The Twin Sails Bridge (also known as The Second Harbour Crossing) is a double leaved

bascule bridge A bascule bridge (also referred to as a drawbridge or a lifting bridge) is a moveable bridge with a counterweight that continuously balances a span, or leaf, throughout its upward swing to provide clearance for boat traffic. It may be single- or ...

Poole Poole () is a large coastal town and seaport in Dorset, on the south coast of England. The town is east of Dorchester and adjoins Bournemouth to the east. Since 1 April 2019, the local authority is Bournemouth, Christchurch and Poole Counc ...

Dorset Dorset ( ; archaically: Dorsetshire , ) is a county in South West England on the English Channel coast. The ceremonial county comprises the unitary authority areas of Bournemouth, Christchurch and Poole and Dorset (unitary authority), Dors ...

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe b ...

. The bridge provides a second road link from Poole Town Centre to

Hamworthy Hamworthy is a village, parish, peninsula and suburb of Poole in Dorset, England. It is sited on a peninsula of approximately that is bordered by the town of Upton to the north, Poole Harbour to the south, Lytchett Bay to the west and Hol ...

. The intention is that the bridge will allow development of four major sites, two in

Poole Town Centre Poole Town Centre is an area of Poole, Dorset. It is just to the west of Poole Park. Poole Old Town is home to many historic buildings like the 15th-century Scaplen's Court, the 18th-century Custom House and the Victorian St James' Church. H ...

and two in Hamworthy, including the old power station, which was closed in 1988.

Location

The bridge spans the Backwater Channel which links

Holes Bay A hole is an opening in or through a particular medium, usually a solid body. Holes occur through natural and artificial processes, and may be useful for various purposes, or may represent a problem needing to be addressed in many fields of en ...

with

Poole Harbour Poole Harbour is a large natural harbour in Dorset, southern England, with the town of Poole on its shores. The harbour is a drowned valley (ria) formed at the end of the last ice age and is the estuary of several rivers, the largest being th ...

. The bridge and approach roads are connected to the junction of West Quay Road in the East and to urban feeder roads in the West.

Design

The new bridge is intended to operate alongside the existing

Poole Bridge Poole Bridge (also known as Poole Lifting Bridge and Hamworthy Bridge) is a bascule bridge in Poole, Dorset, England. Constructed in 1927, the bridge provides a road link across a busy boating channel. In February 2012 a second bridge was compl ...

with one of the bridges always open for vehicular traffic (except during closures for maintenance or in a marine emergency), the intention is that

variable-message sign A variable- (also changeable-, electronic-, or dynamic-) message sign, often abbreviated VMS, CMS, or DMS, and in the UK known as a matrix sign, is an electronic traffic sign often used on roadways to give travelers information about special ...

s will direct traffic to the open bridge. The bridge comprises a wide carriageway with two vehicular lanes and two separate

cycle lane Cycle, cycles, or cyclic may refer to: Anthropology and social sciences * Cyclic history, a theory of history * Cyclical theory, a theory of American political history associated with Arthur Schlesinger, Sr. * Social cycle, various cycles in soc ...

s. Additionally two wide footpaths are provided which cantilever from the bridge. The bridge is constructed in five spans, with a total length of roughly . The approaches comprise two spans, the centre lifting span consists of two triangular leaves that span between the main bearings to provide a clear channel of when open. To permit the passage of boats through the navigation channel, the lift spans were planned to pivot to 88 degrees powered by two

hydraulic rams A hydraulic ram, or hydram, is a cyclic water pump powered by hydropower. It takes in water at one " hydraulic head" (pressure) and flow rate, and outputs water at a higher hydraulic head and lower flow rate. The device uses the water hammer e ...

which operate up to 15 times per day and take two minutes to fully open. Two high masts are fitted to the lifting leaves, the top two metres illuminated with white

LED A light-emitting diode (LED) is a semiconductor Electronics, device that Light#Light sources, emits light when Electric current, current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy i ...

lights. Four high pillars housing the barriers, lights, speakers and traffic controls which link the bridge with the control room are located on the two fixed spans adjacent to the lifting section. Hochtief (UK) Construction was awarded the £18.5 million contract for the construction of the bridge. The contract for the supply of around 900 tonnes of steel was awarded to Cleveland Bridge UK. Gifford UK (

Ramboll Rambøll Group A/S (also known as just "Ramboll") is a Danish consulting engineering group. History Rambøll was founded in October 1945 as "Rambøll & Hannemann" in Copenhagen. In 1991 the company merged with "B. Højlund Rasmussen A/S" into ...

) worked with

Wilkinson Eyre Architects WilkinsonEyre is an international architecture practice based in London, England. In 1983 Chris Wilkinson founded Chris Wilkinson Architects, he partnered with Jim Eyre in 1987 and the practice was renamed WilkinsonEyre in 1999. The practice ha ...

as lead design consultants. Metamont Ltd installed marine grade stainless steel balustrade including the variable colour DMX lighting.

History

Plans for a new bridge date to the 1980s, with the second lifting bridge concept being suggested in 2000 after a fixed bridge crossing

and linking with the A31 was cancelled by the government in 1998. The council submitted detailed plans to

Department for Transport The Department for Transport (DfT) is a department of His Majesty's Government responsible for the English transport network and a limited number of transport matters in Scotland, Wales and Northern Ireland that have not been devolved. The d ...

in 2004 and following a public inquiry in 2005, the £37 million ''Twin Sails'' bridge project was given approval in 2006/7 but construction was initially delayed due to a stalemate between the

council A council is a group of people who come together to consult, deliberate, or make decisions. A council may function as a legislature, especially at a town, city or county/shire level, but most legislative bodies at the state/provincial or natio ...

and the land owners. After negotiations were settled in August 2009, there was a further delay in the allocation of the £14.14 million government grant which was finally agreed in March 2010. Construction began in May 2010 with completion and opening planned for late February 2012. Problems with the road surface caused the bridge to remain closed although the opening ceremony and visit by

The Princess Royal Princess Royal is a style customarily (but not automatically) awarded by a British monarch to their eldest daughter. Although purely honorary, it is the highest honour that may be given to a female member of the royal family. There have been sev ...

went ahead in early March 2012. The bridge opened to traffic on 4 April 2012 after the road surface had been relaid, the first motor vehicle crossing at 9.38AM. Problems with the bridge operation continued in the summer of 2012 with delays caused through the barrier operation and lifting mechanism as well as continuing defects in the road surface. The bridge was closed again beginning 16 November 2018 due to a hydraulic issue with its lifting mechanism. In 2019 BCP Council, of which Poole Borough Council was absorbed by, convened an emergency meeting due to the issues with the bridge become "unacceptable". The bridge continued to be closed down due to technical problems up to 2020. These design issues are apparently caused by a design issue with the bridge as the bridge itself has an unusual design compared to a typical bascule bridge. On 16 January 2023, a section of the bridge snapped due to a technical fault.

References

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External links

Borough of Poole – Twin Sails BridgeTime lapse of bridge construction
Bridges in Dorset Buildings and structures in Poole Bascule bridges Poole Harbour Bridges completed in 2012 2012 establishments in England