A laterally sliding type opening/closing gate of a torsion structure of reasonable cost is implemented. The gate includes: the torsion structure having a closed cross-section consisting of a thin wall installed such that it may cross a sluice and be composed such that its cross-section may make an in-plane rotation around a restriction point on the cross-section and that a torsion moment generated by an applied load and reaction force on the restriction point is transmitted to its terminal due to its torsion rigidity; and a rail that is installed such that it may cross the sluice; and a plurality of axle type supports that has a function of a restriction point and moves along the rail.

A laterally sliding type opening/closing gate of a torsion structure of reasonable cost is implemented. The gate includes: the torsion structure having a closed cross-section consisting of a thin wall installed such that it may cross a sluice and be composed such that its cross-section may make an in-plane rotation around a restriction point on the cross-section and that a torsion moment generated by an applied load and reaction force on the restriction point is transmitted to its terminal due to its torsion rigidity; and a rail that is installed such that it may cross the sluice; and a plurality of axle type supports that has a function of a restriction point and moves along the rail.

A marine gate has a buoyant variable length barrier and a cable management system employing two cables or lines. An opening line extends through the barrier to move the barrier from an expanded position (gate is closed) to a retracted position (gate is open) via a winch. A closing line moves the barrier from the retracted position to the expanded position using a winch. A weight is attached to the closing line for moving a submerged portion of the line to the seafloor when the barrier gate is retracted and the closing line is payed out by operation of its winch. The weighted line allows a portion or the entire cable system to be under tension at all times. The resulting cable geometry allows vessel operators confidence in knowing the cable location in the water depths at the gate, whether the gate is fully or partially opened.

A marine gate has a buoyant variable length barrier and a cable management system employing two cables or lines. An opening line extends through the barrier to move the barrier from an expanded position (gate is closed) to a retracted position (gate is open) via a winch. A closing line moves the barrier from the retracted position to the expanded position using a winch. A weight is attached to the closing line for moving a submerged portion of the line to the seafloor when the barrier gate is retracted and the closing line is payed out by operation of its winch. The weighted line allows a portion or the entire cable system to be under tension at all times. The resulting cable geometry allows vessel operators confidence in knowing the cable location in the water depths at the gate, whether the gate is fully or partially opened.

A mobile marine barrier (1) comprising a base (2) and a hood (8) located at a distal end thereof is described. The hood (6) comprises a funnel (15) and a distal surface (18) located therein which allows the hood (6) to morph its shape, size and strength so as to give adaptable coastal protection against naturally occurring events. This is achieved by incorporating a telescopic funnel such that the length of the hood (6) and thus the area of its open end can be altered so as to vary the quantity of water directed towards the distal surface (18). The hood (16) may also comprise a mobile face (17) that forms part of variable volume chamber (26) located within the hood (8) which can be filled and emptied with fluids.

A mobile marine barrier (1) comprising a base (2) and a hood (8) located at a distal end thereof is described. The hood (6) comprises a funnel (15) and a distal surface (18) located therein which allows the hood (6) to morph its shape, size and strength so as to give adaptable coastal protection against naturally occurring events. This is achieved by incorporating a telescopic funnel such that the length of the hood (6) and thus the area of its open end can be altered so as to vary the quantity of water directed towards the distal surface (18). The hood (16) may also comprise a mobile face (17) that forms part of variable volume chamber (26) located within the hood (8) which can be filled and emptied with fluids.