Modjeski and Masters

Modjeski and Masters is a bridge engineering firm headquartered in Mechanicsburg, Pennsylvania, founded in 1893 by Ralph Modjeski and responsible for a long run of American long-span crossings. The practice covers new bridge design, inspection and load rating, movable bridge engineering, structural rehabilitation and construction engineering, with a specialty in vessel collision protection that has become considerably more visible since 2024. The firm served as prime consultant on the Delaware Memorial Bridge ship collision protection system, designing the eight dolphin cells sized to absorb a 120,000 deadweight ton Neopanamax vessel striking at roughly seven knots. Its work spans suspension, cable-stayed, movable and long-span truss structures for state transportation departments, bi-state authorities and federal agencies nationwide.

The firm’s vessel collision practice can be traced to one disaster. After a bulk carrier struck an anchor pier of the Sunshine Skyway Bridge in Tampa Bay in 1980, bringing down 1,300 feet of the southbound span and killing 35 people, Modjeski and Masters took part in the collapse investigation. It then wrote the criteria for designing bridge piers against ship collision in Louisiana waterways, a document several states used until AASHTO published its own guide specifications in 1990. That lineage carries through the Oklahoma Statewide Vessel Collision Risk Assessment, the Paris Road Bridge study, and protection systems assembled from dolphins, large-diameter drilled shafts and fender arrangements.

The broader practice is organized into 27 named service areas. Alongside new design and inspection, they include accelerated bridge construction, hydraulics and scour analysis, load rating, non-destructive testing, paint and coatings evaluation, seismic analysis, service life design, instrumentation, forensic investigation, lighting design, demolition design and railroad services. Five engineering disciplines are kept in house, structural, construction, highway, mechanical and electrical, which is what lets the firm carry a movable bridge from machinery through controls. Project pages are filed by bridge type: arch, bascule, cable-stayed, girder, suspension, swing, truss and vertical-lift, plus tunnels, pedestrian bridges and retaining walls.

Modjeski and Masters is employee-owned and led by president Mike Britt, who started at the firm as an intern. Outside the Mechanicsburg headquarters it staffs regional offices in Littleton, Colorado; Washington, D.C.; four Florida locations; Edwardsville, Illinois; New Orleans; Grand Rapids; Kansas City and St. Louis; Mount Laurel, New Jersey; Poughkeepsie, New York; Raleigh; Philadelphia; Round Rock, Texas; and Charleston, West Virginia, and it takes projects outside the United States through the corporate office. Anniversary writing published by the firm marks 90 years of involvement with the Huey P. Long Bridge, 25 years since the Harpers Ferry Bridge replacement, and 20 years since the Florida Avenue Bridge changed marine traffic in New Orleans. Newer assignments include the I-74 Mississippi River bridge replacement connecting the Quad Cities, the award-winning Hawk Falls Bridge replacement, and a lighting system for the Crescent City Connection.