Civil Engineering heritage: Scotland - Lowlands and Borders
Date 2007
Event ID 606518
Category Descriptive Accounts
Type Publication Account
Permalink http://canmore.org.uk/event/606518
This magnificent bridge is a good example of Telford’s dictum that in a bridge of multiple arches the spans
should increase slightly towards the centre and the roadway parapet line seen in elevation should be on the
arc of a great circle from one abutment to the other. It is Telford’s largest Scottish bridge and its functionality
is enhanced by modest embellishment in his favourite Gothic style which is successful in harmonising
with its dramatic surroundings.
Construction began in 1804, the main contractor being John, Duke of Atholl, and the bridge was opened in
November 1808. It cost ‘above £30 000’. Until Dunkeld was bypassed by the new A9 road in 1977, the bridge
carried the A9 Perth to Inverness road over the Tay. It now serves mainly local and tourist traffic.
The width of the river at this point and its shallowness allowed the bridge to be constructed in two halves, each
half being built in a dry channel while the river flow was diverted into the other.
The bridge, about 685 ft long, has seven arches of dressed masonry with spans of 20 ft, 74 ft, 84 ft, 90 ft, 84 ft, 74 ft and 20 ft and the roadway at the centre span is about 54 ft above the water level. Internally it conformed to Telford’s practice for large masonry spans in being constructed with hollow spandrels to reduce the weight on the foundations and allow inspection of the internal workmanship. The piers have typical triangular cutwaters surmounted by semicircular masonry towers rising to the parapet level where they form pedestrian refuges.
The bridge, which replaced inconvenient and often hazardous ferries, was a toll bridge and the original toll
house still stands (NS04SW 49 ). The tolls were abolished in 1879 when the bridge was taken over by Perthshire County Council.
The new A9 bridge, erected in 1976–77 to the north of the town, is 738 ft long with three spans supported on
twin steel girders. It was designed by Babtie, Shaw and Morton.
R Paxton and J Shipway
Reproduced from 'Civil Engineering heritage: Scotland - Lowlands and Borders' with kind permission of Thomas Telford Publishers.
