The cycle/pedestrian bridge, originally built as a railway viaduct in 1882, was abruptly closed in March 2004 when holes appeared in the 48-year-old timber deck. The viaduct is Grade II Listed, so repairs were actually renovation costing £880,000 and taking over a year (and counting...).
The scaffolding is a working platform below the deck level, for shotblasting and painting of the stone and ironwork. It also keeps debris out of the river.

[The result.]