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Historic truss bridge in Savage, Maryland, US

The Bollman Truss Railroad Bridge across the Little Patuxent River at Savage, Maryland, is one of the oldest standing iron railroad bridges in the United States and the sole surviving example of a revolutionary design in the history of American bridge engineering. The 160 feet (49 m) double span was built in 1852 at an unknown location on the main line of the Baltimore and Ohio Railroad. It was moved 35 years later to its present location, where it replaced the very first Bollman bridge. It was the first successful all metal bridge design to be adopted and consistently used on a railroad. The design employs wrought iron tension members and cast iron compression members. It was an improvement over wooden structures, as the independent structural units lessened the possibility of structural failure. After receiving a patent on January 6, 1852, the company built about a hundred of these bridges through 1873. Their durability and ease of assembly greatly facilitated expansion of American railroads in this period. Bollman's Wills Creek Bridge has also survived, but it employs a different type of truss system.

In 1966, the American Society of Civil Engineers introduced its National Historic Civil Engineering Landmark program, designating the bridge as the first landmark. The bridge was listed on the National Register of Historic Places on December 18, 1972, and was designated a National Historic Landmark on February 16, 2000. The bridge was surveyed for restoration in 1978 by Modjeski and Masters, which noted deterioration of the floor trusses. A $214,200 restoration contract was let to Dewey Jordan of Frederick, Maryland, in September 1982. Bollman published a booklet describing the Harpers Ferry bridge and the system in general as a “suspension and trussed bridge,” which is accurate as the design lacks an active lower chord required of a strict truss bridge. Later descriptions used "suspension truss" for the design.