The Barton swing bridge and aqueduct in Barton-Upon-Irwell, which crosses the Manchester Ship Canal as it carries the river Mersey and the Bridgewater Canal. The Mersey is a river in north west England which stretches for 70 miles (112 km) from Stockport, Greater Manchester, ending at Liverpool Bay, Merseyside. For centuries, it formed part of the ancient county divide between Lancashire and Cheshire.02