Horseshoe Curve
The Horseshoe Curve (Horseshoe Curve) is a famous railway turn the railway Pittsburgh-Harrisburg at Altoona in Pennsylvania . Since its completion, it has been part of the important railway line from Harrisburg to Pittsburgh over the Allegheny Mountains . Because of its importance, the Horseshoe Curve has had the status of a National Historic Landmark since November 1966 and is a structure on the National Register of Historic Places .
Position and dimensions
The Horseshoe Curve is located about five miles west of Altoona on the eastern slopes of the Allegheny Mountains. The route follows the small valley of the Burgoon Run , which is formed by the Glenwhite Run and the Kittanning Run . Both side valleys had to be overcome when building the curve. Today Glenwhite Road also runs under the railway line.
The curve consists of an arc of 220 degrees and has three tracks. The radius of the northern part is 194 m (637 ft) slightly larger than that of the southern half of 186 m (609 ft), resulting in a length of 724 m (2375 ft). The entire section of the route in the Burgoon Valley achieves an altitude gain of 37.2 m (122 ft), which corresponds to an average gradient of 1.73% (91 ft per mile). In the Horseshoe Curve itself, the gradient is reduced to 1.45%.
In 1992 a visitor center run by the Altoona Railroaders Memorial Museum was built for $ 6 million , including a short funicular up to the railway line. A steam locomotive of the Pennsylvania Railroad class K4 was set up in the park next to the tracks from 1957 to 1985 . Then it replaced an EMD GP9 diesel locomotive .
history
In the 1840s the Pennsylvania Railroad (PRR) built a railroad to connect eastern Pennsylvania with Pittsburgh in the west. The construction of a route on the steep east side of the Allegheny Mountains caused particular difficulties. The Allegheny Portage Railroad had existed a little south of today's railway since 1834, but it could only negotiate the mountains with the help of a total of ten funiculars.
PRR engineer John Edgar Thomson designed a track that followed the natural watercourses of Burgoon Run and Sugar Run . Since a direct line between the two valleys would have had too steep a gradient of more than 4%, Thomson led the route above the Burgoon Run along the slope to the mountain Kittanning Point and then through the Horseshoe Curve a little further out of the valley. So the slope could be reduced to an acceptable 1.75%.
Up to 450 Irish immigrants from County Cork were employed in the construction from 1851 to 1853 . Using simple tools such as pickaxes, shovels and gunpowder , they had to dig the railway line into the mountainside on the one hand and to fill the embankment over the valleys of the Glenwhite Run and the Kittanning Run on the other . On February 15, 1854, the Horseshoe Curve was opened as part of the double-track railway over the Alleghenys.
The hairpin has remained essentially unchanged since then. Due to the strong increase in traffic, the technical equipment of the section was constantly improved. In 1875 block signals were introduced that worked automatically from 1900 onwards. The originally double-track line was expanded by one track in 1898 and another track in 1900. In the first half of the 20th century, sidings led from the Horseshoe Curve to coal mines in the Kittannig and Glenwhite valleys, there was also a small cargo station and the Kittanning Point passenger stop .
As part of landscape measures, the inside of the curve was given a park-like condition in 1879. This was accessible from the Kittanning Point station. Starting in 1890, the Pennsylvania Railroad began promoting the Horseshoe Curve as the company's technical masterpiece. In 1932, a road was built into the inside of the curve, which allowed easy access. The curve soon became an important attraction for railway enthusiasts and other tourists.
So significant was the railway line that the Horseshoe Curve and the nearby Gallitzin Tunnels were guarded during the two world wars. During the Second World War, they were the target of the sabotage company Operation Pastorius .
After the collapse of the PRR successor company Penn Central , Conrail consolidated the East American rail system in the 1970s. For the Horseshoe Curve, this meant dismantling the current three tracks.
Since the division of Conrail, the Horseshoe Curve has been part of the Norfolk Southern Railway network . Around 60 to 80 freight trains and the Amtrak “Pennsylvanian” passenger train now travel through the Horseshoe Curve every day . Altoona's baseball team, the Altoona Curve , is named after the Horseshoe Curve.
The Horseshoe Curve was added to the List of Historic Civil Engineering Landmarks by the American Society of Civil Engineers in 2003.
See also
Individual evidence
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↑ Listing of National Historic Landmarks by State: Pennsylvania. National Park Service , accessed February 12, 2020.
Horseshoe Curve on the National Register of Historic Places , accessed February 12, 2020. - ↑ Dennis P. McIlnay: The Horseshoe Curve: Sabotage and Subversion in the Railroad City. 2007
literature
- David W. Seidel: Horseshoe Curve. Arcadia Publishing, Charleston 2008, ISBN 978-0-7385-5707-6 .
- Horseshoe Curve. 150 years . In: Trains . Kalmbach Publishing, August 2004, ISSN 0041-0934 , p. 38-61 .
Web links
Coordinates: 40 ° 29 ′ 50.5 ″ N , 78 ° 29 ′ 3.5 ″ W.