Positive Train Control Implementation

Client: Southeastern Pennsylvania Transportation Authority
Location: Southeastern Pennsylvania

Click image for a larger view.

Gannett Fleming developed a Positive Train Control (PTC) Development Plan and a PTC Implementation Plan for the Southeastern Pennsylvania Transportation Authority (SEPTA), in accordance with the Federal Railroad Administration Rail Safety Improvement Act of 2008. Our firm evaluated the interoperability requirements between SEPTA trains and trains operating on their territory and for SEPTA trains operating on other railroads. The firm also evaluated SEPTA’s existing safe braking/stopping curves and criteria.

Our firm designed a complete carborne system for each train type and vehicle so that they were consistent with the new system. Design considerations included the available physical space for PTC on-board computer and radio equipment racks, the aspect display unit (ADU), radio and transponder antenna and cable routing, and radio system frequencies and transmission strength. FRA requirements for crash-hardened event recorders and ADU’s interoperability with Amtrak, CSX, and other host railroads also were taken into account.

In addition, our firm developed a vital wayside interface between the existing wayside signal system and the new PTC components. The interface provides data from the interlocking logic processor, or vital relays, to the approved wayside interface unit, which will exchange the data with the on-board computer in the locomotive via data radio. Our firm provided the requirements for the aggregate SEPTA regional rail system’s base mapping, which incorporates horizontal and vertical accuracy, data schema, engineering, and ATC GIS database for identifying permanent speed restrictions.