Southern Pacific Lines

Coast Line Division 

“The Route of the Octopus”


General Information

TOPS Description

  1. All the computers were used for "TOPS" Total Operations Processing System. It was the system that keep track of all cars and locomotives, where they were and where they were going. It also keep track of all of the trains as they traveled the system.

  2. With TOPS you now had a system wide tagging system and a coded number was placed into the computer and on waybill that would direct the car directly to its correct spot. With computer terminals in each yard office and given yardmaster could have his clerk pull up any information in his terminal so that cars could be correctly spotted. Every station had a 999 track; this was where you placed all lost cars until you could find them and get them headed to the correct destination. In the early days of TOPS 999 track had more cars that any other track.


  1. S.P. had the largest computer room setup in the world, so it was said. It’s just assumed that the equipment was for dispatching purposes.

  2. SP TOPS was started in 1960 and the first phase went on line mid 1968 after 660 man-years of effort. The work was spearheaded by TOPS On-line Inc a small consultancy 80% owned by SP with IBM. TOPS was subsequently sold to a number of US/Canadian railroads including UP and CN but the biggest purchase was British Rail going on-line in the UK in Oct 1970. The sale price was $11.2m. However, in its first year of operation it saved $58m on the UK operations budget.

  3. Written in TOPS-TRAN specifically designed language for SP the core is known as the TOPS Black Code. This language is so old its like publishing a current newspaper in Sanskrit but is still taught to a small core of programmers. The Black Code is archived and preserved because no-one is left who knows how it works.

  4. UP did not want to be tied to SP and developed TCS (foisted on SP in 1996). The core of TCS is the same Black Code as resided in SP TOPS but this is closely guarded secret. When Wisconsin Central (firmly in the UP TCS camp)  purchased BR freight they tried to ditch TOPS. They brought in UP to introduce TCS but found that the UK SP TOPS had been enhanced beyond anything that UP had done. After many months of struggle and meager bucks (and the departure of the King of Wisconsin) they quietly ditched TCS. It is interesting to ponder that SP saw UP off in the corner of a foreign field which shall forever be SP!

  5. In 1968 SP had a vision as how TOPS was to be developed led by T. K. Strong.  This never came to fruition but the vision was sold to the UK with the code and UK/SP TOPS was developed with TSDB (train service database) and TRUST (train running through TOPS) currently managing ALL UK operations in the way SP intended. Parts of the developed system was sold back to SP in the late 1980s.  

TOPS, How it Works

  1. "The actual station or yard number is represented by STANOX. This stands for station (STA) number (NO) the X being added because TOPS requires 6 characters in its fields. Within a STANOX is SPINS because there are so many location within a location which needs cars to be spotted. You(BR)do not need SPINS because there are more locations in Los Angeles alone than in the whole of your railway. Therefore you can use only STANOX for the foreseeable future".

  2. SP TOPS must have used the 6 character STANOX but how it related to SPINS is unclear. In 1970 the STANOX field was 6 numerics. BR adopted a version of SPINS within this, the first two characters being the TRA (TOPS Reporting Area), the next two the line within the TRA and the last two the location on the line.

  3. Ray State


  1. For a technical discussion of the TOPS computer system, please visit the following URL:


  3. Be advised that the PDF file is more than 20 megabytes covering 454 pages, and govern yourself accordingly. That document is much more than a description of a computer system. There are all kinds of operational data pages near the end of the document for Oregon, California, Utah, Texas, etc mostly for the year 1960. Section A-57 onwards has the station names and the numbers.

Southern Pacific Lines
General Info
TOPS Description
TOPS, How it works?