I have heard of railroads typically keeping units of common manufacturers together but do railroads (past and present) typically keep the same model units together? Would a GP40 and SD40 be in the same lashup? would you see SD35s with 40s and 45s?
Only by random chance. Yesterday I decided to keep track of the loco numbers I was seeing. The transition era is my era and I don’t know anything past GP and SD40’s. While I think I saw two SD40’s in the same consist today, that was the first time in the several months I’ve been watching the webcams on Youtube.
Almost always they are by themselves on a short local train or in a consist with 3 or 4 more modern locos. My observations may be skewed because I am watching webcams that have a lot of CSX.
I feel like I need those flash cards, like they used in WW2 to identify ship and airplane silhouettes.
4 and six axle units were mixed during the time of those units. Railroads would mix units to get the horsepower that the train needed. Nowadays, mainline trains are mostly 6 axle units, with 4 axle units being used for local freights.
So you could see SD45 followed by a GP30, SD35, GP40, SD40, GP35, on the lead of a train?
Thanks I was just curious.
Steven, other than required horsepower and which way the cab of the lead unit was facing, there are four other considerations I can think of when building a power consist: (1) minimum continuous speed. Will the train spend a consderable amount of time crawling over grades at maximum power? (2) Maximum speed required by schedule. Don’t put a unit that is geared for 50 mph on a train that is expected to run at 65 or 70 mph most of its run. (3) Dynamic braking. Units without DB were operated in the same consist as DB equipped units but, at least on the Southern Pacific, they had to have pass-thru wiring to pass DB commands from the lead unit to those against the train. SP limited most consists to 18 axles of DB, counting from the unit coupled to the cars. The dynamics on everything else had to be isolated. (4) Another SP practice was the positioning of SW-1500 and MP-15AC units in a road consist. First, to operate in a road consist, the “little” units had to have coupler swing limiting blocks in their draft gear. Then, they must be cut in right behind the lead unit, and the lead unit’s DB cut out. Not more than two SW-1500/MP-15AC shall be in a power consist with road units. When making a reverse move with switchers in the consist, the lead unit must be isolated (not loading) because the higher horsepower of the road lead unit vs. the switchers tends to jack knife the switchers due to their much shorter wheelbase. As far as mixing units of different manufacturers and horsepower, it became less of an issue as the first generation came to a close especially on roads with extensive rosters. One of the last examples of pure consists I saw was on the Southern Pacific in the very late 1970s. They chain-ganged four unit sets of 7600 series of consecutively numbered GP-40-2s into “fuel-saver” sets. These locomotives had special equipment th
I recently saw a picture of a BN freight that had SDs, GPs, Fs, and a switcher all in one lash up.
At the club they tend keep power in the same groups so GP10s with GP10s, SD40s with the same, ect… I find it a bit boring, thats why I was asking as my collection grows.
Often, but not always, the switcher was being carried dead-in-tow to a maintenance facility for its periodic inspection or other work that couldn’t be done at a distant terminal.
Regards, Ed
In the mid-50s you were more likely to see matched sets of road power, in part because the different manufacturers had not made their MU connections fully compatible. That was soon corrected. So, you could have an RS-3 leading an SD40, or vice versa, and a third unit might easily be a B-unit. I once saw an ABA set of cab units, one each of F-M, EMD and Alco design.
There are exceptions to be aware of. Switchers mostly did not have any MU capability and would be towed dead behind the operating power. The few that did have MU mostly had a simplified version and would only MU with a similar unit. Most Baldwin road engines had a completely different system and would only MU with another BLW.
One factor that sometimes continued to lead to matched power sets was when a small roster of “oddball” locomotives were assigned to a terminal to simplify maintenance. In the 1970s that tended to happen with Alco designs, as well as the other minority builders.
Instructions for the building of a power consist were formulated by each individual railroad, often after an event involving some expensive noise and gritted teeth. The Southern Pacific, San Antonio Division employees timetable, effective April 24, 1977 contains the following on handling switchers WITHOUT alignment control couplers dead-in-train: provided the train does not exceed 800 tons, they may be moved on the head end. On trains of more than 800 tons, these engines must be moved not less than five cars nor more than 10 cars ahead of rear of train and behind any helper engine. Not more than two of these engines may be moved in a train and, when two are moved, they must be separated by a car no longer than 50 feet. Also, if a switcher is operated in MU with a road unit, the switcher must be the lead unit, if reverse moves are going to be made. It’s all about coupler swing, jack knifing, and track damage.
