AN AUTOMATED TRAIN DISPATCHING SYSTEM

Nick R. Sparozic, P.E.

SEPTA 1515 Market Street

Suite 600 Philadelphia, PA 19102-1906

Abstract

The Automated Train Dispatching System (ATDS) is a computerized fault tolerant train schedule tracking and status information system.

It consists of thirty-eight DEC PC workstations interconnected by modems, thick and thin wire ethernet and fiber optic cable to a central VAXft computer acting as a database server. Three DECserver 700's provide forty-eight ports to drive nine end of line printers and three hundred "Transit Information Display Sign" (TIDS) Displays - The ATDS will not control the movement of trains in an automatic mode. It will be used by dispatchers and tower operators to monitor and administer the movement of trains in their territory by providing an accurate, real time status of train location.

This system replaces existing manual paper train sh?ets used to record and monitor train movements with electronic based media. It may be the first system of its kind in the United States to be used primarily for passenger operations.

The inner workings of the traditional paper inrrensive system used to "Run the Railroad'' will be examined. The problems common to this system wi.L1 be identified and their impact assessed.

The functionality of the new system will be described. The streamlined operations under the electronic system will be explained together with a discussion of the problems encountered implementing the new design.

The impacts on not only Railroad operations but other departments with respect to the introduction of new technology, new technology/work interface ancl organization structure will be explored.

Integration of the design into the Authority's overall modernization plans will be explored and finally, the lessons learned in implementation of this project will be listed.

Background

System Service Area -

The Southeastern Pennsylvania Transportation Authority (SEPTA) has the fifth largest commuter railcar fleet in the United States operating on over 550 track miles. SEPTA is headquartered in Philadelphia, Pennsylvania and services a twenty- two hundred (2,200) square mile area encompassing five (5) counties. This is a truly multi-modal system containing subways, buses, subway surface cars, light rail, trolley-bus and commuter rail cars.

The commuter rail or "Regional Rail" system service extends out of the state of Pennsylvania to Wilmington, Delaware and Trenton, New Jersey. The fleet of over 340 "Regional Rail" cars range in age from 7 to 30 years and contain a mix of over five vehicle types. The majority of the fleet are Multiple Unit electric cars but the newest thirty five cars are of the "Push Pull" type. Special road maintenance track cars and non-SEPTA vehicles increase the complexity of the vehicular mix. Revenue service operations start at 0500 hours (5AM) and end at 0100 hours (1AM) the next day, seven days a week. During the Monday through Friday weekday schedule, SEPTA operates over five hundred (500) trains.

About sixty (60) percent of the Regional Rail's track miles are owned by Amtrak and another seven ( 7 ) percent belongs to Conrail. The remaining, with few exceptions is owned by SEPTA.

SEPTA has dispatching responsibility for Conrail's equipment operating over SEPTA territory as Amtrak has over SEPTA'S equipment operating on theirs. Overall dispatching operations are regulated by the Federal Railroad Administration (FRA). The FRA requires many of the dispatching documents and defines special features of these documents.

In 1991, SEPTA decided to replace the current manual train dispatching system with an automated one that met the FRA's requirements. The new system would not actually automate dispatching trains but would serve to improve the information available to monitor and control the movement of trains. Eventually, the system could be expanded and used as a spring board for a more advanced automated train operation and control system.

Train Dispatching The Old Way

The present manual method of train dispatching dates back to the 19th century. The primary function of the Regional Rail Operations Control Center (RROC pronounced "rock") is to dispatch trains and to control revenue and non-revenue equipment moves. These functions are accomplished by personnel manning the RROC under the direction of the Superintendent of Train Operations (STO). The STO's has overall responsibility for the daily operation of the Railroad. The STO supervises a chief dispatcher, three dispatchers and the delay clerks.

The three Train Dispatchers interface with Tower Operators located at Broad, A, Mark, Media, Wayne, Wind (contained within Wayne), and Chestnut Hill West (CHW) Towers as well as with AMTRAK's Phil and North Broad Towers and Conrail's Norris and Trent Towers to receive train passing information via telephone.

