Commissioning authority: FRB Joint Board.
Designer WA Fairhurst & Partners.
Inscription: 'Innovative complex design for restricted space without disruption to traffic.'
Live loading of the structure that was twice that of the original design led to a unique design solution.
To strengthen the 150m steel plate legs of the tower over the 1,006m span bridge, new central steel columns were installed inside the legs and next to the existing columns. Steel in 1m lengths was delivered to the site by barge and fed through 3.9m by 0.85m openings cut in the existing legs, before being hoisted up internally.
A single new column in each of the four legs with 6,000t jacked into them is believed to be unique in civil engineering.