Civil Engineering heritage: Scotland - Lowlands and Borders

Date 2007

Event ID 610017

Category Descriptive Accounts

Type Publication Account

Permalink http://canmore.org.uk/event/610017

Civil Engineering heritage: Scotland - Lowlands and Borders

There was no road bridge over the Forth downstream from Stirling until 1936 when Kincardine Bridge was completed at a site where the river is 2400 ft wide at high water. Even though the Forth Road Bridge, completed in 1964, attracted some of its traffic the bridge still serves as a major artery carrying the A876 road.

In the 1930s the Forth was navigable to Stirling and vessels of up to 2000 tons traded to Alloa with coal, oil

and timber. To accommodate upstream shipping a turning section was incorporated into the bridge which

swung about a central support to provide twin openings of 150 ft. The circular track and rollers at this support

were so finely made by Sir William Arrol & Co. that it required only 2 hp to turn the span. Because of the decline in shipping the bridge is no longer turned. The shipping clearance at high water was when closed, and is now, 30 ft.

Adjoining the turning section there are ten approach spans of 62 ft–100 ft to the north and 16 approach spans of 50 ft–100 ft to the south. The south approach ends in a piled reinforced concrete viaduct 265 ft long. The total

length of the bridge is 2696 ft and when built it was the largest swing bridge in Europe and Scotland’s longest

road bridge. The delay to road traffic in opening and closing the bridge for shipping was 13 minutes. The consulting engineer for the bridge was J. Guthrie Brown of Sir Alexander Gibb & Partners, and the main

contractor was the Cleveland Bridge & Engineering Co. Ltd, Darlington, who subcontracted some work to Sir

Wm. Arrol & Co.

R Paxton and J Shipway 2007

Reproduced from 'Civil Engineering heritage: Scotland - Lowlands and Borders' with kind permission from Thomas Telford Publishers.