Prototype Pusher - How to Model?

[Rusted]

On lunch break today, I watched a UP freight pull into the Mankato, MN yard - two AC6044s on the lead with another pusher. It was a mixed freight of about 100 cars.

The train was uncoupled at about mid-point on the mainline beside the switching yard. The two on the lead pulled ahead and then backed into and out of several switch tracks, dropping off and picking up cuts of cars. I couldn't stay long enough to see if the pusher was also put to use.

I model this same yard and the same consists. My pusher is an Athearn dummy. I've finally got it rolling freely enough that it creates the desired illusion without causing derailments. At times though, it would nice if the pusher really pushed.

So, I'm thinking, with DCC, would it be possible for someone to program a running mode that responded to the trains performance? Push but never so much that it "pinches" the cars between it and the lead.

Lenz? Digitrax? Are you monitoring?

Would anyone else benefit from a function like this on their DCC?

 

[Gary Pfeil]

Rusted, I'm no expert on DCC, but you have at least two options here. One is to consist locos which all have back emf decoders (speed stabilization). Another is to actually have an "engineer" for the lead units and another for the pusher, with the pusher engineer having to adjust his speed to keep the proper pressure on the train. With Digitrax, which has controls for two trains on each throtle, the two controls can be used to run the lead and pusher locos independently. A while back pete, One of the members here, visited and brought a train utilizing a couple articulated units, used one as a lead and one as a pusher, ran all night with no problem using the throttle in this way. I do not know how often he had to adjust speeds but I had him starting and stopping quite often. So it does work and works well.

 

[sumpter250]

The speed of the pusher had to be constantly adjusted. The big secret about running a helper is basicly, the helper engine should be able to slip before it can push the train off the track.
The articulated locos I was running, are the Heritage series 2-8-8-2. the train was larger than one engine could handle, so if the lead engine stalled, the helper would slip.
I will never use the Rivarossi Allegheny as a helper, when I am running the whole train, because, with the traction tires, it would pile the train up in a heartbeat, if the lead engine stalled. If someone else is running the locos on the point, I would have no problem running the Allegheny as a helper.
So far, this has all been in consideration of running steam. In the case of modern diesels, I would recommend reducing the weight in the "helper" unit. The combined engines can move the train, but the helper would slip if the lead engine stalls. If there is another engineer on the lead, the helper doesn't have to be modified. You just have to pay attention!!!!
I have also run my Bachmann 2-8-0s with one in helper service. They are so closely matched in speed that there hasn't been any problems.........yet.(that's on straight DC)
BTW, Gary's well built trackwork was a contributing factor in the sucessful operation of the helper service. Both units had soundtrax systems, and I ran on independent throttles, so I could "whistletalk". It was definitely neat to have the train go by, hearing the lead engine, and then hearing the helper when it passed by. The two engines could be consisted together with no problems. I have run them that way, but then I can't operate the helper's whistle.
On the club layout, I have used a Rivarossi D&H Challenger(w/ traction tire) as a helper. Pushed a string of ore cars, with a Bigboy on the point, up one of the steeper grades, around one of the tighter curves. I wouldn't recommend trying to do that all day.
Pete

 

[marty w.]

Originally posted by sumpter250
It was definitely neat to have the train go by, hearing the lead engine, and then hearing the helper when it passed by. The two engines could be consisted together with no problems. I have run them that way, but then I can't operate the helper's whistle.

Pete-
I have done the same. I have found that if you are using a Digitrax system and a DT400 throttle you can consist both loco's and still operate the whistle on the helper. Consist them as normal with the lead or "top" loco on the right knob then MU the helper which will be on the left knob. Do not select another loco for the left. The right knob will control the consist. Whenever you what to operate the helper loco (the left knob) select it, then you can control the whistle, horn, lights only. Then you would select the right knob to control the speed of the consist and the whistle, horn, lights for the lead loco.
As you said if the two loco's are matched in speed it works great.
Thanks for the tip on the helper must "slip". Never thought of that.
So as you can see Rusted it does work and there are a few ways to do it.
Marty

 

[sumpter250]

if you are using a Digitrax system and a DT400 throttle

But,,, if all you have is a DT100 throttle.........besides, I don't have to "unconsist" to use the helper for switching, and I'd rather spend the price of a DT400, on another shay!
Pete

 

[brakie]

At the club I go to we use a helper on DC.This is very easy to do.The train stops in the next block,the dispatcher lines the block for the pusher engineer,the pusher engineer runs the helpers out of the helper pocket and couples on to the caboose,then off they go,the DS keeps lining the blocks for the pusher as the lead engine clears the block ahead of the pusher. Believe this or not it is very easy to do. Now if the DS forgets (very unlikely) to line the block for the pusher the lead engineer will run the pusher as he runs the lead units.

I use the DT300 throttle and have ran a local with engines on each end of the train,this is not very hard to do. I address one unit and let it start taking up the slack while I address the 2nd unit. The DT300 has 2 control knobs and I use both to control the units.Again not hard to do.

 

[MCL_RDG]

An obtuse response (due to technical/mental) difficulties.

The point of modelling a pusher service is to emulate a situation where heavy tonnage is being shoved up long grades (generally- no nitpicking here).

Choice of locos to "help" are the operators resposibility. You are the engineer and should know what equipment you have to get "that thing" up and over. To me that means selecting appropriate equipment that plays well with others- or as the girlfriend would say, well forget what she would say, it'd be an argument.

Despite the rude bucking on occasion of different locos pressed into service in tandem with several other locos (sans DCC) providing pushers is a rare event for model railroaders. An unpowered unit pushing??? What is it supposed to do when it reaches it's cutoff?

Power baby! Power!

I realize you're perhaps trying to model a particular train/event and I know nothing of DCC yet. I feel sad for the poor little loco with no gogo.

Have we forgotten? I once ran a 200+ car train with Blake at a club we belonged to. 5 lead engines, 120 cars, 2 mid-train helpers, 80+ cars and a pusher on the end. All Athearn equipment. No DCC, no computers, no club rules, no nothing. We just did it. Because.

Okay, I feel much better now.

Thank you,

Mark