Allegheny Portage Railroad
The Allegheny Portage Railroad was the section of the Pennsylvania Main Line of Public Works that traversed the Allegheny Mountains in Pennsylvania. It consisted of alternating level and inclined plane stretches of rail, pulling canal boats on carriages. Although dangerous, and often unprofitable, it was a key part of the fastest route between Philadelphia and Pittsburgh in its day. However, it passed its prime in the 1840s. A new Portage Railroad was devised to connect the Juniata and Western canals without the inclines. Even that was outstripped by the Pennsylvania Railroad, which roared past it and consigned the system to history.
Crawling over the Alleghenies
When the main line was being designed, it was determined that the region would be too steep for either a canal, or for horses or steam locomotives of the day. A four mile tunnel was discussed, but would have been unfeasable. The commissioners of the Main Line discussed and put off the section, until the rest of the system was well under way. Finally, in December 1828, they commissioned Moncure Robinson to design a railroad for this stretch. This plan, with modifications by Major John Wilson and Colonel Stephen Harriman Long was approved on March 31, 1831. The railroad was constructed under the superintendency of Samuel Jones, and the engineer in charge was Sylvester Welch. The thirty-seven miles of railroad lie between Hollidaysburg in the east, and Johnstown in the west. It consists of five level and five inclined planes on either side of the peak, or ten in total of each. The entire length had two lines to allow travel in both directions. The first line was completed on March 18, 1834. The second line was completed late spring in 1835. The full cost of the railroad was $1,828,461.38
The level planes were laid with square sandstone blocks called sleeper stones. These were used rather than wooden ties because the cars were originally pulled by horses, and the blocks were both easier to walk on and less dangerous for them. Two holes were drilled in the stones, and wooden sills topped by iron rails were attached via spikes fixed into these holes.
The inclined planes were the unique part of the railroad, and one of its primary attractions. A hitching shed was installed at the foot of the plane, where the cars were unhooked from the horses (later locomotives) and attached to cable. At the head of the plane was a large shed which contained the steam engine and its gears. A two-cylinder engine was powered by three large steam boilers. The engine drove a series of gears which pulled the cable: there were two vertical and one horizontal gears, and the vertical gears turned in opposite directions. This way, as one car was being pulled up the incline, the other car was lowered down it. A water brake was part of the gearing system, and this controlled the movement of cars when there was a weight imbalance. The cable itself was about a mile long, and was originally made of hemp rope. In 1844, John A. Roebling designed a steel wire cable for the railroad, which increased durability and greatly reduced accidents.
In addition to the rail lines themselves, there were several structures to allow the lines to pass over, under or through obstacles. The railroad had one tunnel, the Staple Bend Tunnel along Level Number 2, which was the first railroad tunnel in the United States. There was the Conemaugh Viaduct, 80 feet long and also on Level Number 2. It also had the Skew Arch Bridge along Incline Number 6, so called because the rail line and the overpassing turnpike were not perpendicular.
The railroad began to see heavy use almost as soon as it was completed, increasing to its peak in the 1840s. Some actually traveled the Main Line rather than other westward paths like the Erie Canal because of the uniqueness of the railroad. The horses which drew the majority of cars originally gave way to a number of steam locomotives. In addition, a segmented canal boat was developed, which could be carried over the railroad. This allowed goods and passengers to travel uninterrupted across the Main Line.
A failed reincarnation, and overtaken
However, throughout its use the railroad was dangerous. The hemp ropes would stretch with age, particularly during the winter months. When they snapped, cars would hurtle down inclines, often resulting in injury or death. While the steel cables made them safer, accidents still occurred. Even the addition of safety cars, small sleds that were carried behind the cars to slow a descent, didn't fully protect the workers on the inclines.
In 1839-1840, Pennsylvania commissioned a study for an alternate rail route across the Allegheny Mountains, that would not need the time or danger of inclined planes. As the 1850s began, the New Portage Railroad began to be laid; by 1852 it had passed the first three inclines, shutting off their activity and ceasing traffic through the Staple Bend Tunnel. While still unfinished, the Pennsylvania Railroad completed work on a rail line between Philadelphia and Pittsburgh, allowing uninterrupted traffic. Public opinion moved away from the large investment of the Main Line and looked to the new railroad. Even still, construction on the New Portage Railroad progressed, and its 45-mile length was completed in 1854 for a cost of $2,143,355.49. This was just in time for the sale of the entire Main Line to the Pennsylvania Railroad in 1857, who immediately set about dismantling the now redundant line. Within a year, all rails had been removed, and the Portage Railroad was silent.
From memory to park
The Allegheny Portage Railroad National Historic Site was authorized on August 31, 1964. A version of Engine House 6 was built over top of the original foundations. The house itself was constructed to be larger than the original, so that the foundations could rest undisturbed within it. Inside, a nonworking example of the engine, gears and rope were added. Nearby, an local tavern known as the Lemon House was restored. Currently, the National Park Service maintains these structures, along with the Skew Arch Bridge and the Staple Bend Tunnel.
- Pennsylvania State Archives: The Allegheny Portage Railroad
- William H. Shank, P.E. (2001) The Amazing Pennsylvania Canals ISBN 0933788371
- Funimag 28: The First Mountains Railroads in the World!
- About.com: US/Canadian Parks