Horseshoe Curve is a three-track

railroad Rail transport (also known as train transport) is a means of transport that transfers passengers and goods on wheeled vehicles running on rails, which are incorporated in tracks. In contrast to road transport, where the vehicles run on a prep ...

curve In mathematics, a curve (also called a curved line in older texts) is an object similar to a line, but that does not have to be straight. Intuitively, a curve may be thought of as the trace left by a moving point. This is the definition that ...

Norfolk Southern Railway The Norfolk Southern Railway is a Class I freight railroad in the United States formed in 1982 with the merger of Norfolk and Western Railway and Southern Railway. With headquarters in Atlanta, the company operates 19,420 route miles (31 ...

's Pittsburgh Line in

Blair County Blair County is a county in the Commonwealth of Pennsylvania. As of the 2020 census, the population was 122,822. Its county seat is Hollidaysburg. The county was created on February 26, 1846, from parts of Huntingdon and Bedford counties. B ...

Pennsylvania Pennsylvania (; ( Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, ...

. The curve is about long and in diameter. Completed in 1854 by the

Pennsylvania Railroad The Pennsylvania Railroad (reporting mark PRR), legal name The Pennsylvania Railroad Company also known as the "Pennsy", was an American Class I railroad that was established in 1846 and headquartered in Philadelphia, Pennsylvania. It was named ...

as a way to reduce the westbound grade to the summit of the

Allegheny Mountains The Allegheny Mountain Range (; also spelled Alleghany or Allegany), informally the Alleghenies, is part of the vast Appalachian Mountain Range of the Eastern United States and Canada and posed a significant barrier to land travel in less devel ...

, it replaced the time-consuming

Allegheny Portage Railroad The Allegheny Portage Railroad was the first railroad constructed through the Allegheny Mountains in central Pennsylvania, United States; it operated from 1834 to 1854 as the first transportation infrastructure through the gaps of the Alleghen ...

: the only other route across the mountains for large vehicles. The curve was later owned and used by three Pennsylvania Railroad successors:

Penn Central The Penn Central Transportation Company, commonly abbreviated to Penn Central, was an American class I railroad that operated from 1968 to 1976. Penn Central combined three traditional corporate rivals (the Pennsylvania, New York Central and th ...

Conrail Conrail , formally the Consolidated Rail Corporation, was the primary Class I railroad in the Northeastern United States between 1976 and 1999. The trade name Conrail is a portmanteau based on the company's legal name. It continues to do bus ...

and Norfolk Southern. Horseshoe Curve was added to the

National Register of Historic Places The National Register of Historic Places (NRHP) is the United States federal government's official list of districts, sites, buildings, structures and objects deemed worthy of preservation for their historical significance or "great artistic ...

and designated a

National Historic Landmark A National Historic Landmark (NHL) is a building, district, object, site, or structure that is officially recognized by the United States government for its outstanding historical significance. Only some 2,500 (~3%) of over 90,000 places liste ...

in 1966. It became a National Historic Civil Engineering Landmark in 2004. 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.

Location and design

Horseshoe Curve is west of Altoona, in Logan Township,

. It sits at railroad milepost 242 on the Pittsburgh Line, which is the

Pittsburgh Division main line between

Pittsburgh Pittsburgh ( ) is a city in the Commonwealth (U.S. state), Commonwealth of Pennsylvania, United States, and the county seat of Allegheny County, Pennsylvania, Allegheny County. It is the most populous city in both Allegheny County and Wester ...

and

Harrisburg Harrisburg is the capital city of the Commonwealth of Pennsylvania, United States, and the county seat of Dauphin County. With a population of 50,135 as of the 2021 census, Harrisburg is the 9th largest city and 15th largest municipality in ...

, 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

, 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 curve is long and, at its widest, about across. For every , the tracks at the Horseshoe Curve bend 9 degrees and 15

minutes Minutes, also known as minutes of meeting (abbreviation MoM), protocols or, informally, notes, are the instant written record of a meeting or hearing. They typically describe the events of the meeting and may include a list of attendees, a stat ...

, with the entire curve totaling 220 degrees. 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 at which the rails coming west out of Altoona make their first detour north to the curve, to a point across Lake Altoona where the rails are on their one mile straight run south before turning westward 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. Even the reduced grade created by the curve sometimes requires three or four "helper" locomotives to push westbound trains. Each track consists of , welded rails that were, , laid in 2011. Before dieselization and the introduction of

dynamic braking Dynamic braking is the use of an electric traction motor as a generator when slowing a vehicle such as an electric or diesel-electric locomotive. It is termed " rheostatic" if the generated electrical power is dissipated as heat in brake grid ...

