Communicating down the line
The dispatchers radio system functions as the heart of the Union Pacific Railroad, an enormous industrial operation that spans 23 states and more than 3 6,000 miles of track.
The daily activities of the Union Pacific (UP) Railroad, one of the largest in North America, represent a massive, well-organized operation. The rail system operates in the western two-thirds of the United States, serves 23 states and links every major West Coast and Gulf Coast port. The railroad is also the primary rail connection between the United States and Mexico, and it interchanges traffic with the Canadian rail system.
An efficient, reliable communications system is essential to servicing more than 36,000 miles of Union Pacific track and coordinating about 52,500 railroad company employees. At any given moment, as many as 1,800 trains could be moving along the UP rail system. As for the human element, this highly mobile user group is communicating constantly via about 13,000 vehicle radios, 1,700 track fleet radios and 22,000 hand-held radios.
Maintenance on this massive fleet of radios requires precise coordination. Although initial testing is done at 13 rapid-repair centers located across the UP’s coverage area, complete radio maintenance is handled at a centralized repair shop in Council Bluffs, IA.
At the heart of Union Pacific’s multifaceted operation is the dispatcher radio system, the railroad’s vital means of communications for the safe movement of trains, locomotives and all employees working along the tracks. Dispatcher operations are managed in Omaha, NE, out of the Harriman Dispatch Center (HDC), which is perhaps the largest and most sophisticated rail command center of its kind in the world.
Complex communication needs Union Pacific’s multitude of radio units allows the mobile workers to communicate with the dispatchers who control specific sections of track and with the yardmasters who handle the trains and locomotives within their yard. The mobile workforce also needs instant communication with the diesel shops that maintain the locomotives, the car men who maintain the cars, maintenance-of-way (MOW) forces that maintain the track, the signalmen who maintain the signal system along the tracks and any other departments involved with train movement. Interdepartmental communication is also necessary for ensuring efficient daily operations.
The dispatchers at the HDC and the yardmasters in the field must maintain constant communication with their massive mobile workforce. To do this, they rely on three console systems to access all the radios used by the different departments. An Avtec Dspatch system provides dispatchers access to the radios. A Safetran DTX system is used for yard operations-where more than five consoles are needed in any one yard. Larry McGee 10-line consoles are used for employees who require access to fewer than 10 lines (radios, intercom and hotlines). All three of these console types can share access with certain radios that are needed to manage a specific yard location.
While the Safetran and Larry McGee systems generally manage communications among local radios, the Dspatch system handles the entire UP dispatcher radio network. The dispatchers rely on two radio types: * Dispatcher radios – VHF simplex radios are spaced along the right-of-way to provide radio coverage for a specific track section. They are controlled by a dispatcher responsible for all train movement along that section. Adjacent dispatchers operate on different frequencies to avoid interference among dispatchers. Base radios on a track section usually use the same frequency. If a base radio fails, overlapping coverage provides redundancy. The use of simplex radios allows all employees using mobile and hand-held units to hear the dispatcher as well as all other communications along the track.
Field personnel can make normal or emergency calls to the dispatcher by generating the appropriate three-digit DTMF code. Each dispatcher radio uses a dedicated four- or six-wire audio circuit from the radio to one of 13 system hubs. All 13 hubs are interconnected via radio tie trunks and a data circuit, which allows users to access radios from different hubs.
*Mobile-tel radios – VHF full-duplex radios are tied to Union Pacific’s PBX network throughout the system to provide dial tone services to UP’s mobile fleet. With this system, track forces can place phone calls and obtain track warrants from the dispatcher if the dispatcher radio system is being used. (Track warrants give the user permission to work around the track.) Each Mobile-tel radio uses a dedicated four- or six-wire audio circuit from the radio to the PBX. The radio is controlled by an MTC5000 card designed by the UP Wireless Engineering Group. This card also connects the paging system to the Mobile-tel radios to provide paging service to areas without commercial paging service. The dispatchers also can access these radios via their consoles.
A systematic digital evolution UP’s shift from analog to digital technology reached its final stage this summer, as it neared its scheduled completion date of July 31. This process included streamlining five analog console systems accumulated during the last 10 years of mergers into one digital system.
In 1987 the Union Pacific Railroad contracted with Avtec, Gilbert, SC, to develop an integrated radio and telecommunications system to be implemented at HDC. The following year, the railroad centralized all of the dispatchers in Omaha’s center. At that time, three 240-line Avtec Access systems, one each for the western, central and southern regions, controlled about 550 radios supervised by 36 dispatchers. These Access systems were configured so that each dispatcher radio served as a four-wire extension number off the PBX network. The system would select a dedicated tie trunk to the PBX and then dial the extension number of the radio selected. The Access systems went online in 1989.
