top of page
The History of Armstrong Siddeley and its Associated Companies

For most people, the Armstrong Siddeley name is only associated with motor cars, few if any would expect the Siddeley name to have a connection with aircraft or aero-engines, add in the names Armstrong Whitworth Aircraft, Hawker Siddeley or Bristol Siddeley and confusion abounds! Yet all of these companies are associated through one John Siddeley.


To appreciate how over a period of some 40 years the Siddeley name prevailed, it is convenient to start our investigation as the first World War came to an end. The years which followed would see mergers, take-overs and the creation of new subsidiaries due to market demand and technical developments. Sadly, there would be not a little interference from successive governments, especially in the aero industry and wherever government contracts were involved.

Appointed in 1909 as General Manager of the Deasy Motor Company, John brought the Company into substantial profit and created an organisation to which he was proud to add his name. In June 1915 the now, Siddeley-Deasy Company, was awarded one of only five government contracts given for the production of aircraft and aero engines despite being the smallest of those selected. This sudden turn of events caused Siddeley Deasy to expand the workforce and turnover most dramatically. How to replace this volume of business when the Government no longer required 'war work' was now the foreseeable problem. So it was in 1918 most of British Industry found itself with massive overcapacity. Failing to see alternative work for their employees some companies simply closed down their facilities.  Not so John Siddeley, who having already given thought as to how he should prepare for the future took a very different approach. He was convinced there was a future beyond warfare for aircraft and looked around for some other company with whom he could work.


During the WW1 Siddeley-Deasy had developed a strong relationship with Armstrong Whitworth who supplied them casting for their Aero-Engines, accordingly  John Siddeley approached them and suggested a merger as being beneficial to both companies. After protracted negotiations, Armstrong Whitworth aquired Siddeley-Deasy in May 1919  and a new subsidiary company was formed to be known as the Sir W.G. Armstrong Whitworth Development Co.  Interestingly John Siddeley was not appointed to the board of this company and was kept at arm's length as MD its new subsidiary company of Armstrong Siddeley Motors which was in effect Siddeley-Deasy under a new name.


During WW1 Armstrong Whitworth manufactured aircraft under the name of Armstrong Whitworth Aircraft (AWA). Following the cessation of hostilities, the company announced that it saw no future in continuing to make aircraft and commenced the winding down of its facilities.


In April 1920 Armstrong Siddeley Motors submitted to the Newcastle board a proposal the company "should continue aircraft work on a limited scale by forming a subsidiary company". The board agreed, and shortly afterwards, on a date not specifically noted, there came into existence The Sir W. G. Aircraft Co Ltd [1]. It is unclear who was managing director of this company but it was located in the facilities of Armstrong Siddeley Motors and was certainly under the day to day direction of John Siddeley.   

By 1920 all former aircraft production was transferred from Newcastle to the Armstrong Siddeley Motors Parkside works in Coventry. These changes created a stable organisation which proved able to withstand the vagaries of the following years thus ensuring the continuation of employment for many of John Siddeley's workforce and for the few who chose to move south from Newcastle. The new company structure is shown in the attached chart.

ASD 15th March 202 V3.PNG

The first Armstrong Siddeley motor car was announced in 1919 as the 30hp with full production and deliveries commencing in 1920, this was followed by a scaled-down version known as the 18hp in 1921 with a family sized car known as the 14/4 beings introduced in 1923. Throughout the 1920s and '30s car production continued apace with new improved models being introduced regularly, these ranged from the relatively moderated sized 12hp family saloons through to the spacious 20/25 limousines.

Work on motors car, aero-engines and aircraft were initially centred on the Parkside works until in 1920 the company purchased the former RAF aerodrome at Whiteley just outside of Coventry. The facility had been used as a storage depot by the RAF, in the opinion of John Lloyd, the chief aircraft designer, it was too small and a rather awkward shape for aircraft testing but John Siddeley when ahead regardless!

