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 vehicles and
aircraft engine
An aircraft engine, often referred to as an aero engine, is the power component of an aircraft propulsion system. Most aircraft engines are either piston engines or gas turbines, although a few have been rocket powered and in recent years many ...
s.
The company was created following the purchase by
Armstrong Whitworth of
Siddeley-Deasy, a manufacturer of fine motor cars that were marketed to the top echelon of society. After the merge of companies, this focus on quality continued throughout in the production of cars, aircraft engines, gearboxes for tanks and buses, rocket and torpedo motors, and the development of railcars. Company mergers and takeovers with
Hawker Aviation and
Bristol Aero Engines saw the continuation of the car production which ceased in August 1960.
The company was absorbed into the
Rolls-Royce conglomerate which was interested in the aircraft and aircraft engine business. Eventually, the remaining spares and all motor car interests were sold to the Armstrong Siddeley Owners Club Ltd, which now owns the patents, designs, copyrights and trademarks, including the name Armstrong Siddeley.
Considered "an elegant car appropriate for
royal use", the "Armstrong Siddeley Saloon" was used by the
Prince of Wales (later King Edward VIII) during his 1930 tour of
Uganda.
History
Siddeley Autocar

The Siddeley Autocar Company, of
Coventry, was founded by
John Davenport Siddeley (1866–1953) in 1902. Its products, made for him by a
Vickers subsidiary, were heavily based on
Peugeots using many Peugeot parts and fitted with English-built bodies. J. D. Siddeley was appointed London sales manager of Vickers Limited's subsidiary
Wolseley in early 1905 at the same time as Wolseley purchased the goodwill and patent rights of his Siddeley car.
["The Wolseley Tool and Motor-Car Company Limited has absorbed the Siddeley Autocar Company Limited and has acquired Niagara Westminster for premises for a London office and garage. The two companies have long been associated, the Siddeley cars being made by the Wolseley company." The Times, Monday, 13 Feb 1905; pg. 9; Issue 3762] A few months later
Herbert Austin left to form his own business and Siddeley was appointed general manager.
[Lambert (1968), Chapter 6: The Austin Motor Company is formed]
Without the consent of the Vickers brothers Siddeley added his own name to the Wolseley nameplate but it was dropped on his departure.
Siddeley-Deasy
In 1909 J. D. Siddeley resigned from Wolseley and in 1910 took on management of The Deasy Motor Car Manufacturing Company, Limited. The shareholders were so pleased with his success in that post that on 7 November 1912 they unanimously agreed to change the company's name to The Siddeley-Deasy Motor Car Company Limited. Siddeley's name had been added to the product's radiator earlier in 1912. His cars began to use the slogan "As silent as the Sphinx", sporting a
Sphinx as a bonnet ornament.
Armstrong Siddeley

In April 1919 Siddeley-Deasy was bought out by
Armstrong Whitworth Development Company of
Newcastle upon Tyne and in May 1919 became Armstrong Siddeley Motors Ltd, a subsidiary with J. D. Siddeley as managing director. In 1927, Armstrong Whitworth merged its heavy engineering interests with
Vickers to form
Vickers-Armstrongs. At this point, J. D. Siddeley brought Armstrong Siddeley and
Armstrong Whitworth Aircraft into his control. In 1928, Armstrong Siddeley Holdings bought
Avro
AVRO, short for Algemene Vereniging Radio Omroep ("General Association of Radio Broadcasting"), was a Dutch public broadcasting association operating within the framework of the Nederlandse Publieke Omroep system. It was the first public broad ...
from
Crossley Motors. Also that year Siddeley partnered with
Walter Gordon Wilson, inventor of the
pre-selector gearbox, to create Improved Gears Ltd, which later became
Self-Changing Gears – the gearbox that should be credited with enabling the marketing tagline "Cars for the daughters of gentlemen".
Armstrong Siddeley manufactured luxury cars, aircraft engines, and later, aircraft. In 1935, J. D. Siddeley's interests were purchased for £2 million by aviation pioneer
Tommy Sopwith
Sir Thomas Octave Murdoch Sopwith, CBE, Hon FRAeS (18 January 1888 – 27 January 1989) was an English aviation pioneer, businessman and yachtsman.
