Amtrak Train Control System
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
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.