Entered by SH Structures Limited
A cable-stayed swing bridge in south London has improved pedestrian riverfront access, whilst maintaining a navigable channel.
The bridge has a 44m cable stayed main span, supported from a single mast with a central stay plane. A short 8m backspan contains a 120t counterweight to balance the structure and two pairs of backstays support the tip of the mast laterally and longitudinally.
The structure is supported on a 3.7m diameter slewing ring bearing underneath the mast, with a set of four electric motors to drive the bridge clear of the navigation channel concealed in the machine room, within the main concrete pier.
Faceted planes create an elegant and visually massive backspan and reduce to a more slender main span with a central spine box supporting diagonal struts to the edge of the deck.
The plated concept is continued through the main mast, where two vertical flat plates supported by diagonal stiffeners create an innovative open vierendeel type structure. The inclined web plates create openings to the sky to lighten the appearance for maximum transparency.
SH Structures Ltd fabricated and delivered the bridge deck to site in three main sections. These were transportable by road, albeit with a police escort through London.
Onsite assembly of the bridge was conducted on the bank of the creek and in a position that was identical to the structure's open position. The backspan was lifted into place first and using a 300t capacity mobile crane it was lifted onto the slew bearing that had previously been installed into the bridge's foundations concrete substructure.
The two main spans were welded together and then welded to the backspan. Three sections were also welded together to form the bridge deck structure.