Clyde Arc

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Clyde Arc
ClydeArc.jpg
View of the Clyde Arc from the East
Official name Clyde Arc
Carries Motor vehicles, cyclists and pedestrians
Crosses River Clyde
Locale Glasgow, Scotland
Width Dual two-lane carriageway, two cycle/footpaths (total width 22m)
Longest span 96m
Opened 18 September 2006
Toll Free
Coordinates 55°51′26″N 4°16′57″W / 55.85722°N 4.28250°W / 55.85722; -4.28250
Clyde Arc

The Clyde Arc (known locally as the Squinty Bridge), is a road bridge spanning the River Clyde in Glasgow, in west central Scotland, connecting Finnieston, near the Clyde Auditorium and SECC with Pacific Quay and Glasgow Science Centre in Govan. A prominent feature of the bridge is its innovative curved design and the way that it crosses the river at an angle. The Arc is the first city centre traffic crossing over the river built since the Kingston Bridge was opened to traffic in 1969.

The bridge was named the "Clyde Arc" upon its official opening on 18 September 2006. It has been previously known as the "Finnieston Bridge" or the "Squinty Bridge".[1]

Design[edit]

The bridge was designed by the Halcrow Group and built by Kilsyth-based civil engineering company Edmund Nuttall. Glasgow City Council instigated the project in conjunction with Scottish Enterprise and the Scottish Government. Piling works for the bridge were carried out from a large floating barge on the Clyde, whilst the bridge superstructure was fabricated offsite. The bridge-deck concrete-slab units were cast at an onsite pre-casting yard. Planning permission was granted in 2003 and construction of the bridge began in May 2005. It was structurally completed in April 2006. The bridge project cost an estimated £20.3m.[2] The Bridge is designed to last 120 years.[3]

The bridge has a main span of 96 m with two end spans of 36.5 m (total 169 m). The design of the main span features a steel arch. The supports for the main span are located within the river with the abutments located behind the existing quay walls. The central navigation height at mean water height is 5.4 m.

It was officially opened on 18 September 2006 by Glasgow City Council leader Steven Purcell, although pedestrians were allowed to walk across it the previous two days as part of Glasgow's annual "Doors Open" Weekend.

The bridge connects Finnieston Street on the north bank of the river to Govan Road on the southern bank. The bridge takes four lanes of traffic, two of which are dedicated to public transport and two for private and commercial traffic. There are also pedestrian and cycle paths. The new bridge was built to provide better access to Pacific Quay and allow better access to regeneration areas on both banks of the Clyde. The bridge has been designed to cope with a possible light rapid transit system (light railway scheme) or even a tram system.

The bridge is the first part of a massive development project planned to regenerate Glasgow. There are two more bridges planned - the £40m Tradeston Bridge and a further pedestrian bridge linking Springfield Quay with Lancefield Quay on the north bank. The canting basin and graving dock next to Pacific Quay are to be developed along with Tradeston and Laurieston. Plans are afoot to transform Rutherglen and Dalmarnock as the 'athletes' village' for the 2014 Commonwealth Games in Glasgow.[4]

Design Criticisms[edit]

1. The Clyde Walkway is broken by the bridge road and therefore requiring toucan crossings for cyclists and pedestrians to cross resulting in lengthy waiting times. A better design feature would have been to have the pedestrians and cyclists pass unobstructed under the bridge.

2. Cyclists access to the bridge on the south side when travelling from Govan Rd heading west is very poor. Cyclists are either expected to use the same route as the car, which requires them to travel an extra 1km or leave the road and use 3 sets of traffic lights. This is a major inconvenience.

3. Pavement width. The pavement widths on either side of the bridge are narrow and thereby creating the uncomfortable situation of close passes with traffic.

Overall the design is specifically for vehicles and other modes of transport were neglected.

Support hanger failure[edit]

The bridge was closed between 14 January and 28 June 2008 due to the failure of one support hanger, and cracks found in a second.

On the night of 14 January 2008 the connecting fork on one of the bridge's 14 hangers (supporting cables that transfer the weight of the roadway to the bridge's arch) snapped; Strathclyde Police quickly closed the bridge to traffic.[5] Robert Booth, a spokesman for Glasgow City Council said:

We don't believe the integrity of the bridge is affected. The Clyde Arc is designed to allow for the removal of one of the bridge supports at a time for repair and maintenance without affecting its operation. However, our number one priority is public safety and until we are completely satisfied the bridge is safe to use, it will remain closed.

A detailed inspection on 24 January found a stress fracture in a second support cable stay, like the one which had failed previously. Engineers determined that all of these connectors would have to be replaced; rather than a brief closure the bridge would have to remain closed for six months.[6] In addition traffic on the river below was also halted.[7] In March Nuttall began installing five temporary saddle frames atop the bridge's arch; these allowed the weight of the bridge to be supported without the hangers. This allowed them to replace defective fork connectors at the top and bottom of each hanger.[6]

The bridge recommenced on 28 June 2008 with just two of its four lanes in use, having had all the cast steel connectors replaced with milled steel connectors.[8] Once reopened Glasgow council estimated that 6500 crossings will be made every day using the bridge.[9]

On 8 January 2009, New Civil Engineer reported that subcontractor Watson Steel was suing Macalloy, the supplier of the suspect connectors, for £1.8 million.[citation needed]

According to reports, Watson alleges steel obtained from Macalloy did not meet British Standards or their own specifications; parts were inadequately manufactured, and did not tally with test certificates provided by the firm.[citation needed]

References[edit]

  1. ^ "Evening Times" [1]. 2006. Accessed 18 September 2006.
  2. ^ "Road Traffic Technology" [2]. 2006. Accessed Sept 18th, 2006.
  3. ^ "Public will not foot bridge bill". BBC News. 2008-01-25. Retrieved 2008-01-29. 
  4. ^ "The Glasgow Herald" [3]. 2006. Accessed Sept 18th, 2006.
  5. ^ "Clyde Arc closed by cable 'snap'". BBC Scotland. 2008-01-15. Retrieved 2008-01-15. 
  6. ^ a b "Sitting pretty in Glasgow", p3 Construction News Issue 7060, 20 March 2008
  7. ^ "Second fault on 'Squinty Bridge'". BBC Scotland News. 2008-01-24. Retrieved 2008-01-24. 
  8. ^ "Clyde Arc reopens after repairs". BBC News. 2008-06-29. Retrieved 2008-06-30. 
  9. ^ "Date for 'Squinty Bridge' opening". BBC. 2008-06-04. Retrieved 2008-06-04. 

External links[edit]