Construction of the City of Manchester Stadium roof

Cast iron is very strong in compression and remained the preferred material for columns in buildings throughout the nineteenth century. Today, the safe load capacity of cast iron columns, struts or arch ribs in existing buildings or bridges is usually estimated using a form of the nineteenth century Gordon–Rankine formula. This is a semi-empirical fit to the results of a series of pioneering experiments begun in Manchester in the 1830s by Eaton Hodgkinson (Fig 1). The paper presents an overview of Hodgkinson’s work, describes the background to the obsolescence of cast iron columns in buildings, gives details of some present-day problems in their structural assessment, and describes some recent full-scale laboratory tests. Thomas Swailes, BSc (Hons), CEng, MIStructE, MICE Eduardo Aja Fernandez de Retana, BEng (Hons), MSc Manchester Centre for Civil and Construction Engineering, UMIST