0-7803- 1890-0/94/$4.00 0 1994 IEEE 47

Train Dispatchers use a manual recording system to track train passing times at towers, control points or other "On Sheet" locations. (on sheet or "OS" refers to the actual train passing time recorded on paper by the Tower Operator.) Model boards in each of the towers show by light indications the position (by block signal) of each train on the system.

At present, the system lacks an automatic train identification system. As a result, once a Tower Operator sees an indication on the model board he must note the time of day, consult the schedule, decide the train number or designation and record this information on a "Train Sheet".

The most common method of communication between the towers and the RROC is the telephone. Recording procedures and communication mechanisms now in use diminish the decision making opportunities of tower operators and train dispatchers since they spend more time processing paperwork than in monitoring and controlling trains.

Major Forms and Their Functionality

Several forms are used to dispatch or OS trains. A sampling of the present manual paperwork process that the new system will "automate" includes:

' The Train Sheet - "Record of Train Movement" - Is the master or base document of the system. It contains the time a train arrives and departs by control points, the reasons for delays, unusual occurrences, track number, weather conditions, engine number, consist information and lists any extra movements, i.e., freight trains, track cars, etc. The average train sheet has over 2,200 hand entries and is about 1 . 2 5 meters wide by 5 meters long.

Form "Ds" - Are "Orders" issued to direct train movements, whenever exceptions to normal operation occur. It may be necessary to send the Form Ds to a certain train or group of trains.

Other important forms are:

' BDA/BDR (Blocking Device Applied/Removed) - Blocking device applied is a device placed on the model board to prevent a Tower Operator from throwing a particular switch. to remove a BDA.)

' C & S 39 - Takes the crossing protection system "Out of Service". The engineers (train operators) must then follow certain speed instructions.

(A BRR is needed

- TPR (Traction Power Request) - A form used to remove the traction power (11Kv and 22Kv).

Train Station Line Up - Lists the order in which trains come into a station.

Problems with the Old Manual System

A summary of salient problems with the present manual system follows:

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. Time Requirements - The system is time consuming as many phone calls are required. Accuracy depends on repeating and recording verbal messages and correction if necessary.

. Labor Requirements - The manual operation is labor intensive. Tower Operators, Dispatchers and Delay Clerks handwrite in thousands of entries each day.

. Information Accuracy - Thousands of verbal messages sometimes result in errors.

. Efficiency of Communications - Calls are passed along the line of towers for all trains, freights, track cars, and test vehicles, etc.

. Level of Complexity - The system is cumbersome as there is a lot of paper everywhere, train sheets, form Ds, signal out notices, etc. There are over twenty-five forms in all.

. Timeliness of Data - Entries are not always current. Sometimes they are 30 to 45 minutes old. Dispatchers call tower operators with train arrival and departure times at selected intervals. These phone calls may be delayed.

. Dissemination of Information - Transmission of information is slow especially in emergencies when it is needed the most. Phone traffic peaks during an emergency. This makes it even more difficult to update train times while addressing the emergency.

The Automated Train Dispatching System (ATDS)

The ATD System is designed to replace over twenty- five handwritten forms and most of the voice communications required by the current manual system. The system will provide dispatchers and tower operators with accurate and real time information on the status and location of trains.

Each of the thirty-eight workstations electronically re-creates a facsimile of existing manual forms on a high resolution 15 inch monitor (1280 X 1024 X 256 color). Data entered on the electronic forms may be edited or printed and easily distributed to remote locations. Multiple users at any tower may edit the "same form". The updated information can be distributed system wide within five seconds. Users can also access, edit and print any other forms used to control trains in a similar fashion.

Unlike the present system, Tower operators can customize the portion of the train sheet they need. Scheduled train times are shown on the screen. If a train is on time, an operator simply "clicks" a mouse to enter the time and the "system clock time'' recorded is consistent for a l l users.

