PTC system passes critical test - Rail Update - North American Joint Positive Train Control Project

Railway Age, Jan, 2003

The North American Joint Positive Train Control Project reached a milestone when Build 1 of the program--the LDS (Location Determination System), which tracks train position and speed--passed a 110-mph test on a 23-mile stretch of Union Pacific right-of-way between Bloomington/Normal and Chenoa/Bailard, Ill.

Systems integrator Lockheed Martin describes the technology as a set of "functional building blocks." Key location determination requirements were tested for the Build 1 configuration, according to Project Manager Brian Caine and Systems Engineering Manager Charles Reibeling. For the Build 1 test, two Amtrak P42 locomotives and three coaches were outfitted with LDS, OBC (On-Board Computer), and OBD (On-Board Display) equipment, and a LIM (Locomotive Interface Module). This equipment communicated via ATCS digital radios to a remotely located PTC server. Grade crossings were closed off and manned by local law enforcement for the high speed run.

The next phase will incorporate track occupancy monitoring, movement authority issuance, speed management, high speed grade crossing activation, and predictive enforcement. A field test is anticipated for third-quarter 2003.

Lockheed Martin is partnered with Wabtec Railway Electronics (onboard equipment); Union Switch & Signal (wayside equipment); University of Virginia (safety modeling), and PB Transit and Rail Systems (field engineering). TTCI, the program office, has ARINC, CANAC, and Battelle under contract. FRA, Illinois DOT, and AAR are jointly sponsoring the project. The system is being installed on UP's Joliet and Springfield subdivisions on the Chicago-Springfield corridor.

Lockheed Martin's PTC system is based on an open system architecture providing interoperability, compatibility, and portability through commercial off-the-shelf hardware and software. The objectives of the PTC system are to manage track occupancy, issue movement authorities, track trains and assure safe train separation, enforce limits of authority, automatically enforce speeds, monitor and control wayside systems, and enable passenger train speeds above 79 mph.

Lockheed Martin developed a multi-sensor "fused" LDS, which does not require wayside hardware. The LDS, which is designed to meet a 10-foot accuracy requirement, incorporates Differential GPS, inertial sensors, a wheel tachometer, filtering software algorithms, and a track database. The system is able to discriminate between tracks on the IDOT multi-track main line, including interlockings and curves.

The project is providing the wayside ATCS Spec-200 data radio network, which interfaces with UP's existing communications backbone. Wabtec is providing the LIM, which consists of a wheel tachometer interface, locomotive trainline sensors, brake pipe pressure sensor, full service brake and emergency brake penalty interfaces, PCS (pneumatic control switch) interface, and enforcement enable interface. A color LCD fiat panel with analog and digital readouts provides graphical displays for use by the locomotive engineer. The onboard system is connected via an industry-standard LonWorks network and a POSIX-compliant operating system. Sixteen UP and Amtrak locomotives are being equipped.