The Trent and Mersey Canal is a 93+1⁄2-mile (150 km) canal in Derbyshire, Staffordshire and Cheshire in north-central England. It is a "narrow canal" for the vast majority of its length, but at the extremities to the east of Burton upon Trent and north of Middlewich, it is a wide canal.
The narrow locks and bridges are big enough for a single narrowboat 7 feet (2.1 m) wide by 72 feet (22 m) long, while the wide locks can accommodate boats 14 feet (4.3 m) wide, or two narrowboats next to each other.

Quelle: Wikipedia