Once Whitely had been acquired John Siddeley established a flying school with Major Griffiths as its chief instructor, by 1923 a Government contract to train pilots of the RAF reserve had been secured. This enterprise proved to be very lucrative for Armstrong Siddeley and in future years became a very important part of the companies business.


1923 was also the year that aircraft manufacture moved from Parkside to Whiteley although the design staff remained at Parkside until 1930. Aircraft manufacture was mainly limited to prototype production with an early Siskin being one of the first aircraft to fly out of the airfield. It was not until the following year that full production got underway with a Government contract for Siskin aircraft for the RAF. Aero-engine production remained at Parkside with the very successful Jaguar engine and its derivatives entering full and profitable production by 1923.



By 1926 the Armstrong Whitworth Development Co was prospering; the Jaguar and Lynx Aero-engines had entered full production, the Siskin MkII aircraft was entering service with the Royal Air Force and there was a strong demand for the full range Armstrong Siddeley motor cars.


The same could not be said for the parent company, shipbuilding and heavy engineering had suffered from falling orders following the end of WW1 and they had made a disastrous foray into paper pulp manufacturing in Canada. According to Harold Chapman, a future managing director of Armstrong Siddeley, the £1 shares had slumped from £5 in 1924 to little more than 10 pence in 1926, accordingly, a board of reconstruction was appointed under the chairmanship of Lord Southbourough who invited John Siddeley to join his team. Siddeley was appalled to find that the profits of his company propping up the remainder of Armstrong Whitworth.


This was not an acceptable situation for Siddeley who approached the Midland Bank to seek a loan with a view to purchasing the Development Company from Armstrong Whitworth. The Midland Bank chairman, Reginald Mckenna, who had high regard for Siddeley, immediately advanced an unsecured loan sufficient to buy out the development company together with sufficient working capital. 


In November 1926 Siddeley approached the Newcastle board with an audacious bid of £1,500,000  for the Development Company, at first they turned the offer down but such was the dire straits that they found themselves in they finally accepted his offer in December of that year. In 1927 Armstrong Whitworth was acquired by Vickers limited to become Vickers Armstrong.

One of John Siddeley's first actions was to stamp his own authority upon the new company, in March 1927 he called a general meeting for the purpose of changing the name from the Armstrong Whitworth Development Co. to the Armstrong Siddeley Development Co. The main assets of this new company were Armstrong Siddeley Motors and Sir W. G. Armstrong Whitworth Aircraft Co. together with 250,000 shares in the Chelmsford firm of Crompton and Co. manufacturers of electrical equipment.


1927 was a year of considerable success for Siddeley's new company with the Siskin Mk IIIA being brought into production together with a large order for the Atlas aircraft, this was also the year that the first of three AWA Argosy passenger planes were delivered to Imperial Airways. Aero-aero engines were still selling well and Armstrong Siddeley Motors had a strong order book.

The A. V. Roe aircraft company was one of the earliest British Aircraft manufacturers and during WW1 its type 504 aircraft saw front line service in the initial phases of the war and then found a second life as a training aircraft. Following the end of hostilities, they found themself in financial difficulties and were acquired by Crossley Motors. By 1928, Crossley needed a cash injection and offered A. V. Roe to Siddeley for a sum of around £250,000. The proposition was attractive to Siddeley as the type 504 trainer was still in production and was now powered by his Lynx aero-engine, the purchase of A. V. Roe was quickly completed ensuring that the 504 would continue to be powered by the Lynx engine. 


The Jaguar aero-engine relied upon Aluminium pistons supplied by Peter Hooker Ltd had gone into liquidation, Wallace Devreux who was their manager at the time approached Siddeley for help with funding to form a company to fulfil the large order that had been placed with Hookers. Siddeley advanced him £10,000 which was quickly absorbed and further injections of cash ultimately lead to High Duty Alloys becoming a subsidiary of the Development Company. For as little as £30,000 Siddeley had aquired an important company both for his aero-engines and for the nation as this alloy became an essential part of the aero industry during WW2. 

Armstrong Siddeley Development company structure looked like this together with future acquisitions :

1927 V2.JPG

In 1935 

bottom of page