Building B2 St Pancras / Kings Cross Gateway
Hargreaves Foundry has been awarded the contract to manufacture cast iron columns in a partnership between Argent, David Chipperfield Architects, BAM Construction, Techcrete and Hargreaves Foundry.
We will be manufacturing 396 cast iron columns which will form part of Building B2, Pancras Square, now under construction. The building, designed by the international, award-winning David Chipperfield Architects, will be one of six buildings around Pancras Square between St Pancras International and King’s Cross Station. On the ground floor, the columns will form a colonnade around the building, with a wide range of shops, cafés and restaurants, a reception for the offices above and a new subway link to the stations. The eight upper floors comprise 56,000sq ft (net) of office space with a south facing balcony on every floor. The building will meet the BREEAM ‘Outstanding’ sustainability accreditation and is due to be completed in late 2013.
The use of cast iron columns on the building is a response to the Victorian heritage of the site. From the 1850s this area was home to many cast iron gas holder guide frames and both railway stations have large roof structures made using cast and wrought iron.
The ground floor columns are approximately twice the size of the columns on the upper stories. The lie of the land means that the ground floor columns range from 6 metres high at one end to 4.8 metres high at the other. They all have a diameter of 800mm and the heaviest way 2.2 tonnes. The upper story columns are 3.2 metres high by 800mm wide and weigh 1,300kg. All of the columns have an intricate weave design to their exterior surfaces which can best be realised by casting in iron. There will be a total of 396 columns on the finished building.
The larger columns will take 3 days each to make and the smaller ones 1 day. There will be between 8 to 12 men directly involved on the shift dedicated to making these columns. Of course this figure does not include the work of the pattern makers and administrative support.
This has meant an enormous investment in the pattern making, re-organising our shift system, making bespoke moulding boxes, a bespoke core box and a bespoke core extractor.
At Hargreaves Foundry all our castings are made from 100% recycled iron, supplied from the automotive industry, construction waste and returns from our foundry.
Cast iron is one of the few materials which would allow for the specific weave design to be created on the surface area of the columns, whilst still providing a useful function in the construction of the building. The weave design itself was designed by the architect, Mattias Kunz, an associate of David Chipperfield Architects.
Hargreaves Foundry is probably the only foundry left in the country who could cope with this project in terms of the size and volume of the castings.