It wasn’t long, however, before addressing the railroad’s communications requirements became more complicated. Union Pacific’s merger with the Chicago & North Western (C&NW) Railroad in 1995 added a 90-line Access system to the HDC to allow nine dispatchers control of 120 additional radios. The system served as a touch-screen interface to a modified Penta system, which actually controlled the radios. The Avtec system would send a series of DTMF digits to one of six Penta hub switches, which in turn would route the request to the proper radio.
In 1997, UP merged with the Southern Pacific (SP) Railroad, which relied on a three-hub, early version of the Dspatch system to control about 300 dispatcher radios with 34 dispatchers. These SP hubs were in Houston, Roseville, CA, and Denver, where the SP dispatcher centers were located. The hubs were trunked together via dedicated radio tie trunks. At the time, two of the three UP systems and the 90-line C&NW system were completely full, and 34 more SP dispatchers were to move to the HD
With equipment space already limited at the HDC, the railroad decided to select a system that could immediately handle present needs and provide expansion options.
Officials chose the digital Dspatch system because it would allow the UP to reuse existing SP Avtec equipment with some minor modifications. It also would allow the HDC hub system expansion capability of more than 2,000 lines. The plan called for a 2,000-line switch to be housed at the HDC, while 12 additional hub switches, connected to the HDC switch via radio tie lines, were placed throughout the network.
The current dispatch system used to control the UP radio network continues to grow daily. In addition to one 2,024-line system, the HDC includes: *eight 19-inch cabinets (which replaced 34 existing cabinets of equipment). *16 T-1 interface cards for direct T-1 interface (T-1 = 24 channels per card). *12 remote hub locations varying from 128 to 1,024 lines. *control of about 950 dispatcher radios. *236 radio tie lines to 12 remote hub locations. *185 workstation consoles (30 operating on PCs running Windows NT 4.0). *305 PBX-phone extensions (including phone extensions and hotlines). *18 dedicated four-wire talk circuits.
The dispatch team of 95 dispatcher positions, manned 24 hours a day, seven days a week, includes: *72 dispatchers at the HDC in Omaha. *14 dispatchers at the dispatcher center in Spring, TX. *4 dispatchers co-located at the office in San Bernadino, CA. *2 dispatchers co-located at the BNSF office in Fort Worth, TX. *3 terminal train dispatchers in Proviso, IL, Forth Worth, TX, and Kansas City, MO.
An interesting future Railroad dispatch radio system technology could evolve further in the near future. As progress continues with APCO Project 25 and the impending FCC radio frequency refarming, it is a matter of time before dispatchers see benefits to their radio systems.
Project 25, APCO’s suite of interoperability standards, is a project supported by railroads, as well as equipment manufacturers, public safety groups and federal government agencies. The main objective of this project is to define interface standards for a new digital radio platform. Some of the more promising features of Project 25 for dispatchers include integrated voice and data, backward compatibility with analog equipment, push-to-talk identification and voice and data encryption for secure communications.
As for radio frequency refarming, the railroad industry presently has access to 97 VHF channels (91 U.S. channels; six Canadian channels) in the range of 160.215MHz to 161.565MHz, which are 25kHz wide and spaced every 15kHz. The Association of American Railroads (AAR) performs frequency allocations and assignments. Following refarming, the industry will have 182 VHF channels, which will be 12.5kHz wide and spaced every 7.5kHz.
The 97 existing channels are primarily used for voice communications. Refarming, which will almost double the number of VHF channels, will allow better use of the frequency band, thus allowing implementation of data communications along with voice radio.
As radio systems migrate to APCO’S Project 25 standards and the FCC frequency refarming, much more information, both voice and data, can be brought into and passed out to the field. The addition of data communications will bring such benefits as GPS-derived location information (e.g. train locations, speed and direction), locomotive health, fuel level and text messaging. This information will need to interface with the radio console system to display the information to the user as needed.
Miles of Track: 36,026
States Covered: 23, linking all major West Coast and Gulf Coast ports
Major Gateways Served: Chicago, St. Louis, Memphis and New Orleans
Locomotives Owned: 6,913
Freight Cars Owned: 155,308
Mobile Radios: About 36,700
World Record: The Guinness Book of World Records recognized the Union Pacific’s Bailey Yard in North Platte, NE, in 1995 as the world’s largest railroad yard. The massive yard covers 2,850 acres, reaching a total length of eight miles. Bailey is tied to the Harriman Dispatching Center in Omaha, which controls hundreds of trains operating daily throughout the UP’s system. Source: www.uprr.com and Harriman Dispatch Center