Photographs & History

Photographs and History

The Paoli Local: 100 Years of Electrification on the Pennsylvania Railroad

At 5:55 AM, Saturday, September 11th 1915 the first scheduled electric powered train departed Paoli for Philadelphia marking the beginning of one of the most famous railroad electrification projects in the United States. 

Overbrook Station marks the location where the Pennsylvania Railroad crosses from the Philadelphia city line into the suburban district knows locally as the Main Line. This location is full of PRR character including the station built in 1860, a PRR standard design interlocking tower and the original details from the first phase of the PRR's great electrification project. 

Overbrook Station marks the location where the Pennsylvania Railroad crosses from the Philadelphia city line into the suburban district knows locally as the Main Line. This location is full of PRR character including the station built in 1860, a PRR standard design interlocking tower and the original details from the first phase of the PRR's great electrification project. 

At the close of 1910 the Pennsylvania Railroad had certainly accomplished some remarkable projects. The building of Penn Station and the Hudson and East River Tunnels was an engineering feat that put the railroad at a major advantage over many others, giving them direct access to New York City while establishing a through connection to New England markets.  Out of necessity the new terminal utilized trains running on a proven direct current third rail system, as steam engines would literally suffocate passengers in the lengthy tunnels. The PRR had already begun utilizing DC propulsion on routes previous to the terminal as a way to economize operations and included subsidiaries Long Island Railroad and part of the West Jersey & Seashore. To the north the New Haven had just inaugurated heavy electrified main line service utilizing a new alternating current installation in 1907, but with little time to observe the New Haven’s technology the PRR’s conservative management instead chose the proven DC system.

Soon after the New York terminal project was completed, engineering forces turned their attention to a major traffic bottleneck in the PRR’s corporate home of Philadelphia. Broad Street Station, built by the Wilson Brothers in 1881 and expanded by Frank Furness in 1892-93 was a 16-track stub ended terminal that was situated in the city center directly across from city hall. Broad Street saw a host of trains including commuter and long distance trains that stopped, terminated or originated here; because of the nature of a stub end terminal and a lengthily and congested reverse move to the engine facilities west of the Schuylkill River, trains faced a host of delays limiting Broad Street’s capacity and efficiency. In order to ease congestion the PRR turned to engineering consultant Gibbs & Hill to develop a solution utilizing electric traction, but this time with AC propulsion. Now several years into the New Haven’s electrification the PRR could capitalize on their triumphs while incorporating technological advances to perfect the new installation. A simplified infrastructure and commercial power purchased from Philadelphia Electric made AC propulsion very economical over DC which required the railroad to construction dedicated power plants. With a supply agreement in place the PRR and Philadelphia Electric could easily expand the network over the next several years, sharing the power generation expansion cost with other commercial and industrial customers.

The western terminus of the 1915 electrification was Paoli, Pennsylvania just 20 miles west of Broad Street Station. Here in a modern view we look west toward the interlocking tower and former shop facility used to service the MP54 MU cars. Telltale details of the 1915 electrification include both the lattice style and tubular trolley poles that support the catenary system. Note: This photograph was taken with Amtrak permission under watchman protection, the author does not condone any type of trespassing on railroad or private property. 

The western terminus of the 1915 electrification was Paoli, Pennsylvania just 20 miles west of Broad Street Station. Here in a modern view we look west toward the interlocking tower and former shop facility used to service the MP54 MU cars. Telltale details of the 1915 electrification include both the lattice style and tubular trolley poles that support the catenary system. Note: This photograph was taken with Amtrak permission under watchman protection, the author does not condone any type of trespassing on railroad or private property. 

The initial phase of electrification would be a costly investment due to the complexities of the Philadelphia Terminal’s trackage.  Once completed however, it could not only support electrified Paoli service but also main line service to Wilmington, Trenton, the West Chester Branch and Chestnut Hill branch freeing up valuable terminal space while maximizing the benefit of the initial cost. Power would be supplied by the Schuylkill River generating station and transmitted across the river to the Arsenal Bridge sub-station then on to the West Philly, Bryn Mawr and Paoli sub-stations. Here the 25 cycle 44,000 volt single phase power would be stepped down to 11,000 volts and fed to trains via overhead trolley lines supported by cable suspension supports strung between tubular steel trolley poles. The route to Paoli was 20 miles in length and electrification included wiring a coach yard and service facility in the West Philadelphia shops as well as a new facility in Paoli, a total of roughly 93 miles of track. Initially limited to just the Paoli commuter runs the electrification would power some 80 plus trains a day while affording an 8% overall increase in capacity at Broad Street. Though this seems like a small advantage for such a significant investment, the PRR looked to the future making this the first of several steps to dramatically increase capacity by expanding electric operations off the initial hub.

