Altoona to Johnstown, "The Horseshoe Curve".

History:

The Pennsylvania Railroad (PRR or Pennsy) constructed the Altoona to Johnstown section of the Philadelphia to Pittsburgh railroad in the mid 19th century, with the famous Horseshoe Curve being completed in 1854.

Upon the opening of the line, the Allegheny Mountains were no longer a barrier in transporting freight and passengers across Pennsylvania. The construction and operation of the railroad gave rise to the City of Altoona, home of locomotive, passenger and freight car shops with the PRR being the primary industry of the region. As the railroad grew, so did Altoona itself. In 75 years, Altoona went from farmland to a population of 75,000.

The Horseshoe Curve itself was designed by John Edgar Thomson and Herman Haupt, and opened on February 15, 1854, as part of the Pennsylvania Railroad's main line to the west. The curve has been in continuous operation since then, when it originally had two tracks. Between 1898 and 1900 it was widened to four tracks.

The curve was considered so important to railroad traffic that it was guarded by Union soldiers during the American Civil War and the Nazis attempted to sabotage it during World War II. The Curve covers about 220 degrees of arc; on the north side, the radius measures 637 ft (194 m), tightening to 609 ft (186 m) on the south side.

Route:

The route extends from Altoona in the East to Johnstown in the West. These areas of industry are separated by the Allegheny Mountains which is crossed by travelling approximately 45 miles of curves and steep gradients. The summit of the route is at Gallitzin around the iconic tunnels. The Horseshoe Curve is the most famous of the curves on the route and is located about 5 miles from Altoona.

Focus Time Period:

The route has been constructed based on reference in the mid 1950's. During this time, diesels were dominant on the route and the track layout at Altoona was frequently changing. This was before PRR stopped using steam engines in 1957 so there is still some steam based infrastructure on the route. The 100th anniversary of the Horseshoe Curve was in 1954.

Much of the route remains today, but with some differences. The four-track mainline layout has now been streamlined down to three, and much of the track at Altoona has either been removed or neglected. However, most of the original Position Light Signals remain.