A FEAT of engineering on the Lancaster Canal is to be flagged up as a treasure of transport history.

The Hincaster Tunnel was built to take the canal close to Sedgwick Gunpowder Works and was completed on Christmas Day 1817.

The limestone portals at each end of the 345-metre-long passage are already Grade II listed - and now the Transport Trust charity wants to bring the tunnel to the attention of an even wider audience.

It plans to flag up the structure with one of its Red Wheel plaques, the equivalent of English Heritage's blue plaques on historic buildings linked to famous people.

The Transport Trust is described as the only charity dedicated to preserving Britain's transport heritage by road, rail, air and water.

So far it has bestowed around 100 of its distinctive round red plaques at sites such as the Farnborough Aerodrome, Brooklands motor racing circuit, the Manx Electric Railway, London's Victoria Coach Station, and the birthplace of the Mini Cooper car.

Closer to home, Morecambe's art deco Midland Hotel, the Ravenglass and Eskdale Railway and the Lune Aqueduct - which carries the Lancaster Canal over the River Lune at Lancaster - have also been adorned with Red Wheels.

The Canal and River Trust, guardian of 2,000 miles of waterways, is seeking special planning consent to fix the red-painted plaque to the west portal of the Hincaster Tunnel.

An existing sign marking the tunnel's opening on June 18, 1819 is to be moved to the east portal.

According to plans lodged with South Lakeland District Council, every effort will be made to avoid damaging the 200-year-old masonry by drilling into the mortar joints rather than the limestone.

The Hincaster Tunnel has no towpath, and barges laden with coal and limestone would have been rope-hauled by horses taken over the hill on a purpose-built path, rather than "legged through" the tunnel.

The structure was built by engineer Thomas Fletcher and the controversial decision to line it with bricks, rather than stone, was taken to save money.

It was last used by commercial boats in 1944.