Two of the original sub-station buildings still survive along the main line at Bryn Mawr (L) and Paoli (R). Note to the right of the Paoli sub-station the vacant land which was the location of the Paoli shops.

Two of the original sub-station buildings still survive along the main line at Bryn Mawr (L) and Paoli (R). Note to the right of the Paoli sub-station the vacant land which was the location of the Paoli shops.

While planning, design and construction of the Paoli electrification was taking place, the PRR turned to the proven class P54 steel coach that was already in production. Though only a basic coach design the PRR had incorporated provisions in the plans to accommodate electrification and operating components when it was time to develop a fleet of self-propelled multiple unit (MU) cars. These motorcars would largely makeup the initial fleet of the PRR’s electric operations until suitable locomotives were developed to haul long distance trains. Classified as MP54's many were already in electrified service on the Long Island and WJ&S utilizing DC propulsion. The MP54 fleet eventually comprised of over 1400 cars; 480 ran on the PRR proper, 923 on the Long Island Railroad and 18 on the WJ&S /PRSL, some of which outlasted the PRR itself, remaining in operation through 1981.

Detail of the Union Switch & Signal interlocking machine at Paoli tower. Though still in service the interlocking plant here and the facility's importance has been greatly reduced with the elimination of the shops. The model board reflects the abandoned #2 and #3 main tracks west of the interlocking. 

Detail of the Union Switch & Signal interlocking machine at Paoli tower. Though still in service the interlocking plant here and the facility's importance has been greatly reduced with the elimination of the shops. The model board reflects the abandoned #2 and #3 main tracks west of the interlocking. 

With the first phase of electrification a success the railroad continued expansion from the Broad Street terminal, next on the Chestnut Hill branch in 1918 and the White Marsh branch in 1924. Concurrent to the expansion of the PRR’s electrified network other notable projects commenced, one of great importance was the Philadelphia Improvements. With heavy construction beginning in 1927 the PRR sought to replace Broad Street Station with a new subterranean station and office tower called Suburban Station and Penn center respectively. All north-south oriented main line trains would utilize a new through station on the west bank of the Schuylkill River called 30th Street Station. East-west trains utilized an upgraded facility out on the main line in North Philadelphia to eliminate the need to reverse out of the terminal to continue after stopping since 30th was actually off the New York-Pittsburgh Main Line. Commuter trains in and out of Suburban would also service 30th Street from a separate upper level reducing the concentration of travelers separating commuter operations from the long distance and regional trains. 

Though the massive Philadelphia Improvements took years to complete electrification continued at a rapid rate extending south to Wilmington on the main line including the branch to West Chester in 1928 and north on the main line to Trenton and the Schuylkill Valley Branch to Norristown in 1930 completing the electrification of all Philadelphia region suburban lines. Further studies reiterated the economical advantage of electrification outside the commuter zones for regional and long distance trains between New York, Philadelphia, Washington DC and Harrisburg, prompting PRR president William Wallace Atterbury to close the gaps in electrification beginning late in 1928. Despite the Great Depression the electrification project continued through 1933, completing the retrofit of the New York Terminal for AC traction and finishing catenary work to complete the network to Wilmington and Paoli. Understanding that Wilmington would not be a suitable southern terminal for electrification, catenary was pushed south to Washington DC including Potomac Yard, financed by a $70 million loan secured from depression era federal recovery programs. Beginning in January of 1934, various reports say up to 20,000 men went to work, comprising of furloughed railroad employees and new hires in the electrical / construction trades to complete the electrification of the New York – Washington DC main line, which opened for business on February 10th 1935. As a result of the success on the north-south “corridor” the PRR sought to complete electrification from the eastern seaboard west to the Harrisburg terminal including all associated freight and passenger main lines. Work commenced on the Low Grade from Morrisville to Enola, the main line from Paoli to Harrisburg, the Columbia Branch and Port Road. Completed in 1938 the entire electrification created a powerful conduit that put the railroad in an excellent position to handle the impending pressure of wartime traffic demands.

