How do day do dat? - Numbering locomotives

[tstage]

I realize that this may be a loaded question and have a multi-faceted answer, but here goes. I was musing last night, as I was running my trains around the layout. How does a railroad go about numbering their locomotives?

Now, I have a NYC 2-8-2 Mike that is obviously older than my NYC Alco S1 switcher. The 2-8-2 is #1852; the S1, #687. I know that my S1 was manufactured in early 1941. Some S1s with a 900 series number were also manufactured in 1941, while some with an 800 series number weren't manufactured till 1950. (See "Diesel Shop" NYC ALCo S1 link, http://www.thedieselshop.us/Alco_S1.HTML)

So, how do they come up with the numbering system? It doesn't seem to be sequentually based on the number of particular units manufactured by a particular manufacturer. Nor sequentually, as the railroad bought each locomotive. It's got me baffled...[%-)] (Hopefully, the answer isn't going to make me feel like a [D)])

Anyway, thanks for your responses...[:)]

Tom

[coalminer3]

Good questions all.

The numbering scheme/plan depended on the railroad, and, to a great extent, on the history of the particular railroad. Many larger roads came about from combining smaller lines. This meant that they might have have five locomotives all numbered "1." Not a good thing, obviously. Typically, the railroad that absorbed thse engines would renumber them into a common scheme such as 1,2,3,4, and 5. Confusion and disaster were thereby prevented.

Other roads assigned blocks of numbers to particular classes or wheel arrangements of locomotives. Others put them into blocks of numbers that were vacant on the roster. Still others numbered them by horsepower or date of purchase.

Sometimes even this was not enough and there would be a wholesale r# of locomotives to try and bring order out of anarchy. For example, the Western Maryland had a big r# in 1905.

Then there was the Pennsylvania which seemingly (though not actually) had a random numbering system for its power. Hirsimaki's two books on the PRR and their locomotive policies will give you a good understanding as to how and why things were done the way they were regarding locomotive classification and numbering on the P Company.

A little more recently, the NYC, PRR, and NYNH&H all had a big r# when the Penn Central came about. Today you see something similar going on in the case of the UP. Anyway, it sure does make things interesting. The rr historical socieities that are all over the place are repositories of information regarding numbering and rosters. It's fascinating stuff. Incidentally, if you want to look at things a little differently, examine a railroad's roster by date of locomotive purchase - most revealing as it will give you some insight into the state of locomotive construction at the time, and also give you some explanations as to why the railroads made some of the decisions they did.

Hope this helps

work safe

[IRONROOSTER]

From what I have seen, there seems to have been several methods and not all are logical.

Small railroads or larger ones when they started seem to start with 1 and just go up the line. They do however sometimes skip. The Ma&Pa pretty much went 1,2,3,... and then jumped from 30 to 41. The first diesel they jumped from 43 to 70. The second diesel was 80 followed by 81 and 82. I have no idea why they skipped.

Larger railroads usually have classes of locomotives and each class will be numbered consectively, but I think different roads had different schemes for where to start the class numbering.
Enjoy
Paul

[dehusman]

The numbering of locomotives has no set pattern, it varies from road to road, from era to era. Normally one type of locomotive will end up in a series or group of series.

Dave H.

[ndbprr]

A small railroad with say under ten engines typically just adds the next engine # in sequence. So when you see # 96 it doesn't mean they have 96 engines now but over the history of thr railroad probably did. Larger railroads assign blocks of numbers to classes of engines like 50-78 are Sw-1200's and 82-125 are GP-7's. Why the gap? In case they get more and need the numbers. Really big railroads can do just about anything. The PRR had 598 I-1 2-10-0's at one time and there was no order to the numbering or to divisions. They tended to change this with diesels however and the was more of a pattern. The UP assigned the 4-8-4 numbers to GP-30's so the famous #844 used for excursions became # 8444 until the GP-30's were retired and now has its old number back. I don't think I have ever seen a five digit number unless it was a temporary number on any US engine. It is one of the things to think about if you have a freelance railroad. I used four digit numbers based on the model number so GP-7's started with 7. GP - 35's started with 35. This leaves 99 numbers for each class. Alco's like a C-628 get 628 with a single digit. the only fly is when a siwtcher and a road unit have the same numbers like GP-15 and SW-1500. Then you have to say that 1-50 are switchers and 51-99 are road engines or some other rule.

[dehusman]

You can also number by hp:
GP7 1500 series
RS3 1600 series
SD40 3000 series
C628 2800 series.
etc.

Dave H.

[dehusman]

I believe the PRR engines were very orderly numbered, but only from the PRR's view. It was my understanding they were numbered as they were built. But because they had several plants building dozens of locomotives of several different classes all at once, when you look at them by class, they are scrambled. If you look at them by built date or delivery date, they are in order.

Dave H.

[BR60103]

I'll use Britain for my examples.
The LNER had a chaotic numbering system through the 1930's and they were assigning their new crack lcomotives to any gaps in the system. In 1948 they renumbered everything and started with 1 for the A4 class (included Mallard, world's fastest steamer) then worked their way through the rest of the Pacific classes. They left certain gaps in there. 2-6-2 started at 800, 4-6-0 at 1000 and 4-4-0 at 2000. 8 coupleds were in 3100 and 0-6-0 from 4100 to 5934.
Other railways started with the smallest locos at 1 and worked up.
The Great Western grouped locos by the hundreds digit.
(One book about the Midland said that there freight car numbering rule seemed to be "There should be no gaps in the system.")
British Railways (the current one) assigned power clssifications from 0 to 5 (now 6) and assigned classes based on the power class plus a sequence (e.g. classes 30, 31, 32 were built by different companies.) The engine number is the class plus a sequence number starting at 001. Some classes were subdivided as train heating equipment, brakes, etc. were modified and this was shown in the third digit.
When older classes were largely scrapped, their numbers would be re-used. Often they would be renumbered when to a tighter group.

[Anonymous]

Milwaukee Road did assign 5-digit road numbers to its electric motors (e.g., 10250)from time of delivery in the WWI era until the general locomotive renumbering of 1939 on that road. In 1939 the electrics were renumbered with an "E" prefix and a one or two digit number. IIRC the 10250 became the E-1.

[WSOR 3801]

On the WSOR it's not too bad.

GP-7 -- 700 series
GP-38 -- 3800 series 3801-3808 (3805 is non-dynamic)
SD-20 -- 2051-2056
SD40-2 -- 4001-4009, 4025(25th ann. motor)
non-dynamic SD40-2 -- 4050, 4051

A little bit inconsistent, but it works.