Kemira 15-year paint system for landmark Docklands steel footbridge

Kemira 15-year paint system for landmark Docklands steel footbridge

Keywords Bridges, Kemira, Paints

The 15-year paint system which decorates and protects the South Quay footbridge at Canary Wharf in London's Docklands was provided by Kemira Heavy Duty Coatings of Bury.

The 180m long £2.5million structure comprises some 350 tonnes of elegant steelwork. The elongated "S"shape provides a sinuous link across the dock between South Quay and Heron Quays, neighbouring the Docklands Light Railway and Canary Wharf Tower. It consists of two identical curved halves, each supported by cables from a tall raking mast. The northern half is fixed and the other swings about its mast to allow boats to pass (Plate 1). The long-term plan is for the stationary half to be moved 100m further down the dock to the east, while the southern half will simply swing into its new alignment.

 Plate 1 The 15-year paint system which decorates and protects the 180m long South Quay footbridge at Canary Wharf in London's Docklands was supplied by Kemira Heavy Duty Coatings of Bury, Lancs

The 32m high raking masts are shaped and tapered from a 1,800mm diameter cylinder section at the base to a"leaf" at the head. They slope in opposite directions, each leaning towards the inside of the curve at that point and supporting an array of stay cables carrying a cylindrical spine beam from which the steel deck structure is cantilevered. The deck itself is of European oak. On one side is a raking steel balustrade with an aluminium handrail incorporating continuous linear lighting. On the other, a curved, perforated stainless steel screen acts as a man-made hedge to protect from prevailing winds.

The Kemira paint system had to be designed for a 15-year life to first maintenance, besides according with BS 5493 requirements for both content and performance. The first coat was of Temashield EPY 310 at 75 microns, a two-component epoxy zinc phosphate fast curing primer. Formulated for speed of application and handling in workshop conditions, it provides excellent build and hold up on edges and good resistance to undercutting for damaged areas. It is widely used in chemical and petrochemical environments and can be overcoated by most generic top coats.

For the South Quay Footbridge, this was followed by 100 micron coats of Temashield EPB 112 (natural grey) and EPB 113 (silver grey). EPA Compliant-1996, this is a two component epoxy with selected micaceous iron ore, giving an attractive matt finish. It possesses excellent anti-abrasion, toughness, durability and weathering characteristics, and is ideal for onshore or offshore use. A further coat of Temashield EPB 113 was applied on site.

The project, bringing together Chris Wilkinson Architects with consulting engineer Jan Bobrowski &Partners, was awarded a "special commendation for outstanding fusion of architecture and engineering in bridge design" in the British Construction Industry Awards. The steel structure itself was fabricated, painted and erected by Kent Structural & Marine Ltd of the Isle of Sheppey. Main contractor for London Docklands Development Corporation was Christiani & Nielsen.

Further details from Kemira Coatings Limited. Tel: +44 0161 7646017; Fax: +44 0161 7646102.