Just an intellectual curosity - I’m sure that live steamers do it (introduce steam into cylinder, pushing piston back and forth, and so via the Piston Rods moving the locomtive drivers), but can’t think of a model steam locomotive (HO scale; well, O scale at the largest) driven by track (electric) power which used this principle (for the obvious reason that a worm or geared drive from the electric motor to the wheels is far more efficent than, say solenoids or an cam arrangement stuffed into the area of the cylinders/front of boiler and moving the rods) - but I refuse to believe it wasn’t done on a lark (I can almost imagine a 1950s MR article, with a electrical nerd/model railroader proudly showing off his rod-driven steam engine model handiwork).
BTW, I don’t mean to include proto geared locos like shays or climaxes - just a regular piston rod driven arrangement.
http://www.hornby.com/customer-support/faq/hornby-live-steam,42,HAR.html
There have been other commercially-made HO live steam models over the years. There used to be a bloke here in Sydney who built N-scale live steamers, too.
I can remember seeing a photo in an old MR of a solenoid/rod driven 0-6-0 mechanism…
Cheers,
Mark.
It is not the best quality video but the Hornby promo is on Youtube
The man you recall was Arthur Sherwood, who was an assistant professor of Mechanical Engineering at Sydney University. His Live Steam models were not N scale but 1:240 scale, even smaller than Z scale. I remember watching his model of PRR K4s 3768 (streamlined) running around its tiny circular track, with its weird high pitched beat owing to its tiny size.
These were indeed driven by their connecting rods, and had special design features to allow for inherent inaccuracy in the machine tools used to make them.
There will probably never again be anything like them.
Fortunately they are preserved by Sydney University. Unfortunately, they are no longer on show, as they were maybe ten years ago.
Arthur also built 1:480 scale electrically powered models, including a Reading Railroad G-3 pacific (the large Wootten firebox being needed to conceal the tiny motor!).
M636C
This just so cool!!
I think that chutton01 means an electric locomotive powered through the drive rods.
I don’t think magnets are efficient enough to do that even now let alone in the 50’s. It probably wouldn’t be a very smooth type of drive either.
What someone needs for something like this are Linear Induction Motors. They work like pistons without having and parts that rotate. Just a smooth back and forth motion
It’s going to surprise many folks when those new fancy steamers start “Walking” side to side under a load just like the real ones.
If I read you right, the short answer is none.
is that Sean Bean doing the voiceover? 
You are correct, that is exactly what I meant [:)] - I knew about the Hornby engine from a MR review awhile back (hence the “I’m sure that live steamers do it” - eh, guess I should have said “I know some live steamers”, but I have made worse mistakes in my life) - I was just thinking of electrically powered models using some sort of rocking or oscillating motion to drive the piston rods and hence the wheels, as opposed to the universal gearing.
marknewton: “I can remember seeing a photo in an old MR of a solenoid/rod driven 0-6-0 mechanism…”
That sounds like what I’m looking for
loathtar “I don’t think magnets are efficient enough to do that even now let alone in the 50’s. It probably wouldn’t be a very smooth type of drive either.”
You’re probably right, but it is very impressive what our predecessors did with analog electrical circuitry and transducers in the 1930-1960s period - control circuits that you’d think impossible without digital circuitry they pulled off, and with a surpisingly small number of tubes, capacitors, & resistors (to keep current drain low). Somehow a cam driving a sprung rocker-type arm arrangement (back and forth, one side pushing while the other pulls) comes to mind, no magnets need apply.
I remember in MR, pictures from a NMRA national convention, somebody had made a HO CB&Q 4-6-2 (I think) that was powered through the pistons and siderods, by electricity. Might have to look things up…