Market-Frankford Line - Reconstruction

Reconstruction

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.

In 2003, SEPTA also completed replacement of the old Bridge-Pratt terminal with a new $160,000,000 Frankford Transportation Center located on private right-of-way.

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.