Collapse of The South Street Bridge

When poet Beth Feldman-Brandt wrote Taking Down the South Street Bridge in 2009, she had no idea how powerfully her final line, “We are used to finding our way among ruins,” resonates in PhillyHistory.

The original South Street Bridge was supposed to be a marvel of Philadelphia’s Iron Age. Giant iron columns, versions of a design innovated by the Phoenix Iron Company of Phoenixville, Pennsylvania, supported sections spanning the Schuylkill River. The manufacturer had hoped for more of a splash in Philadelphia at the Centennial Exhibition in 1876. For the grounds of the first American world’s fair, they proposed a 1,000-foot observation tower. If built, this would be about twice the height of City Hall, then under construction, and about as tall as the Eiffel Tower, started a decade later. Metaphorically, the Phoenix Tower would rise from the ashes of the bitter, bloody Civil War. Had the proposal been approved, the Phoenix Tower would literally have been cast from recycled government military canon. But it wasn’t approved. Instead, the biblical sentiment of beating swords into plowshares would play out at the South Street Bridge, which opened for traffic months before, and miles away, from the Centennial grounds.

Just a few seasons later, the bridge’s columns began to crack. Engineers diagnosed the cause as moisture in the rubble fill packed inside, expanding as it froze. They strapped on a series of iron belts that kept the cracks from spreading, but there wasn’t anything engineers could do to retrofit a design flaw at the bridge’s western approach. Beneath the roadbed, brick arches resting on granite piers which, in turn, rose from hundreds of wooden piles driven into the muddy riverbed. Problem was, in critical places, the piles had been driven down through only fifteen feet of mud, as far as packed gravel.

When the gravel shifted, piles slipped, piers tipped and arches cracked. Then, early one February Sunday morning in 1878, “the crippled arches gave way at the haunches and fell,” as assistant project engineer David McNelly Stauffer later put it. Like dominoes, “arch after arch went down, and the bridge was not much more than a wreck.”  There had been no casualties, but the two-year-old South Street Bridge was now useless.

Having died a year before the bridge was completed, project engineer John W. Murphy wasn’t around to present his side of the story. Stauffer stepped in, blaming “the tremor produced in the piles by travel on the bridge” allowing “percolation of water down their sides.” Stauffer admitted “the ground underlying this approach is an alluvial deposit, treacherous and unstable in character” but defended the project’s construction. “It is a matter of record that the piles under pier No. 2 were from 28 to 30 feet long,” he wrote. Possibly so, but that wasn’t enough to compensate for the fact that the piles under the pier that failed first were only half that length.

Stauffer’s reputation didn’t seem to suffer much, if at all. Before and even after the collapse, he had capitalized on his bridge expertise. He had written of the innovative construction technique (the Plenum-pneumatic process in sinking the cast-iron columns) in the Journal of the Franklin Institute. After the collapse, in a markedly different tone, Stauffer promoted his services for City Council’s investigations in order that “the public may be enabled to form a correct judgment as to the methods actually pursued by the builders.” Later, he continued to boast about the bridge’s successful arches at its eastern approach. Decades later, Stauffer was still in the business, having included tunnels in his repertoire. But he also pursued another passion, collecting historical prints and compiling a four-volume dictionary of their artists. Stauffer’s American Engravers Upon Copper and Steel, published in 1907, soon became a classic research tool.

In all of the discussion of the new, new, South Street Bridge, the collapse of the first South Street Bridge in 1878 drifted from memory. Today, we find some comfort in the claim made of Street Department’s chief engineer and surveyor, that here is “the largest and most complex project in the history of the Streets Department.” It’s bicycle-friendly, pedestrian-friendly and has a wild lighting scheme. But history compels us to ask: does all of this rest on a foundation of solid rock?