Locks

In Britain, the very first lock flight was built on the Sankey Canal in 1757. There were pound locks on the Exeter Ship Canal in the 16th century, although this was more of a river navigation. But the earliest of any size was the flight at Runcorn which brought the Duke's Canal down to the River Mersey and was constructed in 1773.

However, the chamber lock had been around for centuries before its general use in England. The first chamber lock was built around 1452 on the Canal de Bereguardo, near Milan.

Stunning views

Large lock flights became increasingly common as the canal era drew to a close. In fact the trans-Pennine canals (Rochdale and the Huddersfield Narrow) are almost entirely composed of locks from beginning to end – tiring work but nothing beats the views.

Caen Hill Locks

Perhaps the most impressive lock flight in the UK is the 16 locks at Caen Hill. They were engineer John Rennie's solution to climbing the very steep hill in Devizes, and were the last part of the 87 mile route of the Kennet & Avon Canal to be completed.

Because of the steepness of the terrain there was not the space to use the normal arrangement of water pounds between the locks. As a result, the 16 locks utilise unusually large side ponds to store the water needed to operate. The Caen Hill Locks are part of a longer 29-lock flight at Devizes, all packed into just over two miles.