Artificial Intelligence helps to protect historic canal bridges from vehicle strikes

As well as inconvenience to local residents and boaters, vehicle strikes on 200-year-old stone bridges cost us annually up to £1 million in repairs, diverting vital funds away from work to conserve our waterways.

How does it work?

We care for 2,800 historical bridges across 2,000 miles of canals, and we will be testing the new system on Cockerham Road Bridge (no 79), near Forton, Lancashire, which was hit twice in 2022. In the past, the use of CCTV to providing constant recording of bridge strike hot spots in rural areas has proved prohibitively expensive due to a lack of power supply.

However, this new system is controlled by AI using a mobile phone signal and doesn’t continuously record but takes a few photos when it detects vehicle movement. The AI then assesses if the bridge has been impacted. If there is no strike, the photos are deleted and if damage has been caused, Trust staff receive a notification, allowing them to identify number plates to track down the offenders and claim full repair costs on their insurance.

Last summer Cockerham Road Bridge had to be repaired again after yet another strike, at a cost of £25,000. The full-length white steel railings on the top of the stone parapet were also damaged and, in another innovation, have been replaced in sections, leaning away from the road to minimise the risk and make future accident repairs cheaper.

Icons of the canal

Andy Dobson, our asset engineer, said: “Hump-back bridges, an iconic part of Britain’s canal network, were built for the passage of horse-drawn carts, not for today’s modern vehicles and HGVs. Due to the large number of rural, narrow roads crossing the Lancaster Canal, it has more bridge strikes than any other. The bridges are part of the canal’s special character and heritage, and each time one is hit a small piece of history is lost.

“The canal bridges in this area are of particular interest, as their stone parapets were lowered and replaced with railings in the Second World War to deny shelter to invading enemy tanks and troops. Lancashire’s gently shelving beaches were considered a perfect spot for a large invasion force to land.

“With all this wonderful heritage to protect, the Trust’s asset team has worked hard to think of innovative ways not only to reduce repair costs but also to prevent strikes from happening in the first place. We desperately need motorists to slow down and take more care. We are grateful to Lancashire County Council who have been working with us over the last two years to install better approach signage to 15 at-risk bridges over the Lancaster Canal. Hopefully the combination of all these innovations will mean our precious historic canal bridges will be preserved for future generations.

“And if the AI CCTV system works effectively, it could potentially be rolled out at other accident blackspots and even be used on sites at risk from vandalism and fly tipping, saving the Trust time and money and most importantly protecting the nation’s precious canal heritage.”