Verrazano Narrows Bridge Dehumidification - Brooklyn to Staten Island, N.Y.
To increase the life span of the suspension cables for the Verrazano Narrows Bridge, the Triborough Bridge and Tunnel Authority contracted Kiewit Constructors Inc., a subsidiary of Kiewit Corporation, to dehumidify the anchorages. Each anchorage measures 350-ft.-long, 100-ft.-wide and more than 160-ft.-high. Bridge cables occupy a large portion of the 35,000 sq. ft. of space inside each anchorage, restricting the work area.
The scope of work included erection of four steel-framed, metal-clad cable enclosures - two in each anchorage; installation of dehumidification systems; and replacement of bridge deck joints with pre-formed elastic seals of prevent water infiltration through the anchorage ceilings.
With approximately 2,500 lb. of tension on each wire spanning thousands of feet across the bridge, dropping a bolt, tool or structural member could easily damage one or more strands, potentially reducing the bridge's load carrying capacity. Absolutely no damage was done due to extensive coordination and planning by crews while working with heavy equipment around the suspension cables.