The Market–Frankford Line (MFL) (also called the Market–Frankford Subway–Elevated Line (MFSE), Market-Frankford El (MFE), the El, or Blue Line) is a rapid transit line in Philadelphia, Pennsylvania, United States, operated by the Southeastern Pennsylvania Transportation Authority (SEPTA).
The Market–Frankford Line begins at 69th Street Transportation Center, in Upper Darby. From there it is elevated over Market Street until 46th Street, where it curves north and descends underground via a portal at 44th Street. At 42nd Street, the tunnel returns to the alignment of Market Street.
At 32nd Street, the tunnel carrying the Subway-Surface lines joins the MFL tunnel. The MFL tracks are in the center and the trolley tracks are on the outside. 30th Street station consists of an island platform between the two innermost tracks for Market–Frankford Line trains, and outboard "wall" platforms for Subway–Surface route 10, 11, 13, 34, and 36 trolleys. After passing beneath the Schuylkill River, the next stop to the east for Market–Frankford Line trains is at 15th Street; Subway-Surface trolleys also have stations at 22nd Street and 19th Street. 15th Street is the central interchange station for the MFL, Subway-Surface trolleys, and Broad Street Line. The Subway-Surface tracks end in a loop beneath 13th Street at Market just after crossing above the Broad Street Line.
Though it now tunnels in a straight line directly beneath Philadelphia City Hall, prior to 1936, the original MFL trackage between 15th and 13th Street stations separated and looped around the foundation of City Hall (eastbound trains around the south side returning to be westbound trains from the north side). Parts of that original alignment can still be seen from subway-surface cars as they pass south of City Hall en route to 13th Street station (as well as the bridgework in the ceiling of the southbound platform of the City Hall stop on the Broad Street line). The Market Street tunnel continues east to Front Street and then turns north, where it rises in the median of I-95. The rail line and freeway share an elevated embankment for about ½ mile (0.8 km), including Spring Garden station (which replaced Fairmount station on the Frankford Elevated). The line then heads under the southbound lanes and over Front Street on an elevated structure that turns northeast onto Kensington Avenue, which merges with Frankford Avenue, which the line follows to its end. Just North of Pratt Street, a curve to the north brings the line to its current terminus at the Frankford Transportation Center, which replaced the original Bridge-Pratt Sts. terminal.
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 unusual 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 unusual 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.
Between 1988 and 2003, SEPTA undertook a $493,300,000 complete reconstruction of the Frankford Elevated between Bridge-Pratt Terminal and the 2nd Street portal. The new Frankford Elevated was built with new stringers and deck installed on the original columns, thus giving not only a reduction in cost, but also reducing the street-level impact on adjoining neighborhoods. The old ballasted trackage was replaced with a direct fixation system used on contemporary systems such as BART and the DC Metro, where the rails are now directly affixed to concrete blocks or a concrete slab, with no need for ties or ballast. These blocks or slabs are placed on neoprene padding on a concrete deck, in what is known as a "floating slab," which significantly reduces noise and vibrations created by the trains. In addition to the new Elevated structure, all of the stations were replaced with new stations with higher boarding platforms and elevators, allowing customers with disabilities to easily board and depart from Market-Frankford trains. Unfortunately, the basic design of the reconstructed Frankford elevated did not allow the structure to expand and contract with seasonal temperature changes; and the concrete has started to fracture and drop onto the street below. The problem was first discovered in 1997, but at that time was simply attributed to faulty construction, without evaluation of the root cause. As built, the concrete beams in the underside of the deck cannot move properly over the supporting steel girders, causing chipping and breaks, with pieces falling into the street. As a temporary fix, SEPTA has installed 8,000 metal mesh belts on the underside of the structure, and plans to install 2,000 more. Estimates for a permanent fix place the cost at about $20 million, and SEPTA has filed suit against the engineering companies that contributed to the design flaw to recover part of the repair cost.
Between 1999 and 2009, SEPTA then undertook a $567,000,000 complete reconstruction of the Market Street Elevated between 69th Street Terminal and the 44th Street portal. The new Market Street Elevated, which utilizes single-pillar supports in place of the old-style dual pillar design, will allow the Pennsylvania Department of Transportation (PennDOT) to undertake a planned widening project on Market Street to four lanes between 63rd Street and 44th Street. In addition to the new Elevated structure, all of the stations (including Millbourne) were again replaced with new stations having higher boarding platforms and elevators, allowing customers with disabilities to easily board and depart from trains. The reconstruction of the Market St. Elevated superstructure was completed in 2008, and the last station, 63rd Street, was completed and reopened on May 4, 2009. The Market St. Elevated is not of the same design as the Frankford Elevated, so it does not share any of the Frankford design flaws.
