Articulated Loco with only One Engine Operational

[beiland]

In general the articulated locos are made up of 2 engines, one in the rear 'truck', and one in the front.
Often in our model trains there is only one actual motor, then some sort of linking drive shaft, often a flexible tubing that allows the articulated bending.

When reconditioning/refurbishing some of the older models and some of the brass models, extra efforts have to be 'invented' to make these two engines operate better together, and with less noise from the drive shafting, etc.

I believe I ran across a rebuild posting/subject thread that ask, ....'why not just let the front engine go unpowered'? The modeler seemed happy with the results. Can anyone find such a subject thread/posting??

 

[trailrider]

A while back, before the Mantua loggers came out, I wanted an articulated, but couldn't afford any of those brass ones. I took a couple of Mantua 2-6-2 Prairies and spliced them together. The problem with making the front engine powered was the screw that held the rear engine to the stretched plastic boiler, also held the rear cylinders, and there wasn't any convenient way to power the front engine. In addition, there was no gearbox that could be attached to the front engine either. The motor was the original open-frame job that angled down and connected directly to the bull gear. I weighted down the front engine so it would track well. Tractive effort wasn't bad with a traction tire on one of the rear engine drivers. I did three of these. Don't know about a thread. If I get some time (ha! ha!), I'll try to post some pictures.

 

[beiland]

Sounds like you created an interesting articulate !

 

[Colorado Midland Modeler]

I've never seen a thread anywhere on leaving the front set of drive wheels unpowered, (I don't see any reason why it couldn't be done, other than a loss of pulling power. I'd imagine all you would have to do is remove the drive shafts to the front truck and and remove the gear box and worm gear for it.) but if you're interested, I did run across something awhile back on another forum about doing double motors in Rivarossi articulateds so that both sets of drivers could be independently powered. I don't know if it could be done in other makes or smaller articulateds, but I do have a screenshot of what it looks like.

 

[beiland]

Can you explain where you got that screen shot from? Was there any text that with along with those images?

There is NOT a stock Rivarossi in those photos. Stock Rivarossi(s) did not have motors like those.

BTW I once did a double motored Riv articulate. Had to make sure the motors were exactly the same.

 

[roadbear]

Beiland those are not stock they were reworked by Mel Perry did those years ago here's his blogger site for more info

He passed away June of 22 I had many discussions with him back in the day

https://melvineperry.blogspot.com/p/blog-page_15.html

 

[beiland]

Wish i could have found his actual remotoring projects?

 

[beiland]

BTW, this posting over on another forum is what brought up this question of mine,...leaving off power to the front engine to simplify things,

PFM 2-6-6-2 Sierra - Major Mechanical Modifications

About two years ago, I picked up a PFM Sierra 2-6-6-2 in mint condition. This model used a spur gear drive to power the gearbox and forward driveshaft to the front engine. Incredibly noisy. Not acceptable if I was going to go to the trouble to install a sound system . I recently acquired a...

forum.mrhmag.com

About two years ago, I picked up a PFM Sierra 2-6-6-2 in mint condition. This model used a spur gear drive to power the gearbox and forward driveshaft to the front engine. Incredibly noisy. Not acceptable if I was going to go to the trouble to install a sound system .
I recently acquired a Samhongsa high/low gearbox set that was sold as a conversion part other locomotives. My first installation was in the conventional locations for the Sierra, which had the main engine gearbox on the lead axle and the articulated engine gearbox on the trailing axle. This created to sharp an angle between the gearboxes and made the very short driveshaft unreliable. After putting it away for two years, I finally had the chance to work on it in the days following Christmas.
This was major surgery that involved soldering the main engine valve gear hangars to the frame with reinforcing brass strips soldered inside the frame to the hangars, then cutting away the transverse brace between them. This made room for the gearbox on the middle axle of the main engine, lengthening the drive shaft to the articulated engine and dramatically reducing the angle between the two gearboxes. The bottom plate of the main engine was similarly revised to accommodate the new location of the gearbox, soldering in a new section to cover the old gearbox location on the plate, and adding an second lower crossbrace between the frames just behind the middle axle to better secure the bottom plate to the frame.
The result of all of this is a much quieter and smoother-running locomotive that will now go to the paint shop prior to installation of a long-awaited Tsunami 2 sound system.
By the way, that square can motor was purchased on eBay for about $2.00. It was intended for adjustable automotive outside rear view mirrors. Very low current draw, powerful torque at somewhat lower speeds than most motors. But these Sierras were not known for speed - just strength!