Early life
Sopwith was born in Kensington, London, on 18 January 1888. He was the eig ...
, owner of
Hawker Aircraft
Hawker Aircraft Limited was a British aircraft manufacturer that was responsible for some of the most famous products in British aviation history.
History
Hawker had its roots in the aftermath of the First World War, which resulted in the bank ...
, to form – along with the
Gloster Aircraft Company and Air Training Services –
Hawker Siddeley
Hawker Siddeley was a group of British manufacturing companies engaged in aircraft production. Hawker Siddeley combined the legacies of several British aircraft manufacturers, emerging through a series of mergers and acquisitions as one of onl ...
, a famous name in British aircraft production. Armstrong Whitworth Aircraft and Armstrong Siddeley Motors became subsidiaries of Hawker Siddeley, with Sopwith himself becoming the new chairman of Armstrong Siddeley Motors. At this time, there remained an "unbroken business association" between the
Siddeley family and the Middleton-Joy family who were manufactures of
Filtrate Oil and had enjoyed considerable success in
car-racing rallies.
Armstrong Siddeley was merged with the aircraft engine business of
Bristol Aeroplane Company
The Bristol Aeroplane Company, originally the British and Colonial Aeroplane Company, was both one of the first and one of the most important British aviation companies, designing and manufacturing both airframes and aircraft engines. Notable a ...
(Bristol Aero Engines) to form
Bristol Siddeley as part of an ongoing rationalisation under government influence of the British aircraft and aircraft engine manufacturers. Armstrong Siddeley produced their last cars in 1960. Bristol Siddeley and
Rolls-Royce merged in 1966, the latter subsuming the former which remained for a while as an aircraft engine division within Rolls-Royce.
In June 1972, Rolls-Royce (1972) Ltd sold all the stock of spares plus all patents, specifications, drawings, catalogues and the name of Armstrong Siddeley Motors Ltd to the Armstrong Siddeley Owners Club Ltd. This meant that "Armstrong Siddeley" and "A-S Sphinx Logo" are trademarks and copyright of the Armstrong Siddeley Owners Club Ltd.
The "Siddeley" name survived a while longer in aviation, through Hawker Siddeley Aviation and Hawker Siddeley Dynamics. In 1977 they joined with others to become
British Aerospace (BAe) which with further mergers is now
BAE Systems
BAE Systems plc (BAE) is a British multinational arms, security, and aerospace company based in London, England. It is the largest defence contractor in Europe, and ranked the seventh-largest in the world based on applicable 2021 revenues. ...
.
Products
Motor cars
The first car produced from the union was a fairly massive machine, a 5-litre
. A smaller 18 hp 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
Wilson may refer to:
People
* Wilson (name)
** List of people with given name Wilson
** List of people with surname Wilson
* Wilson (footballer, 1927–1998), Brazilian manager and defender
* Wilson (footballer, born 1984), full name Wilson Ro ...
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 last 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
The engine configuration describes the fundamental operating principles by which internal combustion engines are categorized.
Piston engines are often categorized by their cylinder layout, valves and camshafts. Wankel engines are often categorize ...
12 hp was kept in production until 1936.
In 1932 - or thereabouts, a line of special, rather more sporty designs was started which resulted in the Rally Tourer series. The aim was to help shake off the somewhat pedestrian image of what was in fact a rather advanced product. Of the 16 rally tourers built, many were used by the owners or senior directors, and were entered into various rallies, achieving some good results and making for good publicity. Only one of those 16 special cars is now known to exist: a 1933, Long-15 Rally Tourer which, according to the records, shared the same body as the 20 hp version (which had a slightly longer bonnet).
In 1933, the 5-litre six-cylinder Siddeley Special was announced, featuring a
Hiduminium aluminium 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
A convertible or cabriolet () is a passenger car that can be driven with or without a roof in place. The methods of retracting and storing the roof vary among eras and manufacturers.
