Williamsport Railroad Lift Bridge Structural Investigation

This lift bridge was built in 1923 by the Western Maryland Railway Company to deliver coal across the C&O Canal and Towpath to the Potomac Public Service Company Power plant. The unique asymmetric design of the bridge allowed the mules to pass under the bridge without having to be unharnessed. When the canal stopped operating, the bridge remained in use as a stationary rail bridge then later as a pedestrian bridge over the canal.

McMullan’s evaluation of the bridge included a structural condition assessment of all the column, beams, bracing, counter weights, rollers, cables, links and pulleys, and a mechanical evaluation of the direct current powered motors located above the bridge. We also investigated the feasibility of delivering electrical power to the motors to allow the bridge to be operational. We provided the National Park Service (NPS) with options to stabilize the bridge in place, raise the bridge into a fixed position, or restore it to be fully operational.

The NPS adopted the option of raising the bridge to a fixed, non-operable position which allows canal boats to once more pass under the bridge for the first time since 1924. Additional bracing was added to ensure stability of the bridge in its fixed raised position. However, all such bracing is completely reversible should the NPS decide to restore the bridge to its 1922 condition.

Williamsport, MD

National Park Service-National Capital Region

Peck, Peck & Associates