Abstract: Apparatus allowing ventilation through a ventilation shaft to an underground ventilation duct fluidly communicating through the ventilation shaft to an atmospheric opening of the shaft and on threat of flooding operable to prevent downward flow of surface water into the underground ventilation duct includes support sidewalls fitting in the shaft providing a ventilation passage between support top and bottom openings and a suspension member supported on opposed lateral sidewalls unobstructively horizontally spanning the passage proximate the top opening and holding one or more hinge connected panels in the passage that manually release to rotationally close the passage and prevent flooding and are manually rotationally liftable to a home position allowing ventilation. The suspension member is liftingly removable from the support and may include end keys received in keyed supports to allow the suspension member to fit in the supports so a specific panel closes to a specific sidewall.

Abstract: Apparatus allowing ventilation through a ventilation shaft to an underground ventilation duct fluidly communicating through the ventilation shaft to an atmospheric opening of the shaft and on threat of flooding operable to prevent downward flow of surface water into the ventilation duct includes support sidewalls fitting in the shaft providing a ventilation passage between support top and bottom openings and a suspension member supported on opposed lateral sidewalls proximate the top opening holding one or more hinge connected panels that manually release to rotationally close the passage and are manually rotationally liftable to a home position allowing ventilation. A releasable latching system between panel and a suspension member holder catches rising panels to hold them in home position ready for release.

Abstract: Apparatus for allowing ventilation as usual for underground tunnels through a ventilation shaft opening to atmosphere yet preventing underground flooding from surface waters pouring through the grate, comprises an assembly that fits within the ventilation shaft and includes one or more panels held in an upright home position that allows ventilation as usual but is releasable to rotationally gravitate to a lower sealing position closing a passage between the ventilation shaft and atmosphere to prevent water from entering the underground tunnels. A panel position indicator moves from a hidden position to a visible position with lowering of the panels to visually signify that the panels are lowered and that flooding protection is activated.

Abstract: Apparatus for allowing ventilation as usual for underground tunnels through a ventilation shaft opening to atmosphere yet preventing underground flooding from surface waters pouring through the grate, comprises an assembly that fits within the ventilation shaft and includes one or more panels held in an upright home position that allows ventilation as usual but is releasable to rotationally gravitate to a lower sealing position closing a passage between the ventilation shaft and atmosphere to prevent water from entering the underground tunnels. A panel position indicator moves from a hidden position to a visible position with lowering of the panels to visually signify that the panels are lowered and that flooding protection is activated.

Abstract: A floodwater barrier for protecting the shore side of a shoreline from flooding includes at least one self-actuating floodwater barrier unit for installation between a pair of walls transverse to a shoreline. The unit includes a flexible resilient panel, a plurality of rigid members connected to the panel, at least one watertight chamber of size and arrangement to give the unit water buoyancy, hinged to be rotatable upward about a horizontal axis longitudinal to the shoreline under the influence of buoyancy and hydrostatic pressure from a rise of the body of water acting on the unit, and further includes flexible tension members positioned to act on the floodwater barrier unit to limit upward rotation of the unit to a predetermined extent.

Abstract: A buoyant flood guard barrier panel passively buoyantly rotationally pivotable upward from horizontal about a first horizontal axis overlays a subframe unattached to the panel. A secondary mechanism for raising the panel has one or more lift arms below the panel transverse to the first axis are rotationally mounted on a second horizontal axis parallel to, below and forward of the first axis. One or more powered drivers act on one or more driven member units each attached to a lift arm rearward of and lower than the second axis to pivot the lift arm on the second axis, rotating the arm upwardly under the panel to rotationally raise the panel. The powered driver may be a winch or a hydraulic actuator.

Abstract: A buoyant flood guard barrier panel passively buoyantly rotationally pivotable upward from horizontal about a first horizontal axis overlays a subframe unattached to the panel. A secondary mechanism for raising the panel has one or more lift arms below the panel transverse to the first axis are rotationally mounted on a second horizontal axis parallel to, below and forward of the first axis. One or more powered drivers act on one or more driven member units each attached to a lift arm rearward of and lower than the second axis to pivot the lift arm on the second axis, rotating the arm upwardly under the panel to rotationally raise the panel. The powered driver may be a winch or a hydraulic actuator.

