This section covers the company history and information on the various sites
The two photos below come from the book "B. T. H. : Reminiscences, sixty years of progress ", compiled by H. A. Price-Hughes and published in 1946; The BTH site was built in 1900 on approximately 25 acres of land, known as Glebe Farm, bought from Thos. Hunter & Co. (railway wagon builders).
This map was published in 1964 but is probably based on site information from 1960. It shows the company at its fullest extent. The company had become AEI in 1960 and would become GEC in 1967.
North of the river Avon was the Boughton Road site.
South of the river was the Mill Road site, presumably so named because the main entrance to the site was on Mill Road.
In the top right hand corner is BR57, the new AEI Research Laboratory. The western part had been completed and opened in 1960, with completion of the eastern part in 1961. BR57A would not be built until the late 1970s.
The shaded area shows the extent of the site in 2026. The rest is now retail and housing.
This is an aerial view of the site as it was in 1963