Several weeks ago i started this new subject thread over on MRH forum.
A little over a year ago I discovered these 2 Roco steam engines in my inventory.
bought a couple of Roco steam engines a few months ago,....to run some experiments with my 'pusher/helper' ideas. It's opened my mind up to a new way to design steam engines, not only European ones, but even our American models.
First thing I did was take the engine portion (boiler,drivers,et) out of the box and put it on the track. It was amazing rolling this engine along the track,..silky smooth,..no binding whatsoever of the connecting side rods, and of course being without a motor,..no resistance from any gearing.
Then I tried rolling it thru a curve,..an 18" r one at that! This 2-10-0 loco (5 big drivers) ran just as smooth thru that curve as it had on straight track...
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Even with its tender it could negotiate the 18r inch curve
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I repeat, "It was amazing rolling this engine along the track,..silky smooth,..no binding whatsoever of the connecting side rods, and of course being without a motor,..no resistance from any gearing"
And what was more amazing is it pulled a LONG train of freight cars by itself !
I have now pushed a Mantua 2-6-6-0 succesfully.
And I have now pushed a Broadway Ltm 2-8-8-2 succesfully.
Have a look thru this rather long subject thread, where i document this, and fend off a number of naysayers,...
https://forum.mrhmag.com/post/is-it-possible-pushing-an-unpowered-articulated-steam-engine-13635241
I need some more articulates to run experiments on,...and the thought occured to me that Bachmann might have a number of warranty engines I could utilize in my further experiments?
I posted this request on several different websites,..
Is there anyone out there that has an articulated steam engine they have given up on.??
I'm looking to run some experiments on 'tender powered pusher'...
I would be stripping out the motor/drive system in the boiler portion, and building a motor/drive system in the tender,..
to show folks that you could have a tender powered articulated steam engine
Regards, Brian Eiland,...railandsail
Not articulated, but Tyco came out with a tender powered 0-8-0/2-8-0 back in the 70's. Essentially they stuck in fairly heavy, relatively speaking, power truck from one of their diesels in the tender and it pushed to loco along. As long as the loco is free rolling, there should not be any reason for something similar to work with an articulated loco.
Len
One thing that tender powered steam locomotives did was tend to rotate to one side with the momentum of the motor at start.
This is not a new idea. Bachmann did it with their own old time 4-4-0, so did AHM back in the Jurassic, and there was a particular old fashioned light 2-8-0 that had it, the brand I cannot remember.
The 2-8-0 was Tyco. They also did the same loco as an 0-8-0 by removing the pilot truck. It's the loco that came in their "Chattanooga Choo-Choo" set. The difference from the 4-4-0 locos was the drive mechanism. The 4-4-0's used a drive shaft between the motor in the tender and gears in the loco. The Tyco 0-8-0/2-8-0's used a motor assembly from one of their diesel locos in the tender to push the loco along the tracks. There was no drive shaft connecting the two.
Len
So who might i ask if Bachmann would have an old articulated loco without a working motor nor driveline to use in verifying a pusher mode is possible.
I seem to have a LOT of naysayers to being able to do it with a variety of existing articulates.
Design Considerations to Build a Cheaper Articulated Loco
https://forum.mrhmag.com/post/is-it-possible-pushing-an-unpowered-articulated-steam-engine-13635241?highlight=design%20considerations%20build%20cheaper%20articulate&pid=1342697234
What if Questions? I want to compose these questions by looking at how one of the better (best) production articulates might have a runner-up product at a much cheaper production cost.
The Broadway Limited 2-8-8-2 is a marvelous creation of design engineering & build quality. I love mine, but for one fault,..later.
Its a pretty heavy engine with its boiler and truck frames built of casted metal. My first question is it cheaper to build these parts of cast metal rather than plastic injection? We do know that the heavy loco will have more traction power, but do we need that sort of traction power on an un-powered articulate?
Could the un-powered articulate have a plastic shell with the extra weight disposed into its voluminous interior via traditional lead weights? Perhaps the trucks themselves could be metal to assist in tracking well?
The BLI trucks are marvelous creations, but I think the un-powered version could have a much simpler design,...like these mentioned above
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simply straight axles laid into simple full or partial bearings,...and of course no need for that gear.
Here is the BLI truck,..
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.......twin traction drivers, spring suspension, and somewhat complex bearing boxes.
No wonder this loco has so much pulling power, its got 2 traction tires per truck,..4 in all. Of course we all know how much traction tires are adored by many members??
Those axle bearings are both complicated in their shape, and a complicated retainer shape needs to be provided in the truck frame.
I'm really beginning to question spring suspension, ....more so in such a short in-line driver configurations we see with 3 or even 4 drive axles per truck?? And if still desired, could we use a single spring located at the center of one axle on the truck?
Look at what is crammed into the boiler section of that BLI loco,..
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And its a job to get the top portion of that shell down over that and screwed into position. Let alone there is no boiler barker nor other primary speakers in there. There is no keep-alive, etc.
What if that motor and its gear towers were to be removed from that boiler and put into a pushing tender?
And last, how about servicing? It turns out BOTH of the drive gears in mine are cracked,..
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Can you imagine what a headache it is going to be to replace them !!
I don't think anyone has said nay, but rather articulated (no pun intended) the history of tender mounted motors.
I seem to remember another instance of tender mounted motors, and that was one of the very early iterations of Athearn's Pacific way back in the early 1960s. I've only heard about it, I can't speak to its success or failure.
I would think there would be no reason that a steam locomotive tender containing a motor, driving the tender trucks just like diesel trucks, could be successful. The only challenge might be getting enough weight in the tender if there wasn't much room, depending on the tender and the motor chosen.
I am more concerned as to why a high end loco like a Broadway Limited has traction tires. Those are the hallmark of a cheaply constructed loco where the designers attempted to overcome it being underpowered by using rubber tires on the wheels. A properly designed and weighted locomotive does not need them to pull a respectable train even on grades of up to 4%. This is especially true now that free rolling freight cars have eliminated most of the drag in the train. Traction tires on a high end locomotive would make me lose interest in buying that locomotive.
As for the tender drive idea, I think it has some merit. The best pullers I have are Atlas diesels, with 4 or 6 wheel trucks. Their basic design is similar to a tender, and you should be able to design a solid drive to fit. The only major change would be adding gearboxes to the shorter wheelbase tender trucks (as opposed to diesel trucks) but maybe a modified N scale gearbox would work. Those are far smaller than what we usually work with in HO, but you'd still be able to get the necessary gear reduction even in the smaller space. This would take some engineering to do, something far beyond my capabilities.
This is the tender drive Tyco 0-8-0/2-8-0. You can see the diesel drive mounted in the center of the tender, with leading/trailing wheels mounted on pivots to give the appearance of 4-wheel trucks under the tender. The cam between the third set of 'drivers' was to give a puff effect to the smoke unit. ETA: Power pickup was from the right side tender wheels and left side loco drivers. They are far enough apart stalling on switch or crossing points was never a problem.
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Len