# Multiple DC engines



## Hesh (Dec 11, 2017)

I'm gathering my stuff for a retirement layout that I've been schlepping around N gauge trains, track, buildings, transformers, etc. for close to 30 years now. All my "vintage" stuff works including my Controlmaster 20 transformer.

I'll be building in a layout once I understand what I want and for now I am using four 8' tables to explore options. My runs are a little over 50' for now and larger later.

I like very long trains and as such I need multiple engines to pull them.

Would folks be so kind as to share some guidance for using multiple engines on a DC configuration with long trains please? For example which engine is the first one, second, etc? Do I check them against each other to determine who's superior in speed, pulling capacity etc?

Any down side to running multiple engines on DC transformers, I know I will be using pretty high powered ones?

I know many of you are DCC fans but I am specifically going DC because I would like to do something not involving micro processors. I was a systems analyst and programmer all my life and it's the last thing I want to do in my retirement....

TIA (thanks in advance not this is Africa)


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## traction fan (Oct 5, 2014)

*Multi-engine running*



Hesh said:


> I'm gathering my stuff for a retirement layout that I've been schlepping around N gauge trains, track, buildings, transformers, etc. for close to 30 years now. All my "vintage" stuff works including my Controlmaster 20 transformer.
> 
> I'll be building in a layout once I understand what I want and for now I am using four 8' tables to explore options. My runs are a little over 50' for now and larger later.
> 
> ...


Hesh;

When running multiple engines with DC, the fastest engine should be the first one in the consist, the second fastest should be second, etc. Speed is the determinant factor. Pulling power will be collective for the entire engine consist, and the pull of individual locos won't mater as far as placement is concerned.
If the fastest loco were second, third,etc. it would tend to put some of its effort into pushing the other engines, rather than using it all to pull the train. Besides wasting some pulling power, this pushing action can sometimes cause uncouplings, and derailments.

All the wheels on all the locos should be clean, and all of the mechanisms clean and lubricated for their best performance. Since these locos are about thirty years old, the original grease from the factory may well have congealed, and hardened. The loco's mechanisms really should be disassembled, have all of their parts cleaned with alcohol, then be LIGHTLY lubricated with plastic-compatible oil, or grease. (Labell is one firm that sells both) One drop of oil, or one tiny dab of grease, on each worm gear is all that's needed. Running the loco will distribute the lubricant, in a thin layer, where it's needed.
After this maintenance is done, you can do speed tests. Put all the locos you plan to use in the consist on the same oval of track. Then turn on the power and watch them run. The faster locos will catch up with the slower ones, and you can select which one to put first, second, etc.

Thirty year old N-scale locomotives are not going to perform like current production locos do. They are in very different quality classes. The old ones typically have higher current; three-pole motors, no flywheels, and overly fast gearing.
Today's typical diesel has a low current; five-pole motor, two flywheels, and a lower gear ratio. These features all add up to superior running, especially at low speed. You might consider gradually phasing out the old engines and replacing them with the much better-performing new ones.

The only concern with running multiple DC locos on a power pack is not to exceed the current that the pack is rated for. You can check this with a multi-meter, set for amps, (current) and hooked up in series with one of the wires from the power pack to the track. With all engines going, the meter reading should be less than the maximum current rating printed on the power pack.
If the pack is old, and cheap (especially if it came as part of a train set) It may not be able to handle multi-loco operation. Also some of those old cheap packs had pretty poor speed control. You might consider a newer power pack that has transistors in it for better performance, and get one with a one, or two-amp current rating. Such packs are common on e-bay. 

good luck, and have fun!

Traction Fan:smilie_daumenpos:


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## Hesh (Dec 11, 2017)

traction fan said:


> Hesh;
> 
> When running multiple engines with DC, the fastest engine should be the first one in the consist, the second fastest should be second, etc. Speed is the determinant factor. Pulling power will be collective for the entire engine consist, and the pull of individual locos won't mater as far as placement is concerned.
> If the fastest loco were second, third,etc. it would tend to put some of its effort into pushing the other engines, rather than using it all to pull the train. Besides wasting some pulling power, this pushing action can sometimes cause uncouplings, and derailments.
> ...


Thanks much Traction Fan! That tells me what I needed to know.

