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.

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.

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.

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.

A split air cabin ventilation system for construction of tunnel inclined shafts, including a first air cabin and a second air cabin which are both in a hollow closed structure with an air inlet end and an air outlet end respectively at both sides. The two air outlet ends are arranged away from each other. An end of the split air cabin is provided with an air inlet, and the other end is provided with an air outlet. The air inlet is connected to an air source, and the air outlet is connected to the air inlet ends of the first and second air cabins, respectively. The air inlet end of the first air cabin is connected to another air source.

A split air cabin ventilation system for construction of tunnel inclined shafts, including a first air cabin and a second air cabin which are both in a hollow closed structure with an air inlet end and an air outlet end respectively at both sides. The two air outlet ends are arranged away from each other. An end of the split air cabin is provided with an air inlet, and the other end is provided with an air outlet. The air inlet is connected to an air source, and the air outlet is connected to the air inlet ends of the first and second air cabins, respectively. The air inlet end of the first air cabin is connected to another air source.

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.

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.

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.

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.