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

flange A flange is a protruded ridge, lip or rim (wheel), rim, either external or internal, that serves to increase shear strength, strength (as the flange of an iron beam (structure), beam such as an I-beam or a T-beam); for easy attachment/transfer of ...

s of passing steam locomotives and rail cars, thereby extending their life.

History

Origin

In 1834 the Commonwealth of Pennsylvania built the

across the Allegheny Mountains to connect

Philadelphia Philadelphia, often called Philly, is the largest city in the Commonwealth of Pennsylvania, the sixth-largest city in the U.S., the second-largest city in both the Northeast megalopolis and Mid-Atlantic regions after New York City. Since ...

and Pittsburgh, as part of the Main Line of Public Works. The Portage Railroad was a series of canals and inclined planes and remained in use until the mid-19th century. The

was incorporated in 1847 to build a railroad from Harrisburg to Pittsburgh, replacing the cumbersome Portage Railroad. Using surveys completed in 1842, the state's engineers recommended an route west from Lewistown that followed the ridges with a maximum grade of 0.852 percent. But the Chief Engineer for the Pennsylvania Railroad,

John Edgar Thomson John Edgar Thomson (February 10, 1808 – May 27, 1874) was an American civil engineer and industrialist. An entrepreneur best known for his leadership of the Pennsylvania Railroad (PRR) from 1852 until his death in 1874, Thomson made it the large ...

, chose a route on lower, flatter terrain along the

Juniata River The Juniata River () is a tributary of the Susquehanna River, approximately long,U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map , accessed August 8, 2011 in central Pennsylvania. The river is c ...

and accepted a steeper grade west of Altoona. The valley west of Altoona was split into two

ravine A ravine is a landform that is narrower than a canyon and is often the product of streambank erosion. Work on Horseshoe Curve began in 1850. It was done without

heavy equipment Heavy equipment or heavy machinery refers to heavy-duty vehicles specially designed to execute construction tasks, most frequently involving earthwork operations or other large construction tasks. ''Heavy equipment'' usually comprises five e ...

, only men "with picks and shovels, horses and drags". Engineers built an earth fill over the first ravine encountered while ascending, formed by Kittanning Run, cut the point of the mountain between the ravines, and filled in the second ravine, formed by Glenwhite Run. The line between Altoona and Johnstown, including Horseshoe Curve, opened on February 15, 1854. The total cost was $2,495,000 or $80,225 per mile ($49,850 /km). In 1879, the remaining part of the mountain inside the curve was leveled to allow the construction of a park and observation area—the first built for viewing trains. As demand for train travel increased, a third track was added to the curve in 1898 and a fourth was added two years later. From around the 1860s to just before

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...

passengers could ride to the PRR's Kittanning Point station near the curve. Two branch railroads connected to the main line at Horseshoe Curve in the early 20th century; the Kittanning Run Railroad and the railroad owned by the Glen White Coal and Lumber Company followed their respective creeks to nearby coal mines. The Pennsylvania Railroad delivered empty

hopper car A hopper car (US) or hopper wagon ( UIC) is a type of railroad freight car used to transport loose bulk commodities such as coal, ore, grain, and track ballast. Two main types of hopper car exist: covered hopper cars, which are equipped with ...

s to the Kittanning Point station which the two railroads returned loaded with coal. In the early 1900s, locomotives could take on fuel and water at a coal trestle on a spur track across from the station. A reservoir was built at the apex of the Horseshoe Curve in 1887 for the city of Altoona; a second reservoir, below the first, was finished in 1896. The third reservoir, Lake Altoona, was completed by 1913. A

macadam Macadam is a type of road construction, pioneered by Scottish engineer John Loudon McAdam around 1820, in which crushed stone is placed in shallow, convex layers and compacted thoroughly. A binding layer of stone dust (crushed stone from the ...

road to the curve was opened in 1932 allowing access for visitors, and a

gift shop A gift shop or souvenir shop is a store primarily selling souvenirs, memorabilia, and other items relating to a particular topic or theme. The items sold often include coffee mugs, stuffed animals, toys, t-shirts, postcards, handmade collec ...

was built in 1940. Horseshoe Curve was depicted in brochures, calendars and other promotional material; Pennsylvania Railroad stock certificates were printed with a vignette of it. The Pennsylvania pitted the scenery of Horseshoe Curve against rival

New York Central Railroad The New York Central Railroad was a railroad primarily operating in the Great Lakes and Mid-Atlantic regions of the United States. The railroad primarily connected greater New York and Boston in the east with Chicago and St. Louis in the Mi ...

