The stately Conemaugh Viaduct was an historic “jewel” of the Portage Railroad. The destruction of this massive stone bridge exemplifies the power of dam breach floods, foretelling the calamity that was about to descend on the villages and boroughs downriver. Collapse of the viaduct released a surge of floodwater with a peak discharge rate of ~7090 to 8060 m3 s−1. A remnant of the viaduct still survives and reveals how it was built. Also, an important record comes down to us from an engineer who visited the site immediately after the flood, and before the Pennsylvania Railroad erected a temporary wooden trestle to carry the rail traffic. A new masonry viaduct was completed in the last half of 1889.
“The latent power of a serpent lies in its coils.”
— Neil Coleman
KeywordsJohnstown flood 1889 Conemaugh viaduct Portage railroad Little Conemaugh Solomon Roberts Frederic Burt LiDAR Engineering news John Durno Neil Coleman Loyalhanna
- Eng. News (1889) “The work of the flood at Johnstown,” Engineering News, Jun 22 1889 p 570Google Scholar
- Leonard JW (1907) Who’s who in New York city and state, LR Hamersly & Co, NY, p 223Google Scholar
- Roberts SW (1878) Reminiscences of the first railroad over the Allegheny Mountain. In: Pennsylvania magazine of history and biography, vol 2. The Historical Society of PA, Philadelphia, pp 370–393Google Scholar
- Snyder A, Vandivort T, Wakefield AE (1889) Map of the valleys of the south fork and [little] Conemaugh rivers, showing the path of the great wave from its origin in the western reservoir to and beyond the stone bridge at Johnstown, Cambria County, PAGoogle Scholar