The resulting speed and ease of use is dramatic. Operators are relieved of the repetitive task of manually entering arrival and departure times and phoning other tower operators to relay the informat ion.

During emergencies, the ATDS allows decisions to be made with more "up-to-date" and accurate information. Problems can be addressed more effectively because error in data transmission is reduced. Information is available virtually "on

demand" and orders can be distributed almost immediately.

System Links

The system is also linked with three hundred ( 3 0 0 ) monitors from SEPTA'S Transit Information Display System (TIDS). The TIDS monitors are placed throughout the Regional Rail stations and display information on the schedule status of up to four trains. Th information includes the destination code, type of train (local or express) departure time, track, section and status (on time 01 number of minutes late). TIDS monitors can also be used to display special messages like: "I'URCHASE TICKETS AHEAD OF TIME AND AVOID THE EXTRA CHARGE"

SEPTA plans to place two workstations in AMTRAK's Northeast Corridor's Centralized Electrification and Traffic Control Center (CETC) so that information on SEPTA's trains entering and leaving both properties will be available to both agencies.

Graphical Interface

A key to the success of the system is the Graphical User Interface (GUI - pronounced "gooey") presented on the workstation screen. Forms on the monitor are presented to railroad personnel in a familiar format. Forms have buttons, checkboxes, spaces for comments, drop down menus and other features that make them even easier to use than their paper equivalent. No special computer experience is needed. Each rail line is also color coded to match the existing scheme.

Less visible, but just as important, is the role of the VAX server. This central processing unit provides a system-wide information repository that can be accessed from any of the 38 Transactions are recorded and redistributed automatically when the event occurs. This eliminates the need for workstations to constantly poll for status updates. The VAX server also has functionality to facilitate archival record keeping and to interface with other systems: the SEPTA's Management Information Services (MIS) group's IBM mainframe, and AMTRAK's CETC Tandem computer.

Advantages of the ATDS

In addition to the speed and accuracy improvements, several other advantages result from the ATDS:

Easy Schedule Data Inputting - The system is designed to accept ASCII text files from SEPTA's new "Trapeze" scheduling software. It is no longer necessary to enter train times on a schedule which may change several times a year. This saves about three man weeks each time for each schedule change.

' Information Archival - The most recent 31 days of operations are disk resident for on-line review. Cartridge tape archives historical data for seven (7) years as required by the FRA. Data retrieval is greatly improved

Hard Copies - The FRA required copies are now easily obtainable at the day of generation or weeks ].ater.

Disk Operating System (DOS) - A DOS emulation program is provided with the ATDS so that the workstations may be used to network any software run under DOS. This includes t h e Unix version of the "Word Perfect" word processing program.

' SQL - The system software has "Structured Query Language" capabilities which provide a standardized method to allow ease of data analysis and generation of custom reports.

ATDS - SEPTA envisions ATDS as a building block to a planned f u l l y automated train control system.

Reliability

High reliability is mandatory for a ATDS operating twenty-four ( 2 4 ) hours a day, every day of the year. Loss of data can be catastrophic. The system automatically tolerates the presence of a fault and the resulting errors and subsystems failures. It continues in operation with full system integrity without denying service to users. This fault tolerance includes error detection, damage confinement and assessment, error recovery and fault treatment in conjunction with continued service. No single point of repair exists. As a result, it is not necessary to interrupt the application service to effect hardware maintenance or repair. Fault tolerance is implemented through the hardware for this project.

Security

System security meets the Department of Defense Trusted Computing Base class 2 rating. Access rights are limited and controlled. Users need to identify themselves by password before gaining access to the ATDS. All actions taken by users are auditable. The audit trail itself is protected. Hardware used for security control is protected and isolated.

