Folks,
I’m still ramping up my knowledge or RR operations and am constantly running across the term “subdivision”. I constantly read about the XYZ Subdivision but have no idea what this naming convention connotates. I don’t have a good concept of what this is. Can somebody give me a good definition of what a subdivision is and an example of how they fit into the RR world?
Thanks in advance.
wickhamman a subdivision is a smaller part of a division. for instance BNSF has the Texas division which in turn is broken into smaller subdivisions like the Galveston sub Sweetwater sub etc, also some subdivisions cross state lines like the BNSF madill sub which runs from madill, oklahoma to irving, texas.
hope this clears up your confusion
tom
if you can get hold of a railroad’s rule book you will see how it works…here’s an example…the SP (when it was the SP) was divided into Routes, like the sunset route, the valentine route, ect… within the route were subdivisions…like here where i live in texas the sunset route came thru…it was divided into subdivisions like the kerrville subdivision, near san antonio or the del rio, sanderson, and el paso subdivisions in west texas…in other words each route was divided into subdivisions along the mainline tracks from New Orleans to Los Angeles on the southern portion of SP tracks and each subdivision had a yard that the subdivision would work out of…chuck
A “division” was an administrative portion of a railroad which had its own senior manager (traditionally called a “superintendent”) and other managers who reported both to the division superintendent and to their department heads at corporate headquarters. Typical departments were mechanical, operating, bridges & buildings, transportation (a/k/a marketing), signals, engineering, etc.
A division and its managers had authority over designated lines of the railroad, which also were known as the “division.”
A “subdivision” was a designated portion of a division’s lines of railroad. A designation of a “subdivision” was important mostly for traffic control or operating purposes. Employee timetables were typically issued on a subdivision-by-subdivision basis, and under traditional operating rules, a train could not leave its initial terminal on any given subdivision without a written “clearance” form issued by authority of the train dispatcher.
So, if I understand this correctly, a “subdivision” is simply a small portion of a mainline operation. It has no specific functional requirements associated with it although it may have a yard out of which some group of locos operate. Are subdivision locos responsible for any particular aspect of operation within their sub? Do locos assigned to a sub ever leave it? Or, are locos not actually assigned to a sub and a sub is simply a physical description of a portion of a mainline that may happen to have servicing facilities for locos?
Thanks again.
EdW
Locomotive assignments varied quite a bit from one railroad to another, and from time to time on any individual railroad. Much depended on the size of the railroad and its traffic mix.
Traditional “divisions” were pretty well self-contained, so they usually had a principal locomotive servicing facility, which also served as headquarters for the division’s chief mechanical officer. This facility was generally capable of handling all routine locomotive inspection and servicing functions, and perhaps heavy repairs or rebuilding (although the latter functions often were conducted at one major shop servicing the entire railroad). Smaller servicing facilities might be spread out at different locations on a division, depending on traffic concentrations and operating needs.
A division’s mainline might or might not be divided into subdivisions. It was common for branchlines to be designated as subdivisions separate from one another and from the mainline.
Probably the most common form of locomotive assignment was on a division-by-division basis, subject to reassignment of engines from one division to another, as dictated by the company’s senior management. Within a division, locomotives usually were assigned, based on type of service (e.g., through freight, local freight, helper, yard switching, etc.). Such assignments might coincide with service on a particular subdivision, but mostly that would indeed be a matter of coincidence.
This is really helpful. I’m guessing a “branchline” is simply then a deviation (a branch)from the mainline of a specific railroad. I’m also assuming that branchlines were designed as “feeders” to service customers “off the main” , to ferry customer freight (and passengers) to the mainline much in the same way that feeder airlines work to shuttle customers to mainline carriers. Right?
Thanks again.
EdW
Well, regarding locomotive assignments per division/subdivisions, there can be some logic to the mix. For example, on the Southern (now NS) “Rat Hole” Division (NOT subdivision), they would assign the most powerful locomotives which were geared for pulling power, but lower top speed. The same goes for the West Virginia and Kentucky coal mining areas. This was because the lines had numerous steep hills and heavy tonnage, but they didn’t need to move this at high speed. On the Piedmont Division (runs from Atlanta to Greensboro, NC) they would assign 4 axle and 6 axle lower horsepower, higher speed locomotives to move the fast freight because this division isn’t as hilly, and the freight isn’t as heavy, but it needs to move quickly. The reason for the lower horsepower units is because they use less fuel. In another instance, a RR might assign (or even buy) lighter weight locomotives for a branchline that may have poor track, light weight rail, or a weak bridge to meet weight restrictions on that line. So, that kind of gives an insight to why they might assign certain locomotives to certain divisions (or even subdivisions) as the case may be.
A general rule one could say a division covers a region or line from one major city to another, whereas a subdivision may be from a major city to a division point, major customer or yard, junction with another RR, or possibly a smaller city, state line, or other geographical feature. Nowadays, a “sub” could be what was once a branchline or shortline that got absorbed into the class 1 RR.
On my model pike, I’m modeling the Southern Railway in 1957, but on a line that actually folded in the '30’s. My premise is that the Southern bought the line out of bankruptcy and ran it as the Gainesville Northwestern Subdivision of the Piedmont Division. It’s common for RR’s to name a subdivision after the predecessor RR in these situations. On my line, I will have a bridge with a low weight limit, and will model it appropriately, complete with operating ru
Help me out here guys also. I think most subdivisions were created to be the distance a steam engine could go before it needed servicing such as coal and water. So what is the average mileage of a subdivision? I read in the Jan 06 issue of Trains that CP’s Belleville sub is 211.5 miles.
I don’t think thats right now days but back in the steam days it was probably right.
Ah, yet another clarification needed for me. What is a “division point”? Is it some point along the division that marks the seperation of “subs”? Was there typically any type of structure or servicing facility at a “division point”?
Thanks again and sorry to make this such a termonology tutorial.
EdW
A “Division Point” could either be where 2 divisions meet, or where a brachline divides off the main (possibly on its own division or subdivision). For example, Atlanta is where several divisions start/end, and as such, is the home of “Milepost 0”, which is in downtown. Of course, each RR would have its own Milepost 0, or a Class 1 RR may have several, perhaps one Milepost 0 for each division. When Southern and M&W merged in 1982, the N&W line had its own MP 0 in Norfolk. Southern had their MP 0 (well, one of them) in Atlanta. After the merger, I don’t think any of the mileposts were changed, they simply referred to the appropriate lines as either divisions, or subdivisions.
I suppose the easiest way to answer this question is to research the RR you model, and find out what they did and why they did it. Each RR did things a little differently (especially the Pennsylvania RR, the so-called “Standard RR of the World”. They had more tendency to do things differently, backwards, “wrong”, one-off’s, experiments, unusual, different, or just plain weird, than any other RR in the US. I think their locomotive number scheme was about the least organized I’ve seen, I think they simply numbered locomotives sequentially as they came onto the roster.)
Brad