The first bridge only lasted until 1866, when it was considered inadequate for the ever-increasing loads carried by the railroad. It was replaced by a heavier wooden structure, which reused the original piers. All that remains of the first bridge is an elevated approach west of River Drive on the Iowa side, and a reconstructed pier on Arsenal Island.[19] The second bridge had two decks: a lower deck for pedestrians and an upper deck for railroad traffic.[20] In 1868, an ice storm damaged the bridge's piers and timber spans. Later that year, a tornado also severely damaged the bridge; construction crews from Chicago were able to reopen it.[21]
Third bridge 1872[edit]
The wooden structure was replaced by an iron, twin double-deck bridge in 1872 which carried a single-track rail line and a roadway.[9][22] This bridge was at a new location on the western tip of Arsenal Island, and the original bridge and rail line were abandoned. The relocation was driven by the federal government, which still owned the island and wished to redevelop it as an arsenal. The original bridge and rail line divided the property in two, and the development constraint was removed by moving the bridge to one end of the island. The federal government used this bridge for access to the railroad, giving rise to its name.[9]
The railways used the upper deck, and wagons, livestock and pedestrians used the lower deck. This bridge was 366 ft (112 m) long, and was located near the Rock Island shore. During the 1880s, it accommodated horse-drawn trolley cars and electric trolleys; this tradition was continued on the fourth bridge until 1940.[22]