Royal Victoria Dock Footbridge - London, UK - Satellite Imagery Oddities on Waymarking.com

Wikipedia has an article about the bridge that tells us:

The Royal Victoria Dock Bridge is a signature high-level footbridge crossing the Royal Victoria Dock in the Docklands area of east London designed by London-based architects and designers Lifschutz Davidson Sandilands. The bridge provides a direct link from Eastern Quay and Britannia Village, a residential development to the south of the dock, to the ExCeL Exhibition Centre and Custom House station, both situated to the north of the dock.

The bridge takes the form of an inverted Fink Truss, with six masts rising above the deck at 25.5 m (84 ft) centres, varying in height from almost 30 m (100 ft) at each end to just 10.6 m (35 ft) for the smallest masts. The shape of the bridge is designed to reflect the masts of the sailing boats which use the dock. The bridge crosses the dock with a clearance of some 15 m (50 ft) above the water, a height which was necessary to allow yachts to pass below the bridge deck. The bridge is accessed at each end by lift and stair towers.

The bridge was completed in 1998, at a cost of £5 million. A second construction stage envisaged in the bridge's design involves the addition of a glass passenger cabin travelling on a rail of the underside of the deck to make this a transporter bridge.

The Lifschutz Davidson Sandilands website also tells us:

Won in competition in 1995, the Royal Victoria Dock Bridge is a 150m long footbridge spanning one of the largest docks in East London. 

The bridge structure is a steel Fink truss spanning 130m onto a pair of trestles at each end. The six tapering conical masts are of varying length and are linked by cables to tie down points. At each end a further cable carries tension forces to ground via a distinctive ‘bowsprit’.  The very slender aerodynamic profile is achieved by extending the box section deck upwards into the pedestrian zone as required to meet the loads. These extensions form distinctive steel mounds or ‘keels’ which are concealed by the inclined balustrading along both edges of the bridge. The upper bridge deck, 15m above water level, provides a spectacular route for pedestrians and is accessed at either end by stairs and panoramic lifts.

The materials are steel for all structural elements and perforated stainless steel cladding to the stairs, lifts and balustrading.  Hardwood is used for the decking and handrails and perforated aluminium extrusions are fitted to the stair treads.

This open bridge was designed to feature a gondola slung beneath, supported on cables hung from a cable driven carriage moving on a rail.

The upper bridge deck affords spectacular views of the Millennium Dome, Canary Wharf and the leisure activities in the dock itself.