Horseshoe Curve (Pennsylvania)

The Horseshoe Curve is a three-track railroad curve on Norfolk Southern Railway's Pittsburgh Line in Blair County, Pennsylvania, United States. The curve is roughly long and in diameter. Completed in 1854 by the Pennsylvania Railroad as a way to reduce the westbound grade to the summit of the Allegheny Mountains, it replaced the time-consuming Allegheny Portage Railroad, which was the only other route across the mountains for large vehicles. The curve was later owned and used by three Pennsylvania Railroad successors: Penn Central, Conrail, and Norfolk Southern.

Horseshoe Curve has long been a tourist attraction. A trackside observation park was completed in 1879. The park was renovated and a visitor center built in the early 1990s. The Railroaders Memorial Museum in Altoona manages the center, which has exhibits pertaining to the curve. The Horseshoe Curve was added to the National Register of Historic Places and designated as a National Historic Landmark in 1966. It became a National Historic Civil Engineering Landmark in 2004.

Location and design

thumb|A topographic map of the area around the Horseshoe Curve

Horseshoe Curve is west of Altoona, Pennsylvania, in Logan Township, Blair County. It sits at railroad milepost 242 on the Pittsburgh Line, which is the Norfolk Southern Railway Pittsburgh Division main line between Pittsburgh and Harrisburg, Pennsylvania. Horseshoe Curve bends around a dam and lake, the highest of three Altoona Water Authority reservoirs that supply water from the valley to the city. It spans two ravines formed by creeks: Kittanning Run, on the north side of the valley, and Glenwhite Run, on the south. The Blair County Veterans Memorial Highway (SR 4008) follows the valley west from Altoona and tunnels under the curve.

Westbound trains climb a maximum grade of 1.85 percent for from Altoona to Gallitzin. Just west of the Gallitzin Tunnels, trains pass the summit of the Allegheny Mountains, then descend for to Johnstown on a grade of 1.1 percent or less. The overall grade of the curve was listed by the Pennsylvania Railroad as 1.45 percent; it is listed as 1.34 percent by Norfolk Southern.

The rise of a westbound train through the curve can be described in several ways. One measurement is from the point where the rails north of the curve start to bow out to a point on the line directly south, across the original Kittanning Reservoir: across this north–south distance of , a train rises from above sea level to .

Another measurement is from the point where the rails coming west out of Altoona make their first detour north to the curve, to a point across Lake Altoona where the rails begin their one-mile straight run south before turning west to the Gallitzin Tunnels; this measurement encompasses the entire Curve structure, including both reservoirs built in its bounds to protect the curve from flooding. Across this north-south distance of , a westbound train rises from to . This latter rise—133 vertical feet in 1,006 linear feet—is a 13.2% grade, completely unascendable by conventional railroads, which usually stick to grades of 2.2% or less.

Each track consists of , welded rail. Before dieselization and the introduction of dynamic braking and rail oilers, the rails along the curve were transposed—left to right and vice versa—to equalize the wear on each rail from the flanges of passing steam locomotives and rail cars, thereby extending their life.

History

thumb|Four trains on four tracks passing each other on the [[Pennsylvania Railroad's mainline near Horseshoe Curve, ]]

Origin

In 1834, the Commonwealth of Pennsylvania built the Allegheny Portage Railroad across the Allegheny Mountains to connect Philadelphia and Pittsburgh, As demand for train travel increased, a third track was added to the curve in 1898 and a fourth was added two years later. The Pennsylvania Railroad delivered empty hopper cars to the Kittanning Point station which the two railroads returned loaded with coal. A third reservoir, Lake Altoona, was completed by 1913. A macadam road to the curve was opened in 1932 allowing access for visitors, and a gift shop was built in 1940. A raised-relief, scale model of the curve was included as part of the Pennsylvania Railroad's exhibit at the 1893 World's Columbian Exposition in Chicago. Pennsylvania Railroad conductors were told to announce the Horseshoe Curve to daytime passengers—a tradition that continues aboard Amtrak trains.

World War II and post-war

thumb|The 100th anniversary celebration of Horseshoe Curve in 1954

During World War II, the PRR carried troops and materiel for the Allied war effort, and the curve was under armed guard. The military intelligence arm of Nazi Germany, the Abwehr, plotted to sabotage important industrial assets in the United States in a project code-named Operation Pastorius. In June 1942, four men were brought by submarine and landed on Long Island, planning to destroy such sites as the curve, Hell Gate Bridge, Alcoa aluminum factories and locks on the Ohio River. The would-be saboteurs were quickly apprehended by the Federal Bureau of Investigation after one, George John Dasch, turned himself in. All but Dasch and one other would-be saboteur were executed as spies and saboteurs.

Train count peaked in the 1940s with over 50 passenger trains per day, along with many freight and military trains. Demand for train travel dropped greatly after World War II, as highway and air travel became popular.

During the 1954 celebration of the centennial of the opening of Horseshoe Curve, a night photo was arranged by Sylvania Electric Products using 6,000 flashbulbs and of wiring to illuminate the area. The event also commemorated the 75th anniversary of the incandescent light bulb. Steam locomotive No. 1361 was placed at the park inside the Horseshoe Curve on June 8, 1957. It is one of 425 K4-class engines: the principal passenger locomotives on the Pennsylvania Railroad that regularly plied the curve. The Horseshoe Curve was listed on the National Register of Historic Places and was designated a National Historic Landmark on November 13, 1966. The operation of the observation park was transferred to the city of Altoona the same year. The Pennsylvania Railroad was combined with the New York Central Railroad in 1968. The merger created Penn Central, which went bankrupt in 1970 and was taken over by the federal government in 1976, as part of the merger that created Conrail. The second track from the inside at the Horseshoe Curve was removed by Conrail in 1981. No. 1361 was removed from the curve for a restoration to working order in September 1985 and was replaced with an ex-Conrail EMD GP9 No. 7048 that was repainted into its former Pennsylvania Railroad scheme. The renovations were completed in April 1992 with the dedication of a new visitor center. It was designated a National Historic Civil Engineering Landmark by the American Society of Civil Engineers in 2004.

Current operations

thumb|Three [[Norfolk Southern freight trains pass each other on the curve in 2006]]

The curve remains busy as part of Norfolk Southern's Pittsburgh Line: , it was passed by 51 scheduled freight trains each day, not including locals and helper engines, which can double the number. Coupled to the rear of long trains, helper engines add power going up and help to brake coming down. For some years before 2020, Norfolk Southern used SD40Es as helpers; since then, EMD SD70ACU locomotives are used. In 2012, Norfolk Southern said annual traffic passing Horseshoe Curve was , including locomotives.

Trackside attractions

The Railroaders Memorial Museum in Altoona manages a visitor center next to the curve. The center has historical artifacts and memorabilia relating to the curve and a raised-relief map of the Altoona–Johnstown area.

Horseshoe Curve is popular with railfans; watchers can sometimes see three trains passing at once. In August 2012, the former Nickel Plate Road (NKP) steam locomotive No. 765 traversed Horseshoe Curve: the first steam locomotive to do so since 1977, while deadheading to and from Harrisburg as part of Norfolk Southern's 21st Century Steam program. No. 765 returned to the curve in May 2013 with public excursion trains from Lewistown to Gallitzin.

Notes

References

External links

Pennsylvania Locomotives on Horseshoe Curve