Mixing of B and C units together

[Anonymous]

I have watched numerous videos on various railroads and subjects and I can't ever recall seeing a mixture of B and C units together on long distance freights. Do railroads ever mix B and C units together or are they all B or All C units together?

[SSW9389]

The trend has been to more C-C units on mainline freight trains. The other day I saw a B-B road locomotive lashed up to a B-B slug with a C-C locomotive trailing. On the CSX trains around here a pair of C-C locos is common.

[eolafan]

In the "old days" of early dieseldom you had to have matched sets of models from one builder, etc. but today a railroad can la***ogether pretty much anything that has wheels on it...four axle, six axle, a/c, d/c, emd, ge, whatever but some lashups work better together and you will generally find groupings of "like" units such as SD70MAC's on coal drags, GP60's on intermodals, etc., but still you will find really exotic lashups on general merchandise freights. As time passes, though, the motive power game is such that we are starting to see real "common" types, such as SD40-2, SD70 (either comfiguration), Dash 8 and Dash 9, etc. where not so many years ago you would see over 20 different models with real regularity. Oh, for those good old days.

[wabash1]

here on the ns they still make up a train with what ever they have around. i have ran several trains where they will have a dash 9 in the lead and a sd40 behind it or a gp38 just so you have enough power to handle the tonage. not long ago ns come out with a memo stating that all trains will have same power match ups. that lasted about 5 min as most generally i dont ever have like power on any train. the only rule they do keep is all ac traction motors or all dc traction motors. they wont mix those.

[Anonymous]

On BNSF we try to use Dash 9's on all our intermodal stuff. Now on our manifest trains we use anything we can find. Like on our LA to Barstow manifest trains you will see A lot of 4 axle yard engines going to Barstow for service. Like all railroads we have to maintain A certain horsepower per ton and number of dynamic brakes per ton. 4 axle engines tend to be on the low end of both of these requirements so it takes more of them to equal say A Dash 9.

[cabforward]

a unit = streamliner, leads pass. train
b unit = follows streamliner, power only, no controls, no head-end, never leads
c unit = ??

[Gluefinger]

I think I know what he means

B- GP50, B23-7, etc. (4 Axle Trucks)
C- SD60, C44-9W, etc. (6 Axle Trucks)


Also, B's are normally local / yard units, C's are mainline.

[Gluefinger]

B Units do have controls. Thats what the portholes are for- driver can look out side and operate B Unit. Also, B Units can have head-end. A notable B Unit would be the CNW's Power Car "Oak Creek." It was set up for executive trains so non-HEP equipped engines can pull a business train.

[edbenton]

On the ATSF they numbered the F series of units L,a,b,c so it was possible to see c units leading the train unless it was ealry in the FT era till 1944 they bought just one cab and 3 boosters such as 100 L,a,b,c this on was not converted due to the more primate db system it had on it

[edblysard]

Diesel/electric locomotives do not use the whyte wheel arrangment that steam did, such as a 4 6 6 4, ect.
B means two powered axles per truck
C means three powered axles per truck
A 1 A means three axles, center axle unpowered as on E and F streamlined passenger units to distribute the weight evenly.
Unit desigenation..EMD
F unit, most common EMD streamlined unit, often ran in combination with-
B, booster unit, had a simple set of hostler controls.
FP9, six axle, A 1 A designed for both freight and passenger, still see some in comuter service in the north east, I belive.
Some Alcos had a B truck in front, a C truck in the rear.I think these were know a C Liners...
GP stands for general purpose, had B style trucks, most commonly recognized examples, GP7 GP9, and the GP30. Ran on everything from passenger to local drag freights, now found mostly in yard service due to age.
SD special duty, has six axle trucks, all 6 powered, common example is a SD40, SD40-2, SD 70Mac and the new SD90M
Above are EMD designations,
GE used-
B for two powered axles per truck, as in B23, B30, B30 7A, (cabless booster built in the 70s) with the letter standing for the truck arangment and the number standing for horsepower, B30 having 3000 hp two powered axles per truck, b23 2300 hp...C30 three powered axles per truck, 3000hp. The - in the model, as in B 23-7 stands for the 7th model in that series. The reason the model numbers and series dont seem to run consectutively for both EMD and GE is that they made units that didnt sell, or were never produced, and they had assigned the missing #s to them. EMD had a GP8, never got off the drawing table.
GE changed model designations with the dash series,
Now using C for three powered axles, so a C44-9
means C trucks, 4400 hp, model#9 in the series.
Number of axles dosnt restrict where a motor is used, mainline or yard, Santa Fe had B trucked GE motors on their preimun intermodel, and the GP7 and GP 9 helped kill mainline steam locomotives. But you will find 4 axle motors on lighter rail, as the weight of a six axle and the restrictions on the turn radius of 6 wheels will prevent the C truck from working in a tight turn found in older industry tracks and on older lines, build when 4 axle diesels or 0-6-0 steam switchers were the norm, and in yards, where the tracks are often decades old. Beside, you dont need the extra powered wheel in yard service. In the tight raidus curves found in yards, the center wheel will bind, as the distance between the centerline of the front and rear wheel is greater than the turn or track radius, causing the middle wheel to bind, and overide the railhead, which will either derail the motor, or lay the rail over on its side. The reason for six axles is to distribute the weight of a larger locomotive over the rails more evenly, and the added powered axle helps with traction.
To used Gluefinger's example, the last motor he list, C44-9W would go as follows.
C(six axles truck, all powered) 44(4400hp)-9(9th model in that series) W(wide cab, also know as a north american cab, or comfort cab, isolated from the frame to reduce noise and dampen vibration)
Trains ran an excellent article on modern wheel and model designation a few years ago, and you may find it in the links here also.
Stay Frosty,
Ed

[bfsfabs]

Ed,
Those "ALCO"s with the B truck in front and C truck in the rear. Were most likely Fairbanks Morse C-Liners of the B A-1-A flavor.

Lowell

[edblysard]

Good to know, I never saw one in person, but in the photos I have seen it a good looking engine. Wonder why it didnt seem to sell?
Ed

[Anonymous]

Sorry for the confusion, but I was referring to 4 Axle and 6 Axle units as B and C units.
Larry

[edblysard]

Question, if the rear truck was A 1 A , what was in the rear of that unit that needed the additional support? It kinda makes sense to power all three for tractive effort, but why the dummy axle except for support?
Thanks
Ed

[bfsfabs]

Ed, The "Regular Way" C Liner was B B as a freighter. The passenger flavor had a steam generator living above the A 1 A truck. There were not too many of these built. Not too many C Liners either as far as that goes.
C Liners hit the scene just when the railroads were falling in love with "Hood" units. A bit too late to arrive, the covered wagon era was ending.

Lowell

[edblysard]

I assume the additional weight of the equipment and the water needed the support. Shame, its a good looking locomotive, kinda styled like a automible of that era...
Thanks Lowell,
Ed