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Brynmawr Rubber factory, site of
near Ebbw Vale, South Wales, UK
Brynmawr Rubber factory, site of
associated engineer
Sir Ove Arup
Ronald Jenkins
Ove Arup & Partners
date  1945 - 1951
UK era  Modern  |  category  Building  |  reference  SO187114
photo  Sydney Newbury, see note at the end of the text
The Brynmawr factory complex — used for the manufacture of rubber and PVC flooring — provided engineer Ove Arup with a chance to demonstrate his command of reinforced concrete shell structures. Despite its Grade II* listing, the factory was demolished in 2001.
In his new-found role as consultant, as opposed to design engineer for a contractor, and working in conjunction with the Architects Co-Partnership, Arup acted as structural engineer for this landmark building. He had become a reinforced concrete specialist while working for contracting firms Christiani & Neilsen (from 1922 to 1934) and J.L. Kier & Co (from 1934 to 1938). Around the time of World War II, he founded the practice that in 1948 became Ove Arup & Partners, now known as just Arup.
The centrepiece of the Brynmawr factory was the roof of the main factory floor. It consisted of nine concrete shells, grouped three by three, each 25.9m long and 18.9m wide. Each shell — a two way span — was slightly domed to make use of the compressive strength of the reinforced concrete, which at less than 90 mm thick appeared to be wafer thin.
The shells were a design and technical collaboration between Arup and partner Ronald Jenkins. Arup remarked on a visit to the USA in 1955, having learned that a three-point shell support designed for the Kresge Auditorium at MIT by Eero Saarinen had cracked through deflection, "possibly they don’t know how to calculate the thing not having Ronald around". Jenkins had worked with Arup at contractor Kier.
The shells were punctuated by circular roof lights in a style popular with Modern Movement architects (see the atrium at the 1932 Boots Packed Wet Goods Factory at Beeston by Owen Williams). This, together with the clerestory glazing made possible by the geometry of the roofs, gave an extraordinary cathedral-like quality to the factory space.
The roof sections were supported at each corner by groups of angled finger-like concrete columns just 4.3m above the floor, giving the vast space a human scale. As the factory focused on assembly and production work, extra height was unnecessary. However, the low clearance restricted the number of possible alternative uses for the building which may ultimately have helped seal its fate.
The columns were grouped in fours, in tight 'V' formations at floor level then angling outward as they rose until parallel to the edges of the shells. Their positioning and proportion contributed the apparent lightness of whole — any need to increase the column cross-sections or thicken the shells at points of maximum bending moment was avoided. Beams ran round the perimeters of the shell sections at springing-point height. Power, water and other services were carried on their undersides.
Around the perimeter of the main factory were a series ancillary buildings roofed by a multiplicity of small-scale barrel vaulted concrete construction, over-poured in situ. Visually-uncompromising featureless vertical concrete wall slabs in the Modernist style gave emphasis to the lakeside elevations.
Gwynne Bosley, who worked in the factory between 1956 and 1960, has described how rubber flooring in sheet and tile form was produced in the former Mill Room in the basement area. PVC flooring was produced on the first floor. He also described how workers were plagued by the leaky roof. Some sources claim that the plastic explosive known as Semtex was later produced at Brynmawr but this is untrue.
After fifty years, the building was deemed unsuitable for present day use, and was considered by local authorities to be an obstacle to progress in the expansion of the local economy. In 2001, despite Grade II* listing and the best efforts of conservationists, the complex was demolished, depriving future generations of a wonderful example of engineering excellence.
Note: the photo is reproduced from "Proceedings of a Symposium on Concrete Shell Roof Construction - 2-4th July 1952" published by the Concrete and Cement Association, in an article entitled "Various Forms of Shell Roofing and their Application" by Edward David Mills, pp22, uncredited, reproduced with the permission of The Concrete Society.
Research: ND
"A History of Architecture on the Comparative Method" by Sir Banister Fletcher
17th Edition, revised by R.A. Cordingley, Athlone Press, London, 1963
"Built for a Better Future, The Brynmawr Rubber Factory" by Victoria Perry
White Cockade Publishing 1994
With thanks to Gwynne Bosley
reference sources   OA

Brynmawr Rubber factory, site of