Niagara Falls Suspension Bridge - Maintenance and Replacement

Maintenance and Replacement

Budget concerns forced Roebling to build the Suspension Bridge primarily with wood; the cost of casting the components out of iron and transporting them " out West" was exorbitant. The organic material decayed and rotted because of the moisture present around Niagara Falls. As the industrialization of the United States moved forward rapidly, the introduction of the Bessemer process greatly lowered the cost of the more durable steel and iron. By 1880, the Suspension Bridge's wooden trusses, beams, and flooring were replaced with steel. The wire cables were not replaced; their cores were still in pristine condition. The outer layer of wires in the cables was, however, lightly corroded and had to be replaced. Due to severe deterioration, the limestone towers were replaced in 1886 with steel framed versions. These renovations increased the bridge's strength and helped it handle heavier loads for a few more years.

The weight of trains in North America had greatly increased by the mid-1890s. Larger and more powerful locomotives were required to pull cars that handled an increasing number of passengers and goods; compared to the 23-short-ton (21 t) locomotives crossing the bridge in the 1850s, 170-short-ton (150 t) locomotives were the common engines 40 years later. The weight of these trains exceeded the specifications of the Suspension Bridge, and the bridge companies took the opportunity to review and request the replacement of the bridge. Civil engineer Leffert L. Buck, who had been hired to maintain the Suspension Bridge, was selected to design the replacement bridge. He settled for a bridge of the arch design. At that time, arch bridges were the new models for railway bridges and were more cost-efficient than suspension bridges. Buck built the new bridge around and below the Suspension Bridge, replacing it a piece at a time. His plan allowed bridge traffic—train and pedestrian—to continue without disruption. By August 27, 1897, the last pieces of the Suspension Bridge were dismantled, leaving the Lower Steel Arch Bridge—later renamed the Whirlpool Rapids Bridge—in its stead. On inspection, the cores of the cables that formerly held up the Suspension Bridge were found to be as sound as on the day the bridge was built.