The fellow did a VERY nice job of repowering his engine, I just questioned the amount of effort it took.

 

[Espeefan]

I've worked with articulated steamers for a number of years, mostly brass. I have one model where one of the "engines" is unpowered. It's this AM-2 4-6-6-2, and old Balboa model:

The rear engine is not powered. it just rolls along for teh ride. I'm in the process of re-motoring it prior to painting. There are two issues: Room for an adequate can motor. With only one set of drivers providing power I'm afraid she won't pull much besides herself. Interesting model, but no long trains are in its future without assistance, maybe a stealth powered box car or something similar.

 

[beiland]

Hi Alan,
i assume that brass loco does not have any traction tires?
When you said only one set of drivers providing power were you speaking of only one wheel set, or one engine set of 3 axles??

Are you aware of my experiments with pusher-helper express freight cars pushing totally dead steamers?

B

Post in thread 'RTR powered freight/reefer 'pusher' car'

Sep 20, 2025

Santa Fe Mechanical Refrigeration Pusher Car

I happen to have 2 SF steam engines that could use a little help,....a Heritage 2-8-8-2, and a Bachmann 4-8-4.
Here is my choice for a pusher-helper refrigerator car for those SF locos,..







I have a couple of versions of that mech-refrig car's shell,...and its 'refrigeration' is spelled out on the other...

• beiland

• 

 

[Espeefan]

Hi Alan,
i assume that brass loco does not have any traction tires?
When you said only one set of drivers providing power were you speaking of only one wheel set, or one engine set of 3 axles??

Are you aware of my experiments with pusher-helper express freight cars pushing totally dead steamers?

B

Post in thread 'RTR powered freight/reefer 'pusher' car'

Sep 20, 2025

Santa Fe Mechanical Refrigeration Pusher Car

I happen to have 2 SF steam engines that could use a little help,....a Heritage 2-8-8-2, and a Bachmann 4-8-4.
Here is my choice for a pusher-helper refrigerator car for those SF locos,..







I have a couple of versions of that mech-refrig car's shell,...and its 'refrigeration' is spelled out on the other...

• beiland

• 

I've probably seen that thread, and the concept has been around for a long time. The Coach Yard made powered passenger car trucks that could be installed in passenger cars to provide extra oomph, and others have done what you did as well.

As to your questions about my model: No traction tires. I've never seen a brass loco that has them, and I've seen quite a few!

The front "engine" (three sets of drivers) is powered. Even if I could figure a way to get the rear engine powered it is not connected to the boiler by any sort of suspension, so I wouldn't be able to get any locomotive weight on those drivers without extensive modification to the rear engine frame and the boiler. Considering this is a Balboa "Master Series" and a relatively rare model I have decided not to risk extensive mods I've never tried before. She can do cab hops or maybe short passenger trains of plastic cars. By SP standards this design was a failed experiment. They were all gone by the end of WW2. It has an interesting history though and is a good-looking piece. I'll try some "Bullfrog Snot" and see of that helps when the time comes.

 

[Colorado Midland Modeler]

Beiland those are not stock they were reworked by Mel Perry did those years ago here's his blogger site for more info

He passed away June of 22 I had many discussions with him back in the day

https://melvineperry.blogspot.com/p/blog-page_15.html

Yes, that's one of his photos, but I couldn't remember his name. I think I got that photo from Model Railroader Magazine's forums, but it's been in my files for such a long time that I'm not sure if that's where it came from.