A detailed maintenance programme involving over 240 separate repairs has been completed on an unusual concrete viaduct in East Renfrewshire.
The six-arch Aurs Burn Viaduct, built in 1901, used to carry a rail line but has been shut for more than 80 years. It is now managed by National Highways on behalf of the Department of Transport – despite being neither a highway nor in England – because National Highways is home to the Historical Railway Estate (HRE), looking after redundant rail structures.
Aurs Burn viaduct is unusual because it is made of concrete.
The viaduct runs for 350 ft over Aurs Burn stream flowing from Glanderston Dam and down towards Barrhead. It was part of the former Paisley and Barrhead District Railway, which included a number of passenger stations that were never used as the line only ever carried freight. It closed in 1941.
Phase one of the restoration work was completed by Balfour Beatty in November 2021 and included the resurfacing of the deck and repairs to the concrete arches in spans five and six, which were in the worst condition.
After phase one was complete the access cradles were used for a detailed inspection of the other four spans. Some of these repairs required stainless steel anchor studs drilled into sound, underlying concrete to anchor the repair mortar to the existing structure. Repairs to four closed-up refuge areas were also carried out to make the structure safer for pedestrians. Work started again in March 2023 and was completed by the end of May.
HRE engineer Colin McNicol said: “We only have five concrete viaducts in the whole of the estate which makes Aurs Burn very special and we’re delighted the work has been successful and the viaduct is preserved for many years into the future.
“This was a big job with concrete repairs involving mortar, carefully colour-matched with the original, covering almost 400 sqm of surface area. The deck and footpath were resurfaced and pipes were cleared to minimise water dripping on to the structure. Japanese knotweed and other vegetation were also removed before it could cause any new damage.
“It’s very satisfying to see the viaduct back in good condition particularly as it is so well used by the local community, including two schools that sit on either side of the burn.”
The Historical Railways Estate (HRE) is a collection of over 3,100 structures and assets (including 583 in Scotland) which were once part of Britain’s rail network. National Highways has received much criticism from campaigners from simply infilling smaller redundant bridges to minimise its liability exposure, cutting off existing or potential rural pathways.
However, despite having had its cack-handedness exposed, National Highways is sometimes sensitive to heritage. Infilling these larger structures would be a trickier proposition. Around 80 renovations, maintenance and repair works were completed in Scotland in the year to 31st March 2023, including several major restoration schemes on standout structures.
Colin McNicol added: “These structures are important reminders of our industrial history and we are dedicated to keeping them safe. We already have over 40 maintenance projects programmed for this financial year and more will be added as works are identified from our structures’ examinations. We are also developing larger repair schemes on 18 structures in Scotland over the next couple of years; including the prominent underbridges crossing Cumberland Street and Cathcart Road in the Gorbals.”
Maintenance and repair work across the country is carried out by a panel of six contractors: Hammond ECS, Amco Giffen, Balfour Beatty Construction, Beaver Bridges, Bethell and Dyer & Butler.
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