St Paul's Cathedral




St Paul's Cathedral seen from a bombsite, 1940s. © Architectural Press Archive / RIBA Library Photographs Collection

Built after the Great Fire of London, 1666, St Paul's was at one point in danger of collapse in the early 20th century. In what now is a small footnote in its long history, this threat was for a short time an alarming development. In July 1913, the major architectural journals were reporting about the possibility that the dome of St Paul’s could collapse due to subsidence and the weakness of the supporting piers. The dome was sinking and its lean to the south-west had increased noticeably. On the 2nd July the  Architects’ and Builders’ Journal (former name of today’s Architects’ Journal) reported that the piers were no longer solid due to the settlement, since Wren’s time, of the poor-quality rubble inside, which included the “remains of the previous cathedral. Among them was a portion of a Roman column” (1).

Perhaps no greater feat has ever been achieved by man than the building of St Paul’s dome; but Wren, through lack of knowledge of design, inadvertently left too small a margin of safety in his supports.

Architects’ and Builders’ Journal  , 9 July 1913, vol. 38, p.27

By the 4th, the  Building News  revealed that cracks had appeared in the piers, and that the ground beneath the cathedral had been seriously disturbed by the construction of sewers nearby and the existence of deep basements of neighbouring buildings. Architect Thomas G. Jackson mentions the possibility that vibrations from traffic may also be a culprit. In the  Building News  he states there was only one way to save St Paul’s: “my opinion is that the only hope is to bind the construction so firmly together as to make it a homogeneous fabric.” (2)

We hope that whatever is necessary to ensure the stability of the structure will be done without hesitation or consideration of cost. quote

Builder, 4 July 1913, vol.105, p.3

Elsewhere, 22 out of the 32 buttresses – a structural element not normally used in classical architecture, which Wren consequently received some criticism for – were also damaged. Iron was used extensively by Wren to hold the cathedral’s stonework in place. In the clock tower, rust had taken hold and expanded the iron dowels, cracking the stones they were meant to hold together. But repairs had already begun. The iron was being replaced and new stone put in, and liquid cement poured into the cracks of the buttresses (3).

The cathedral survived the Blitz, despite direct hits. At the start of the 20th century, the well-publicised concerns about the stability of St Paul’s led to remedial action which continued right up to the 1930s. The fabric of the building was thus strengthened before World War II and this work contributed to its miraculous and symbolic survival during the dark years ahead.

St Paul's Cathedral in 1896. © RIBA Library Photographs Collection St Paul's Cathedral seen from a bombsite, 1940s. © Architectural Press Archive / RIBA Library Photographs Collection

References (available from the  British Architectural Library , RIBA)

  1. Architects’ and Builders’ Journal, 2 July 1913, vol.38, p.19
  2. Building News ,  4 July 1913, vol.105, p.8
  3. Architects’ and Builders’ Journal, 2 July 1913, vol.38, p.19

Article by Wilson Yau, British Architectural Library, RIBA