A convertible car's design allows an open-air driving expe ...
coupe. The names of these models echoed the names of
aircraft produced by the
Hawker Siddeley Group
Hawker Siddeley was a group of British manufacturing companies engaged in list of aircraft manufacturers, aircraft production. Hawker Siddeley combined the legacies of several British aircraft manufacturers, emerging through a series of mergers ...
(the name adopted by the company in 1935) during the war. These cars all used a 2-litre six-cylinder (16 hp) engines, increased to 2.3-litre (18 hp) engines in 1949. From 1949 to 1952 two commercial variants of the
18 hp Whitleys were produced, primarily for export. The Utility Coupé was a conventional
coupe utility
A coupe or coupé (, ) is a passenger car with a sloping or truncated rear roofline and two doors.
The term ''coupé'' was first applied to horse-drawn carriages for two passengers without rear-facing seats. It comes from the French past parti ...
style vehicle, while the Station Coupé was effectively a dual cab vehicle, although it still retained only two doors. However, it did have two rows of seating to accommodate up to four adults and the doors were larger to allow better access to the rear. 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 might have looked to some of marque's loyal customers like a radical departure from the traditional Armstrong Siddeley appearance. However, in truth, they were simply too conservative in a period of rapidly developing automotive design. If the "baby Sapphire" heralded the beginning of the end for Armstrong Siddeley, it was because Jaguar had launched the unitary-construction 2.4 saloon in 1955, which was quicker, significantly cheaper, and much better-looking than the 234 and 236.
The last new 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 list
Cars produced by Armstrong Siddeley had designations that came from the
tax horsepower rating of their engines.

A feature of many of their later cars was the option of an electrically controlled pre-selector gearbox.
Armstrong Siddeley 12.jpg, Twelve 1½-litre
Armstrong Siddeley Long 15 1935.jpg, Fifteen 2-litre
arm-sid.1939.16hp.arp.750pix.jpg, Sixteen 2¼-litre
1938 Armstrong Siddeley 17 saloon.jpg, Seventeen 2½-litre
KV5824 Armstrong Siddeley.jpg, Thirty 5-litre
Vintage Car - Armstrong Siddeley 234 Sapphire MFF 496 110612 Sandringham.jpg, Sapphire 234
2.3-Litre 4-cylinder
Armstrong Siddeley motif - Flickr - exfordy (1).jpg, Armstrong Siddeley's sphinx
Armstrong Siddeley Sapphire 346 BW 1.jpg, Sapphire 346
3.4-Litre 6-cylinder
Classic Car Day - Trentham - 15 Feb 2009 - Flickr - 111 Emergency (43).jpg, Star Sapphire
4-Litre 6-cylinder
RAF Museum Cosford - DSC08648.JPG, Sapphire 200
turbojet
Clubs
Like many British cars of this era, there are active owners' clubs supporting their continued use in several countries, e.g. the UK, Australia, New Zealand, the Netherlands and Germany. Armstrong Siddeley Owners Club Ltd has members worldwide and many members of the ASCC in Australia are resident overseas.
In the United Kingdom, ASOC publishes a monthly members magazine ''Sphinx''. In Australia, the Armstrong Siddeley Car Club publishes ''Southern Sphinx'' six times a year. In the Netherlands, ASOC Dutch also publishes six times a year, and in New Zealand, Armstrong Siddeley Car Club in New Zealand Inc. publish ''Sphinx-NZ'' monthly.
Aircraft engines

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, another name for the
snow leopard, for ultralight aircraft.
The company started work on their first
gas turbine engine in 1939, following the design pioneered at the
Royal Aircraft Establishment
The Royal Aircraft Establishment (RAE) was a British research establishment, known by several different names during its history, that eventually came under the aegis of the Ministry of Defence (United Kingdom), UK Ministry of Defence (MoD), bef ...
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
Adder may refer to:
* AA-12 Adder, a Russian air-to-air missile
* Adder (electronics), an electronic circuit designed to do addition
* Adder Technology, a manufacturing company
* Armstrong Siddeley Adder, a late 1940s British turbojet engine
* ''B ...
turbojet.
