right|thumb|An example of converted [[London Underground 1938 Stock|1938 Tube Stock on the Island Line, Isle of Wight. Under TOPS, this train and other examples of the same type are designated as British Rail Class 483.]]
Total Operations Processing System (TOPS) is a computer system for managing railway locomotives and rolling stock, known for many years of use in the United Kingdom.
TOPS was originally developed between the Southern Pacific Railroad (SP), Stanford University and IBM as a replacement for paper-based systems for managing rail logistics. A jointly owned consultancy company, TOPS On-Line Inc., was established in 1960 with the goal of implementing TOPS, as well as selling it to third parties. Development was protracted, requiring around 660 man-years of effort to produce a releasable build. During mid-1968, the first phase of the system was introduced on the SP, and quickly proved its advantages over the traditional methods practiced prior to its availability.
In addition to SP, TOPS was widely adopted throughout North America and beyond. While it was at one point in widespread use across many of the United States railroads, the system has been perhaps most prominently used in the United Kingdom. During 1971, the country's nationalised rail operation, British Rail (BR), opted to procure and integrate TOPS into its operations. The acquisition of an existing system rather than develop an indigenous programme was reasoned to be both cheaper and quicker to implement; it was noted, however, that TOPS was not capable of performing all desired functions. Since its implementation during the mid 1970s, both BR and its successors have continued to operate the system. SP itself has developed a newer system called the Terminal Information Processing System (TIPS), which replaced TOPS entirely during 1980.
During the late 1950s, SP entered into discussions with the American technology company IBM about implementing its technology for rail management purposes. The project gained the name Total Operations Processing System, or TOPS, and its development was handled by a specially established consultancy company, TOPS On-Line Inc., which was 80 percent owned by SP with the remaining stake held by IBM.
TOPS was to take all the paperwork associated with a locomotive or rolling stock - its maintenance history, its allocation to division and depot and duty, its status, its location, and much more - and keep it in computer form, constantly updated by terminals at every maintenance facility. but none has yet fully supplanted the TOPS system.
Sample output
This is a typical report that a TOPS clerk could generate. The train in question is a 25 wagon freight train travelling from Over & Wharton, near Winsford, to Reading West Junction, Berkshire.
<pre>
K383400 0010 2837 22/10/86 U483 ON N199 BY KO
TRAIN ENQUIRY RESPONSE FOR 377Z380 22 TFA - 9KJ
ACTUAL TRAIN ID 377Z380 22 BOOKED 7Z380
DEP OVER&WHAR 1520 22 2 HRS 20 MINS LATE FOR REASON L CAT B SECTOR 5
LOCO 25901
LOCO 25908
25 LDS 0 MTYS 886 TONNES 799 T/FT 418 POTENTIAL VAC BRAKE FORCE
STATION CONSIST ARR DEP LDS MTYS SCHEDULE
37015 OVER&WHAR 1520 025 000 71212
65700 BESCOTYD NRP 1707 EST 1709 EST 025 000
74260 READINGWJ DETAIL 2007 EST 025 000
END
</pre>