Historic Bridge Foundation

The Schell Memorial Bridge in Northfield, Massachusetts is one of New England’s most unusual and ambitious early steel highway bridges—and as of December 2025, it is still standing.
Completed in 1905, the bridge was built to replace an earlier double-deck timber bridge that carried both wagons and railroad traffic across the Connecticut River. What might have been a purely utilitarian replacement became something far more refined when Francis Robert Schell offered to fund a memorial bridge in honor of his parents. His gift allowed the structure to be designed not only for function, but also for permanence, dignity, and beauty.
Engineered by Edward S. Shaw, the bridge is a rare example of a highway Pennsylvania truss adapted into a three-span configuration that behaves as a continuous structure under live load, yet functions as a simple span with cantilevered ends under dead load. This sophisticated structural concept was uncommon for highway bridges of its era. The bridge’s er****on—documented in multiple articles in *The Engineering Record*—was itself a feat, involving cableways, temporary counterweights, and carefully controlled deflection during construction.
Beyond engineering, the bridge was clearly intended as a civic monument. Its polygonal top chords form a graceful arching profile, while Gothic-inspired portal bracing, finials, and carefully detailed granite piers elevate it far above a standard steel truss. It is a bridge meant to be seen and remembered.
The Schell Memorial Bridge has long been recognized as historically significant and was determined eligible for the National Register of Historic Places in 1981. While it has experienced alterations and deterioration over time—particularly to its deck and lower chord members—the bridge’s essential form, materials, and engineering intent remain clearly legible.
The modern preservation story began as an effort focused on stabilization, rehabilitation, and long-term preservation of the bridge. Unfortunately, over time that effort encountered significant organizational and coordination challenges, and the project was unable to move forward as a viable restoration initiative. As a result, the current plan has shifted toward demolition and replacement. The Historic Bridge Foundation regards this outcome as deeply regrettable, particularly given the bridge’s recognized historical and engineering significance.
Today, the Schell Memorial Bridge stands as both an engineering landmark and a reminder of what thoughtful early-20th-century bridge design could achieve. Its continued survival offers an opportunity to move forward with clearer communication, stronger partnerships, and a renewed commitment to preserving one of Massachusetts’ most distinctive historic bridges.

Tucked into the commercial heart of Brownsville, Pennsylvania, the Dunlap’s Creek Bridge (also known as the Market Street Bridge) carries Main Street over a narrow ravine on the old National (Cumberland) Road. It is easy to cross without noticing—but from the creek bed the view reveals what makes this structure extraordinary: five cast-iron, hollow, tubular ribs springing between tall sandstone abutments. Completed for traffic in 1838 and finished on July 4, 1839, this was the first cast-iron bridge built in the United States. Its designer was Capt. Richard Delafield of the U.S. Army Corps of Engineers, who adopted cast iron after earlier timber and suspension bridges at this site repeatedly failed and suitable arch stone was lacking for a 100-foot span.
Delafield’s scheme was both technically bold and methodical. Each of the five elliptical tubes that form the main ribs consists of nine hollow cast-iron voussoirs with flanged collars, bolted together into continuous arch barrels. Cross-plates at the voussoir joints and triangulated spandrel frames brace the system, while iron floorplates once carried a macadamized roadway. The ribs bear on iron springing plates bedded into sandstone abutments roughly 42 feet high and 25 feet wide. Tests in the early twentieth century showed the iron to be of high quality and remarkably sound, which helps explain the bridge’s longevity.
The project also embodies a distinctive moment in American engineering culture. Delafield and his West Point–trained team fused French-style scientific engineering with the hands-on craft tradition of local foundrymen John Snowden and John Herbertson, who cast the pieces in Brownsville using pig iron brought by river. Construction began in 1836 under Keys & Searight; by 1838 the arches, spandrels, and flooring were in, and traffic began using the crossing before the decorative railings were simplified and the job officially opened in 1839. The bridge quickly earned praise as a “handsome and substantial” structure that passed heavy loads with barely a tremor—a quiet triumph of careful design, good iron, and robust details.
Even as the National Road’s mainline shifted and Brownsville’s river trade ebbed, the Dunlap’s Creek Bridge endured. In 1920, sidewalks were cantilevered on each side and later railings replaced the originals, but the iron ribs remained essentially as built—proof that early American cast iron, properly detailed, could achieve both strength and staying power. Today, plaques and listings acknowledge its national significance.
In short, this modest span is a “first” that still carries the street it was built to serve. It proves that the United States’ earliest cast-iron bridge was not a fragile experiment but a working piece of infrastructure—one whose fabric warrants the highest level of conservation craftsmanship.
In 2025 the Dunlap’s Creek Bridge is undergoing a thorough, conservation-grade restoration focused on its cast-iron arch system. The project is a collaboration in which the prime contractor dismantled the bridge and shipped the historic cast-iron arch segments to Bach Steel’s Michigan facility for specialized work. There, the ribs and associated castings are being evaluated, conserved, and—where necessary—repaired using methods appropriate to 19th-century cast iron.
Progress has been deliberately paced for a reason: cast iron isn’t mild steel. It behaves differently in tension and under heat, and repairs to cracked or locally deteriorated castings must be designed and executed with exceptional care. That means extensive non-destructive evaluation (NDE), test coupons, mock-ups, and procedure qualifications to demonstrate that any proposed will perform as intended without introducing new stresses or embrittlement.
Right now, much of that testing and procedural vetting has proven more challenging than hoped. Several attempted repairs have not passed the specified verification steps on the first try. That is not failure; it is the quality-assurance making sure the final repairs will be effective and safe. Because this is a PennDOT project, each procedure must also be reviewed and accepted by the Department before production work proceeds. Those formal reviews have taken a long time, slowing the project schedule.
The Dunlap’s Creek Bridge restoration is still moving—carefully. The cast-iron ribs are at Bach Steel’s shop; testing and approvals have slowed hands-on production, but that caution protects irreplaceable historic metal. With those issues resolved, work can resume in earnest. When it does, Brownsville will get back not just a crossing, but a renewed national first.