and MP2 class wooden MU coaches. The 19 purchased in 1909 had steel instead of wooden ends and featured PRR porthole style windows on each end. There were six MO1 class passenger-baggage combines including two with steel ends, four MBM1 baggage-mail cars and two MB1 baggage-express cars. In 1912, the PRR assigned two MPB54 all-steel combines and 15 all-steel MP54 coaches to WJ&S. WJ&S and the Reading subsidiary Atlantic City Railroad were merged into Pennsylvania-Reading Seashore Lines (P-RSL) in 1932. Electric MU service between Newfield and Atlantic City ended Sept. 26, 1931 so P-RSL only inherited the electrified Millville commuter rail service from WJ&S. On Oct. 20, 1948, New Jersey's public utility regulators ordered P-RSL to remove all remaining 26 wooden MU coaches from service as a safety hazard should they be involved in fire or collision. P-RSL management already was considering replacing the MUs due to an aging power distribution system and obsolete rolling stock. So nearly two-thirds of the MU fleet was removed from service. With only the PRR style all-steel MUs left for passenger service, P-RSL cut back the electrified commuter service to Glassboro, New Jersey in fall 1948 and management then ordered an end to all remaining electrification as of Sept. 8, 1949. On that date a morning commuter run from Glassboro to Camden ended 43 years of electrification. Non-electrified commuter rail service to Glassboro and Millville continued until March 5, 1971. New York Terminal Electrification was installed from Sunnyside Yard in Queens, through New York Penn Station to Manhattan Transfer station in New Jersey. A third rail (Top Contact) system was used. Electrification was later changed to overhead catenary, when the PRR electrified its mainline to Washington, D. C. in the early 1930s. Third rail is still installed in the East River Tunnels in order to provide power the LIRR trains. Third rail is also installed in the North River Tunnels for use in emergencies should power be lost to the overhead catenary. Paoli A section of the Chicago-Philadelphia Main Line (now part of Amtrak's Keystone Corridor) was electrified in 1915. The suburban service runs between the former Broad Street Station in Philadelphia and the village of Paoli. The PRR electrification utilized overhead catenary wires electrified at , and was fed by four substations in Arsenal, West Philadelphia, Bryn Mawr, and Paoli. It was expanded in 1919 on the PRR's Chestnut Hill line, and in