Aire and Calder Navigation

The Aire and Calder Navigation is a river and canal system of the River Aire and the River Calder in the metropolitan county of West Yorkshire, England. The first improvements to the rivers above Knottingley were completed in 1704 when the Aire was made navigable to Leeds and the Calder to Wakefield, by the construction of 16 locks. Lock sizes were increased several times, as was the depth of water, to enable larger boats to use the system. The Aire below Haddesley was bypassed by the opening of the Selby Canal in 1778. A canal from Knottingley to the new docks and new town at Goole provided a much shorter route to the River Ouse from 1826. The New Junction Canal was constructed in 1905, to link the system to the River Don Navigation, by then part of the Sheffield and South Yorkshire Navigation.

Steam tugs were introduced in 1831. In the 1860s, compartment boats were introduced, later called Tom Puddings, from which coal was unloaded into ships by large hydraulic hoists. This system enabled the canal to carry over 1.5 million tons of coal per year at its peak, and was not finally abandoned until 1986. In order to handle trains of compartments, many of the locks were lengthened to 450 feet (140 m).

Although much of the upper reaches are now designated as leisure routes, there is still significant commencial traffic on the navigation. 300,000 tons were carried in 2007, although most of the traffic is now petroleum and gravel, rather than the coal which kept the navigation profitable for 150 years.