By rosebell
The UK’s Canal & River Trust is undertaking a detailed inspection of Preston Brook Tunnel, one of the world’s oldest canal tunnels still in operation.
The 1.14km-long tunnel on the Trent & Mersey Canal in Cheshire is more than 250 years old. Engineers are surveying the structure using a traditional techniques and cutting-edge technology, working at night to allow the tunnel to remain open during the day.
The team are travelling through the tunnel by boat to assess any structural changes, including checking for cracks and damage to the brickwork. Specialist structural engineers will also carry out rope-access inspections of four air shafts and a construction shaft up to 17m deep.
The inspection will involve the use of poles, hammers and spikes, as well as hi-tech equipment including drone fly-through footage and 3D image mapping.
Construction of the tunnel began in 1766 under the direction of canal pioneer James Brindley, one of the foremost engineers of the Industrial Revolution. Following Brindley’s death, the project was completed by his student and fellow engineer Hugh Henshall in 1775.
Today, Preston Brook Tunnel has heritage status, with Grade II-listed portals and two air shafts.
Principal engineer (tunnels & culverts) Peter Simpson said a trip through the tunnel was like stepping back in time.
“It’s amazing to think this tunnel was built by hand using pickaxes and shovels more than 250 years ago,” he said.
“Long before railways and modern infrastructure projects, engineers such as James Brindley were pioneering tunnelling techniques that helped transform Britain and fuel the Industrial Revolution.
