NEW HOPE, PA – The current vehicular and pedestrian travel restrictions at the 120-year-old New Hope-Lambertville Toll-Supported Bridge must be extended several more months due to an unforeseen structural condition in one of the bridge’s six spans, the Delaware River Joint Toll Bridge Commission (DRJTBC) announced today.
The bridge has been undergoing a comprehensive rehabilitation project throughout much of this year. To carry out the project, a New Jersey-bound traffic detour has been in effect since late January and pedestrian crossings have been restricted to a temporary walkway on the bridge’s roadway deck since mid-July.
It originally was anticipated that the structure could be reopened this fall, with a return of two-way traffic on the bridge’s roadway deck and pedestrians using a soon-to-be-completed new walkway facility.
However, the discovery of a deteriorated critical structural connection in the bridge’s second span from the Pennsylvania side will force postponement of the walkway opening until sometime in December. Meanwhile, the current New Jersey-bound vehicular traffic detour will likely need to be extended into early 2025, when an uninterrupted two-week-long shutdown of the bridge would be implemented to fully repair the deteriorated structural connection.
“We understand the importance this bridge has to New Hope and Lambertville, and we are committed to resolving this issue as quickly and safely as possible,” said DRJTBC Executive Director Joe Resta. “The public’s safety and the bridge’s structural integrity are top priorities.”
A critical issue
At issue is a critical connection on the lower downstream chord of the bridge’s second truss span from the Pennsylvania side. A 4-inch-diameter, 18-inch-long steel pin that supports a critical joint of 11 structural steel members has rusted and worn to the point where it poses a potential risk for failure under heavy load.
It was not possible to see the compromised pin in prior inspections because its condition was shielded by other steel components at the pin’s location. Indeed, were it not for the current project’s sandblasting activities, the pin’s condition might not have been discovered.
The severity of the pin’s deterioration has been confirmed with ultrasonic testing that yielded readings indicating a problem in the pin’s structural integrity. (Note: As a precautionary measure, the bridge’s other lower- and upper-chord pins have been ultrasonically tested and all have been determined to be sound.)
Engineers have determined that the compromised bridge span can remain in service in its present state with a single lane of Pennsylvania-bound traffic and pedestrian traffic remaining on the current adjoining temporary walkway.
As an additional safety measure, the Commission has been strictly enforcing the bridge’s four-ton vehicle weight limit through September at the bridge’s Lambertville approach. This stepped-up enforcement measure will continue through the fall. The critical pin-joint also has been outfitted with strain gauges to monitor stresses in the connection with the corroded pin.
Next steps and temporary full bridge closures
The Commission is in the process of finalizing a two-step plan to bring vehicular traffic back onto the bridge in both directions and put pedestrians back onto the new permanent walkway that is nearing completion alongside the bridge’s downstream truss.
The first step involves the design, fabrication, delivery, and installation of a customized device called a friction-collar system that would allow the compromised structural joint to work without risk of failure under heavy load.
If all goes according to plan as currently scheduled, the friction collar could be installed over a two-week period later this fall, approximately around Thanksgiving. The installation of the device is not anticipated to cause additional travel impacts; PA-bound traffic can continue crossing the bridge in the upstream lane and pedestrians can continue to use the adjoining temporary walkway while the device is installed on the bridge.
But activation of the device – a process called post-tensioning – is expected to require closure of the bridge to all vehicles and pedestrians on two successive nights in early- to mid-December. If this process goes according to plan, it would then be safe to open the bridge’s new permanent walkway to pedestrian traffic and have Pennsylvania-bound traffic back on the bridge’s upstream lane. However, the bridge would remain closed to New Jersey-bound traffic until sometime in early 2025.
The Commission anticipates it will be able to provide a firm schedule for the friction-collar installation process sometime in November.
The second step involves design, fabrication, delivery, and installation of a new steel pin and repairs to various steel structural members connected by that pin. The installation process for the permanent fix could begin once the friction collar device gets installed, but this work would require an uninterrupted two-week closure of the bridge to all vehicular and pedestrian traffic. Rather than do this work immediately before the winter holidays, the Commission plans to schedule it for early 2025, thereby mitigating some of the impacts to New Hope and Lambertville during the winter holiday season.
Details still need to be worked out, but the Commission expects it will be able provide specific dates for the uninterrupted two-week-long bridge closure shortly after the start of the new year.
Impacts to current bridge rehabilitation
The unforeseen structural issue with the critical joint in the bridge’s second span is going to delay completion of the current bridge rehabilitation project. At this time, it is anticipated that only alternating single-lane travel restrictions will be needed to complete any remaining rehabilitation project construction tasks carried over into the new year.
