Abstract: An assembly that fits within a ventilation shaft open to atmosphere and leading from underground ventilation ducts such as to subways prevents surface waters from flooding the underground ducts while maintaining the ventilation. The assembly fits in the ventilation shaft and houses a buoyant float in a chamber surrounding a passageway in fluid communication with the ventilation shaft. A grate covers the passageway. An outside wall of the chamber adjacent the ventilation shaft is open at top to atmosphere and allows flooding water into the chamber, buoying the float upward in the chamber, elevating the passageway above the flooding water. The chamber suitably has means for drainage and admission of flush water to flush flood water debris from the chamber through the drainage.

Abstract: An assembly that fits within a ventilation shaft open to atmosphere and leading from underground ventilation ducts such as to subways prevents surface waters from flooding the underground ducts while maintaining the ventilation. The assembly fits in the ventilation shaft and houses a buoyant float in a chamber surrounding a passageway in fluid communication with the ventilation shaft. A grate covers the passageway. An outside wall of the chamber adjacent the ventilation shaft is open at top to atmosphere and allows flooding water into the chamber, buoying the float upward in the chamber, elevating the passageway above the flooding water. The chamber suitably has means for drainage and admission of flush water to flush flood water debris from the chamber through the drainage.

Abstract: Flood barrier assemblies in land near a water frontage shoreline have next adjacent panels actively erectable into a continuous barrier preventing flooding of the land. In one configuration one lateral side of a panel is a contact surface and the other lateral side carries a gasket. The panels are sequentially raised with a first to raise panel presenting a contact surface to the gasket of the next adjacent second to raise panel. In another configuration, a contact surface is on opposing lateral sides of two panels separated by a next adjacent panel between them having gaskets on both its lateral sides. The spaced first panels raise before the second panel. The raised panels may be in a linear or curved array or a combination of linear and curved arrays. Either configuration and order of raising erects a flood barrier wall sealed panel to panel by the gasket between adjacent panels.

Abstract: A wall resident in a subterranean chamber and not obscuring a horizontal ground level view is situated between buoyant panels flanking the chamber and is configured to be passively rotationally raised out of the chamber to an upright position by one or both of the flanking panels when the panels rotationally buoy upward to form a barrier against water invading the position that the wall, chamber and panels occupy. When flood waters recede, the wall passively lowers so the horizontal ground level view is again not obscured. Provision is made for cleaning flood laden debris from the subterranean chamber to allow the wall to be operated repeatedly after recurring floods.

Abstract: Apparatus and process for securing a grating over an atmospheric opening of a ventilation shaft fluidly communicating through the ventilation shaft to an underground ventilation duct. A vertically extending support for arrangement in the shaft has horizontal flanges for projecting across a top of at least two opposing sides of said shaft to hang said support in said shaft for over topping by said grating. An anchoring member is supported in the support at a level below the flanges and proximate the atmospheric opening. A hold-down connects to the anchoring member to secure the hold-down and the grating to the anchoring member.

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 panel drain automatically closes when the panel is raised to home position so it is already closed when the panel is released to rotationally close the passage.

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 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 one or more hinged panels closing a ventilation passage between the top and bottom of a support fitting in the shaft to prevent flooding. The panels have handles on their topside and pivotable arms on their underside and are liftable to an upright home position allowing ventilation, using tools to reach through grating covering openings on the shaft and lift the panel handles and after the panels are partially lifted, using reach tools to engage and lift the arms to press them again support sidewalls to exert lateral force on underside of the panels to complete upward rotation to the home position.

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 panel drain automatically closes when the panel is raised to home position. A releasable latching system between panel and a suspension member holder catches rising panels to hold them in home position. The suspension member may include end keys received in keyed supports so a specific panel faces a specific sidewall.

Abstract: Flood barrier assemblies in land near a water frontage shoreline have next adjacent panels actively erectable into a continuous barrier preventing flooding of the land. In one configuration one lateral side of a panel is a contact surface and the other lateral side carries a gasket. The panels are sequentially raised with a first to raise panel presenting a contact surface to the gasket of the next adjacent second to raise panel. In another configuration, a contact surface is on opposing lateral sides of two panels separated by a next adjacent panel between them having gaskets on both its lateral sides. The spaced first panels raise before the second panel. The raised panels may be in a linear or curved array or a combination of linear and curved arrays. Either configuration and order of raising erects a flood barrier wall sealed panel to panel by the gasket between adjacent panels.

Abstract: An upper level of a multi-level building is guarded from flooding by water present in one of the levels of the building where the upper level is reached from the lower level (or vice versa) by connecting stairs. A flight of stairs bridging the levels is buoyant and pivotally connected to the building at one end of the flight adjacent one of the levels such that on occasion of water rising originating in one of the levels, the flight rotates upward on the axis of the pivot to block water from entering the upper level.

Abstract: An upper level of a multi-level building is guarded from flooding by water present in one of the levels of the building where the upper level is reached from the lower level (or vice versa) by connecting stairs. A flight of stairs bridging the levels is buoyant and pivotally connected to the building at one end of the flight adjacent one of the levels such that on occasion of water rising originating in one of the levels, the flight rotates upward on the axis of the pivot to block water from entering the upper level.

Abstract: Apparatus for allowing ventilation 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 mounted on a pivot axis and rotatable upwardly by human action raising the panel past a center point of the pivot axis to an upright inwardly leaning home position that allows ventilation as usual but by manual push or pull of the panels past the center point of the pivot axis lets the panels rotationally fall under gravitational impetus to a lower sealing position closing a passage between the ventilation shaft and atmosphere to prevent water from entering the underground tunnels.

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: Apparatus and process for securing a grating over an atmospheric opening of a ventilation shaft fluidly communicating through the ventilation shaft to an underground ventilation duct. A vertically extending support for arrangement in the shaft has horizontal flanges for projecting across a top of at least two opposing sides of said shaft to hang said support in said shaft for over topping by said grating. An anchoring member is supported in the support at a level below the flanges and proximate the atmospheric opening. A hold-down connects to the anchoring member to secure the hold-down and the grating to the anchoring member.

Abstract: Apparatus for allowing ventilation 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 mounted on a pivot axis and rotatable upwardly by human action raising the panel past a center point of the pivot axis to an upright inwardly leaning home position that allows ventilation as usual but by manual push or pull of the panels past the center point of the pivot axis lets the panels rotationally fall under gravitational impetus to a lower sealing position closing a passage between the ventilation shaft and atmosphere to prevent water from entering the underground tunnels.

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 panel drain automatically closes when the panel is raised to home position. A releasable latching system between panel and a suspension member holder catches rising panels to hold them in home position. The suspension member may include end keys received in keyed supports so a specific panel faces 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 underground ventilation duct includes one or more hinged panels closing a ventilation passage between the top and bottom of a support fitting in the shaft to prevent flooding. The panels have handles on their topside and pivotable arms on their underside and are liftable to an upright home position allowing ventilation, using tools to reach through grating covering openings on the shaft and lift the panel handles and after the panels are partially lifted, using reach tools to engage and lift the arms to press them again support sidewalls to exert lateral force on underside of the panels to complete upward rotation to the home position.

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 panel drain automatically closes when the panel is raised to home position so it is already closed when the panel is released to rotationally close the passage.