Market-Frankford Line - History

History

The original subway tunnel from City Hall to the portal at 22nd Street, as well as the bridge to carry the line across the Schuylkill River, just north of Market Street, were built from April 1903 to August 1905. Construction on the Market Street Elevated west from this point began In April 1904, and the line opened on March 4, 1907, from 69th Street Terminal to a loop around City Hall at 15th Street. The line was elevated west of the river and underground east of the river. The tunnel was also used by streetcar lines, now SEPTA's Subway-Surface lines, that entered the line just east of the river and turned around at the City Hall loop. Philadelphia was fairly unique in that construction of its initial downtown subway was undertaken using PTC private capital only, with no contribution from public funds.

Extensions took the subway east to 2nd Street on August 3, 1908, and via a portal at 2nd street and several elevated curves it reached the Delaware River between Market Street and Chestnut Street on September 7, 1908. The Delaware Avenue Elevated (also called the Ferry Line, because of the multiple ferries across the river) opened on October 4, 1908, as a further extension south along the river to South Street. The only two stations on this extension were Market–Chestnut and South Street.

Although the Frankford Elevated had been built several years earlier, disagreement with the City of Philadelphia (who built the line) over the terms of operation meant that it wasn't opened officially until November 4, 1922. With the adoption of regular service the following day, trains from 69th would alternate between Frankford and the Ferry Line endpoints. Following the opening of the Delaware River Bridge in 1926, traffic on the Ferries line declined sharply. Beginning on January 24, 1937, operations were changed to use the Ferry Line only during the day and not at all on Sundays and holidays, though Sunday and holiday service was temporarily resumed during the summers of 1937 and 1938. On May 7, 1939 the line to the ferries was closed temporarily, although PRT was forced to return service in 1943. Service was finally ended permanently in 1953, and the structure was demolished. The old interlocking tower and stub remains of the junction with the Ferry Line survived until the realignment into the median of I-95 in 1977.

As part of a program of railroad improvements undertaken by the City of Philadelphia and the Pennsylvania Railroad, a new section of tunnel from 22nd Street to 46th Street was started in 1930, which would allow for removal of the elevated structure east of 46th Street and the old Schuylkill River Bridge. Coinciding with this project, a new bridge was also to be built across the river for automobile traffic; this raised the level of the street to permit the roadway to pass over the underground tracks of the Pennsylvania Railroad near their new 30th Street Station. This resulted in a reduction of vertical clearance under the old elevated structure from 20' to only 8', which was expected to be only a temporary problem until the new subway tunnel was complete. Unfortunately, funding ran out before the subway extension could be finished. Although streetcar tracks were installed in the new Market Street Bridge, there was insufficient clearance to pass any cars under the elevated, and no service would ever be provided over the new tracks. Subway construction resumed in 1947, and the current configuration opened on November 6, 1955. The old elevated structure was removed by June 20, 1956. While the track was redirected into the new subway, a short stub of the old elevated structure remained at 45th Street until the reconstruction of the Market Street Elevated in 2008.

In addition to extending the Market Street subway tunnel west to 46th Street, with new stations at 30th, 34th and 40th streets, a new trolley tunnel was built under Market, Ludlow and 36th streets and the former Woodland Avenue, leading to a new western portal at 40th Street for routes 11, 13, 34 and 36 (route 10 trolleys use a portal at 36th and Ludlow). New stations for the trolleys were constructed at 22nd, 30th, 33rd (between Market and Ludlow), 36th (at Sansom), and 37th (at Spruce) streets. The 24th Street trolley station and tunnel portal was abandoned. The tunnel mouth was visible from Market Street until the Philadelphia Gas and Electric Company (now PECO) built an office building on the site in 1969.

Skip-stop operation began on January 30, 1956. In the original skip-stop configuration, in addition to the A and B stops shown on the map above, 2nd and 34th Street were "A" stations, and Fairmount (replaced by Spring Garden) was a "B" station; the A and B designations at these stations were changed to "All-Stop" because of increased patronage in the 1990s. As I-95 was built through Center City Philadelphia in the late 1970s, part of the Frankford El was relocated to I-95's median, and the Fairmount station was replaced by Spring Garden, on May 16, 1977.

As with many other rail lines, the signal system on the Market–Frankford Line has progressed from the original lineside block signals using semaphores, to three-aspect Type D color light (green, over yellow, over red) signals, to cab signalling, eliminating the lineside block signals.

The Market-Frankford line is fairly unique as subway-elevated systems go. Notable features include being built with broad gauge of 5 ft 2 1⁄₂ in (1,588 mm), and in its use of bottom-contact third rail. As such, any possible future physical connection to other rapid-transit lines in Philadelphia is limited to cross-platform transfer only, as both the Broad Street Subway and the Norristown High-Speed Line are both standard gauge (4 ft 8 1⁄₂ in/1,435 mm) with top-contact third rail. The Market–Frankford Line and Metro-North Railroad are the only railroads in North America that use bottom-contact third rail, known as the Wilgus-Sprague system. Its advantages include a reduced risk of electrocution for track workers and fewer disruptions due to icing conditions during winter weather. The Market-Frankford Elevated's original construction also had some marked differences from that of other US elevated systems (such as Chicago or New York City). While those systems' elevated lines were built with rails laid on ties (sleepers) that were bolted directly to large steel girders, the Market-Frankford's structure consisted of steel girders supporting a concrete trough deck, which then supported the more conventional railroad construction of rails laid on floating ties with loose rock ballast. This was done in an attempt to reduce noise and vibration, as well as protect the streets below from rain and "operational fluids."

In November 2011, the Federal Transit Administration (FTA), through its competitive Fiscal Year 2011 Sustainability Initiative, awarded $1.4 million to SEPTA to install a "wayside energy storage system" on the Market-Frankford line. The system stores energy from braking trains in a battery that may be used later.