Amtrak Train Control System

Amtrak, in a joint venture with the Long Island Railroad, retained The Sombers Group to build a new train control system to manage train traffic into and out of its busy Penn Station in New York City. Because of the extreme reliability specifications and the very high performance requirements for this system, Tandem systems (now HP NonStop servers) were chosen to be the heart of the Penn Station Control Center, or PSCC.

The Tandem systems communicate with track-side equipment via Remote Terminal Units, or RTUs. These RTUs carry commands to the switches and signals that control the routing of trains and return detected status information such as train locations and hazardous conditions (hot bearings, dragging equipment, and so forth).

Trains are monitored and routed by dispatchers at two dozen Sun workstations. These workstations have access to the current state of the railroad as kept by the central Tandem systems so that each dispatcher can be graphically shown the current location of all trains in his territory and the current and reserved status of all routes through his territory. The Sun workstations each have up to four monitor heads that act as a single long window to accommodate the display of long stretches of track. Each head incorporates touch screen technology so that a dispatcher can query status and enter routing commands by simply touching the screen.

Though each dispatcher typically only sees his assigned territory on his workstation, the entire PSCC track complex is shown on a football field length overhead display for all to see.

The passage of trains to and from neighboring rail systems such as the Long Island Railroad, Jersey Transit, and Metro North is handled automatically by exchanging train descriptions between the various railroad control systems.

A particular design problem came about because of the sub-second response time required between the time a dispatcher issues a control command and the time a confirmation is returned from the field and is displayed on his workstation. There simply was not enough time to gather all of the required status information from the Tandem systems to support this function.

The problem was solved by the use of the NetWeave middleware product, developed by The Sombers Group, to reliably broadcast in real-time to the workstations all track status changes so that each workstation would have this data locally.

The PSCC system went into operation in mid-1999 and has been flawlessly controlling Amtrak train traffic in the New York City area ever since.