The Calder and Hebble Navigation
The Calder and Hebble Navigation completed in 1770 consisted of artificial improvements to the River Calder and River Hebble to allow canal boats use what used to be un-navigable rivers.
It ran for 21 miles from the Aire and Calder Navigation at Wakefield to Sowerby Bridge, was one of the first navigable waterways into the Pennines. It was an extension westwards of the Aire and Calder Navigation.
Work began in 1758 to make the River Calder navigable above Wakefield. The navigation to Sowerby Bridge was completed in 1770, including a short branch to Dewsbury.
In 1828 a branch to Halifax was opened, rising 110 feet to a terminus at Bailey Hall, behind Halifax Railway Station. There were 14 locks on the branch which closely followed the route of the River Hebble. Most of the branch was abandoned in 1942 apart from the short section from Salterhebble to Exley.
About half of the navigation is along the course of the River Calder, with short man-made cuts with locks to by-pass weirs. There are two lengthy man-made sections, from Calder Grove to Ravensthorpe and from Brighouse to Sowerby Bridge.
Most commercial traffic on the Calder and Hebble had ceased by 1955, although coal was still carried to Thornhill power station until 1981. However, the whole of the Calder and Hebble remained open for leisure use. The re-opening of the Rochdale Canal between Sowerby Bridge and Littleborough summit in 1996 and Manchester in 2002 has increased the traffic along the Calder and Hebble and it now forms part of the South Pennine Ring.
Flood Locks
"A flood lock is to prevent a river from flooding a connected waterway. It is typically installed where a canal leaves a river. At normal river levels, the lock gates are left open, and the height of the canal is allowed to rise and fall with the height of the river.
However, if the river floods beyond a safe limit for the canal, then the gates are closed (and an extra lock created) until the river drops again. Since this is a true lock it is possible for boats to leave the canal for the flooded river despite the difference in water levels (though this is not likely to be wise) or (more sensibly) to allow boats caught out on the flood to gain refuge in the canal.
Note that if the canal is simply a navigation cut connecting two stretches of the same river, the flood lock will be at the upstream end of the cut (the downstream end will have a conventional lock).
Flood locks which have been used only as flood gates are often incapable of reverting to their former purpose without refurbishment. That is, where only outer gates are ever closed (probably because a waterway is not a true commercial one, and therefore there is no financial imperative for a boat to venture out onto a flooded river) inner gates soon suffer from lack of maintenance. A good example is on the Calder and Hebble Navigation, where structures referred to in the boating guides as "Flood Locks" are clearly only capable of being used for flood-prevention, not for "penning" boats to or from the river in flood."
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Anchor Pit Lock
This is an example of a Calder and Hebble Navigation flood lock where the gates are only closed during times of flood, and then by Canal and River Trust staff rather than boaters.
It has two sets of water level markers, one at the entrance and one inside the chamber below the sign with the name of the lock. Each of these sites has the height inscribed in Roman Numerals from the time the lock was constructed, and a more modern board attached to the stone work.
There is a wooden footbridge over the chamber of the lock but is normally locked and restricted to use by members of the Bradford no. 1 Angling Association.
The lock is a Historic England Grade II Listed Building.
"Entry to canal cut from the River Calder. Lock. Late C18. Dressed stone lock walls with large rectangular stone cappings with well formed curved ends and recess for gates at both ends. Water level marked by incised Roman numerals. Iron mooring hooks."
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