Editing Lock (water navigation) (section)

===Cill===
The ''cill'', also spelled ''sill'', is a narrow horizontal ledge protruding a short way into the chamber from below the upper gates. Allowing the rear of the boat to "hang" on the cill is the main danger when descending a lock, and the position of the forward edge of the cill is usually marked on the lock side by a white line. The edge of the cill is usually curved, protruding less in the center than at the edges. In some locks, there is a piece of oak about {{convert|9|in|cm|abbr=on}} thick which protects the solid part of the lock cill. On the Oxford Canal it is called a babbie; on the Grand Union Canal it is referred to as the cill bumper. Some canal operation authorities, primarily in the United States and Canada, call the ledge a ''miter sill'' (mitre sill in Canada).<ref name="MERRIAM">[http://www.merriam-webster.com/dictionary/miter%20sill Merriam-Webster Dictionary, definition of miter sill], Retrieved Jan. 28, 2015.</ref>
{{Anchor|Gates}}

==== Photo gallery ====
<gallery mode=packed>
File:Canal Saint-Denis-Ecluse N°1-Le petit bief.JPG|The cill exposed in the deep Pont de Flandre lock on the [[Canal Saint-Denis]], Paris
File:Eynsham Lock - geograph.org.uk - 5594146.jpg|The balance beams typical of many locks on the [[River Thames|Upper Thames]] at [[Eynsham Lock]], [[Eynsham]], [[Oxfordshire]], England. Visible on the gates are the paddle winding gears, used to operate the [[sluice|sluice gates]].
File:JesusGreenLock-Cambridge.jpg|Top gates of [[Jesus Lock]], a beam lock on the [[River Cam]] in [[Cambridge]], England
File:ZSchützmechanik.jpg|200-year-old paddle gear on the [[:de:Wiener Neustädter Kanal|Wiener Neustädter Kanal]], Austria
File:BCN water conservation lock.jpg|Water conservation gear on the [[Birmingham Canal Navigations]]
File:Lock gate cogs, Montgomery Canal - geograph.org.uk - 1806427.jpg|Lock gate controls on a [[canal]]
File:Caversham Lock - geograph.org.uk - 5907080.jpg|[[Caversham Lock]] on the River Thames, with its chamber nearly filled. Visible on top of the gates are the [[hydraulics|hydraulic mechanisms]] that raise and lower the sluices in their raised position. To the right is one of two pedestals which are used to operate the gates and sluices, as well as the lock cottage.
</gallery>