The Kylesku Bridge (officially known since 2019 by its

Gaelic Gaelic is an adjective that means "pertaining to the Gaels". As a noun it refers to the group of languages spoken by the Gaels, or to any one of the languages individually. Gaelic languages are spoken in Ireland, Scotland, the Isle of Man, and Ca ...

name Drochaid a' Chaolais Chumhaing) is a distinctively curved concrete box girder bridge in north-west Scotland that crosses the

Loch a' Chàirn Bhàin Loch a' Chàirn Bhàin (Gaelic for "White Cairn Loch"), or Loch Cairnbawn, is a sea inlet off Eddrachillis Bay on the west coast of the Scottish Highlands north of Ullapool Ullapool (; gd, Ulapul ) is a village and port located in Northern S ...

in Sutherland. It is

listed Listed may refer to: * Listed, Bornholm, a fishing village on the Danish island of Bornholm * Listed (MMM program), a television show on MuchMoreMusic * Endangered species in biology * Listed building, in architecture, designation of a historicall ...

as category A, the highest grade.

History

In June 1978 the Highland Regional Council asked

Ove Arup Sir Ove Nyquist Arup, CBE, MICE, MIStructE, FCIOB (16 April 1895 – 5 February 1988) was an English engineer who founded Arup Group Limited, a multinational corporation that offers engineering, design, planning, project management, an ...

& Partners Scotland to prepare a feasibility study for a bridge, in their capacity as consulting civil engineers, and was prepared by March 1979. Construction for the approach roads, costing £4 million, began in summer 1981. Construction of the bridge began in August 1982, with Morrison Construction and

Lehane, Mackenzie and Shand Lehane, Mackenzie and Shand was a British civil engineering and construction company, and responsible for some of Scotland's bridges. History Lehane Mackenzie & Shand Ltd was incorporated on 8 April 1974. In February 1981, the Alexander Shand grou ...

the chief contractors. It was constructed by building out the supporting legs and then lifting into place the central span, which had been constructed on land and then moved onto a barge by rail and weighed . The cost of the bridge was £4 million, although was earlier budgeted at £2.75 million. The bridge opened to traffic in July 1984, and was formally opened by the Queen on 8 August 1984. In 2019, the bridge was classified by

Historic Environment Scotland Historic Environment Scotland (HES) ( gd, Àrainneachd Eachdraidheil Alba) is an executive non-departmental public body responsible for investigating, caring for and promoting Scotland's historic environment. HES was formed in 2015 from the mer ...

as a Category A structure, recognising it as "visually striking and technically innovative". It was also officially renamed to the Gaelic translation of its name, ''Drochaid a' Chaolais Chumhaing''.

Geography

The bridge crosses water which is approximately wide and up to deep, leading to fast tidal currents. It replaced the ferry between Kylesku and Kylestrome, which was 400 metres to the east.

Design

The bridge is 275 metres (902 feet) long with a 79 metre long main span. The bridge deck is at a height of above high water to provide navigation for ships. The bridge deck is supported by V-shaped inclined piers, with eight inclined legs, in order to reduce the length of the main span. The lateral forces from each leg balance, so the total force on the foundations is vertically downwards. The spread of legs supports the bridge in winds which can exceed , and also loads resulting from the curvature of the bridge. There is no joint between the legs and the deck of the bridge, with the

expansion joint An expansion joint, or movement joint, is an assembly designed to hold parts together while safely absorbing temperature-induced expansion and contraction of building materials, and vibration, or to allow movement due to ground settlement or seis ...

s and bearings being located at the abutments to facilitate straightforward maintenance. The legs are formed from reinforced concrete and the deck from

prestressed concrete Prestressed concrete is a form of concrete used in construction. It is substantially "prestressed" ( compressed) during production, in a manner that strengthens it against tensile forces which will exist when in service. Post-tensioned concreted i ...

using cables tensioned at up to 52200 kN. The bridge is designed to be sympathetic to the surrounding country, and the approaches were chosen to minimise changes to the landscape.

References

External links

{{commons category
Construction at night

Video clips

Aerial view in 2012

View in 2009

Former ferry in 1966
1984 establishments in Scotland Box girder bridges Bridges completed in 1984 Bridges in Highland (council area) Concrete bridges Ove Arup buildings and structures Road bridges in Scotland Buildings and structures in Sutherland Category A listed buildings in Highland (council area)