SJ6475 : Anderton Boat Lift, Cheshire
taken 13 years ago, near to Anderton, Cheshire West And Chester, England
In this image, look closely at the largest version, and see that the glass-topped trip boat "Edwin Clark" is in caisson this side and is halfway down. In the far caisson, is a red narrowboat which is halfway up. Gerard Hoffnung had the right idea about the operational principle in describing his encounter with "the barrel". When the lift was electrically operated it was possible (but very time consuming) to use a single side independently.
Compare this image with one taken about thirty seconds earlier: Link
Stephen McKay adds some historical details:
Ranking alongside the Pontcysyllte Aqueduct as one of the great icons of the British canal network, the boat lift at Anderton was an ingenious Victorian solution to the problem of transferring boats the 50 feet between the Trent and Mersey Canal and the River Weaver. It was originally built in 1875 with two caisson, one of which is lowered as the other is raised. In the original design, steam operated hydraulic rams were assisted by pumping some water out of the ascending caisson, thus making it lighter. Unfortunately the equipment proved unreliable mainly due to corrosion caused by using polluted canal water for the hydraulics, and the lift was extensively modified in 1908 using an electric system. The lift had to be closed again in 1983 when corrosion was found in the superstructure and it seemed unlikely that it would ever operate again; contemporary photographs show the lift in a very dilapidated condition. However, towards the end of the 1990s, with a contribution from the Heritage Lottery Fund, money was raised to restore the lift using a version of the original hydraulic system - this time using oil rather than canal water. The fully restored lift was opened in 2002 and is now a major tourist attraction as well as an important component of the canal network.