During rush hours (trains beginning from about 7 a.m. to 8:30 a.m. and 4:00 p.m. to 5:30 p.m.), SEPTA uses skip-stop operation. Trains marked "A" stop only at the stations marked "A" and "All Trains" on system maps, and "B" trains stop only at "B" and "All Trains" stations. Trains run on the line from about 5 a.m. to 12:30 a.m., and buses provide night service every 15 minutes from midnight to 5:30 a.m.
Fare for riding the line is $2.00 cash or single-ride tokens, which sell for $1.55 each. Tokens can be bought either at vending machines in most stations, or in multi-packs available at the cashier's booth in major stations such as 69th Street Terminal or Frankford Transportation Center. Payment of base fare includes free transfer to the Subway-Surface Lines at 30th, 15th, and 13th Street stations, as well as to the Broad Street Line at 15th street. However, while the Broad-Ridge Spur connects at 8th St. Station, there is no longer a free-transfer passageway between the lines. Transfers requiring a paper transfer slip are available for $1.00 at any station.
SEPTA's "TransPass" and "TrailPass" weekly/monthly zone-based passcards are also accepted as fares. Use of these passcards is unlimited during their valid dates, making paid transfers unnecessary.
In FY 2005, 25,220,523 passengers rode the Market–Frankford Line. Weekday average ridership of 178,715 made it the busiest line in the entire SEPTA system. The Market–Frankford Line required 142 vehicles at peak hours, cost $86,644,614 in fully allocated expenses, and collected $54,309,344 in passenger revenues, for an impressive farebox recovery ratio of 63 percent.
On February 11, 2008, SEPTA expanded morning and afternoon weekday service with off-peak trains running every six minutes instead of eight. It represents a 12% increase in MFL Service through the day.
Extension proposal 
Rolling stock 
The original cars for the Market Street subway, numbered 1-135 and later designated as Class A-8 by SEPTA's predecessor, the Philadelphia Transportation Company (PTC), were built by the Pressed Steel Car Co. of Pittsburgh, Pa. between 1906 and 1911. An additional set of cars, numbered 136-215, were built by the J.G. Brill Co. of Philadelphia, Pa. between 1911 and 1913. The Frankford Elevated portion opened in 1922 along with another set of cars, numbered 501-600, also built by Brill that year, later receiving the designation Class A-15. The two rail lines were soon merged, resulting in a combined fleet of 315 cars (215 Market Street cars, 100 Frankford cars). By 1960, when the PTC began replacing the cars, the Market Street cars had been in operation for 56 years, thus having the longest lifespan of any Philadelphia subway cars, surpassing that of the original Broad Street subway fleet, which had 54 years of operation. (The Broad Street cars were built in 1928, and phased out in 1982.) The Frankford cars were not much younger, at 38 years of operation. After retirement, two of the "Market" cars (cars 69 and 163) and six of the "Frankford" cars were retained as work train cars (Cars #532, 551, 559, 583, 585, and 589) for some time. It is currently unknown when these cars were withdrawn, but all had been removed from SEPTA property by 2000, with none reported to have been saved for museums.
The "Market" and "Frankford" cars were replaced by a fleet of 270 new stainless steel cars built in 1960 by the Budd Company. The PTC had designated Class A-49 cars numbered 601-646 as Class A-49, and numbers 701-924 as A-50 and A-51. All cars were re-designated as Class M-3 when SEPTA assumed operation of the line. The cars had been nicknamed "Almond Joys" by many riders as their distinctive ventilation fan housings resembled the almonds atop the Peter Paul (now Hershey's) Almond Joy bar. These cars, while mostly an improvement in quality compared to their predecessors, had been plagued with faulty wheel frame assemblies, causing the body to shake, sometimes violently, as the car moved. The cars' fan housings had provisions for air conditioning units, however, only one car, number 612, had ever been air conditioned, which the transit authority had found to be uneconomical at the time.
Early in their service lives, some M-3 cars had fareboxes by their center side doors; these were necessary for collecting fares during the hours after midnight, when SEPTA closed cashier's booths at many stations during the era of 24-hour rapid transit service. "Night Owl" service (midnight–5:00 AM) trains operated on a twenty-minute headway (interval between trains) at that time. Since the 1990s, SEPTA has operated (along with the Broad Street Subway) all "Owl" service using buses, but similar to the old "Owl" trains, they run between 69th Street and Frankford Transportation Center on a slightly more frequent 15-minute interval.
