Kylesku Bridge
| Kylesku Bridge | |
| Sutherland | |
|---|---|
 Kylesku Bridge in October 2016 | |
| Location | |
| Carrying: | A894 road, and footway |
| Crossing: | Loch a' Chàirn Bhàin (Caolas Cumhann) |
| Location | |
| Grid reference: | NC233330 |
| Location: | 58°15’1"N, 5°-0’40"W |
| Structure | |
| Length: | 902 feet Main span: 260 feet |
| Design: | Prestressed box girder |
| Material: | Concrete |
| History | |
| Built 1982 | |
| Information | |
The Kylesku Bridge is a distinctively curved concrete box girder bridge in western Sutherland that crosses the Loch a' Chàirn Bhàin. It is a category A listed building.
The bridge crosses water which is approximately 394 feet wide and up to 82 feet deep, leading to fast tidal currents.[1] It replaced the ferry between Kylesku and Kylestrome, which crossed 450 yards to the east.
History
In 1978 a feasibility study was commissioned for a bridge, which was prepared by March 1979.[1] Construction for the approach roads, costing £4 million, began in summer 1981. Construction of the bridge began in August 1982.[1]
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 640 tons.[2][3]
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.[1]
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.
Design
The bridge is 902 feet long with a main span of 260 feet long main span. The bridge deck is at a height of 78.7 feet (24.0 m) above high water to provide navigation for ships.[1]
The bridge deck is supported by V-shaped inclined piers, with eight inclined legs, in order to reduce the length of the main span.[1] The lateral forces from each leg balance, so the total force on the foundations is vertically downwards.[1] The spread of legs supports the bridge in winds which can exceed 100 mph, and also loads resulting from the curvature of the bridge.[3][1] 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.[3] The legs are formed from reinforced concrete and the deck from prestressed concrete using cables tensioned at up to 52200 kN.[1]
The bridge is designed to be sympathetic to the surrounding country, and the approaches were chosen to minimise changes to the landscape.[1]
Outside links
 |
("Wikimedia Commons" has material about Kylesku Bridge) |
- Construction at night
- Video clips:
- Aerial view in 2012 - YouTube
- View in 2009 - YouTube
- Former ferry in 1966 - YouTube
References
- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 Stears, H.S. (January 1985). "The Kylesku Bridge - Design and Construction". The Journal of the Institution of Highways and Transportation & HTTA 32 (1): 16-20.
- ↑ "D-block GB-220000-933000 Bridge Building at Kylesku". bbc.co.uk. http://www.bbc.co.uk/history/domesday/dblock/GB-220000-933000/picture/3. Retrieved 3 February 2015.
- ↑ 3.0 3.1 3.2 Martin, J. M. (1986). "The Construction of Kylesku Bridge". ICE Proceedings 80 (2): 317. doi:10.1680/iicep.1986.737. http://www.icevirtuallibrary.com/content/article/10.1680/iicep.1986.737.