Just wondering, do any of you who model the modern era ever operate trains with distributed power? I would think DCC would make this type of operation possible.
Yes, we sometimes do that at our HO scale club. As you say, DCC makes this possible by speed matching locomotive performance.
Distributed power is all under the control of the engineer in the lead unit. A helper is under the control of an engineer in the helping unit. Now what do you want your model? If you gave each unit a different number, then you could control the units separately. I do not think that most modelers are up to this, but on the big train, the engineer could use that rear unit to either string out or bunch up his train. In other words, his head units are MU’s and work as a team, the distributed power works independently at the engineers beck and call.
I have ran DP several times at home and on the club layout, smaller trains it works fine but on the longer trains I would some time get derailments. I suspect it was how the slack action was taking place as it would enter one of the layouts turns but in the real world that is where the engineer would adjust the DP power independently.
I will sometimes run a couple CP AC4400CW’s leading and one at the end of a train but I don’t do it that often.
LION runs six car subway trains. Some with one powered car, others with two. They are always somewhere in the middle. I have no trouble with them fighting with each other. Usually they are in the 2 and 5 spots. All cars are linked with draw bars. If there is one power car it is in the 3 or 4 spot.
LION has no problems with running his trains.
ROAR
Hi,
I run freights with two or three diesels up front and a pusher in the back. After they made it up the helix, the helper gets to run back down the inside loop of the helix while the freight takes the “scenic” route. At the bottom is my main yard, there the engines meet again and I start it over.
My layout is in DC, but there are several power packs power different sections. So it is a matter of flipping toggle switches and also making sure that the engines speed match.
Frank
DCC certainly makes it easier but I used to do it with DC as well. I would put powered units at the head of the train and use a dummy unit as a mid train or pusher unit. That way you wouldn’t have to worry about speed matching or if the lead and helper units were in different electrical blocks if the train stopped. Inexpensive and easy. I realize dummy units aren’t available any longer but they used to be a great option for these types of applications.
I have a 2% grade on the backside of the layout. Occasionally a train stalls on the hill. Instead of crawling under the layout to the access hole, I just pickup another throttle and send an engine around the layout to push the train up the hill. Saves wear and tear on the knees.[:D]
Wonder if the Ring Rail Pro with its 2-way communication between units would make this easier as it does its speed matching within the decoder?
I’ve done it in DC, with both diesels and steam, and also a combination of both. As mentioned, slack action is the variable and it’s minimised the most with locos distributed fairly evenly throughout the train. It was probably easier to operate than multiple locos on the front end or split between front-end power and pushers, but again, that was due to slack run-in and run-out. My layout is mostly grades and curves, so is not particularly well-suited to 70-plus car trains, but it was an interesting experiment.
Most trains are considerably shorter, and get by with simple doubleheading, although some heavy trains occasionally require a pusher, too.
Wayne
Ive only been exposed to DCC a couple years and I find it very easy to run DPU trains with it. As long as your loco’s are speed matched and you have cars with the proper weight you should be fine. I run stack trains with DPU’s, grain, coal, and even manifest with different sized cars. it definitely adds some realism to operations. Distributed Power is becoming all to common on Class 1 trains due to the length and tonnage they want to run. Mid-DPU’s are becoming even more common place in areas where the grade is fairly flat due to the fact that it helps save fuel, or at least that’s what my employer has been doing. The hardest thing Ive found with running DPU on model trains is setting up the marker head light on the DPU. Of course this is simply done with a CV but I’m not that good at programming stuff.
I have found that if you place your DPU units 2/3 the way back in the train you will minimumize derailments. This is due to the fact that the helper (DPU) unit is pushing against 2/3 of the train weight and pulling the 1/3, thus reducing the strngline effect because part f its power is being used to pull the extra weight and not pushing against the trains.