Another pioneer in the production of the RAE engine design was
Metrovick
Metropolitan-Vickers, Metrovick, or Metrovicks, was a British heavy electrical engineering company of the early-to-mid 20th century formerly known as British Westinghouse. Highly diversified, it was particularly well known for its industrial el ...
, who started with a design known as the
Metrovick F.2
The Metropolitan-Vickers F.2 is an early turbojet engine and the first British design to be based on an axial-flow compressor. It was an extremely advanced design for the era, using a nine-stage axial compressor, annular combustor, and a two- ...
. 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 rocket engines for missiles.
Diesel engines
In 1946 Armstrong Siddeley produced their first
diesel engines. They were medium-speed engines for industrial and agricultural use. Initially there was a single-cylinder engine producing 5 bhp (3.7 kW) at 900 rpm and a twin-cylinder version. Each cylinder had a capacity of 988 cm
3 (60.2 cubic inches). The power output and speed was progressively increased. By the end of 1954 the single-cylinder engine was rated at 11 bhp (8.2 kW) at 1800 rpm and the twin-cylinder engine 22 bhp (16.4 kW) at the same speed. In 1955 the range was extended with the introduction of a 3-cylinder engine rated at 33 bhp (24.6 kW).
The engines were built at Armstrong Siddeley's factory at Walnut Street in
Leicester
Leicester ( ) is a city status in the United Kingdom, city, Unitary authorities of England, unitary authority and the county town of Leicestershire in the East Midlands of England. It is the largest settlement in the East Midlands.
The city l ...
until that factory closed in August 1957. Production was transferred to the factory of Armstrong Siddeley (
Brockworth
Brockworth is a village and parish in the Borough of Tewkesbury, Gloucestershire, England, situated on the old Roman road that connects the City of Gloucester with Barnwood. It is located 4 miles (6.5 km) southeast of central Gloucester ...
) Ltd in Gloucestershire and in 1958 to the factory of
Petters Limited at Staines, Middlesex. The engines built by Petters were designated AS1, AS2 and AS3 to distinguish them from that company's other products. Production ended in 1962 when Petters
introduced a replacement range of lightweight small high-speed air-cooled diesel engines.
In April 1958 the company obtained a licence to build the
Maybach MD series high-speed diesel engines.
[Armstrong Siddeley Motors, Minutes of Board Meetings, 2 April 1958 and 28 April 1958] Several hundred were built by
Bristol Siddeley Engines Ltd after that company took over Armstrong Siddeley's manufacturing activities in 1959.
See also
*
List of aircraft engines
This is an alphabetical list of aircraft engines by manufacturer.
0–9 2si
*2si 215
*2si 230
* 2si 430
* 2si 460
*2si 500
* 2si 540
* 2si 690
3W
''Source: RMV''
*3W 106iB2
*3W-110
*3W-112
*3W-170
*3W-210
*3W-220
A
Abadal (Fr ...
*
List of car manufacturers of the United Kingdom
:''This list is incomplete. You can help by adding correctly sourced information about other manufacturers.''
As of 2018 there are approximately 35 active British car manufacturers and over 500 defunct British car manufacturers. This page lists ...
Notes
References
Citations
Bibliography
*
*
Further reading
*Robert Penn Bradly: Armstrong Siddeley, the Post War Cars; Motor Racing Publications, Croydon, 1989.
*Robert Penn Bradly: The 346 Sapphire explored to great depth; Pimula PTY Pvt., Bardwell Park, NSW, 2008.
*Bruce Lindsay: Armstrong Siddeley, the Sphinx with the heart of a lion; Lindsay family trust, Thailand, 2010.
External links
Armstrong Siddeley Owners Club for the carsNon-affiliated Internet forum for Armstrong Siddeley enthusiasts world-wide*
{{ASaeroengines
Defunct motor vehicle manufacturers of the United Kingdom
Defunct engineering companies of England
British companies established in 1919
Coventry motor companies
Rocket engine manufacturers of the United Kingdom
Defunct aircraft engine manufacturers of the United Kingdom
Vehicle manufacturing companies established in 1919