's "Water Level Route" during the 1890s. A raised-relief,

scale model A scale model is a physical model which is geometrically similar to an object (known as the prototype). Scale models are generally smaller than large prototypes such as vehicles, buildings, or people; but may be larger than small prototypes ...

of the curve was included as part of the Pennsylvania Railroad's exhibit at the 1893

World's Columbian Exposition The World's Columbian Exposition (also known as the Chicago World's Fair) was a world's fair held in Chicago in 1893 to celebrate the 400th anniversary of Christopher Columbus's arrival in the New World in 1492. The centerpiece of the Fair, hel ...

Chicago (''City in a Garden''); I Will , image_map = , map_caption = Interactive Map of Chicago , coordinates = , coordinates_footnotes = , subdivision_type = List of sovereign states, Count ...

. Pennsylvania Railroad conductors were told to announce the Horseshoe Curve to daytime passengers—a tradition that continues aboard

Amtrak The National Railroad Passenger Corporation, doing business as Amtrak () , is the national passenger railroad company of the United States. It operates inter-city rail service in 46 of the 48 contiguous U.S. States and nine cities in Canada. ...

trains.

World War II and post-war

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 Military intelligence is a military discipline that uses information collection and analysis approaches to provide guidance and direction to assist commanders in their decisions. This aim is achieved by providing an assessment of data from a ...

arm of

Nazi Germany Nazi Germany (lit. "National Socialist State"), ' (lit. "Nazi State") for short; also ' (lit. "National Socialist Germany") (officially known as the German Reich from 1933 until 1943, and the Greater German Reich from 1943 to 1945) was ...

, the ''

Abwehr The ''Abwehr'' ( German for ''resistance'' or ''defence'', but the word usually means ''counterintelligence'' in a military context; ) was the German military-intelligence service for the ''Reichswehr'' and the '' Wehrmacht'' from 1920 to 1944. ...

'', 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 Long Island is a densely populated island in the southeastern region of the U.S. state of New York, part of the New York metropolitan area. With over 8 million people, Long Island is the most populous island in the United States and the 18 ...

, planning to destroy such sites as the curve, Hell Gate Bridge,

Alcoa Alcoa Corporation (an acronym for Aluminum Company of America) is a Pittsburgh-based industrial corporation. It is the world's eighth-largest producer of aluminum. Alcoa conducts operations in 10 countries. Alcoa is a major producer of primar ...

aluminum factories and locks on the

Ohio River The Ohio River is a long river in the United States. It is located at the boundary of the Midwestern and Southern United States, flowing southwesterly from western Pennsylvania to its mouth on the Mississippi River at the southern tip of ...

. The would-be saboteurs were quickly apprehended by the

Federal Bureau of Investigation The Federal Bureau of Investigation (FBI) is the domestic intelligence and security service of the United States and its principal federal law enforcement agency. Operating under the jurisdiction of the United States Department of Justice ...

after one,

George John Dasch George John Dasch (7 February 1903 – 1992) was a German agent who landed on American soil during World War II. He helped to destroy Nazi Germany's espionage program in the United States by defector, defecting to the American cause, but was t ...

, 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. A423, Horseshoe Curve, Altoona, Pennsylvania, USA, 1954 centennial image in railroad museum

A423, Horseshoe Curve, Altoona, Pennsylvania, USA, 1954 centennial image in railroad museum

During the 1954 celebration of the centennial of the opening of Horseshoe Curve, a night photo was arranged by

Sylvania Electric Products Sylvania Electric Products Inc. was an American manufacturer of diverse electrical equipment, including at various times radio transceivers, vacuum tubes, semiconductors, and mainframe computers such as MOBIDIC. They were one of the companies inv ...

using 6,000 flashbulbs and of wiring to illuminate the area. The event also commemorated the 75th anniversary of the

incandescent light bulb An incandescent light bulb, incandescent lamp or incandescent light globe is an electric light with a wire filament heated until it glows. The filament is enclosed in a glass bulb with a vacuum or inert gas to protect the filament from oxi ...