View looking east at the western limits of the Paoli interlocking plant. Number 2 and 3 track mains (center tracks) are basically stub end sidings here used occasionaly for track and maintenance equipment. The surviving infrastructure of the electrification reflects various generations of expansion including the massive singnal bridge, tubular trolley poles and the sub-station. This would have been some of the western most electrified trackage until the 1938 expansion to Harrisburg.  Note: This photograph was taken with Amtrak permission under watchman protection, the author does not condone any type of trespassing on railroad or private property. 

View looking east at the western limits of the Paoli interlocking plant. Number 2 and 3 track mains (center tracks) are basically stub end sidings here used occasionaly for track and maintenance equipment. The surviving infrastructure of the electrification reflects various generations of expansion including the massive singnal bridge, tubular trolley poles and the sub-station. This would have been some of the western most electrified trackage until the 1938 expansion to Harrisburg. Note: This photograph was taken with Amtrak permission under watchman protection, the author does not condone any type of trespassing on railroad or private property. 

The electrified infrastructure of the PRR Main Line has remained visibly the same over the ensuing decades despite modifications and renewal. Surviving the Pennsylvania Railroad, Penn Central, Conrail and Amtrak the sub-stations, tubular catenary poles and surviving interlocking towers remain along with many original station buildings preserving the character of the Main Line, a name synonymous not only with the railroad but towns along the route to Paoli. As Amtrak continues to renew their electric traction system the original details of the 1915 electrification, now part of the successful Keystone Corridor could be on borrowed time. There are plans being developed that would call for a total replacement of the 1915 era catenary system. The construction of larger modern support towers similar to those found on the Northeast Corridor will allow Amtrak to move feeder and transmission lines to the railroad right of way much like later phases of electrification did. For now while you ride the Paoli Local or one of Amtrak’s Keystone Service trains take note of the historical infrastructure that survives, that infrastructure around you was part of the one the most ambitious and successful railroad electrification projects in the world!

Pennsylvania Railroad Electrification

Yesterday, February 10th marked the 78th anniversary of regularly scheduled electric powered passenger trains running between New York City and Wahshington DC, a result of the Pennsylvania Railroad’s effort to electrify the main line system throughout the congested Northeast region.

Formerly known as Germantown Junction, North Philadelphia marked where the 1918 electrification of the Chestnut Hill Branch diverged from the main line to head north into the suburbs. This junction today sees Septa trains diverging on the same route while handling the north - south traffic of the Northeast Corridor. Note the massive signal bridge which originally spanned up to 8 tracks, and the early lattice style catenary pole in the foreground.

Formerly known as Germantown Junction, North Philadelphia marked where the 1918 electrification of the Chestnut Hill Branch diverged from the main line to head north into the suburbs. This junction today sees Septa trains diverging on the same route while handling the north - south traffic of the Northeast Corridor. Note the massive signal bridge which originally spanned up to 8 tracks, and the early lattice style catenary pole in the foreground.

The Pennsylvania Railroad’s electrification projects date back as early as 1895 when the railroad used the Burlington and Mt. Holly Railroad as a test subject for a 7 mile 500 volt DC trolley system. The experiment lasted just six years when the Mt Holly powerhouse caught fire. In 1906 southern New Jersey subsidiary West Jersey & Seashore Railroad, built a third rail 600 volt DC system from Camden to Millville and Atlantic City via Newfield. Like an interurban or trolley system the line utilized overhead wire in congested areas like Camden but also had several installations in the countryside, as way to test the durability of trolley wire versus third rail at higher speeds. The same year the PRR installed yet another 600 volt DC system on a short Cumberland Valley Railroad branch running 7.7 miles from Mechanicsburg and Dillsburg all predecessors to the first large scale use of this technology on the railroad. In 1910, the PRR would construct a similar 650-volt DC system to operate the newly opened New York Terminal. Running from Manhattan Transfer near Harrison, New Jersey east to the beautiful Penn Station and ultimately to the sprawling Sunnyside Yard in Queens.

Map detailing the Pennsylvania Railroad's electrified territory circa 1947. Collection of    Rails and Trails .

Map detailing the Pennsylvania Railroad's electrified territory circa 1947. Collection of Rails and Trails.

