A flap gate includes a door body and a flap ancillary part. When the door body is in its down position, a movable end portion of the door body is located forward of a supported end portion. The door body changes its position between the down position and a maximum up position. The flap ancillary part applies tilt-up moment to the door body only when the door body is located in a position between the down position and a first position. The flap ancillary part also applies tilt-down moment to the door body only when the door body is located in a position between the maximum up position and a second position.

To effectively block a corner portion from an influx of water. A floating flap gate apparatus 1 constructed to enable a forward end of a door body to swing upwards around a base end thereof. The floating flap gate system 1 has floating flap gates 11 and 12 arranged in a first rectilinear region S1 and a second rectilinear region S2 respectively, and a corner flap gate 21 installed at a corner portion C where S1 and S2 intersect. The corner flap gate 21 has a plurality of door bodies 22 divided by straight lines passing through a part of the corner portion C where lines extending in a width-wise direction of a base end side bottom surface of the door bodies 13 of the floating flap gates 11 and 12 intersect. Among the plurality of door bodies 22, a door body adjacent to the door bodies 13 of the floating flap gates 11 and 12 and the door bodies 22 adjacent to the door bodies 13 are connected by hinge structures 32 and 31 that maintain a water-impervious state. The corner flap gate rises or lowers, following a raising or a lowering of the door bodies of the floating flap gates, thereby making it possible to effectively block a corner portion from an influx of water.

To effectively block a corner portion from an influx of water. A floating flap gate apparatus 1 constructed to enable a forward end of a door body to swing upwards around a base end thereof. The floating flap gate system 1 has floating flap gates 11 and 12 arranged in a first rectilinear region S1 and a second rectilinear region S2 respectively, and a corner flap gate 21 installed at a corner portion C where S1 and S2 intersect. The corner flap gate 21 has a plurality of door bodies 22 divided by straight lines passing through a part of the corner portion C where lines extending in a width-wise direction of a base end side bottom surface of the door bodies 13 of the floating flap gates 11 and 12 intersect. Among the plurality of door bodies 22, a door body adjacent to the door bodies 13 of the floating flap gates 11 and 12 and the door bodies 22 adjacent to the door bodies 13 are connected by hinge structures 32 and 31 that maintain a water-impervious state. The corner flap gate rises or lowers, following a raising or a lowering of the door bodies of the floating flap gates, thereby making it possible to effectively block a corner portion from an influx of water.

A gate, leaf, and method for controlling water levels in a body of water. The gate comprises a moveable barrier (which may be a leaf), a restoring device such as a spring, and a profile. The barrier automatically opens or closes an amount to allow less or more water through as a result of changes in the water pressure in the upstream body of water. This helps maintain a water level in the upstream body of water. The profile disturbs the flow of water through the gate to influence the water pressure on the barrier. The profile may help provide a more linear curve for the water moment on the barrier across the range of barrier positions. A more linear curve for the water moment may help maintain equilibrium with the restoring moment across the range of barrier positions. The method comprises disturbing the flow of water over a barrier to redistribute the pressures of the water on the barrier.

A gate, leaf, and method for controlling water levels in a body of water. The gate comprises a moveable barrier (which may be a leaf), a restoring device such as a spring, and a profile. The barrier automatically opens or closes an amount to allow less or more water through as a result of changes in the water pressure in the upstream body of water. This helps maintain a water level in the upstream body of water. The profile disturbs the flow of water through the gate to influence the water pressure on the barrier. The profile may help provide a more linear curve for the water moment on the barrier across the range of barrier positions. A more linear curve for the water moment may help maintain equilibrium with the restoring moment across the range of barrier positions. The method comprises disturbing the flow of water over a barrier to redistribute the pressures of the water on the barrier.

A system and method are provided for presence based automatic operation of a marine barrier gate for protecting a secured area. Embodiments include a system having RFID sensors outside and inside the secured area, and proximal the gate. A controller verifies that a user is authorized to enter the secured area when one or more of the RFID sensors communicate with a user identification unit carried by the user; opens the gate or causes the gate to remain open when the user's authorization to enter the secured area is verified; tracks a location of the user identification unit using the RFID sensors while the gate is open and the user is transiting the gate; and closes the gate when the RFID sensors are no longer in communication with the user identification unit.

A system and method are provided for presence based automatic operation of a marine barrier gate for protecting a secured area. Embodiments include a system having RFID sensors outside and inside the secured area, and proximal the gate. A controller verifies that a user is authorized to enter the secured area when one or more of the RFID sensors communicate with a user identification unit carried by the user; opens the gate or causes the gate to remain open when the user's authorization to enter the secured area is verified; tracks a location of the user identification unit using the RFID sensors while the gate is open and the user is transiting the gate; and closes the gate when the RFID sensors are no longer in communication with the user identification unit.

A water control gate pivotable about a horizontal axis. Control may be by a combination of inflatable actuators and ballast chambers in combination with means for preventing over-rotation. Sealing between gate panels and between gate panels and abutments may be by means of seals inflated hydrostatically. The present invention is bottom hinged water control gate actuated by a combination of ballast chambers and inflatable actuators. The invention further includes an inflatable sealing means. The invention is particularly suited for use as a navigation lock gate system or as a flood control gate in a watercourse such as a navigation canal.

An axis positioning mechanism serving as a rotation bearing of a flap gate includes a housing disposed at the bottom of an opening, a first rotating plate rotationally supported by the housing via a first shaft, a second rotating plate rotationally supported by the housing via a second shaft having a different axis from the first shaft, and a synchronizing rod rotationally connected to the rotating plates so as to synchronize the rotations of the rotating plates. The axis positioning mechanism further includes connecting members rotationally connecting a door base and the rotating plates with different axes. The door is laid flat with a pivot at a higher position than the axes.

A system is provided for automatic operation and status indication of a marine barrier gate. Embodiments include a system having a buoyant barrier gate that is movable between a closed position and an open position. An actuator moves the gate between the open and closed positions, and a sensor is operably connected to the actuator to generate data relating to a position of the barrier gate between the open and closed positions. A processor receives the data from the sensor and processes the data to move the gate between the open and closed positions, and detect the position of the gate. A human-machine interface is operably connected to the processor for communicating the detected position of the barrier gate to a user.