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.
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 at its peak more than 1.5 million tons of coal per year, and was not abandoned until 1986. 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 commercial 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.
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The Lock
This lock is on the Wakefield section of the Aire and Calder Navigation and is a canalised section of the River Calder.
The maximum dimensions for a boat to be able to travel on the waterway are 70 feet and 3 inches long and 17 feet and 9 inches wide. The maximum headroom is 12 feet and 9 inches. The maximum draught is 7 feet and 7 inches.
Because of the size of the locks the lock gates are mechanically operated. For commercial traffic this is always done by a lock keeper. However leisure boat users are allowed to operate the lock via a control panel on the canal side.
A traffic light system indicates whether leisure boaters can operate the lock themselves. An amber light indicates that there is no lock keeper present and the lock can be self-operated by boaters. This is the normal practice these days except when commercial traffic is expected. If there is a green light showing a lock keeper is present and the lock is ready for you to enter. A red light indicates that the lock keeper does not want you to enter the lock because a commercial craft is being handled.
This lock has a set of gates in the middle of the lock to cater for smaller boat sizes. However these gates are no longer used and they have begun to decay.
The lock is a Historic England Grade II Listed Building.
"NORMANTON AIRE AND CALDER SE 32 SE NAVIGATION CALDER CUT 2/48 Birkwood Lock at - SE 359 240 - II Lock on Calder Cut of Aire and Calder Navigation. Opened 1839; Engineers George Leather and Son of Leeds. Sandstone in large dressed blocks (with some concrete repairs); wooden gates. Quadrantally curved entrances at each end; upper and lower gates, and intermediate gates (now operated hydraulically, by electric power, but manual until 1960's). Overflow sluice from north west corner. (Modern control cabin and bridge not including in the item)."
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