In the early 1990s, the Market-Frankford line was in need of new rolling stock. The M-3 cars were approaching the end of their expected useful lifespan, as well as being increasingly scrutinized for their shaky ride quality and lack of air conditioning. To this end, SEPTA placed an order for 220 new rail cars, each costing $1.29 million.
These cars, designated Class M-4, were manufactured by AdTranz and delivered between 1997 and 1999. All of the M-3 cars were retired after the last of the M-4's entered service, with five of the former being converted to work cars. The five remaining M-3's were later retired, with M-4 cars 1033 and 1034 replacing them for work service, and the last of the remaining M-3's had been scrapped by 2005. Two of the M-3's have been preserved, cars 606 and 618 at the Pennsylvania Trolley Museum and the Seashore Trolley Museum, respectively. These cars represent the only preserved examples of Market-Frankford line rolling stock.
March 7, 1990: Four people were killed and another 162 injured when the rear three cars of six-car train #61 derailed leaving 30th Street Station westbound at 8:20AM. It is believed that one of the traction motors dropped out of the rear truck on the third car (M3) somewhere between 15th and 30th street stations, and it became entangled in a switch immediately upon leaving 30th street station. The front truck of the fourth car (M3 #818) followed the third car, while the rear truck of the fourth car took the diverging track, causing the car to shear halfway upon striking the steel pillars separating the tracks beyond the switch.
Station list 
|0.0||69th Street Transportation Center||A||B||aerial||Norristown High-Speed Line, Media-Sharon Hill Trolley Lines 21, 30, 65, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 116, 120, 123, 126|
|0.4||Millbourne||B||aerial||Originally called 66th Street, rebuilt station opened June 16, 2008|
|0.8||63rd Street||A||aerial||21, 31|
|1.1||60th Street||A||B||aerial||Route 46; Previous connection, Route 46 trolley||Rebuilt station opened June 18, 2007|
|1.5||56th Street||A||B||aerial||G||Rebuilt station opened February 27, 2006|
|1.9||52nd Street||A||B||52 *Previous connection, Route 70 trolley|
|2.5||46th Street||A||B||31, 64||*Rebuilt station opened April 14, 2008.|
|3.2||40th Street||A||B||30, 40, LUCY Gold, LUCY Green; diverted/nighttime routes of Subway-Surface lines||Original station at 40th Street was elevated.|
|3.7||34th Street||A||B||31, LUCY Gold, LUCY Green||Original station at 36th Street was elevated. Previous connection at 36th St. was Rte. 67 trolley.|
|4.1||30th Street||A||B||9, 30, 31, 44, 62, 124, 125, LUCY Gold, LUCY Green, Amtrak and SEPTA Regional Rail.||Free transfer to Subway-Surface Lines. Original station at 32nd Street was elevated. Previous connections at 32nd St. elevated station were Subway-Surface Routes 10, 11, 31, 34, 37, & 38 Trolley Lines.|
|5.1||15th Street||A||B||4, 16, 17, 27, 31, 32, 33, 38, 44, 48, 62, 124, 125 Regional Rail at Suburban Station.||Free transfer to Subway-Surface Lines and Broad Street Line.|
|5.4||13th Street||A||B||17, 33, 44, 48, 124, 125.||Free transfer to Subway-Surface Lines.|
|5.6||11th Street||A||B||23; Regional Rail at Market East Station, Greyhound, other intercity buses & New Jersey Transit buses at Philadelphia Greyhound Terminal|
|5.8||8th Street||A||B||47, 61, Broad-Ridge Spur, PATCO Speedline; Previous connection, Route 47 trolley, Route 61 trackless trolley|
|6.0||5th Street||A||B||Previous connection, Route 50 trolley||Access to Independence Hall, National Constitution Center, and Liberty Bell|
|7.1||Spring Garden||A||B||aerial||25, 43||Replaced the Fairmount station when I-95 was built|
|7.8||Girard||A||B||aerial||5, 15, 25|
|8.9||York–Dauphin||B||aerial||3, 39, 89||split between York northbound and Dauphin southbound. Original name of station was Dauphin-York.|
