YARDLEY, PA – The Delaware River Joint Toll Bridge Commission is hiring two engineering firms that will utilize ultrasonic testing technology to evaluate the structural integrity of hard-to-examine metal connections at six bridges.
The metal connections, called pins, are a specialized type of heavy-duty bolt that connect critical joints on certain types of bridges. Pins allow different members in a bridge’s metal superstructure to connect, expand and contract while preventing other unwanted movements. Since the spine of a pin is often shielded by eyebars, hangers, collars, or spacers, they are inherently hard – if not impossible – to inspect and evaluate.
Enter ultrasonic testing technology. Ultrasonic testing involves the use of a transducer and a receiver to transmit high-frequency sound waves to evaluate the internal composition of steel components for damage, deterioration, or other factors that could compromise a bridge’s structural safety. This “non-destructive” inspection tool is well suited for evaluating the condition of critical pin connections in bridges.
At the monthly meeting on Nov. 24, the Commission awarded professional-services contracts for “Non-Destructive Bridge Pin Testing” during 2026. (Note: Most Commission bridges do not have structural pin connections.)
One contract, awarded to Pennoni Associates of King of Prussia, PA. for up to $1,077,133.19, calls for ultrasonic pin testing at three bridges in the Commission’s southern service region (corresponding pin numbers are approximations):
- Calhoun Street Toll-Supported Bridge, an 1884 wrought-iron truss bridge between Trenton, N.J. and Morrisville, PA. (252 iron truss pins);
- New Hope-Lambertville (Route 202) Toll Bridge, a 1971 steel plate-girder bridge between Solebury Twp., PA. and Delaware Twp., N.J., (16 hanger-assembly pins); and
- Lumberville-Raven Rock Toll-Supported Pedestrian Bridge, a 1947 multi-catenary suspension structure between the Lumberville section of Solebury Twp., PA. and the Raven Rock section of Delaware Twp., N.J. (8 anchorage pins).
A second contract, awarded to Modjeski and Masters of Mechanicsburg, PA. for up to $873,488.66, calls for ultrasonic pin testing at three bridges in the Commission’s central service region (corresponding pin numbers are approximations):
- Riegelsville Toll-Supported Bridge, a 1904 multi-catenary suspension structure between Riegelsville Borough, PA, and the Riegelsville section of Pohatcong Twp., N.J. (8 suspension cable pins and 162 suspension rod pins);
- Northampton Street Toll-Supported Bridge, an 1895-96 steel cantilever truss bridge also known as the “free bridge” between Easton, PA. and Phillipsburg, N.J. (98 truss pins); and
- Easton-Phillipsburg (Route 22) Toll Bridge, a 1938 steel truss structure between Easton, PA. and Phillipsburg, N.J. (74 truss pins).
The ultrasonic testing will establish baseline condition assessments of critical pin connections at applicable bridges among the Commission’s 20 river crossing. The results would enable engineers to retest the pins or select pins periodically years later. The baseline readings could then be used to make comparative assessments of any changes in a respective pin’s condition.
The testing could begin as early as February at the New Hope-Lambertville (Route 202) Toll Bridge. Other bridges would be tested after cold weather subsides in 2026. Lane closures are likely for testing at some bridge locations. The Commission plans to post further details of respective travel restrictions prior to their implementation.
The undertaking is being launched in the wake of last year’s discovery of a severely deteriorated structural connection on the 121-year-old New Hope-Lambertville Toll-Supported Bridge. That connection – a four-inch-diameter by 17-inch-long steel pin – was at risk of failing under heavy load. The bridge subsequently was shut down for several weeks early this year so the deteriorated pin could be removed and replaced.
The compromised pin had gone undetected in prior inspections because it was shielded by spacers that disintegrated during paint-blasting work at the bridge. Ultrasonic testing also later revealed “anomalies” in the pin’s structural integrity. (Note: As a precautionary measure, the bridge’s other lower- and upper-chord pins – 210 totals pins — were ultrasonically tested and all were determined to be sound.)
The Commission inspects its bridges on a biennial basis – toll bridges in odd-numbered years and toll-supported bridges in even-numbered years – in accordance with the National Bridge Inspection Standards (NBIS) administered by the Federal Highway Administration (FHWA). Ultrasonic testing, however, is not a required by either the NBIS or FHWA.
