During the 1950s, despite no war damage to Blackburn, the town’s council was keen to ‘replace the worst of the past with buildings which will symbolise the great future of the town’. Alderman G B Eddie, Chairman of the Blackburn Civic Development Committee, said that the opening of a new market showed that Blackburn was to ‘shed the grim cloak of the industrial revolution and build a new town centre that will be in keeping with modern ideas and the space age’.
Blackburn Corporation (1964 slogan, “in touch with tomorrow”) opened its new markets in November 1964. The council’s full page local newspaper advertisement heralded a ‘new era for the shopping public of East Lancashire’. The newspaper’s editorial joined in; ‘Space age styling and spacious facilities...Like an aircraft hangar, which it faintly resembles, the daily market has an abundance of air space to floor space, the blending of off white concrete and glass gives the Salford junction a new focal point’.
Blackburn Daily Market was certainly novel. Because it was built over the River Blakewater three massive portal frames were built across the river to carry its sculptural asymmetric curved roof high above the market floor. Clerestory glazing flooded the hall with sunlight.
‘Just a first step – more fantastic changes to come’ wrote Alderman Eddie. The result was stunning - from the outside a huge white curved roof with extensive glazing and a new restaurant overlooking fountains and gardens, whilst large applied fat-faced Egyptian letters boldly proclaimed MARKET. Eddie was right about change in Blackburn. Festival of Britain style had finally arrived, bringing multicoloured ceramic micro-mosaic, architectural relief signage, Formica with bold colours, pedestrian areas and optimism.
So just where had this new design come from? The technology was revolutionary. Large span reinforced concrete shells had been developed in Germany for Frankfurt Market Hall in 1927, and Budapest, 1931. The first reinforced concrete shells in Britain formed a hangar roof at Doncaster municipal aerodrome in 1935, followed by canopies for surface stations on London Underground and then Wythenshawe bus garage, 1942.
Post war, concrete shells were widely adopted in Britain, when steel shortage made them an ideal solution for roofing large clear spans. British market halls used shells cast in-situ in various ways to provide shelter and light. Plymouth’s 1960 Pannier Market hall with a 148’ clear span has a roof design reduced to simple elements, portal frames with conoidal shells cast in-situ - speedy construction was possible with less shuttering and scaffolding. This was innovation, marking it out from earlier designs.
Blackburn Market took a step further with the use of three scalloped portal frames acting as saddles for pre-cast reinforced concrete shells 44’ long, 7’ 7” wide. Made in Bristol, these were driven up to Blackburn on lorries and craned straight into the saddles.
Why bother bringing these extraordinarily long shells up pre-motorway England?
The shells were engineered and carefully manufactured pre-stressed hyperbolic paraboloids (hypar) shells about 2”thick. Known as System Silberkuhl shells, they were made by Modern Concrete (Bristol) Ltd under a patent developed by Wilhelm J Silberkuhl (1912 -1984), and were widely used in British construction and engineering, roofing factories, breweries, power stations, warehouses and Bristol ATV television studios!
A hypar shell curves in two directions (like a Pringle crisp). Straight lines can be drawn across it. When this design is applied to a pre-tensioned reinforced concrete shell the steel reinforcement bars are straight, keeping the concrete it is cast in and bonded to, under compression. Silberkuhl’s shell technology was first used on the continent to roof warehouses and factories. Modern Engineering (Bristol) Ltd (1961 slogan, “Build the Modern Way”) became licensees of the system; a subsidiary, Modern Concrete (Bristol) Ltd specialised in the precast shells.
Blackburn Corporation’s engineers and architects with the main contractor, John Laing (1964 slogan, “Partners in progress”) took a novel and sophisticated but low cost industrial roofing system and used it in Blackburn to give the market a cool Festival cum airport terminal style à la Saarinen; a marvellous, long overlooked and now doomed gem, following the rejection of a recent application for the market to be listed in recognition of its unique architectural interest.
The Daily Market represents the most important use of Silberkuhl shells in Britain. It is certainly unique in respect of its sculptural form and the most successful use of pre-cast hypar shells in the UK, whilst beneath and behind the many desultory alterations its original bright bold 1960’s designs survived to the end.
On 28 May 2011, Blackburn Markets (2011 slogan, “Blackburn Market - you're in for a surprise”) closed its doors forever, its distinctive scalloped roof profile replaced by a new ‘continental style’ market hidden beneath a new shopping centre.
But across the country some Silberkuhl shells can still be found; Unilever’s Wall’s Ice Cream factory roof at Gloucester can be seen from passing trains. Often Silberkuhl roofs can be hard to identify, as usually the distinctive scalloped edge can only be seen when there is no parapet. These include the former Freeman’s depot in Peterborough and Redwood Country Club near Bristol. Two public Bristol swimming pools in Bishopsworth and Filton allow you to consider the marvel of Silberkuhl shells as you float beneath them; “come on in, the ceiling is lovely!”
© Christopher R Marsden
This article first appeared in The Modernist issue 1 'BOLD'.