How do railroads keep track of their engines?

I have read about railroads 'repaying horsepower hours' and I understand the concept. My question is how does both these railroads know that these engines are far from home rails on the Pan Am Southern in Fitchburg MA? And how do they know how long both these engines were used on this railroad? http://www.rrpicturearchives.net/showPi ... id=3823997" onclick="window.open(this.href);return false;

computers.

Computers are all well and good, but … garbage in, garbage out. I would suppose that, even before computers, railroads kept tabs on which locomotives were on which trains. (Trains not working to the same schedule every day -- so, most freights -- were typically identified by the locomotive heading them: "Extra 2200 South," to make up an example, would be the southbound "extra" -- i.e. not in the timetable -- train led by locomotive number 2200. This identification was used in setting up meets, so a train-order to the crew of that train might say "Extra 2200 South take siding at (location) until Extra 3300 North passes," or something that. So keeping tabs on which locomotives were on which train was important for operational and safety as well as financial reasons.) So they would automatically keep a record of when one of their locomotives left "home" rails for a connection.

What happened after that… was supposed to be a matter of mutual agreement between the railroads. If everybody is honest, you know whether your locomotive has gone on or has stayed shut down at the first yard after the interchange. If not… Somewhere I have read a story -- from the steam era -- that the agreement between the Central Vermont (a CN subsidiary) and the Boston and Maine was that the CV/CN locomotive would come off a Montreal-Boston train and stay quietly at the interchange point to wait for a Boston-Montreal train for it to take home. Things got … interesting … one day when a CN or CV official visiting Boston spotted one of their locomotives at B&M's Boston terminal!

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These days, at least some locomotives are in constant, automated, communication (via Satellite) with a central computer: GE at least advertises this as as a feature of their locomotives: the locomotive's computer communicates with the maintenance base's computer so needed service can be scheduled before it arrives. With this sort of system, locating a locomotive would be… no more difficult than locating a missing airliner!

Remember also, that in the day, divisions were shorter, and much less power made the entire run. Thus, dispatchers and roundhouse foremen had a smaller stable of equipment to track.

What John Perkowski said!

One of the great advantages of the diesel over steam was that even an early diesel unit could operate longer before having to go into a roundhouse for maintenance, so it became possible to have large numbers of locomotives (not just a few specially groomed passenger engines) that traveled hundreds of miles away from their maintenance bases on a regular basis: soon you could have fleets of locomotives that could go pretty much anywhere on a large system. At this point -- in the 1950s -- a more systematic approach to keeping tabs on locomotive whereabouts became amazingly useful! This was possible even without computers (I think Conrail's initial effort, in th 1970s, used magnetic tags with engine numbers that could be moved around a schematic map), and allowed locomotives to be used much more efficiently. I think the Chicago and Northwestern introduced a central motive-power allocation system shortly before the end of steam, and, by using its existing diesels more efficiently, was able to retire steam without buying more diesels! (Source for that belief: an article in "Trains" many years ago, probably the 1970s.)

Yes, right after its formation Conrail established what became known as the "Blue Room" (from the color of the walls) in Philadelphia, on which a schematic of the entire system was displayed. Each locomotive had a magnetic tag with the unit number, as well as a variety of colored stickers indicating, e.g., whether the unit had cab signals, an engineer's seat with armrests, required under the NYC agreement but not PRR (I don't know what the EL agreement called for), and any other feature an employee would have to know about in order to put a properly equipped locomotive at the head of a train. There was also a means of indicating the train symbol of whatever train the units were hauling. The magnets were moved around the board as reports of a train's progress were received; an experienced employee could look at the board and estimate which units would be where a few hours later and make plans for their next assignment. It's all in the computer now, and much less interesting to watch.

The experience on the C&NW provided an interesting example of the advantages of diesel over steam (I think this is from H. Roger Grant's history of the C&NW): what prompted the study was that Ben Heineman wanted to know how many more diesels the railroad would have to buy to get rid of steam altogether. Since they had been replacing steam with diesel on a one-for-one basis, they found that the superior availability of diesels rendered it unnecessary to buy any more diesels at all since they could get so many more work hours out of the diesels.

All RR Equipment including Locomotives are required to have RFID (AEI) tags fitted and to be registered in UMLER(Uniform Machine Language Equipment Register). When ever a Locomotive passes an AEI scanner its location is updated in UMLER and anyone with access to UMLER can find out the most recent location. In addition each Dispatcher records on his train log every train that operates over his territory, and that includes every locomotive in the Engine Consist. Now say BNSF gives NS a locomotive, lets say ES44C4 number BNSF 6600 in Interchange at Chicago and a day later NS sends it to CP. BNSF doesn't care that it is now on CP, they are still charging NS for the locomotive until NS returns it.

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And just think, railroads were keeping track of millions of cars well before computers were invented.

And one could argue that one of the main motives for the invention of the computer was to help large railroads handle all their data! You run a factory, and your foreman can keep an eye on things and let you know when something needs to be re-ordered-- if, on the other hand, you run a railroad you have to get information from many, many sources (operating personnel and customers both) who may be hundreds of miles away from your office: my guess is that, at the beginning of the 20th C, large railroad companies were the biggest non-governmental "data processors." So there were inventors…

Around 1890 Herman Hollerith developed punch-card technology. His company later (in the 1920s) changed its name to "International Business Machines" and was a technological leader in developing… more versatile sorting machines for punched cards, then machines that also did arithmetic with the numbers punched into the cards, then (after WW II) what we now know as "electronic computers": a history of IBM is a large part of the history of computer development between the late 19th and middle 20th centuries.

And who were Hollerith's early customers? Who, in other words, had enough of a data-management task that they thought it was worth investing in new technology to help with it? Well, one was the U.S. Census Bureau who wanted to process the resuls of the 1890 census. Another, however, was … the New York Central Railroad! The computer revolution, in other words, started to help (i) government bureaucracies and (ii) railroads.

(Union Pacific has over 7,000 locomotives; at any one time a significant number of them are off home rails being photographed by rail fans all over the continent. Try to imagine what it would be like to keep track of the mileage they are running up and on which properties without a computer!)

On the subject of tracking equipment in general, someone in car accounting told me he found that professional accountants in other industries were often astounded to discover the extent to which railroads trust each other for accuracy in such matters. I suspect that an experienced railroader can sniff out instances where some other road is fudging the numbers.

Speaking of which… Has anyone ever written up the full story of the La Salle and Bureau County and the Penn Central's, um, difficulties with car-accounting?

There were a lot of reports in the trade press and general-circulation newspapers at the time, but I've never seen the whole story pulled together in one place. The system didn't take "midnight repaints" into account.

The railroads have traditionally been early adopters of electronic communication the earliest being the telegraph not too long after it's invention. In fact some of today's fiber optic cables follow some of the early railroads telegraph routes.

Probably the same way that they keep track of all the components in a locomotive. They must have a database somewhere.

Now many locomotives have GPS, as was mentioned. These not only communicate location. Management can spy on what the engineer is doing too. The most important data is for the onboard computers. Recently the dispatcher called another engineer to tell him to contact mechanical. The unit had some problem brewing, and he needed to check it out. I have had problems too. Sometimes the mechanical troubleshooter will ask what fault is showing on the DID or EM2000 panel. Other times he pulls up the remote satalite data.