running multiple engines on DC rails

[themissingpage]

I have been trying to run multiple GP40's on my layout from the start. I have a relatively short manifest however I really like the look of 3 loco's. I have speed tested and matched them, and have also upgraded my controller for higher output. The problem is that they run good for several weeks and then one of them will start dragging the other one down. How can I correct this problem so I can run more than 1 loco and pull my full manifest of 16 cars which includes a track cleaning car?

[jonathan]

I can share my experience, being aware that I could be wrong.

I doublehead my locos all the time. My favorite way to operate. If the locos are identical, it makes it that much easier.

I have dabbled with tripleheading. I found that with DC, things tend to heat up a bit and I don't get the extra power I was expecting. There may be a diminishing returns thing going on there. As you stated, you get away with it for a while, but it doesn't last.

However, when I run DCC, like the club's traveling layout, I can triple head all day long. I particularly like running my F units in A-B-A fashion. The extra volts and amps probably make the difference. Some club members will even doublehead and add a helper loco at the end of their train. Braver than me.

Just a guess but I think DC configuration in general can only provide a limited amount of volts and amps. Tripleheading may be at the edge of that limit.

Regards,

Jonathan

[themissingpage]

Thanks Johnathan, but switching over to dcc is not an affordable option right now. I did discover that running a dcc equipped loco (bought separately) on my layout was one of the problems I was experiencing. It eventually burned up the decoder so I gutted it and basically made it a dummy loco (or rolling stock). I bought another identical train set, added it to the manifest, and purchased the larger controller (MRC Tech 7), 18-23 volts, 2 amps). All worked well until recently. I sent out a request for help on a model RR group site I joined, and after checking several suggestions on troubleshooting, I found several sections of loose track that was intermittently losing power (I never secured it or ballasted it because it is hidden inside the tunnel), and further investigation revealed an intermittent short in the dummy engine where the pickup wires were grounding on the frame. I made repairs to the track and isolated the wires in the engine. The train has been running well since then with no overheating issues in the controller or either of the 2 power units. Thanks again for your response.

[Trainman203]

Short easy answer:  DC operation does not have motor control fine tuning allowed by DCC.  The best multi unit diesel operation is achieved the old fashioned way:  dummy units.  You can get non operational engines for nearly nothing, remove the motor and gearing, and have instant trouble free multi unit power. Many model engines are vastly overpowered anyway and shouldn't have any problems pulling layout-sized trains.

[rich1998]

I go with Jonathan.
I have run ABBA in DCC quite well.
Edit.
I should have mention, years ago I gave up trying to run them in DC.

Rich

[themissingpage]

Thanks, but if you read my post changing over to dcc is not in the budget, and as I further posted, I solved the problem in both the dummy engine and the track issue. Both of the actual power units are pulling well again.

[redvdub1]

I'm glad you resolved your problem with some repair because you shouldn't have any problem with double
heading in DC or DCC with a 16 car train plus track cleaner.  I double head like that all the time.  I do have one pair of engines (Stewart AS-616s) that will run 20+ cars fine for about 2 hours and then they will just slow down and quit.  It's a temperature problem...the motor/electronics just crowd all the space such that air cannot circulate naturally.  After a cool down (20 minutes or so) they run just fine again.  I plan to (hah) open up some of the air fan moldings to let a little air circulation occur and maybe solve this (little) problem. 

[jward]

So your Baldwins break down just like the real ones did?

[Trainman203]

😂😂😂

[nfmisso]

Years ago, I used to double head a Mantua/Tyco 2-8-2 and 2-8-0 all night long at the club layout at the UIUC.  They both had the original open frame motors, and totally stock drive trains.  The club had more than adequate power supply, but a previous club member (graduated long before and gone) had used 24 ga. telephone wire for power runs.  20 feet from the power supply, on the steep grade, they would stall out while drawing 1½ amps*.  Just too much resistance in the circuit.  The layout was DC block control - long before DCC came about.

Moral: make sure that you have adequate power, and adequate wiring to support the current loads required by the locomotives.  For DC operation, a voltmeter and ammeter are practically required.

* One locomotive would make the grade by itself, drawing an amp to do it.