Iron cast bollards could be installed on Perth Bridge due to its footway being “sub-standard,” it has been revealed.
The bridge, which was built in 1771 by renowned engineer John Smeaton, was surveyed by consultants over the last year after Perth and Kinross Council decided a load assessment was required.
Findings from the assessment showed the footway structure is “sub-standard” for the current permitted levels of loading. As a result, it has been recommended that iron cast bollards be installed along the footways to reduce the risk of vehicles mounting them, safeguarding against a potential future failure.
The move follows concerns recently raised by council chiefs that both the Old Perth Bridge and the Queen’s Bridge will need substantial work carried out in future years because the structures, along with culverts and retaining walls, are said to be declining year-on-year.
The local authority is planning to install the black cast iron bollards around 750mm above surface level, and have stated they will be either root fixed into, or surface mounted onto, a concrete foundation.
A supporting statement submitted by the council for planning approval states: “This (the installation of the bollards) will be achieved by carefully excavating each foundation pocket along the edge of the footway and installing the bollards.
“The entire footway will then be resurfaced afterwards.
“Procurement of a contractor is due to commence this month and once known, the exact construction materials will be submitted for approval.”
The supporting statement says that traffic over the Old Perth Bridge is currently restricted to 7.5 tonnes gross vehicle weight, with a number of exceptions for vehicles such as buses and emergency service vehicles.
The document also states the bridge is designated as a grade A-listed building. It reveals consultants Mott MacDonald were commissioned last year to undertake a load assessment of the various elements of the Old Perth Bridge.
Their findings showed that the 10-span arch structure is generally in good condition for its age, but added that the overall capacity of the footway is “limited” by the capacity of the stone slabs.
It states that where stone slabs are cracked, the assessed capacity of the footway is reduced to zero.
Perth and Kinross Council approved an additional £6 million of investment in its road network and structures over three years in 2016.