Posey Tube Ventilation Tunnel
Beautiful, board-formed curvy concrete in the exhaust system of the 1928 Posey Tube of Alameda / Oakland, California. It was the first tunnel for road traffic built using the immersed tube technique. The 4,436-foot-long tunnel was the first precast concrete tube, and was cast at Hunter Point by California Bridge & Tunnel Company. Each approach to the tunnel is buffeted by Art Deco ventilation buildings designed by architect Henry H. Meyers, which house the massive fans.
Unlike earlier tunnels, which were ventilated in one direction with fresh air coming in one end and vehicle exhaust out the other, the Posey Tube was one of the earliest to use two fan systems, one for exhaust, which was channeled above the vehicles through an elaborate system of louvers and board formed concrete desgned in intracate curves; the other fan system provided fresh air through the floor of the tunnel.
One piece of interesting trivia about the Posey Tube: A pair of canaries were used during construction as living air monitors; although one canary died during construction, it was an accident caused by being penned up with a pet cat and not a toxic atmosphere.
In 2016, the towers were completely rehabilitated and a new security system was added, making the tunnels no longer accessible to illicit explorers looking to photograph the hidden passageways and nooks of the system. We took our last photos here in late 2014.
Posey Tube Ventilation Tunnel
Beautiful, board-formed curvy concrete in the exhaust system of the 1928 Posey Tube of Alameda / Oakland, California. It was the first tunnel for road traffic built using the immersed tube technique. The 4,436-foot-long tunnel was the first precast concrete tube, and was cast at Hunter Point by California Bridge & Tunnel Company. Each approach to the tunnel is buffeted by Art Deco ventilation buildings designed by architect Henry H. Meyers, which house the massive fans.
Unlike earlier tunnels, which were ventilated in one direction with fresh air coming in one end and vehicle exhaust out the other, the Posey Tube was one of the earliest to use two fan systems, one for exhaust, which was channeled above the vehicles through an elaborate system of louvers and board formed concrete desgned in intracate curves; the other fan system provided fresh air through the floor of the tunnel.
One piece of interesting trivia about the Posey Tube: A pair of canaries were used during construction as living air monitors; although one canary died during construction, it was an accident caused by being penned up with a pet cat and not a toxic atmosphere.
In 2016, the towers were completely rehabilitated and a new security system was added, making the tunnels no longer accessible to illicit explorers looking to photograph the hidden passageways and nooks of the system. We took our last photos here in late 2014.