Twin Sails Bridge
Twin Sails Bridge is a novel steel
bascule road bridge that spans a navigation channel linking Holes bay
with Poole Harbour in the UK. The bridge provides a second road link
connecting Poole town centre with Hamworthy - a site of planned
redevelopment. Ramboll worked
closely with architect Wilkinson Eyre and mechanical engineer Bennett
Associates to develop the bridge concept and used
LUSAS Bridge analysis software to assist with its design of the
Twin Sails Bridge is the world’s
first triangular-leaf lifting bridge and was constructed by HOCHTIEF
(UK) Construction Ltd. The bridge has an overall length of
approximately 139m which includes a central opening span of 23.4m
between main bearings and two approach spans of approximately 27m. Its
10.8m wide carriageway incorporates two vehicular lanes segregated
from two cycle lanes. In addition, two 2.5m wide footways cantilever
either side of the bridge. The twin
sail-like structures forming the lifting leaves weigh 65 tonnes each.
Each leaf is connected to pivot bearings at one of the main piers and
rests on a single bearing near the apex of the triangle on the other
main pier. To permit the unrestricted passage of shipping the lift
spans are pivoted through 88 degrees by two hydraulic rams to provide a clear channel width of 19m between the
faces of fenders of the main piers when in the open position.
The bridge opened to traffic on 4th
April 2012 and operates alongside the existing Poole Bridge, with one of the bridges
always open for vehicular traffic when the other is open for shipping.
When closed to
shipping the bridge looks quite unassuming.
the pair of 65 tonne lifting leaves takes
around two minutes
fully raised the bridge creates the impression
of two passing yacht sails
Other LUSAS Bridge case