The locos that I want in a "consist" are both new Katos of the same model, different number. I suspect that it makes no difference if the second one is running backwards just so it's testing as the slower one running backwards?

Right you are on the older ones needing disassembly, cleaning, very light new lubing with plastic safe oil. That made a difference when I did it at someone's recommendation here.

Thanks again.


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## CTValleyRR (Jul 26, 2014)

Hesh said:


> The locos that I want in a "consist" are both new Katos of the same model, different number. I suspect that it makes no difference if the second one is running backwards just so it's testing as the slower one running backwards?


Actually, it makes all the difference in the world. With Digital Command Control (DCC) you can set up the loco to change which way is forward. You can't do that in DC -- the polarity of the electricity in the rails determines which direction your motor turns, thus which direction the loco travels. You will have to align your locos so that they are both traveling in a "forward" direction, or actually swap the motor wiring to make it run the opposite direction.


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## Bwells (Mar 30, 2014)

CTValleyRR said:


> Actually, it makes all the difference in the world. With Digital Command Control (DCC) you can set up the loco to change which way is forward. You can't do that in DC -- the polarity of the electricity in the rails determines which direction your motor turns, thus which direction the loco travels. You will have to align your locos so that they are both traveling in a "forward" direction, or actually swap the motor wiring to make it run the opposite direction.


Are you sure about that?


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## traction fan (Oct 5, 2014)

*I don't think so*



CTValleyRR said:


> Actually, it makes all the difference in the world. With Digital Command Control (DCC) you can set up the loco to change which way is forward. You can't do that in DC -- the polarity of the electricity in the rails determines which direction your motor turns, thus which direction the loco travels. You will have to align your locos so that they are both traveling in a "forward" direction, or actually swap the motor wiring to make it run the opposite direction.


Ctvalley;

Since were using only verbal description, I'm going to arbitrarily designate one direction of travel along a model train track as "west" and the other as "east."
If you put say, a DC diesel F-unit on the track, with it's cab facing "west" and set the direction switch for "west"; the loco will move, cab-first, to the "west." If you then pick up the F-unit and place it back on the track with it's cab facing "east", leave the power pack's direction set for "west"; and turn on the track power, the F-unit will still travel to the west, but this time back end first. 
So, running multiple units with the lead unit cab-first, and the trailing unit back first, they will both run in the same direction. No rewiring of motors is normally needed.

regards;

Traction Fan:smilie_daumenpos:


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## traction fan (Oct 5, 2014)

*You are correct*



Hesh said:


> Thanks much Traction Fan! That tells me what I needed to know.
> 
> The locos that I want in a "consist" are both new Katos of the same model, different number. I suspect that it makes no difference if the second one is running backwards just so it's testing as the slower one running backwards?
> 
> ...


 Hesh;

You're right. The locos should run in the same direction along the track regardless of which way either of the locomotives is facing. If you ever run into a case where the two locos move in opposite directions from each other on the same track and direction switch setting; then the motor in one of them is actually wired backwards, as CTValley mentioned. This is very rare. Virtually all DC locos have the same direction of travel from the factory. If you find one that's backwards it usually means someone has had the motor out, and accidentally put it back in wrong. 
There are some "Murphy's Law" oddities. One is that model steam locomotives (and some diesels too) run more smoothly in reverse than they do moving forward. As a corollary to the steam locomotive problem, Cab-Forward locomotives, like those used by the Southern Pacific will run best with the cab trailing. :laugh: This sort of frustrating behavior is particularly common among old locomotives.
You say you have two fairly new Kato locomotives. That's great. Kato makes excellent products, and if the locos are new, they likely have the 5-pole motor, dual flywheels, and lower gearing, I mentioned. They should run very well. 

Have fun!

Traction Fan:smilie_daumenpos:

PS. I don't know your model railroad experience level. The files below are primarily aimed at relatively new modelers. If you wish, have a look through them at your own convenience, and see if they have anything that will help you build that retirement layout you're thinking about. If they are stuff you already know, just ignore em! :laugh:

View attachment How to better model railroad the first time. Part 1.pdf


View attachment How to build a better model railroad the first time Part 2.pdf


View attachment How to build a better model railroad Parts 3 & 4 benchwork and more track planning.pdf


View attachment How to build a better Model Railroad part 5.pdf


View attachment How to build a better model railroad the first time 6.pdf


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## Hesh (Dec 11, 2017)

Great information everyone, thank you!

