The precise date of the origin of this factory has not been traced, but it is was already in existence before 1939 and at that time it was known as the Vale Royal Electric Lamp Company. At the outset of the second world war it was taken over by the nearby Atlas Lamp Works of Jules Thorn at
Edmonthon, to provide that company with a secondary manufacturing site in case its own factory should have been bombed.
At the time of its origins, it is likely that Tottenham would have been producing ordinary General Lighting Service incandescent lamps. After the Thorn takeover, it produced more specialised varieties, including incandescent projector lamps and a small operation for the production of neon glow lamps. These were also made for Osram and Philips, the latter of which had close co-operation with Thorn in certain areas.
Adjacent to the original Vale Royal factory was the main Thorn Lighting Tottenham Lamp Works (TLW). Until its closure this site manufactured all of the company's fluorescent starter switches, as well as a comprehensive range of tungsten halogen sources. Aside from the photographic / projection halogen types, it also produced Automotive headlamps type H1, H3 and the double-filament H4, which were marketed under various names such as Thorn, GEC, Jahn, FoMoCo and sometimes Lucas. Long after its disappearance for general lighting products, the Ediswan brand name continued to live on for these halogen types, most notably for the headlamps of the New Zealand railway locomotives, where that brand name maintained a particulary strong position. Linear halogen lamps for general floodlighting made up a significant part of the production, along with linear infrared heat sources - these being produced not only for Thorn but also for Sylvania of America, with whom Thorn had close technical relations. A derivative of the halogen heat lamp was a special version created for the emerging market of photocopiers, and these were produced for several of the major manufacturers, such as Rank Xerox.
The plant required a number of specialised materials for its production. All filaments were produced internally by the Thorn factory at
Merthyr Tydfil in South Wales, with formed metal parts coming from the nearby Lamp Presscaps division of Thorn at Edmonton. Quartz tubing was produced by Chance Bros, as well as imported from Corning USA. Special gases such as tritium for starter switches, and bromine and argon for halogen lamps were supplied by the British Oxygen Company, with liquid oxygen being sourced from Air Products Ltd.
In 1981 the site at Tottenham was closed, and most of the production was relocated to Thorn's nearby factory at
Enfield. Enfield had previously made only fluorescent lamps, so it was logical that the manufacture of fluorescent starter switches would be moved to that site. Despite the fact that Thorn had another halogen factory at
Leicester, the Tottenham halogen production was also relocated into the
Enfield fluorescent works.
After lamp manufacturing ceased at Lawrence Road, the site was retained by Thorn for a number of years and accommodated the Sales department which moved out of the company Headquarters on Upper St. Martins Lane, London.
