Fully tested, reliable and proven: Positive Train Control (PTC)

Positive Train Control (PTC) is an emerging train control system with special focus on North America. Siemens offers comprehensive PTC system solutions tailored precisely to specific demands.

PHW PTC ACSES (Advanced Civil Speed Enforcement System)

The Siemens portfolio includes the Advanced Civil Speed Enforcement System (ACSES) for transit/commuter rail operations. ACSES was the first solution to be approved by the Federal Railroad Administration (FRA) under the requirements of the Rail Safety Improvement Act of 2008. It uses passive transponders to enforce permanent civil speed restrictions. The system is also designed to prevent train-to-train collisions, to protect against over speed and react to temporary speed restrictions. The ACSES on board components keep track of the train's position and continuously calculate a maximum safe braking curve for upcoming speed restrictions. If the train exceeds the safe braking curve the train brakes are automatically applied.

Trainguard Sentinel – Positive Train Control for Industrial and Mining Applications

Trainguard Sentinel is Siemens’ Positive Train Control solution for industrial, mining and freight applications. With over 1,000,000 hours of operational service, Trainguard Sentinel has demonstrated safe and reliable PTC operation. Easy to install and maintain, the system comprises a primary Control Module and cab display units, with optional second display. Speed and location is determined through an onboard track database, commercial GPS receiver and axle tachometers. Trainguard Sentinel includes: civil speed enforcement; train separation via movement authority or signal aspect enforcement; switch protection; track bulletin protection. Trainguard Sentinel also offers integrated Head and End of Train operation and open interfaces to data radios or other locomotive equipment via AAR interoperability standards.

Trainguard Sentinel includes:

  • Civil speed enforcement

  • Train separation via movement authority or signal aspect enforcement

  • Switch protection

  • Track bulletin protection


Trainguard PTC OBU (On Board Unit)

With Trainguard PTC, Siemens offers a comprehensive system solution to meet the requirements of the Rail Safety Improvement Act of 2008. Core of the PTC system is the Trainguard PTC On Board Unit (OBU). The vital Trainguard PTC OBU keeps trains on track, safely without compromise. With its precise location determination and its superior braking curve capabilities, the vital On Board Unit provides the ideal combination of safety and performance for every railroad. Providing proven interoperability and the highest safety standards it is the first choice to set locomotives on track towards federal mandate compliance.


Trainguard PTC OBU at a glance:

  • Vital location determination

  • Superior braking algorithms

  • Built-in scalability