Miter gate
A lock type consisting of two wings for locks and docks is called a stem gate . They consist of two gate leaves that can be rotated about vertical axes and brace against each other at an obtuse angle. Occasionally the individual wings are also referred to as stem gates.
Layout and function
In the closed position, these wings are not at right angles to the lock wall, but rather point slightly towards the headwater . As a result, the wings are pressed against each other at the joint when the water is present, which ensures a good seal, and the gate remains reliably closed by itself as long as the water levels in front of and behind the gate are not balanced when the lock chamber is filled or emptied. From a static point of view, the closed mitred gate wings represent a three-hinged arch in which the pressure that acts on the gate due to the water level difference is statically favorably diverted as a compressive force in the longitudinal direction of the gate wing laterally into the walls of the lock chamber without the gate bending strongly ( cantilever arm ) to claim.
In the open position, the wings of the caulking gate usually fold into a corresponding caulking gate niche in the lock walls, so that they do not represent an obstacle for passing ships. These stem niches are in modern locks by artificially generated water movement, z. B. with the help of air bubble systems , kept free of floating debris and ice.
Examples
Opening mortise gate
Bidirectional miter gate pair
Pressure and sealing area of a mortise gate
Opened mitred gate wing in the mitred door niche
Other types of lock gates
- Folding gate as a single-wing lock gate with a horizontal axis of rotation attached to the floor of the lock chamber.
- Lifting gate as a protective board with vertical movement in the direction of the gate level upwards.
- Sliding gate as a one-piece panel that can be moved horizontally.
- Segment gate as a damming body rotatable about a horizontal axis with a circular cylindrical gate skin.
