Precast Protects Vital Ventilation Building for Brooklyn Battery Tunnel
South of Manhattan and west of Brooklyn sits Governor’s Island, a 172-acre island in the heart of NY Harbor. On the northeast corner of the island is the octagonal shaped Ventilation Building for the Hugh L. Carey (formerly Brooklyn-Battery) Tunnel. The Governor’s Island ventilation building is one of four structures that contain dozens of giant fans responsible for pulling vehicle emissions out and can completely replace the tunnel's air every ninety seconds. Protecting this important structure from rising water and future flooding during storms is vital.
On October 2012, the storm surge from Superstorm Sandy completely flooded 6,000 feet of each tube of the tunnel with seawater, damaging mechanical, lighting, and ventilation systems. Part of the rehabilitation project included upgrades to the Governors Island Ventilation Building.
The Governors Island ventilation structure is an octagonal building located over the midpoint of the tunnel at its lowest point. Judlau Construction was awarded the contract which also includes a raised seawall at the Ventilation Building to mitigate potential damage from water intrusion and flooding from major weather events like Superstorm Sandy.
Fort Miller produced 61 precast concrete flood wall panels that were installed around the perimeter of the Ventilation Building. Over 13-ft in height, each panel weighed approximately 38,000-lbs. The haunch shape at the top of the wall further protects the ventilation building by deflecting wave action. All panels were fabricated at Fort Miller’s Easton, NY facility and delivered to a staging yard in Jersey City, NJ before being barged to the island.
After a new reinforced concrete foundation was in place, a barge crane set the 61 precast wall panels (59 standard and 2 doorway units). Fort Miller had cast in corrugated sleeves in the bottoms of the panels during manufacturing. Judlau Contracting drilled anchors into the foundation which were fitted into the embedded sleeves. Panel to panel connections utilized cast-in couplers and threaded dowel bars.
A custom architectural formliner was cast in the front face of each of the panels to add texture and compliment the granite façade of the original structure. The precast panels feature a mix design with white cement and an exposed aggregate finish on the joint ends. The finishes on the reveals that simulate dimensional stone were created with the formliner.
The result is an attractive yet functional fortification against future storms encircling this critical structure.