Multiple "Helper" Locos - DCC Question

Model Railroader Electronics and DCC
1

Hello everyone,

I’m starting to prep my collection of HO model equipment for operation. The layout I am looking at operating them has some moderate grades, and all of the locomotives I have are Bachmann steam locomotives; they are good on level track, but have poor pulling power on grades. I am looking at getting a pair of helper diesel locomotives to operate with the consist (which is about 12 passenger cars long) so they can make it over the steep grades. I have two questions:

  1. Can anyone recommend a brand of HO diesel locomotives that have good pulling power that I could use as helpers?

  2. The layout I will be operating on is DCC. Will I have any trouble getting the diesels to match the speed of the steam locomotive during operation? Is this a feature of the DCC systems?

Thanks for your help!

Matthew

2

It isn’t so much the brand that makes the difference as other factors. Different models do better than others irrespective of the brand name issuing them. So, it’s hard to answer your question without knowing which models you’re likely to want to consist with the steamers. Atlas makes good early diesels, but so do BLI and Intermountain.

You can speed match any DCC locomotive with any other, barring some minor problems with BEMF sensitivity or flawed drive characteristics inherent in the model regardless of whether it is fitted with a decoder or not. A bad mechanical system won’t be improved with a decoder. So, if you have two or more mechanically sound models, each with a decoder, they can be speed-matched. It just takes method and time. And yes, this is a feature of DCC and the systems that operate that way. However, some here still are very heavily invested in DC drives and don’t seem to have problems with speed-matching.

3

Hi Mathew,

Instead of try to speed match the diesels to the steam locomotive, run the diesels on a separate throttle. There was no MU capability between steam and diesel during the transition period so you needed engineers for both. Very much prototypical to have 2 engineers for a train in that period.

As was previously said, you can speed match them but it will take alot of time and effort.

Scott Sonntag

4

For some reason, a lot of people apparently do speed matching by using a speed curve and changing a couple of dozen CVs. If you set your decoders to have a straight line curve (or more accurately, leave them that way, since that’s how they come from the factory) you can usually speed match two engines using CV2-5-6 in about five minutes. Then you can use CV3-4 to set the momentum so they get up to speed and coast to a halt the same. It’s really not that hard or time consuming.

5

When you speed match pairs of groups of locomotives, WRITE DOWN whatever CVs you set. You may not want that same set of parameters when running those same engines alone. Write down what you started with, too.

To be prototypical, I think you should try this first with just steam engines. Forget the diesels. Do you have enough steamers for this?

Another possibility is Bullfrog Snot, a rubbery substance that acts like traction tires. This might make helpers unnecessary. I don’t know your rolling stock, but if you are using older cars with plastic wheels, consider switching to metal wheels which will give better performance and let the same engine pull more cars.

6

Hello All,

I run Bachmann diesels and a couple of steamers; USRA 0-6-0 with a Vanderbuilt tender and a 0-4-0 Dockside Porter.

All have Original Equipment Manufacturer (OEM) Bachmann decoders, all non-sound.

The problem with Bachmann is their OEM DCC decoders- -both the drop-in PCB types or the NMRA 8-pin compatible.

Bachmann non-sound decoders do not support the Configuration Varriables (CVs) that are necessary to successfully speed match- -CVs 5 and 6 (V Mid [6] & V Max [5]) or CV 21 & 22 for consisted function controls.

My DCC pike has a dedicated programming track through the cab. I also use JMRI Decode Pro linked to my Mac with a Digitrax PR3 to a separate programming track.

I have two sets of Multi-Unit diesel consists with Bachmann decoders. One set is four GP40s and the other set is three GP30s.

Yes, these will consist with basic or universal consisting but they don’t support advanced consisting or, as mentioned, speed matching.

If you are freelancing your pike you can augment your steam motive power with diesel on steeper grades, but speed matching might not be possible and cause more problems than it’s worth with the Bachmann OEM non-sound decoders.

Prototypical railroads, in the steam era, did double- and triple-head steam locos before the advent of diesel power.

Have you tried this on your grades with the motive power you currently have in inventory?

I admit that I don’t know much about steam locomotives. I suspect, depending on the type, they might be better MUed with each other than with diesels, if the decoders do not support speed matching and/or advanced consisting CVs.

The “best case practice” would be to replace the OEM Bachmann decoders with others that support the needed CVs for speed matching and consisting. (I have a cow an

7

[#welcome] to the forum. Your intial posts are delayed in moderation.

No one has suggested adding weight to your locos? Bachmann steam is actually quite popular among many members here. Doctor Wayne has written many times about adding weight.

Unfortunately the forum software is obsolete and the search (and other functions) no longer work. You will have to use google.t

This search add weight site: cs.trains.com doesn’t return the most recent discussions. You might play with the search terms before “site: cstrains.com”

As stated above, Bachmann decoders leave a lot to be desired