Grace's Guide To British Industrial History

Registered UK Charity (No. 115342)

Grace's Guide is the leading source of historical information on industry and manufacturing in Britain. This web publication contains 162,349 pages of information and 244,505 images on early companies, their products and the people who designed and built them.

Grace's Guide is the leading source of historical information on industry and manufacturing in Britain. This web publication contains 147,919 pages of information and 233,587 images on early companies, their products and the people who designed and built them.

Plessey Co

From Graces Guide

The Plessey Company' was an electronics, defence and telecommunications company.

  • 1917 The Plessey company was founded in Marylebone, central London. The original shareholders were Thomas Hurst Hodgson, C. H. Whitaker, Raymond Parker and his brother Plessey Parker. A talented German engineer, William Oscar Heyne was employed by the company. Heyne later became the Managing Director and President of Plessey and was one of the key figures in the development of Plessey during the 1920s and 30s.
  • 1919 The company moved to Cottenham Road in Ilford early in 1919 (and then to Vicarage Lane where it remained). Most of the early work carried out by the company was mechanical engineering rather than electronics.
  • During the 1920s Plessey began to diversify into electrical manufacturing, important contracts included the manufacture of early radios for Marconi and the production of telephones for the GPO.
  • In 1929 the television pioneer John Logie Baird had his first production televisions produced by Plessey. The company also produced the first British made portable battery radio in the same year.
  • 1935 Became a private company
  • 1937 Changed name and became a public company
  • 1937 Radio and electrical engineering manufacturers.
  • The manufacture of electrical components also became a key area of growth for Plessey, a vast array of different components was manufactured by the company, many under licence from overseas companies. Plessey became one of the largest manufacturers in this field as the radio and television industries grew.
  • An early customer of Plessey was a galvanising company called British Electro Chemists. One of that companies shareholders was Byron G. Clark, an American, who was also a business associate of T. H. Hodgson, one of the founders of Plessey. The Clark family would eventually dominate the management of Plessey for most of its history. Byron's son Allen George Clark joined the company in 1921, and went on to become a major driving force behind the development of Plessey, followed later by his sons John Clark, and Michael Clark, both of whom rose to prominent positions in the company.
  • Aircraft components was another market into which Plessey diversified. In 1936 Plessey obtained a number of important manufacturing licences from American companies such as, Breeze Corporation for aircraft multi-pin electrical connectors, Federal Laboratories for Coffman starters (an explosive cartridge device used to start aircraft engines), and Pump Engineering Services Corporation for the manufacture of Pesco fuel pumps. Plessey went on to produce large numbers of Pesco fuel pumps for Rolls-Royce Merlin engines, and in 1940 the fuel pump for Britain's first jet engine was also supplied by Plessey.
  • WW II During the war, Plessey produced a vast array of components and equipment for the war effort, including shell cases, aircraft parts, and radio equipment such as the R1155(receiver), and T1154(transmitter). Following the bombing of its Ilford site, Plessey converted a section of tunnel, built for a new extension to the London Underground Central Line, into a munitions factory. The company also built a new factory at Swindon, and opened several other shadow factories around the country. The wartime workforce of Plessey grew to over 10,000 people.
  • 1961 Parent with 23 subsidiaries and based at Ilford. Employs 17,500 persons. Designers and manufacturers of radio and television apparatus and components, electronic equipment, telecommunication equipment, electrical equipment, electrical instruments and commercial hydraulic power systems. Makers of general light engineering products and atomic energy power control equipment.
  • In 1961 Plessey merged with the British Ericsson Telephone Co, and the Automatic Telephone & Electric (AT&E), to become Britain's largest manufacturer of telecommunications equipment including the majority of the country's crossbar switches.
  • Plessey were partners in the development of the Atlas Computer in 1962 and in the development of Digital telephone systems - System X - during the late 1970s. During the 1970s and early 1980s, Plessey manufactured a series of computer systems and peripherals compatible with Digital Equipment Corporation's PDP-11.
  • In December 1985 GEC launched a takeover bid for the Plessey Company, valuing the group at £1.2 billion. Both Plessey and the Ministry of Defence were against the merger, GEC and Plessey were the two largest suppliers to the MoD and in many tenders the only competitors. In January 1986 the bid was referred to the Monopolies and Mergers Commission (MMC), whose report published in August advised against the merger. The government concurred and blocked GEC's bid.
  • In 1988 Plessey and The General Electric Company (GEC) merged their telecom units to form GEC-Plessey Telecommunications (GPT), the UK's leading telecommunications manufacturer.
  • In 1988 GEC and Siemens AG set up a jointly held company, GEC Siemens plc, to launch a hostile takeover of Plessey. GEC Siemens' initial offer was made on 23 December 1988 valuing Plessey at £1.7 billion. Again Plessey rejected the offer and again it was referred to the MMC. The original proposal envisaged joint ownership of all of Plessey's defence businesses, with GPT and Plessey's North American businesses split in the ratios 60:40 and 51:49 respectively. The level of GEC's involvement in the Plessey defence businesses was not likely to meet with regulatory approval and in February GEC Siemens announced a new organisation. The takeover was completed in September 1989.



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