end for Armstrong Siddeley.
The last model produced by Armstrong Siddeley was 1958's Star Sapphire, with a 4-litre engine, and automatic transmission. The Armstrong Siddeley was a casualty of the 1960 merger with Bristol; the last car left the Coventry factory in 1960.
|Model Name||Type||Engine||From||To||No. Produced|
|Eighteen||Various||2400 cc||1921||1925||2500 inc 18/50|
|18/50 or 18 Mk.II||Various||2872 cc||1925||1926||2500 inc Eighteen|
|Twenty||Short and Long chassis||2872 cc||1926||1936||8847|
|Fifteen||Tourer, saloon||1900 cc||1921||1925||7203 inc 15/6|
|Twelve||Tourer, saloon, sports||1236 (1434 cc from 1931)||1929||1937||12500|
|15/6||Tourer, saloon, sports||1900 cc (2169 cc from 1933)||1928||1934||7206 inc Fifteen|
|Siddeley Special||Tourer, saloon, limousine||4960 cc||1933||1937||253|
|Short 17||Coupe, saloon, sports saloon||2394 cc||1935||1938||4260 inc Long 17|
|Long 17||Saloon, tourer, Atlanta sports saloon, Limousine, landaulette||2394 cc||1935||1939||4260 inc Short 17|
|12 Plus & 14||Saloon, tourer||1666 cc||1936||1939||3750|
|20/25||Saloon, tourer, Atlanta sports saloon Limousine, landaulette||3670 cc||1936||1940||884|
|16||Saloon, Sports saloon||1991 cc||1938||1941||950|
|Lancaster 16||4 door saloon||1991 cc||1945||1952||12470 inc Hurricane, Whitley, Typhoon and Tempest.|
|Lancaster 18||4 door saloon||2309 cc||1945||1952||12470 inc Hurricane, Whitley, Typhoon and Tempest.|
|Hurricane 16||Drophead coupe||1991 cc||1945||1953||12470 inc Lancaster, Whitley, Typhoon and Tempest.|
|Hurricane 18||Drophead coupe||2309 cc||1945||1953||12470 inc Lancaster, Whitley, Typhoon and Tempest.|
|Typhoon||Fixed head coupe||1991 cc||1946||1949||12470 inc Lancaster, Whitley and Tempest.|
|Tempest||coupe||1991 cc||1946||1949||12470 inc Lancaster, Whitley and Typhoon.|
|Whitley 18||Various||2309 cc||1946||1949||12470 inc Lancaster, Hurricane, Typhoon and Tempest.|
|Sapphire 346||4 door saloon & Limousine||3435 cc||1952||1958||7697|
|Sapphire 234||4 door saloon||2290 cc||1955||1958||803|
|Sapphire 236||4 door saloon||2309 cc||1955||1957||603|
|Star Sapphire||Saloon & Limousine||3990 cc||1958||1960||980|
|Star Sapphire Mk II||Saloon & Limousine||3990 cc||1960||1960||1|
A feature of many of their later cars was the option of an electrically controlled pre-selector gearbox. Like many British cars of the age there is an active owners club supporting their continued use.
Throughout the 1920s and 1930s, Armstrong Siddeley produced a range of low- and mid-power aircraft radial engines, all named after big cats. They also produced a tiny 2-cylinder engine called the Ounce, for ultralight aircraft.
The company started work on their first gas turbine engine in 1939, following the design pioneered at the Royal Aircraft Establishment by Alan Arnold Griffith. Known as the "ASX" for "Armstrong Siddeley eXperimental", the original pure-turbojet design was later adapted to drive a propeller, resulting in the "ASP". From then on, AS turbine engines were named after snakes. The Mamba and Double Mamba were turboprop engines, the latter being a complex piece of engineering with two side-by-side Mambas driving through a common gearbox, and could be found on the Fairey Gannet. The Python turboprop powered the Westland Wyvern strike aircraft. Further development of the Mamba removed the reduction gearbox to give the Adder turbojet.
Another pioneer in the production of the RAE engine design was Metrovick, who started with a design known as the Metrovick F.2. This engine never entered production, and Metrovick turned to a larger design, the Beryl, and then to an even larger design, the Sapphire. Armstrong Siddeley later took over the Sapphire design, and it went on to be one of the most successful 2nd generation jet engines, competing with the better-known Rolls-Royce Avon.
The company went on to develop an engine - originally for unmanned Jindivik target drones - called the Viper. This product was further developed by Bristol Siddeley and, later, Rolls-Royce and was sold in great numbers over many years. A range of rocket motors were also produced, including the Snarler and Stentor. The rocket development complemented that of Bristol, and Bristol Siddeley would become the leading British manufacturer of British rocket engines for missiles.
Between 1930 and 1955, Armstrong Siddeley produced the 'AS' range of medium-speed diesel engines, with a top speed of 1500 RPM. These air-cooled engines were intended for industrial and marine use, producing 10 horsepower (7.4 kW) per cylinder, and each cylinder had a capacity of 988cc (60.2 cubic inches). 1-, 2- and 3-cylinder engines were produced, designated the AS1, AS2 and AS3 respectively. The engines were often used in barges and narrowboats on British canals, as well in domestic and light industrial electric generator sets.