canal lock
Structure with a lock-chamber that can be filled with water or emptied to raise or lower a ship from one water level to another.
lock filling and emptying opening 
Holes through which the water flows in to fill the lock-chamber or out to empty it.
upper gate 
Watertight door or pair of doors made of wood or metal that open when the water levels between the lock-chamber and the upper level are the same.
lock filling opening 
Holes through which the water flows to fill the lock-chamber.
lock filling intake 
Conduit with a sluice that opens to raise the water level in the lock-chamber.
ladder 
Ladder fixed to the side wall for climbing up out of and down into the lock-chamber.
miter gate recess 
Indentation in the side wall into which a gate fits when open.
lock filling and emptying system 
System consisting of a conduit with sluices alongside the side wall and perpendicular conduits on the canal bed that together raise and lower the water level in the lock.
canal bed 
Thick concrete base that makes up the lock’s foundation.
lock emptying system 
Conduit that evacuates the water from the downstream side causing the water level in the lock-chamber to go down.
approach wall 
Wall along the side wall that guides ships into the lock.
lower gate 
Watertight door or pair of doors made of wood or metal that open when the water levels between the lock-chamber and the lower level are the same.
line hook 
Piece of wood or metal attached to the side wall for securing the rope that holds a ship in place while it is in the lock-chamber.
side wall 
Wall forming one side of the lock-chamber and supporting its doors.