Events - Event View

May 20, 2025 - Virtual Tech Session

12pm - 1pm - 1 PDH

"New-Hope-Lambertville Bridge

Lower Truss Chord Pin Replacement"

with

Steven Burke, PE, Assistant Chief Bridge Engineer

Delaware Bridge Joint Toll Bridge Commission

&

Mike McCandless, PE, Program Manager - Structures

Delaware Bridge Joint Toll Bridge Commission

&

John Schroettner, PE, Project Manager, Assistant VP

Greenman-Pedersen, Inc.

This presentation explores a unique engineering challenge and the innovative solution that was developed: replacing a severely deteriorated structural pin discovered during the rehabilitation of a 120-year-old, six-span, 1,000-foot-long pin-connected Pratt truss bridge over the Delaware River, without compromising the bridge’s integrity or structural performance. As a vital piece of infrastructure and a symbol of early 20th-century engineering, the bridge presented significant logistical and technical challenges. Traditional replacement methods posed risks to the aging components and required prolonged closures. To address this, the team devised a novel technique to safely and efficiently replace the pin: fabricating and installing an assembly of structural steel components—known as a “friction collar”—to locally support and post-tension the eleven (11) eyebars converging at the pin. This removed the load from the pin, allowing for its safe replacement and ensuring the bridge can continue to serve its communities for decades to come.