Tappan Zee

Hudson River, NY | United States

During planned demolition of the Tappan Zee Bridge East Anchor Span a structural failure occurred in a lower chord member destabilizing the structure. Tappan Zee Constructors 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 a sensor suite that allowed for real time determination of stresses, deflections and displacements of critical truss members. Creating an early warning system for personnel in the event of a catastrophic structural failure. Resolve Marine's explosive contractor CDI placed 492 lbs of RDX explosives, packed into 4,000 gr/ft linear shape charges onto the four legs of the anchor span. To prevent the span from toppling into the nearby Hudson River shipping channel Resolve Marine placed two 1000' ft high strength HMPE PLASMA lines from the upper structure of the bridge to two of Resolve Marine's patented chain pullers. Resolve's demolition team was then able to apply a 600ton horizontal toppling force that constrained the bridges path of collapse ensuring the structure fell clear of the channel. The east anchor span was successfully demolished falling into the Hudson River without obstructing the shipping channel.

After the successful emergency demolition of the Tappan Zee Bridge East Anchor Span, Resolve Marine was contracted to remove the span structure in its entirety from the Hudson River. This was accomplished by mobilizing two 300'x100' US flagged Jones Act compliant deck barges from the GoM and outfitting them with 20 of Resolve' Marine's patented 300t chain pullers. The outfitted barge arrangement was capable of lifting up to 6,000 tons. Working through an icy winter in the Hudson River, Resolve Marine prepared the structure for lifting. This required the manual trimming of 1,500 tons (est.) 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 4,500t of lift pulled the structure from the riverbed to the surface.

Once lifted hanging debris was removed from underneath the structure, allowing the bridge span to be shifted south and rotated 90 degrees. This maneuver took careful coordination from multiple vessels and was synchronized with the swift tidal currents. The span was then loaded onto the semi-submersible lift barge the BOA 30. The span was then towed away for processing as scrap steel.