Bikes and pedestrians are separated in plan and in section; pedestrians on the outside of the curve walk above the cyclists riding around the inside and beneath them. The arrangement is dynamic but safe and gives all users spectacular views on both sides. Whether seen from the pedestrian deck above or from the river banks below, the curved profile of the bridge has the elegance of a banked velodrome track. At Dolphin Square and on the south bank, twin ramps with a gentle gradient of 1:22 – suitable for cycles, wheelchair users or walkers – lead up to the bridge. Two slender flights of stairs at Pimlico Garden Shrubbery and on the south bank opposite offer alternative routes for pedestrians only. The bridge structure, ramps and stairs are all supported above the water and ‘kiss’ the banks. The idea of the four landings as linked public gardens is particularly valuable in an area dominated by roads and traffic. Importantly, there is minimal disruption to Pimlico Garden Shrubbery. Its trees are retained and the bridge superstructure partly concealed from St George’s Square Gardens by their foliage.
The access points offer a convenient journey for commuters, but also provide new river walks in an area lacking good public access to the water. To enjoy the riverside on each side of the Thames, pedestrians need only climb the stairs and walk down the ramp, or vice versa. The bridge structure is an innovative and highly tuned three-dimensional truss. The sinuous form is made up of diamond shaped frames linked at top and bottom by slender steel sections and at the sides by concealed members supporting the precast cycleway and footway. The diamonds alter in width and height to respond precisely to bending and torsion, appearing to dance free of the decks and at night this is accentuated by subtle illumination that washes the structure. Although minimal in terms of tonnage, the bridge is designed to be robust and withstand the challenges of time. Avoiding mechanical lifts gives confidence that maintenance costs are reduced over the long term.
The fabricated diamond sections are easily accessible for maintenance without requiring the bridge to be closed. Steelwork is painted Corten to give the longest life between maintenance, cable connections are sheltered from the weather and sealed, and the decks are made of precast concrete and the surface of non-slip bound granite. Our team included Expedition Engineers, Kim Wilkie, Beckett Rankine, Speirs & Major and Soundings.