Two of the earliest spans Brown designed for the Main Line were the crossing of the Conemaugh River in Johnstown and the Conestoga in Lancaster. Though bid separately both were originally to be constructed utilizing iron truss spans until Pittsburgh Division superintendent Robert Pitcairn endorsed the use of stone to Brown instead. Touting stone’s strength, durability and its abundant supply on the PRR, the stone bridge would be a long term solution, able to support the growing traffic and heavier trains the PRR was becoming accustomed to. It was there that the course divided for the two bridges. The Conemaugh bridge was built as planned with four tracks and the first to prove Pitcairn’s endorsement true surviving the wrath of the great flood of 1889 just a year after its completion.
With bridge renewals a major part of the program to expand the PRR’s trademark four track main line across the state of Pennsylvania, the Brandywine Creek bridge in Coatesville and the Conestoga bridge in Lancaster were the last remaining two track spans west from Philadelphia. As discussed previously, the Lancaster terminal was also a choke point in the movement of traffic necessitating the construction of the Lancaster Cut-Off. Just to the east of the junction of this new route with the old main was the Conestoga River, a 61-mile tributary of the Susquehanna. The crossing of the Conestoga saw several successive bridges built for the railroad; the first a 1400’ long series of wood lattice truss spans dating from the P&C which was consumed by fire and later replaced with a fill and a shortened series of iron Whipple trusses around the Civil War. Though Brown had considered another iron design for Conestoga in 1887 its design ultimately followed the fate of the Conemaugh bridge, choosing to use stone instead. Though initial correspondence suggests the Conestoga bridge was to be a four-track span, costs and traffic levels dictated a compromise in design, building a two-track span with provisions in place for expansion. As a result the five arch, 329’ long stone masonry bridge was constructed with foundations to support a four track span. In addition, contractors left stones protruding from the southern side of the bridge, which would allow for any expansion to tie into the existing structure when demand necessitated. Completed in 1888 traffic grew through the next decade but plans were on the horizon that would direct freight off the main line to a new dedicated low-grade from Atglen to Columbia, by-passing Lancaster all together. Though the span in Coatesville was replaced in 1906 to support the combined traffic demands east of Atglen the Conestoga bridge was never expanded, nor was the main line between Lancaster and Royalton since the PRR now had three two-track routes for both freight and passenger moves via the Main Line, Atglen & Susquehanna low grade and the Columbia branch.
Today many of Brown’s bridges are still in service without remark; the only exception of course is Shock’s Mills, which partially failed during Hurricane Agnes in 1972. Building like the Romans for an empire in the transportation world, Mr. Brown and other people like him on competing railroads represented the pinnacle of engineering, design and forethought that built the United States and are largely responsible for the rail networks we have today.