Editing Lock (water navigation) (section)

===Shaft lock===
[[File:Minden Weser-Mittelland Kanal Lock 01.jpg|thumb|left|Entrance to Minden shaft lock]]
Looking superficially similar to the caisson lock is the shaft lock. Shaft locks consist of a deep shaft with conventional upper gates. The lower gates are reached through a short tunnel. The gates only close off this approach tunnel so do not have to reach the full height of the lock. Notable examples have been built at Saint Denis (Paris, France), Horin (near Melnik, Czech Republic) and Anderten (Hannover Germany).<ref>{{cite web|title=The International Canal Monuments List|editor-last=Hughes|editor-first=Stephen|publisher=ICOMOS (the International Council on Monuments and Sites)|url=http://www.icomos.org/studies/canals.pdf|access-date=2015-09-06|archive-url=https://web.archive.org/web/20130810162849/http://www.icomos.org/studies/canals.pdf|archive-date=2013-08-10|url-status=dead}}</ref> 

The shaft lock at Minden {{Coord|52|18|23|N|8|55|11|E}} has a fall of {{convert|12.7|m}} and has eight tanks linked in pairs to the lock chamber.<ref>{{cite book|last=Hadfield|first=Charles|title=World Canals: Inland Navigation Past and Present|publisher=David & Charles| isbn=0-7153-8555-0|date=1986|page=162}}</ref>  As the lock is emptied water is run into each chamber in turn, for filling the water is released from the chambers thus saving the waste of a complete lockfull of water. An earlier attempt at a shaft lock had been made at Trollhättan in Sweden on the line of the present Göta canal. The fall would have been {{convert|16|m}}, astonishing in 1749. However the approach tunnel proved to be unusable in times of flood and the shaft lock was replaced by a 2-rise staircase in 1768.<ref>Hadfield (1986) p. 55.</ref>