. Pennsylvania steam locomotive 1361 was placed at the park inside the Horseshoe Curve on June 8, 1957. It is one of 425 K4s-class engines: the principal passenger locomotives on the Pennsylvania Railroad that regularly plied the curve. The Horseshoe Curve was listed on the

and was designated a

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

in 1968. The merger created

, which went bankrupt in 1970 and was taken over by the federal government in 1976, as part of the merger that created

. The second track from the inside at the Horseshoe Curve was removed by Conrail in 1981. The K4s 1361 was removed from the curve for a restoration to working order in September 1985 and was replaced with the ex-Conrail

EMD GP9 The EMD GP9 is a four-axle diesel-electric locomotive built by General Motors' Electro-Motive Division between 1954 and 1959. The GP9 succeeded the GP7 as the second model of EMD's General Purpose (GP) line, incorporating a new sixteen- cylin ...

diesel-electric locomotive 7048 that was repainted into a Pennsylvania Railroad scheme. Starting in June 1990, the park at the Horseshoe Curve underwent a $5.8 million renovation funded by the Pennsylvania Department of Transportation and by the

National Park Service The National Park Service (NPS) is an agency of the United States federal government within the U.S. Department of the Interior that manages all national parks, most national monuments, and other natural, historical, and recreational properti ...

through its "America's Industrial Heritage Project". The renovations were completed in April 1992 with the dedication of a new visitor center. In 1999, Conrail was divided between

CSX Transportation CSX Transportation , known colloquially as simply CSX, is a Class I freight railroad operating in the Eastern United States and the Canadian provinces of Ontario and Quebec. The railroad operates approximately 21,000 route miles () of track. ...

and Norfolk Southern, with the Horseshoe Curve being acquired by the latter. The Horseshoe Curve was lit up again with fireworks and rail-borne searchlights during its

sesquicentennial An anniversary is the date on which an event took place or an institution was founded in a previous year, and may also refer to the commemoration or celebration of that event. The word was first used for Catholic feasts to commemorate saints ...

in 2004 in homage to the 1954 celebrations. It was designated a National Historic Civil Engineering Landmark by the

American Society of Civil Engineers American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, p ...

in 2004.

Current operations

The curve remains busy as part of Norfolk Southern's Pittsburgh Line: , it was passed by 51 scheduled

freight train Rail freight transport is the use of railroads and trains to transport cargo as opposed to human passengers. A freight train, cargo train, or goods train is a group of freight cars (US) or goods wagons (International Union of Railways) haul ...

s each day, not including locals and

helper engine A bank engine (United Kingdom/Australia) (colloquially a banker), banking engine, helper engine or pusher engine (North America) is a railway locomotive that temporarily assists a train that requires additional power or traction to climb a gradi ...

s, 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 The EMD SD70 is a series of diesel-electric locomotives produced by the US company Electro-Motive Diesel in response to the GE Dash 9-44CW. Production commenced in late 1992 and since then over 5,700 units have been produced; most of these are t ...

locomotives are used. In 2012, Norfolk Southern said annual traffic passing Horseshoe Curve was , including locomotives.

's '' Pennsylvanian'' between Pittsburgh and New York City rounds the curve once each way daily. Average speed for trains at Horseshoe Curve is for freight and about for passenger trains.

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. Access to the curve is by a

funicular A funicular (, , ) is a type of cable railway system that connects points along a railway track laid on a steep slope. The system is characterized by two counterbalanced carriages (also called cars or trains) permanently attached to opposite ...

or a 194-step stairway. The funicular is single-tracked, with the cars passing each other halfway up the slope; the cars are painted to resemble Pennsylvania Railroad passenger cars. A former "watchman's shanty" is in the park. Horseshoe Curve is popular with

railfan A railfan, rail buff or train buff (American English), railway enthusiast, railway buff or trainspotter ( Australian/British English), or ferroequinologist is a person who is recreationally interested in trains and rail transport systems. Rai ...

s; watchers can sometimes see three trains passing at once. In August 2012, the former

Nickel Plate Road The New York, Chicago and St. Louis Railroad , abbreviated NYC&St.L, was a railroad that operated in the mid-central United States. Commonly referred to as the "Nickel Plate Road", the railroad served parts of the states of New York, Pennsylv ...

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 The 21st Century Steam program was conducted by the Norfolk Southern Railway from 2011 to 2015, featuring four classic steam locomotives pulling passenger excursions along Norfolk Southern rails in the eastern United States. The last train was to be ...

program. Nickel Plate 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
{{featured article Transportation buildings and structures in Blair County, Pennsylvania Historic Civil Engineering Landmarks National Historic Landmarks in Pennsylvania National Register of Historic Places in Blair County, Pennsylvania Norfolk Southern Railway Pennsylvania Railroad Rail infrastructure in Pennsylvania Railway lines opened in 1854 Tourist attractions in Blair County, Pennsylvania Railroad-related National Historic Landmarks Altoona, Pennsylvania Rail infrastructure on the National Register of Historic Places in Pennsylvania 1854 establishments in Pennsylvania Railroad museums in Pennsylvania Museums in Blair County, Pennsylvania