Nineteenth-century cast-iron parapet of Blackfriars Road Bridge, London, UK

Blackfriars Road Bridge in London, UK, is a Grade II-listed structure dating from 1869 and widened at the start of the twentieth century. In the 1960s, a concrete staircase was constructed linking the east side of the bridge to the riverside park below. The Blackfriars Millennium Pier reconstruction project is being carried out as part of the work associated with the new Thames Tideway Tunnel ‘supersewer’, designed to tackle sewage overflows into the River Thames. It includes removal of the 1960s staircase and its replacement with a new staircase and lift to improve access between the riverside walkway and the bridge. Alterations, which required listed building consent, were needed to the bridge’s ornate cast-iron parapet, namely infilling of the opening created for the 1960s stair and creation of a new opening to accommodate the new access. This paper discusses what was known about the original parapet construction, what was found during the course of the works and the approach that was taken to minimise loss of the original ironwork. It looks briefly at the issue of design loading on the parapet and the works undertaken on the cast-iron parapets of two other bridges of similar age.