Video: Cast-iron column-casting at the Hargreaves Foundry
The columns on David Chipperfield’s One Pancras Square office at King’s Cross were manufactured by the Halifax-based Hargreaves Foundry. The family owned company is best known for collaborating with sculptor Antony Gormley.
The cast-iron column encasements give order, rhythm and a strong materiality to the facades, and are used both as full circular tubes and half circular casings. With a surface pattern of woven straps, the 396 columns evoke the site’s industrial past and reference Gottfried Semper’s theory involving the role of weaving in the evolution of man-made structures. Casting iron is one of the few processes which allows intricate weave patterns to be created.
The ground-floor casings are 100 per cent recycled cast iron and range in height from 5m to 6.15m, with 800mm diameter. The upper-floor columns, shown here, are 3.25m tall.
The columns were manufactured from recycled iron in a traditional sand cast process by Hargreaves Foundry. This involved pattern making, moulding and casting - a process barely changed since Victorian times.
The columns were installed sequentially with the horizontal precast concrete elements. In the half-round condition, they were mechanically fixed from the inside, and where freestanding they were sleeved over square concrete cores, which have cast-in Halfen channels that house the stainless steel brackets restraining the casings.
Oliver Ulmer, director, David Chipperfield Architects