Kincardine Bridge – An engineering triumph 85 years on

Abstract

When construction of Kincardine Bridge was completed in 1936, it was the longest road bridge in Scotland and the largest swing-span bridge in Europe. 85 years on, the Historic Environment Scotland Category A listed bridge remains in service and carries approximately 12,000 vehicles daily across the Forth Estuary. On occasions when the Queensferry Crossing and Forth Road Bridge are closed simultaneously, the Kincardine Bridge offers the shortest available diversion route across the estuary for unrestricted traffic. A 2019 principal inspection highlighted deterioration to some structural elements and in 2020 DMRB bridge assessment standards were revised. As a result, a quantitative assessment was undertaken to provide confidence that the bridge remains safe for use and fit for purpose and to inform future maintenance requirements. This paper focuses on the multitude of structural forms that comprise the overall bridge and how they: - have comparably performed relating to durability over the past 85 years - have been quantitatively assessed - have comparably withstood present-day traffic loading criteria - will be maintained in future.