Abstract: Apparatus for allowing ventilation as usual for underground tunnels through a ventilation shaft opening to atmosphere yet preventing underground flooding from surface waters pouring through the grate, comprises an assembly that fits within the ventilation shaft and includes one or more panels held in an upright home position that allows ventilation as usual but is releasable to rotationally gravitate to a lower sealing position closing a passage between the ventilation shaft and atmosphere to prevent water from entering the underground tunnels. A panel position indicator moves from a hidden position to a visible position with lowering of the panels to visually signify that the panels are lowered and that flooding protection is activated.

Abstract: A plurality of flood prevention units are vertically stacked one over another inside a frame mounted over ventilation opening on a wall. Each unit includes a buoyant gate pivotally mounted by one or more pivotation members about a horizontal axis transverse to sidewalls of the frame for pivotation of the gate on rise of water buoyantly lifting the gate rotationally upwardly between said sidewalls for engagement with an upper deck horizontally connecting the sidewalls. A limiter limits the extent of self-actuation rotation of the gate. The gates are open during non- flooding conditions, allowing ventilation through the building opening, and sequentially close from lowest to highest on rise of water activating each gate in order, allowing ventilation to continue until the highest gate is closed.

Abstract: A series of self-actuating flood guard units each including a buoyant gate flanked by a pair of the boundary walls and pivotable about a horizontal axis transverse to the flanking boundary walls runs along a shoreline of an adjacent body of water The axis is located at a selected elevation above ground inundated by the body water and is selected to cause the gate to buoyantly rotate upwardly between the boundary walls on rise of water above the selected elevation. The extent of rotation is limited by a restraint acting on the gate. The series of units may be continuous or contiguous and act as a whole to prevent onshore flooding from a rise of the body of water at the shoreline.

Abstract: A buoyant flood guard barrier panel passively buoyantly rotationally pivotable upward from horizontal about a first horizontal axis overlays a subframe unattached to the panel. A secondary mechanism for raising the panel has one or more lift arms below the panel transverse to the first axis are rotationally mounted on a second horizontal axis parallel to, below and forward of the first axis. One or more powered drivers act on one or more driven member units each attached to a lift arm rearward of and lower than the second axis to pivot the lift arm on the second axis, rotating the arm upwardly under the panel to rotationally raise the panel. The powered driver may be a winch or a hydraulic actuator.

Abstract: A floodwater barrier for protecting the shore side of a shoreline from flooding includes at least one self-actuating floodwater barrier unit for installation between a pair of walls transverse to a shoreline. The unit includes a flexible resilient panel, a plurality of rigid members connected to the panel, at least one watertight chamber of size and arrangement to give the unit water buoyancy, hinged to be rotatable upward about a horizontal axis longitudinal to the shoreline under the influence of buoyancy and hydrostatic pressure from a rise of the body of water acting on the unit, and further includes flexible tension members positioned to act on the floodwater barrier unit to limit upward rotation of the unit to a predetermined extent.

Abstract: A series of self-actuating flood guard units each including a buoyant gate flanked by a pair of the boundary walls and pivotable about a horizontal axis transverse to the flanking boundary walls runs along a shoreline of an adjacent body of water The axis is located at a selected elevation above ground inundated by the body water and is selected to cause the gate to buoyantly rotate upwardly between the boundary walls on rise of water above the selected elevation. The extent of rotation is limited by a restraint acting on the gate. The series of units may be continuous or contiguous and act as a whole to prevent onshore flooding from a rise of the body of water at the shoreline.

Abstract: The shore side of a shore line water barrier is protected from flooding caused by storm surge over-topping the barrier. Water overtopping the barrier, such as from wind waves crashing against the barrier, is trapped, impounded and accumulated between a parapet atop the barrier and walls on the sides of a buoyant gate unit taller than the parapet and walls and normally resident below grade on the shore side of the barrier, hinged about an axis generally parallel to the barrier and spaced from the parapet by a distance not less than the height of the gate unit. The accumulated overtopping water is applied to rotationally float the gate unit from the horizontal position initially principally by buoyancy and then principally by hydrostatic pressure to drive the gate unit to an upright position to oppose storm surges having a water level higher than the parapet.