|10.2||Allegheny||A||B||aerial||3, 60, 89|
|10.6||Tioga||A||aerial||3, 89||Original station building on NB side (in Harrowgate Park) was preserved, as it was the only octagonal structure on the line.|
|11.3||Erie–Torresdale||A||B||aerial||3, 56, both of which were previously trolley routes.||Originally called Torresdale.|
|11.8||Church||B||aerial||3, 5||Originally called Ruan-Church.|
|12.3||Margaret–Orthodox||A||B||aerial||3, 5, 59, 75, 89, J, K Routes 3, 5, previously were Trolley Routes.||Originally called Margaret–Orthodox–Arrott (for the Arrott Terminal).|
|12.9||Frankford Transportation Center||A||B||aerial||3, 5, 8, 14, 19, 20, 24, 25, 26, 50, 58, 66, 67, 73, 84, 88, R||This station replaced Bridge-Pratt (Frankford Terminal)|
- SEPTA 2012 Annual Service Plan
- Harold E. Cox, The Road from Upper Darby: The Story of the Market Street Subway-Elevated, (New York, c. 1967), p. 17
- Harold E. Cox, The Road from Upper Darby: The Story of the Market Street Subway-Elevated, (New York, c. 1967), p. 32
- Harold E. Cox, The Road from Upper Darby: The Story of the Market Street Subway-Elevated, (New York, c. 1967), pp. 6-7
- Harold E. Cox, The Road from Upper Darby: The Story of the Market Street Subway-Elevated, (New York, c. 1967), p. 16
- Brian Cudahy: "A Century of Subways: Celebrating 100 Years of New York's Underground Railways", p.279
- ELECTRIC RAILWAY JOURNAL Vol. 60, No. 20; November 4, 1922 p.792
- "Market-Frankford Subway-Elevated Line". SEPTA. Retrieved September 8, 2008.
- Harold E. Cox, The Road from Upper Darby: The Story of the Market Street Subway-Elevated, (New York, c. 1967), p. 24
- Brian Cudahy: "A Century of Subways: Celebrating 100 Years of New York's Underground Railways", p. 280
- Brian Cudahy: "A Century of Subways: Celebrating 100 Years of New York's Underground Railways", p. 363, Note 15.
- Harold E. Cox, The Road from Upper Darby: The Story of the Market Street Subway-Elevated, (New York, c. 1967), p. 28
- Brian Cudahy: "A Century of Subways: Celebrating 100 Years of New York's Underground Railways", p. 202
- Middleton, William D. (September 9, 2002). "Railroad Standardization - Notes on Third Rail Electrification" (PDF). Railway & Locomotive Historical Society Newsletter 27 (4): 10–11. Retrieved March 12, 2011.
- Market Street Elevated Railroad
- FTA divides $112 million among 46 "green" transit projects, Railway Track & Structures,November 18, 2011
- The Frankford Elevated Reconstruction Project
- Paul Nussbaum, "Frankford El with potential to crumble needs repairs", Philadelphia Inquirer, Sep. 18, 2009
- Paul Kurtz, "Septa Sues Two Companies Over Crumbling 'El' Structures", KYW News, Sept. 18, 2009
- PDF (1.96 MB)
- http://www.theelseptaatwork.com/ (September 2006).
- PDF (1.96 MB)
- SEPTA: Fares (Oct 2009)
- SEPTA: Token Machine Locations (Oct 2009)
- SEPTA: Sales Locations (Oct 2009)
- SEPTA: Transit Fares
- "TransPass". SEPTA. Retrieved December 3, 2012.
- "Trailpass". SEPTA. Retrieved December 3, 2012.
- PDF (539 KB)
- Harold E. Cox, The Road from Upper Darby: The Story of the Market Street Subway-Elevated, (New York, c. 1967), pp. 34-35
- Frankford M-3 article
- Trainstation.com video description
- Michael deCourcy Hinds, "Philadelphia Subway Crash Kills 3; 150 Are Hurt", New York Times, March 8, 1990
- AP Wire, "Dragging Motor Is Suspected in Subway Accident", New York Times, March 9, 1990
- NTSB Report Number: RAR-91-01, "Derailment of Southeastern Pennsylvania Transportation Authority (SEPTA) Commuter Train 61 Philadelphia, Pennsylvania March 7, 1990", adopted April 23, 1991
Further reading 
- Pawson, John R. (1979). Delaware Valley Rails: The Railroads and Rail Transit Lines of the Philadelphia Area. John R. Pawson. ISBN 0-9602080-0-3.
|Wikimedia Commons has media related to: Market-Frankford Line|
- NYCsubway.org - SEPTA Market–Frankford Line
- Stan's Railpix - Septa Photo Gallery Page 3* SEPTA Market–Frankford Line Pictures