Engineers have revealed the scale of the task facing them in the rebuild of an A-listed Angus bridge which remains closed a year on from Storm Babet.
As the area marks the first anniversary of the most severe weather event in recent history, Bridge of Dun is at the heart of a painstaking restoration project.
Babet left a gaping hole in the bridge after a flood relief arch almost completely collapsed.
The bridge – which cost £3,128 in 1787 – spans the River South Esk near Bridge of Dun station.
It has now been revealed the original construction was built on wooden planks to stabilise the foundations on the sand and gravel, but have since rotted away.
It carries the U444 west of Montrose. While it’s not a key road, it is well used by locals, particularly farmers.
And its closure means a long detour through the town to access either side of the river.
Drone footage by Courier photographer Kim Cessford shows the latest stage of the painstaking Angus Council restoration project.
And it reveals how far the floodwaters spread to demolish the relief arch on the south side of the bridge.
We can reveal the bill to the end of September is £227,380 – and set to rise.
Engineers say “significant difficulties” have delayed the repair project.
In Babet’s aftermath, Brechin Bridge was the council’s priority. It eventually re-opened in February.
That allowed contractors to move to Bridge of Dun, where further investigations including laser scanning was carried out.
Repair progress
Since then the key milestones have included:
- April 2024 Emergency demolition including sorting of stone to the point where a ground investigation could be safely undertaken.
- May 2024 A Cone Penetration Testing (CPT) rig was brought in from Abertay University to undertake rapid further testing to a depth of around 10.5m. This identified a potentially suitable rock head at around 10.5m below ground level.
- June/July 2024 – Engineering consultants working on outline designs. Masonry cleaned and sorted for rebuild. Temporary propping installed.
- August 2024 Further rotary drilling testing undertaken to 20m depth. Unfortunately results revealed unsuitable ground conditions to rebuild the relief arch and piling is not feasible.
What is the next stage at Bridge of Dun?
Angus Council said: “Engineers are now investigation installing a ‘floating’ concrete raft foundation with ground improvement undertaken to ensure there is sufficient bearing capacity in the soils.”
It is likely to involved a ‘grout’ injection into the soil at the bridge’s southern end.
“A geotechnical specialist has been brought on board by our principal contractor to support this.
“We hope to receive the final design once all testing is complete and will progress with the listed building consent process.”
They say the contractor is in place and ready to start work as soon as those steps are complete.
But there is a warning that may still be months away as Angus battens down for another winter.
“Once groundworks and foundations are complete the rebuilding of the arch using the demolished masonry and lime mortar can commence,” said the council.
“This will be a protracted process and require favourable weather conditions to reinstate the listed bridge.”
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