An engineer calls a ‘Dinky’ railroad bridge unsound

But NJ Transit says recently inspected span over canal is in fine shape.

By: David Campbell
   Is the "Dinky" railroad bridge, a former pivot bridge that still spans the Delaware & Raritan Canal near Alexander Road, structurally sound?
   A Princeton Borough resident and licensed professional engineer says the bridge, located on the train-shuttle route between Princeton and New Jersey Transit’s Northeast Corridor rail line, is in deteriorated condition and could fail. But NJ Transit begs to differ.
   "The bridge itself is structurally sound and it is used on a daily basis," said NJ Transit spokesman Ken Miller, noting the regular trips made by the one-car Dinky train.
   NJ Transit engineers with degrees specific to the field conduct annual inspections of the agency’s bridges statewide, Mr. Miller said. In addition, NJ Transit conducts a more in-depth inspection of each bridge every five years with the assistance of a consultant.
   The Dinky bridge just had its five-year inspection last year and was deemed structurally sound, Mr. Miller said.
   Nevertheless, Scott Lane resident Richard Prospero, an engineer who works in New Brunswick, is concerned about the safety of the old bridge, which once rotated on a stone center column to allow boats with masts to pass by. He said he noticed the bridge "wasn’t looking good" recently while he was walking on the canal tow path.
   The Scott Lane resident said he has conducted work at a steel mill where one of his jobs was to have rusted steel replaced. Ever since, he said, he’s been conscious of erosion like that he said is evident on the bridge.
   In a letter to state officials last month, Mr. Prospero warned that the bridge is corroded with rust throughout its major supporting beams and is so "shockingly deteriorated" that one can break off pieces of it by hand.
   In the letter, he urged the state to take immediate corrective action, pointing out that he has advised his family not to ride the Dinky because of safety concerns.
   The most glaring point of weakness, the letter continues, is the central support of the bridge, where seven steel wheel assemblies appear to support the span. The steel supports here have rusted through completely and may collapse. "This is not a matter of conjecture," the letter states, "but only a matter of time."
   In addition, some of the wooden blocks wedged as shims under the beams in the central section and on beams at both ends of the bridge are out of position, have fallen out or are rotted, the letter says.
   While Mr. Prospero contends in his letter that the bridge is designed to be supported at the center, not the end points, Mr. Miller of NJ Transit said the opposite is in fact the case.
   The NJ Transit spokesman indicated that the wheel assemblies supported the span when it functioned as a pivot bridge that turned on the central pillar, but not so today.
   But Mr. Prospero, while leery of publicity for raising his concerns about the bridge, was unconvinced by assurances by NJ Transit.
   "In my opinion, any remedial work they thought they were doing isn’t going to be sufficient to support any failure of the bridge," he said.