The Zoo to Paoli Electrification Transmission Line Project will upgrade the electrification system along 18 miles of Amtrak’s Harrisburg Line in Pennsylvania between Zoo Substation in Philadelphia and Paoli Substation in Chester County.

The Zoo to Paoli multi-year program will advance major power system upgrades along a critical segment of the Harrisburg line increasing service reliability for Amtrak and SEPTA customers. As owner of the Harrisburg line, Amtrak is working with its partners to advance the Zoo to Paoli Electrification Transmission Line Project.  The overall program covers multiple components including the construction of a new substation, the replacement of deteriorated catenary structures (overhead wires used to supply electricity to a train), the construction of new transmission lines and upgrades to the signal power system.

Once this project is complete, Amtrak’s Keystone Service and Pennsylvanian trains, as well as the SEPTA Paoli Thorndale Line, will benefit from more reliable service thanks to a modern overhead catenary system (OCS) and increased capacity signal power for future signal upgrades. The existing high voltage transmission line (138kV) located off Amtrak’s right-of-way will no longer be in use as Amtrak will have the new transmission line on Amtrak property to access for maintenance, use and overall increase in system reliability.

Planning and public engagement for this project began in 2012 in accordance with the National Environmental Policy Act (NEPA). An Environmental Assessment (EA) was completed and signed by the Federal Railroad Administration in March of 2017.

Amtrak is working with its partners at the U.S. Department of Transportation, Federal Railroad Administration (FRA), PennDOT, SEPTA, and Philadelphia Electric Company (PECO) as well as local municipalities and counties along the project corridor.

This work will be completed across three major components.

The existing and proposed views of the Bryn Mawr substation. 

The existing Bryn Mawr Substation adjacent to Bryn Mawr train station (on Bryn Mawr Avenue in Montgomery County) will be demolished and upgraded to a new substation; equipment to reinforce the power supply for the Philadelphia-Paoli route will be added to ease maintenance by consolidating infrastructure on the right-of-way.

A contract has been awarded for this project and construction began in the fourth quarter of 2024.

This work will include:

• removal of existing substation equipment structures
• demolition of control house building
• expansion of the substation footprint that is all on Amtrak-owned property
• installation of new equipment that will increase the capabilities of the Bryn Mawr Substation
• installation of a brick facade, control building and a signal frequency converter hut
  

Also included are auxiliary power systems, cabling, feeders, lighting, lightning protection, ground grid, grounding wiring and terminations, fencing, civil works, SCADA and all associated steel structures gantries.

Approximately ten miles of Amtrak right-of-way will be upgraded with new OCS structures carrying a new 138kV transmission and upgraded 6.9kV signal power system. Amtrak initiated procurement for this segment in 2024, and construction is expected to begin in 2025.

The current catenary layout along the line between Zoo and Paoli.

Approximately eight miles of Amtrak right-of-way will be upgraded with new OCS structures carrying a new 138kV transmission and upgraded 6.9kV signal power system. Procurement is planned to kick off for this segment in 2028 - 2029.

The existing and proposed transmission right-of-way.

Email your questions, comments or concerns to the project team at ztp@amtrak.com.