Soon after the benefits of electric traction were realize in the New York Terminal, attention was focused on the Philadelphia area to relieve congestion, in particular operations radiating from the stub-end Broad Street Station complex. After considerable research the railroad adopted the use of high voltage alternating current for this and all future projects like that of its northern neighbor the New Haven who began use of this technology as early as 1907. Initial electrification included the district between Broad Street and Paoli on the Main Line, which was completed in 1915, followed by the Chestnut Hill Branch in 1918, and the White Marsh Branch in 1924.

PRR Document ET 1 Circa 1935. This document highlights a number of important specifications and layout of the newly completed electrified system, including catenary cable design, substation locations, insulator types and the completion dates of each segment among other items.  Collection of PRR.Railfan.net

PRR Document ET 1 Circa 1935. This document highlights a number of important specifications and layout of the newly completed electrified system, including catenary cable design, substation locations, insulator types and the completion dates of each segment among other items. Collection of PRR.Railfan.net

Expansion continued south to Wilmington on the main line including the branch to West Chester in 1928 and north on the main line to Trenton and the Schuylkill Valley Branch to Norristown in 1930 thus completing the electrification of Philadelphia region suburban lines. Subsequent studies indicated an economical advantage of electrification outside the commuter zones for regional and long distance trains between New York, Philadelphia, Washington DC and Harrisburg, prompting Pennsylvania Railroad President William Wallace Atterbury to close the gaps in electrification beginning late in 1928. Despite the Great Depression the electrification project continued through 1933, completing the retrofit of the New York Terminal for AC traction and finishing catenary work to complete the network to Wilmington and Paoli.

The PRR electrified network still serves the modern needs of Amtrak, providing propulsion for Acela, regional and local passenger rail service through out the Northeast. At Shore, on the Northeast Corridor a southbound passes as another northbound region approaches. Note the catenary above the void in front of the camera, this is where the line to Delair diverges and used to have multiple tracks, all electrified into Pavonia Yard in Camden.

The PRR electrified network still serves the modern needs of Amtrak, providing propulsion for Acela, regional and local passenger rail service through out the Northeast. At Shore, on the Northeast Corridor a southbound passes as another northbound region approaches. Note the catenary above the void in front of the camera, this is where the line to Delair diverges and used to have multiple tracks, all electrified into Pavonia Yard in Camden.

Understanding that Wilmington would not be a suitable southern terminal for electrification, catenary was extended to Washington DC including Potomac Yard, financed by a 70 million dollar loan secured from depression era federal recovery programs. Beginning in January of 1934, various reports say up to 20,000 men went to work, comprising of furloughed railroad employees and new hires in the electrical / construction trades to complete the electrification of the New York – Washington DC main line, which opened for business on February 10th 1935.

As a result of the success on the north south “corridor” the PRR sought to complete electrification from the eastern seaboard west to the Harrisburg terminal including all associated freight and passenger main lines. Work commenced on the Low Grade from Morrisville to Enola, the main line from Paoli to Harrisburg and the on the Columbia Branch and Columbia & Port Deposit. Completed in 1938 the entire electrification created a powerful conduit that put the railroad in an excellent position to handle the impending pressure of war time traffic demands.

The Harrisburg power Dispatchers office, which was slated to close the beginning of this month controlled the electrical supply network for both signal and catenary systems. This massive installation is an engineering marvel by itself, an impressive monitor and control system consisting of hundreds of push button breakers and miles of wiring. Though this facility remained in service, the actual console was taken off line and replaced by computers which were located out of view.

The Harrisburg power Dispatchers office, which was slated to close the beginning of this month controlled the electrical supply network for both signal and catenary systems. This massive installation is an engineering marvel by itself, an impressive monitor and control system consisting of hundreds of push button breakers and miles of wiring. Though this facility remained in service, the actual console was taken off line and replaced by computers which were located out of view.

The electrified infrastructure has remained visibly the same over the ensuing decades, surviving the Pennsylvania Railroad, Penn Central, Conrail and Amtrak. Though Conrail abandoned the electrified freight service in the 1980's Amtrak continues to maintain and modify where needed the original fixed tension catenary system. With the implementation of CTEC, its centralized traffic and electrical dispatching center, the company has slowly decommissioned all the former PRR power dispatching facilities in favor of new computerized systems. Today, when you ride the Northeast Corridor, look at the details amongst this great infrastructure, they reveal the various phases of construction and symbolize the ingenuity and engineering ability of the great Pennsylvania Railroad.