Kylesku Bridge
Road bridge in Sutherland, northern Scotland
From Wikipedia, the free encyclopedia
The Kylesku Bridge (officially known since 2019 by its Gaelic name Drochaid a' Chaolais Chumhaing[1]) is a distinctively curved concrete box girder bridge in northwest Scotland that crosses Caolas Cumhann (Gaelic for "narrow strait", pronounced "Kyles Cuan"); the channel that connects Loch Glencoul and Loch Glendhu with Loch a' Chàirn Bhàin in Sutherland. It is listed as category A, the highest grade.
Kylesku Bridge | |
|---|---|
| |
| Coordinates | 58.257318°N 5.023792°W |
| Carries | A894 , one footway |
| Crosses | Loch a' Chàirn Bhàin (Caolas Cumhann) |
| Locale | Kylestrome |
| Characteristics | |
| Design | Prestressed box girder |
| Material | Concrete |
| Total length | 276 metres (906 ft) |
| Height | 24 metres (79 ft) |
| Longest span | 79 metres (259 ft) |
| No. of spans | 5 |
| History | |
| Designer | Ove Arup |
| Construction start | August 1982 |
| Construction cost | £4 million |
| Opened | July 1984 |
| Inaugurated | 8 August 1984 |
| Replaces | Kylesku and Kylestrome ferry |
Listed Building – Category A | |
Official name | Drochaid A’ Chaolais Chumhaing, An Caolas Cumhang / Kylesku Bridge, Kylesku |
| Designated | 23 January 2019 |
| Reference no. | LB52497 |
| Location | |
 Interactive map of Kylesku Bridge | |
History
In June 1978, the Highland Regional Council asked Ove Arup & Partners Scotland to prepare a feasibility study for a bridge, in their capacity as consulting civil engineers, and it was prepared by March 1979.[2]
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 the chief contractors.[2]
It was constructed by building out the supporting legs and then lifting into place the central span, which weighed 640 tonnes (630 long tons; 710 short tons).[3][4]
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.[2]
In 2019, the bridge was classified by Historic Environment Scotland 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.[1]
Geography
The bridge crosses water which is approximately 120 metres (390 ft) wide and up to 25 metres (82 ft) deep, leading to fast tidal currents.[2] It replaced the ferry between Kylesku and Kylestrome, which was approximately 400 metres (1,300 ft) to the east.
Design
The bridge is 276 metres (906 ft) long with a 79-metre-long (259 ft) main span. The bridge deck is at a height of 24 metres (79 ft) above high water to provide navigation for ships.[2]
The bridge deck is supported by V-shaped inclined piers, with eight inclined legs, in order to reduce the length of the main span.[2] The lateral forces from each leg balance, so the total force on the foundations is vertically downwards.[2] The spread of legs supports the bridge in winds which can exceed 100 mph (160 km/h; 45 m/s; 85 kn), and also loads resulting from the curvature of the bridge.[4][2] There is no joint between the legs and the deck of the bridge, with the expansion joints and bearings being located at the abutments to facilitate straightforward maintenance.[4] The legs are formed from reinforced concrete and the deck from prestressed concrete using cables tensioned at up to 52,200 kN.[2]
The bridge is designed to be sympathetic to the surrounding country, and the approaches were chosen to minimise changes to the landscape.[2]
Gallery
Kylesku Bridge with the Stack of Glen Coul in the distance
Kylesku Bridge on a sunny day in 2016