Abstract: The shore side of a shore line water barrier is protected by a disclosed construction and method from flooding caused by storm surge over-topping the barrier. Water overtopping the barrier, such as from wind waves crashing against the barrier, is trapped, impounded and accumulated between a parapet atop the barrier and walls on the sides of a buoyant gate unit taller than the parapet and walls and normally resident below grade on the shore side of the barrier, hinged about an axis generally parallel to the barrier and spaced from the parapet by a distance not less than the height of the gate unit. The accumulated overtopping water is applied to rotationally float the gate unit from the horizontal position initially principally by buoyancy and then principally by hydrostatic pressure to drive the gate unit to an upright position to oppose storm surges having a water level higher than the parapet.

Abstract: Method and apparatus for preventing water from flooding along the length of a super elevation surface having a slope from an upper end to a lower end transverse to a longitudinal direction of the surface. A chain of rigid buoyant gate units of increasing heights is flexibly sealingly laterally linked together side by side for pivotable movement of the gate units about at least one pivotation axis, and if more than one axis, then about coplanar pivotation axes. The gate units are situated in a recess in and transverse to the longitudinal direction of the surface between a pair of walls lining the surface parallel to the longitudinal direction to which the pivot axis or axes is/are transverse. One of the walls is at a lower end of the slope and the other wall is at the upper end of the slope.

Abstract: A self-actuating flood guard for a construction holds a buoyant gate at an elevation spaced from ground between flanking spaced vertical boundary walls adapted for connection to the construction. The gate is pivotable on pivotation members about a horizontal axis normal to the boundary walls for buoyant rotation upwardly between the boundary walls on rise of water above the elevation. Optionally, flexible lip seal gaskets along the sides of the gate sealingly wipe the boundary walls, and a flexible strip gasket across the pivotation members along the base of the gate prevents passage of water between the base of the gate and the construction. A restraint acts on the gate to prevent the gate from rotating about the axis more than a predetermined extent when the gate is pivoted upwardly above said elevation.

Abstract: Embodiments are described for preventing downward flow of substantial surface water into an underground ventilation duct communicating upwardly to a ground surface opening. The embodiments comprise a support having a top opening and an opening in a lower portion above a floor. The opening in the lower portion is for venting communication with a proximate portion of the ventilation duct. The support supports at least one seat and paired buoyant gate set. The seat is mounted perpendicularly relative to the gate and a portion of a passageway under the seat for fluidly communicating beyond such portion to the top opening of the support and to the proximate portion of the ventilation duct. The buoyant gate is positioned lower than the seat and the passageway, is of sufficient size to block the passageway, and is responsive to water rising in the support by floatingly pivoting upwardly until engaging the seat, thereby blocking the passageway.

Abstract: Embodiments are described for preventing downward flow of substantial surface water into an underground ventilation duct communicating upwardly to a ground surface opening. The embodiments comprise a support having a top opening and an opening in a lower portion above a floor. The opening in the lower portion is for venting communication with a proximate portion of the ventilation duct. The support supports at least one seat and paired buoyant gate set. The seat is mounted perpendicularly relative to the gate and a portion of a passageway under the seat for fluidly communicating beyond such portion to the top opening of the support and to the proximate portion of the ventilation duct. The buoyant gate is positioned lower than the seat and the passageway, is of sufficient size to block the passageway, and is responsive to water rising in the support by floatingly pivoting upwardly until engaging the seat, thereby blocking the passageway.

Abstract: A storm drain system is provided to prevent rising water from flowing substantially vertically out of a storm drain inlet. The storm drain system comprises a seat generally horizontally mounted within a chamber and a moveable buoyant door assembly responsive to rising water in the chamber to float upwardly to engage the seat to thereby prevent water flowing upwardly out of the storm drain inlet. A support frame may be mounted along a flow passageway leading to the storm drain gating such that the seat and the buoyant door assembly is mounted to or integral with the support frame. In an embodiment, one or more pivot or hinge mountings secure the buoyant door assembly pivotally with respect to the drain support.