Less than three months later, the railroad inaugurated the most famous regularly scheduled passenger train to use the structure: the overnight New York-Chicago Pennsylvania Special, which later became the Broadway Limited. Measuring 3,820 feet long, it carries four tracks at an elevation fifty-two feet above the river's low-water mark.

In all, the bridge required not only 220,000 tons of stone but an estimated 600,000 barrels of cement.

The piers and spandrels (the area between the arches) are filled with concrete, making it technically a composite structure. Today, many people call Rockville Bridge 'the longest stone-arch bridge in the world,' but that's only partly true–only the visible outer layer of its form is stone. Each of the forty-eight arches measured seventy feet long, and the four arches at each end gently curved to accommodate the swing of the tracks as they turned to parallel the river. The Rockville Bridge required the expertise of as many as 300 stonemasons, Italian immigrants or Italians who relocated from Curwensville in Clearfield County, site of some of Pennsylvania's largest quarries and source of much of the sandstone used in the bridge. Under Brown's hand, contractors installed mainline stone-arch bridges at the rate of two or three a year, in sizes and varieties that ranged from a single arch to the majestic forty-eight-arch Rockville Bridge near Harrisburg. Beginning in 1888, he decreed that replacement bridges on PRR's busiest routes, including its Philadelphia-Pittsburgh main line, would reflect a revival of stone-arch technology. As a result, Brown soon began pushing the idea that only costly stone-arch bridges -like those used in the earliest days of railroading - were durable enough to withstand both the passage of time and the growing number of mainline freight and passenger trains. Though iron was stronger than wood, spectacular and often tragic failures on some railroads showed what could happen when iron spans were overloaded and under-maintained. And with the growth of business, PRR's main line no longer carried a mere seven trains a day but as many as 100. Some even went up in smoke from sparks spewed from the stacks of passing steam locomotives. Wooden bridges that were perfectly adequate in the 1840s quickly began to wear out. As the United States matured into an industrialized nation after the Civil War, the trains that moved the nation forward grew longer, heavier, faster, and more frequent. And this amazing stone bridge, composed of 220,000 tons of stone that took 800 workers two years to build, also stands as a monument to overcoming frustration. Second, the bridge's 48 arches do not represent the states of the Union at the time the bridge was built the United States flag bore only 45 stars when the bridge opened to traffic in 1902.Rockville Bridge, an icon of railroad engineering, is the crowning achievement of William Henry Brown, chief engineer of the Pennsylvania Railroad. First, the bridge is properly described as a stone and concrete bridge and is, therefore, technically not the longest stone arch bridge in the world. The author debunks two oft-told myths that have developed regarding the current bridge. The book describes the present bridge from its 1900-1902 construction to the 1997 collapse of a portion of the downstream sidewall and the ensuring repairs. A loss of confidence in iron bridges combined with a continuing increase in the weight of railroad locomotives lead to the decision to replace that structure with the current bridge. In 1877 an iron bridge replaced the earlier structure. In addition to being a fire hazard (portions of the bridge burned in 1868), the bridge became a bottleneck as railroad traffic increased. The first Rockville Bridge was a single-track wooden Howe truss bridge that opened to traffic in 1849. In Rockville Bridge: Rails Across the Susquehanna, noted railroad historian Dan Cupper details the history of the three bridges that have borne the name 'Rockville Bridge.' While the book concentrates on the present bridge, the most famous and longest-standing of the three, the previous structures are described in great detail. This stone and concrete structure, the third bridge to stand at this site, has weathered ice and flood, corporate bankruptcy and merger, and changes in usage, yet it remains a monument to American railroading. More than a century after it was built by the Pennsylvania Railroad, the Rockville Bridge continues to carry mainline rail traffic over the Susquehanna River. Dan Cupper, Rockville Bridge: Rails Across The Susquehanna (Halifax, Pa.: Withers Publishing, 2002) 112pp., illustrated (some col.), maps, plans, $29.95.

Rockville stone arch bridge