The ATDS Architecture

Hardware -

At the heart of the system is the Server, a DEC VAXft 310 rated at 3.8 VUP, 8.9 TPS with 96 Mbyte memory and 2 Gbyte disk. Each of the thirty eight PC Workstations is a DEC 486 - 66 MHz Dx2 with 1280 x 1024 x 256 color 15 inch monitors, 500 Mbyte disk and 24 Mbyte memory. For security reasons, there are no floppy drives on the workstations.

The Network uses Coax, single mode fiber optics, phone (leased lines), and direct (short-haul) 9.600 baud modems. Workstations all use WD 8013 thin Ethernet NIC's. The VAX uses DSSI Ethernet adapters.

Software

The ATDS uses a distributed multi-platform configuration with a VAX computer running VMS, a DEC proprietary operating system. Netweave supports the link to AMTRAK's CETC Center. Communications are supported by a Terminal Conrol Program/Internet Prnctocol (TCP/IP).

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"X Windows" is used with the SCO version of UNIX on the workstations. This allows the programmer to develop the GUI environment. It also has built in networking capabilities. Applications are programmed in C+t. Ingress is the database engine.

Project Management

The ATDS was purchased from a specification prepared by SEPTA'S user department working with an outside consultant. Award was on the basis of lowest responsive and responsible bid. Projects procured on this basis are difficult to manage because limitations are placed on the value of allowed contract "extras". Also, there is little room for either party to make adjustments to rectify any design oversights.

SEPTA'S outside consultant assisted in the technical review. However, from the outset, SEPTA decided to run the project using a "Project Team" under the guidance of a single project manager. The project team consisted o f : two people from SEPTA'S Management Information Services (MIS) Department, an STO who would be the ultimate user, an analyst and co-project manager to handle the financial and record keeping functions, a telephone communications employee, and a stations department representative for the TIDS portion. The project manager is a member of the Railroad's Administration Department with an engineering background.

The Project Team met regularly with the contractor and minutes were kept of meetings. The importance of keeping team members aware of all activities was a lesson learned early in the project. Support of upper management is vital to assure that problem solving responsibility is placed on the team not on an individual or department. As the project developed, team members recognized the strengths and weaknesses of other members and learned to maximize individual strengths.

Minor Problems

A project this complex did have a few problems:

The towers are very old and space is at a premium. Our first question was - "Where can we put these workstations?" During preparation of the specification, we reduced the size of the monitors from the 19 inches used in the RROC to 15 inches in the towers.

O Near the end of the project after thousands of man-hours and hundreds of details had been worked o u t , we realized that the electronic forms did not come with erasers.

O Rapid system response time was always a concern. The ATDS must be fast enough to actually handle electronic dispatching of trains. This requires a system response time of less than 5 seconds between the time any data is entered and the results are seen on all workstations.

"It's almost perfect, but why does my screen go blank?" Software development is sometimes fraught with those "bugs" and our project has had a few.

Conclusion

It is expected that final installation of the system will be completed in early 1994. Special effort is being given to the training portion of the project. It is realized that the successful implementation of the ATDS depends on its acceptance by the users.

Bibliography

[l] Department of Defense, "Trusted Computer System Evaluation Criteria", December 1985, pp. 16-17.

aiography of The Author

- Nick R. Sparozic, P.E. Nick Sparozic holds a BSEE from Newark College of Engineering, class of 1967.

After two years of military service and five years with the Port Authority of NY & NJ as an internal management consultant, he joined the Southeastern Pennsylvania Transportation Authority (SEPTA) . Since 1974, he has engineered SEPTA utility vehicles, heavy trucks, bus, trolley bus light rail, subway and commuter railcars. His analysis of radio communications lead to the establishment of SEPTA'S radio-electronics shop. He was the Authority's first air conditioning instructor and served as the Authority's representative for the purchase of 125 Broad Street Subway Cars and shop modernization program.

During his free time, he works with the South Philadelphia Habitat for Humanities.

A system this secure also had to be fast and easy f o r employees to Log On and O f f . This was solved by having some processes run in the background.

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