A follow-up question if I may please.

I've noticed that modern engines seem to crawl more slowly and reliably than the 20 - 30 year old models that I have. A good thing and something that needed improvement IMO.

My last concern about a multiple loco consist is is there any risk of damage to an engine when a multiple engine consist is crawling and one engine is not as efficient crawling at very low speed as the other and stops? 

Thanks again.


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## Hesh (Dec 11, 2017)

Also thanks again to Traction Fan for the posted resources, they are great - thank you!


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## CTValleyRR (Jul 26, 2014)

Bwells said:


> Are you sure about that?


You're right. Been using DCC too long. Polarity would be polarity, no matter which way the loco was facing.

Now go away while I eat my large slice of humble pie...


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## traction fan (Oct 5, 2014)

*Dead head locomotive*



Hesh said:


> Great information everyone, thank you!
> 
> A follow-up question if I may please.
> 
> ...


 Hesh;

The situation you describe, where one engine is stopped, is a much more extreme version of the "slower loco up front", scenario we talked about earlier. The engine that was not running would act as a very powerful brake and probably stop the train. The worm gears in our model engines don't allow the wheels to free roll like those of a freight car do. The engine's wheels are locked in position and drag along the rails, if the train can move at all.

The situation of a dead model engine in a consist is pretty rare, but it's one reason for not mixing new, and old, model engines. Since the gearing is different, the two don't tend to work together smoothly. The old engine has a much higher (too high really) minimum speed. This may well make it switch from helping to hindering the movement of the train; when you try to run slowly. I suggest using either all new, or all old, engines at the head end of your trains.

regards;

Traction Fan:smilie_daumenpos:


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## traction fan (Oct 5, 2014)

*pdf files*



Hesh said:


> Also thanks again to Traction Fan for the posted resources, they are great - thank you!


Hesh;

I'm happy that you liked the files I sent you. If you want more info, check out our "Beginner's Q&A" section. It has lots of good info from many different modelers, including more of my stuff. Open the first thread, titled "Help a new modeler to get started." My files are there, along with info contributed by other modelers.

regards;

Traction Fan:smilie_daumenpos:


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## Hesh (Dec 11, 2017)

Will do TF, this is a GREAT forum!


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## rrjim1 (Mar 12, 2015)

Hesh said:


> Great information everyone, thank you!
> 
> A follow-up question if I may please.
> 
> ...


Even with modern locos you will still have problems with trying to run locos of different brands in DC. Kato locos still use there old school high speed motor and run faster at the same voltage as most all other brands. I have replaced most all my Kato locos motors with the better running Atlas scale speed motor. Doing this allows me to run Kato loco with other brands very easy. You can place the locos you want to run together on your track about 1 foot apart and run them to see how much faster one is than the other. If one catching the other in a few feet I would not run them together. Really won't hurt anything you'll just wear the wheel out on the faster loco over time.


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## CTValleyRR (Jul 26, 2014)

Now I DID think this answer through before providing it: 

If you're going to run a dead loco as part of a consist, pull the drive train so that the wheels roll freely, and it isn't a bad idea to remove the power pickup brushes to exclude the possibility of a short across the motor or frame. 

On the other hand, if you really want great low speed performance, have another look at DCC. I routinely tweak my locos so that they just barely crawl in speed step one. Very satisfying!


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## dbwr (Feb 11, 2018)

Old thread, but - hey, funny story.
In high school (long ago) 3 of us built an HO layout
with 2 4'x8' sheets of plywood. Made a nice long straight
away. Next we needed a power supply. My dad (ham)
had lots of left over parts: giant 12v CT transformer that
likely had 50 amp capability, 20 amp bridge rectifier, 
filtered with giant electrolytic capacitor 1 f (1000 mf).
Lots of power potential. Needed it, since we liked big
(unprotypical) power. I had 3 DD35 twin motors and a 
pair of FP-45. Get a nice long train ready for virgin run...
big ol' rheostat for delivery. Ready ? ... go ... 
This 12' + train with many engines began to roll ...
nice and slow. Tad more power - nice...... DERAIL !.
What happened. Can you guess ? ... brass rail melted.


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