Verrazano Narrows Bridge Dehumidification?-?Brooklyn to Staten Island, N.Y.
The Triborough Bridge and Tunnel Authority contracted Kiewit to dehumidify the anchorages of the Verrazano Narrows Bridge in order to increase the life span of the suspension cables. Each anchorage measures 350 feet long, 100 feet wide and more than 160 feet high. Bridge cables occupy a large portion of the 35,000 square feet 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 pounds 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.