GREENVILLE YARD FLOAT BRIDGE

Project Highlights / Scope of Work

• Demolished and removed existing building-housed crane-lifted bridge system (damaged in Hurricane Sandy) and replaced with redesigned pontoon bridge

• Performed both marine and land based demolition of pier including 1000 timber piles and 2000 tons of structural steel

• Constructed new pier on pile foundation with concrete pile caps over steel

• Designed new track layout and performed survey to ensure proper elevations and connections

• Installed track on new trestle including tie-ins to existing track

Challenges

• Remove old bridge in a safe and efficient manner

• Maintain schedule as established prior to the storm

Project Description

This Port Authority of NY & NJ transfer facility is a loading and unloading station for NYNJ Rail freight cars to be transported across the Hudson River.  What had been planned as a repair and rehabilitation project developed into the complete demolition, redesign and replacement of the existing float bridge due to the effects of Hurricane Sandy.

Once it was determined that the old trestle was no longer structurally sound, it needed to be completely removed prior to any new construction.  (The existing facility was actually a large building which housed a system of cranes and counterbalances designed to adjust to the tides.  Advances in engineering eliminated the need for the building itself by incorporating a flexible pier.)  A detailed demolition plan was devised in which torches would be used to cut notches in the old structure, similar to the way trees are felled.  After several unsuccessful attempts to bring down the weakened sections, a new method involving a hydraulic shear was used to further weaken the supports.  Then, using cables, one end of the framework was pulled and the resulting domino effect brought down the rest of the span.  

Construction of the new float bridge first required the removal of the existing pier:  1000 timber piles and 2000 tons of structural steel were dismantled using a barge-mounted crane.  A new steel pile foundation was constructed using cofferdams, with concrete pile caps poured over the steel.  Our redesign of the system and survey of the area ensured that the new track would tie-in perfectly with the old remaining sections. 

All the work took place under a strict 90-day deadline to have the railroad back in service.  Meeting the deadline was made possible only because of critical planning, preparation and coordinated scheduling. 

This challenging project proved a great learning experience for all those involved.  Insights gained concerning marine-based work and heavy steel demolition will be implemented on future projects.  And there was one positive outcome from the storm:  the Port Authority gained a more modern and efficient transfer facility.