Tappan Zee

Hudson River, NY | United States

During the planned demolition of the Tappan Zee Bridge East Anchor Span, a structural failure occurred destabilizing the structure. Contractors turned to Resolve Marine to develop and manage a team of specialist organizations to safely conduct an emergency explosive demolition. Resolve Marine worked with VGO Inc. to install and monitor sensors that determined real-time stresses, deflections and displacements of critical truss members. This would create an early warning system for personnel in the event of a catastrophic structural failure. Resolve Marine’s explosive contractor CDI placed 492 pounds of explosives onto the four legs of the anchor span. To prevent the span from toppling into the nearby shipping channel, Resolve Marine placed two 1000 feet high-strength HMPE PLASMA lines from the upper structure of the bridge to two of Resolve Marine’s patented chain pullers. The demolition team then applied a 600-ton horizontal toppling force that constrained the bridges path of collapse, ensuring the structure fell clear of the channel. 

After the successful emergency demolition, Resolve Marine was contracted to remove the span structure in its entirety from the Hudson River. The company mobilized two 300-feet x 100-feet US flagged Jones Act compliant deck barges outfitting them with 20 chain pullers, an arrangement capable of lifting up to 6,000 tons. Working through icy winter conditions, Resolve Marine prepared the structure for lifting. This required the manual trimming of approximately 1,500 tons of twisted steel from the span to free the structure from the bridge caissons at either end. Once prepared, Resolve Marine connected the pullers to the lift rigging and with the application of 4,500 tons of lift, pulled the structure from the riverbed to the surface.

Once debris was removed from underneath the structure, the bridge span was shifted south and rotated 90 degrees. This maneuver took careful coordination from multiple vessels and was synchronized during fast-moving tidal currents. The span was then loaded onto the semi-submersible lift barge and then towed for processing as scrap steel.