I have a video of the Wabash which shows an FM Trainmaster, Alco C424, EMD F7s, GE U25b and EMD GP35 all hauling one train into Detroit from Chicago.
Rick Jesionowski
It all depends on the railroad, the era, the train and the location.
Some railroads kept the same make and model together on some trains and mixed them up on other trains. Some trains always had a certain unit leading. Some trains only had 4 axles, some only six axles.
For example, in the 1990’s and 2000’s on the UP, coal trains had sets of GE C44AC’s almost exclusively. Intermodal trains had sets of C44-9’s and SD70’s. Meanwhile on manifest (general freight trains) in the southern part of the railroad they could have any 6 axle engines.
On the MP and the RDG 6 axle and 4 axle engines were mixed on road freights.
It just depends. There are vaild reasons for both strategies and both are used by the railroads, possibly even the same railroad at the same time.
CNJ and WM did a lot of that too. Found a picture on another forum of a CNJ train with a GP7 in the lead, with an RS3 in the middle and a Trainmaster on the rear.
There a picture in one of the Reading books with an RS3, Alco FB, GP7, and something else (or something like that) which begs to be modeled, mainly because the middle door on the FB is open.
–Randy
I wish someone (like Athearn) would produce a DD35, GP35, and SD35 for SP or UP. That’d be a sight a 6 unit set of 2 GeePs, 2 SeeDs, and 2 DeeDs
The original concept was that the DD35 was only going to be a B unit and would have a GP35 on each end. That keeps the horsepower per axle even. GP35 = 4 axles 2500 hp, DD35 = 8 axles 5000 hp. The MP did that with GP38’s and SD40’s. Both units have 500 hp/axle. The SD35’s probably didn’t run with the DD35’s that often.
Here’s one such occasion.
Here’s three Centennials and two other units on the lead of a train.
D&RGW didn’t make a fuss about keeping like road units together. They freeling mixed 4 axle and 6 axle diesels together as evidenced by countless photo’s.
Of course they also ran sets of tunnel motors together, and other like types.
Basically you can do what you please if you are freelancing since RR’s did what they pleased.
So go ahead, “hook’em” together like those long horns in your siggy [(-D]
As far as those UP DD engines, unless you have a LARGE layout with large radius curves, you might want to “steer” clear of muing 3 of those together.
IIRC, the DD’s were typically ran as a sandwhich, two of them with an SD40-2 in the middle. Athearn ran the UP SD40-2 type a couple years ago which were used with the DD’s.
Correction, that picture has not three but FOUR Centennials and what appears to be a GeeP.
As far as mixing units I’ll take the Bull by the Horns and for the June 2 Op Session at the MSMRC I’ll get two Burlington GP10*s and two Burlington SD40-2s and run them as a consist if no one has them on a train. (*I think they’re 10s but not completely sure) I’ll take a few pictures of them running, which units should lead? Do I sandwich the Geeps between the Seeds or vice versa, or do I alternate Geep, Seed, ect. Or vice versa?
The STRATTON & GILLETTE never mixes models in a locomotive consist. I just like the way it looks better.
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There was a railroad, for some reason I think it was the BURLINGTON ROUTE, that ordered GP-9s geared the same as their F units to be used as boosters. They would commonly run consists of F unit A, F unit B, GP-9, F unit A.
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I hate the way that looks to have a GP in the middle of an F unit A/B/A set.
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In the movie Runaway Train there was an F unit in the middle of the consist that caused problems in getting the train stopped.
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I think that is more than enough fiction and conjecture for one post.
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-Kevin
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I can run two, three, some times four unit matched sets, two, three and again four units in a mixed set and for road names, I can run at least three different road names (PRR-NYC-PC) in the same consist. Never boring. Hows that for variety? I love the PC.
This is likely more due to the locomotive models not being speed matched. You can typically pull three new locomotives out of the box from the same manufacturer/manufacturing run and they will run “okay” together. Start mixing manufacturers, and you end up with one unit doing all the work if you haven’t speed matched them well.
Just a guess.