Transport for London asset D2 is a steel footbridge located near South Harrow Station. The steel footbridge consists of steel members to the main span, missile screens, steel braces and stiffeners along with a cable frame that is attached to the west side of the footbridge. SPG worked alongside Skanska during engineering hours to mechanically prepare the steel substrate prior to the application of a TFL approved, moisture cure urethane, protective coating system.
The track side elements of the steel footbridge contain a cable support framework running across the centre section of the footbridge parapet. All services are protected during the mechanical preparation of the substrate.
There was heavy delamination on the underside deck plates. Root cause of the delamination could have been an incompatible overcoat or inadequate preparation of the underlying coating system. High levels of lead were measured to be present in the retained coating system on the underside elements of the footbridge.
Localised corrosion and failure of the existing coating system was visible. There was also crevice corrosion present on the back to back steel members.
There were also high levels of graffiti present on the cross sectional members of the footbridge walkway and missile screens.
Six Specialist Painting Group ICATS Technicians carried out mechanical preparation to the footbridge, followed by the application of a 3 coat Steelpaint system.