Amtrak's 25 Hz traction power system

Only about half of the system's electrical capacity is used by Amtrak; the remainder is sold to the regional railroads that operate their trains along the corridor, including NJ Transit, SEPTA and MARC.

The system powers 226.6 miles (364.7 km) of the NEC between New York City[a] and Washington, D.C.,[b] the entire 104-mile (167 km) Keystone Corridor, a portion of NJ Transit's North Jersey Coast Line (between the NEC and Matawan), along with the entirety of SEPTA's Airport, Chestnut Hill West, Cynwyd, and Media/Wawa lines.

The Pennsylvania Railroad (PRR) began experimenting with electric traction in 1910, coincident with their completion of the trans-Hudson tunnels and New York Penn Station.

In the 1920s, the PRR decided to electrify major portions of its eastern rail network, and because a commercial electric grid did not exist at the time, the railroad constructed its own distribution system to transmit power from generating sites to trains, possibly hundreds of miles distant.

The circa 1976 Northeast Corridor Improvement Project had originally planned to convert the PRR's system to the utility grid standard of 60 Hz.

[2] Regardless of the source, all converter and generator plants supply power to the transmission system at 138 kV, 25 Hz, single-phase, using two wires.

During the twelve-month period ending August 2009, Safe Harbor supplied about 133 GWh of energy to the Amtrak substation at Perryville.

These rugged machines can absorb large load transients and demanding fault conditions while continuing to remain online.

Today, the outright replacement of motor generators would also be difficult due to the high manufacturing cost and limited demand for these large 25 Hz machines.

The following tables lists sources which are no longer in service: During the beginning of the 20th century, 25 Hz power was much more readily available from commercial electrical utilities.

Power was transmitted to rotary converters (AC to DC machines) for use in the PRR's original third rail electrification scheme.

Like most DC electric distribution systems of the time (Thomas Edison's being the most famous), 25 Hz power was used to drive rotary converters at substations along the line.

[8] When AC overhead electrification was extended in the 1930s, Long Island City connected to the 11 kV catenary distribution system.

40°44′35″N 73°57′29″W / 40.7430°N 73.9581°W / 40.7430; -73.9581 (Long Island City Generating Station (Disused)) Originally constructed by Consolidated Edison to supply power to their DC distribution system in Manhattan, Waterside began supplying power to the PRR's AC system around 1938 when ConEd assumed operation of the Long Island City Station.

Two transformers were installed to supply catenary power from the remaining (three-phase) portions of ConEd's still relatively extensive 25 Hz system.

They proposed a static frequency changer, which was built at Jericho Park (Bowie, Maryland) and placed on service in the spring of 1992.

Shortly after commissioning the 1915 electrification, the railroad discovered that the 44 kV feeders and large inductive loads on the system were causing significant voltage sag.

In 1917, the PRR installed two 11 kV, 4.5 MVA synchronous converters at Radnor, the approximate center point of the system load.

40°02′41″N 75°21′34″W / 40.044725°N 75.359463°W / 40.044725; -75.359463 (Radnor) The PRR's original 1915 electrification made use of four substations at Arsenal Bridge, West Philadelphia, Bryn Mawr, and Paoli.

By 1935, new stations were connected to remote supervision systems, allowing power directors to open and close switches and breakers from central offices without having to go through the tower operators.

Rather than isolating, for example, the south 138 kV feeder between Washington and Perryville, the system would require opening converter output breakers at Jericho Park and Safe Harbor.

Amtrak's capital improvement program which began in 2003 has continued to the present day and has since 2009 received added support from economic stimulus funding sources (American Recovery and Reinvestment Act of 2009 or ARRA).

This, combined with rising traffic levels, resulted in low voltage conditions on the approaches to Union Station and decreased system reliability.

Primary objectives of this expansion include improving the reliability of transmission between Safe Harbor and Philadelphia and reducing maintenance costs.

The new routing will reduce maintenance costs, as Amtrak must maintain transmission poles and control vegetation along the right-of-way, which it neither owns nor uses for revenue service.

SEPTA's own capital improvement plan, formulated in late 2013 after passage of funding legislation in Pennsylvania, allowed for the renewal of all components at Morton and Lenni.

During rush hour the next morning (May 26), the overall capacity became overloaded: By 8:03 am, the entire 25 Hz system, stretching from Washington, D.C. to Queens, New York, was shut down.

[39] Low system voltages beginning at 7:45 am on Tuesday, August 24, 2010, caused Amtrak to order an essentially system-wide stoppage of trains within the 25 Hz traction network.

This loss of electrical capacity forced Amtrak and New Jersey Transit to operate fewer trains, using modified weekend schedules.

[16] After testing the substation's components, the degree of damage was determined to be less than initially feared, and after further repairs, Kearney Substation came back on-line on Friday, November 16, allowing the immediate return of all Amtrak and gradual return of all NJ Transit electric trains into Penn Station through the dewatered North River Tunnels.

Amtrak Avelia Liberty trainset operating under the 25 Hz traction power system near Claymont, Delaware
Old substation built for the 1915 electrification project at Bryn Mawr, Pennsylvania . Outdoor yard is an addition.
West Philadelphia substation 1915
The Safe Harbor Dam generates 25 Hz railroad power via two turbines in the east end of the turbine hall and an M-G set outside against the Dam face.
Waterside Power station in Manhattan, New York
Long Island City Power Plant under construction in New York in 1905
The Pepco Benning Road power station in Washington, D.C., supplied 25 MVA of 25 Hz power via a rotary frequency changer in the hall nearest the Metro tracks from 1935 until 1986.
A picture of one of the 1916 Radnor Synchronous Condensers from Electrical World
Frazer substation on the Philadelphia to Harrisburg Main Line
Old substation remote control panel at Paoli interlocking tower
A one-line diagram of the 1930 era substation at Bowie, MD
The large substation at the Safe Harbor dam is one of the minority that steps-up 25 Hz power to 138 kV for long distance transmission.
One-line diagram of Zoo Sub 9, circa 1997, on the Load Dispatcher mimic board in Philadelphia
The Power Dispatcher's view of substation 43 (New York City Penn Station)
The Load Dispatcher's Mimic Board at 30th Street Station in Philadelphia, Pennsylvania, circa 1996. The entire 138 kV transmission system is represented on this panel.
The four utility-owned 138 kV circuits from Safe Harbor (Pennsylvania) to Perryville (Maryland).
Catenary support with 6.9 kV, 100 Hz transformer for signal power
Catenary supports near Odenton, Maryland. Three-conductor 60 Hz utility lines enter from the left and are carried in either direction along the line. The remainder of the high voltage lines are 25 Hz.
Ivy City Substation 25 under construction in Washington, D.C., in 2010