Supermarket, Canterbury, Kent

For J Sainsbury plc

SSDA COMMENDATION
1985

Architects: Ahrends, Burton & Koralek in association with J Sainsbury plc
Structural Engineers: Ernest Green & Partners
Steelwork Contractors: Tubeworkers Ltd

The design for the supermarket was the winning entry in a limited competition promoted by Sainsbury’s in 1982.

The site lies to the east of the city centre with open views of the city dominated by the cathedral. The building consists of three linked clear span spaces for sales, storage and preparation and goods receiving. Flat roofs are supported on slender steel beams which are suspended from tubular steel masts by stayed tie rods. The silver coloured masts and ties give height and vertical emphasis to an otherwise low lying building on a rather featureless site and provide a visual echo of the tower and pinnacles of the distant cathedral.

The superstructure consists of two distinct elements. The principal element is the clear span suspended steelwork structure, which encompasses the sales, bulk stock and unloading areas with a total of 18 bays at 7m centres and widths of 23-36m. This structure is designed to provide large clear span spaces entirely free of fixed structural elements.

Dropped roofs of 4m width separate these 3 areas and are used for major plant location. The minor elements of the superstructure, are generally of conventional steelwork beam and column construction, with the exception of the lobby area which is also of suspended design. A canopy is suspended from the mast stays along the length of the shop front terminating in a quarter circle at the entrance lobby giving visual emphasis to the main entrance.

All main column masts are twin 245mm SHS at 500mm centres with welded stiffener/connection plates located in pockets in the pilecaps All main rafters are universai.sections and are supported from the top of the twin column masts at approximately ⅓ points on the 36m span, and at mid point on the 23m spans. The suspension system generally consists of twin 60mm diameter solid rods, with turnbuckles for adjustment. Castings are welded to the rod ends and are connected to the plates attached to he columns and rafters by 75mm diameter stainless steel pins.

The roof is of metal deck construction contained within the main rafter depth resulting in a total roof thickness of only 400mm.

Fabrication was carried out to tight tolerances and this ensured correct fit during erection which was essential both in terms of speed of erection and final appearance.

All steelwork is grade 50 and was grit blasted at the works. The surface treatment, mostly works applied, Is finished with a ‘silver’ metallic polyurethane paint to a high specification.

The total area of the building is 4,000m² and the entire building operation was completed in under 12 months.

Judges’ Comments:

The use of steel masts and a suspended roof structure provides a strong and identifiable image for the
supermarket without the bulk of the building becoming obtrusive. The structure is well made, carefully detailed and a delight to the eye.