WORK to lower the tracks under Hunts Mill Bridge in Royal Wootton Bassett is under way.

The three-day challenge of removing the existing rails and ballast, excavating the track bed and putting in new rails started in the early hours of Saturday.

It is one of the final major engineering projects in the town as part of the electrification of the Great Western rail line and is being done so overhead power lines can be installed to accommodate a new fleet of trains.

Over the past year all three of the town’s rail bridges have been closed so they can be adapted. But while the other two were raised, Hunts Mill, which is a Grade II listed structure, has only had its parapets raised.

Built between 1839 and 1841 to take the A3102 over the line, it is described by Historic England has having a characteristic Isambard Kingdom Brunel design with an elegant skew.

The engineering work meant all services through Swindon were affected and replacement buses were running between Reading, Swindon and Chippenham and between Didcot Parkway, Swindon and Bristol Parkway.

More chaos was caused on Friday as services were hit with signalling problems on the line between Swindon and Bath just as travellers were about to make their bank holiday getaways.

Engineers were expected to be on site until 5am on Tuesday and more work is planned for the weekend of June 10.