Scale And Model Locomotive's Engines

Why don’t they make engines that resemble the FDL-16 engine for model locomotives N-G scale. Why are engines in HO scale locomotives flywheels, but model locomotives are strong as hell. Why don’t they make the engines found in model locomotives for scale locomotives?

OK, the first person who chimes in “take this over to the MR Forum” get’s slapped across the face with a slimy, wet fish – see “fish slapping” https://www.youtube.com/watch?v=IhJQp-q1Y1s

A lot of this has to do with physical laws that do not scale proportionately. One of them is the centrifugal force being proportional to velocity-squared divided by the curve radius. In going from, say, HO scale to full scale, the curve radius is multiplied by 87.1 whereas the velocity-squared term needs to be multiplied by 87.1 squared. The consequence of this is that an HO scale model train can negotiate at a scale 150 MPH a scale curve so sharp that it would only be found on an industrial siding.

Things like mass-volume-strength relationships, friction, and heat transfer do not scale in linear proportion. This means that even if you could build an FDL-16 Diesel in HO scale, perhaps by using 3-D printing or maybe even MEMS (used for miniaturized mechanical force sensors used to trigger your car’s airbag in a crash), it wouldn’t be able to operate anything like a proportionally scaled version of the prototype.

This doesn’t stop model engineering hobbyists from trying. Live steam is popular. There is G-scale live steam – I just saw it being exhibited this last weekend – and I am told there are even live steam

Some long while ago, perhaps in the late 1960’s, there was an editorial article in MR titled “Let’s Model the Johnson Bar.” What was meant by that was that the typical variable transformer or rheostat model train “throttle” was far from a realistic experience of operating a Diesel or an electric locomotive. In that era, there were transistor throttles that at least attempted to represent the train’s momentum and have separate controls for throttle and brake. A steam locomotive, however, had three main controls – throttle, brake, and steam cutoff (or reverse), the last being called the “Johnson bar” in reference to steam locomotives before power actuation of the reverse protected crews from the manual exertion along with risk of serious injury from kickback of the “Johnson bar.”

No, the editors weren’t advocating that train modelers be given a realistic railroad experience of risking a broken arm or worse from a model simulation of the pre-power reverse “Johnson bar.” What they were talking about was that there is quite the art to operating a steam locomotive successfully in manipulating both the throttle and reverser controls in such a way to not slip the wheels or stall the train on starting and to not lose boiler pressure from using too much steam at higher speeds, and they thought that using the then transistor throttle to represent that might be interesting to some people.

There is a community of model railroaders who are interested in realistic operation of large model train layouts. The extent to which people go to have the realism of train orders with the train crews following their model train and a dispatcher in a separate windowless room, well maybe I shouldn’t knock it, I have never seen it because even though I have met people who are “into operation”, I am not close enough to their social circles to be invited. But it seems an awful lot like real railroading, which t

A very well intelligent answer and reasoning. It makes sense. Thanks

I can only speak for myself, but when I run the O gauge layout all I want to do is sit back and watch 'em roll, I’m doing it to calm down and relax, not complicate my life further. Others can do what they want, but the above works for me.

I want and need to know how it is like and how it feels to run a live scale railroad in HO scale, even if papperwork has to be involved. I’m going full hardcore in HO scale!

The necessary convergence between hardware and software never quite happened, more because cost-effective satisfaction came to the different communities involved before full working ‘convergence’ came about. But that doesn’t mean you couldn’t do it: all the necessary parts of the ‘puzzle’ were available by the late '90s, and are probably more readily achievable today.

I can date when I saw the ‘future’ coming in HO: it was an article in the old RMC magazine in the early '70s describing the fascinating future use of the CCD camera, which (they said) would permit operators to see a perspective view out the windshield of their model locomotives, on TV. These cameras have, of course, now been manufactured by the hundreds of millions for cell-phone use, easily integrated with simple controls to do tilt, pan, and video corrections, and given wireless transmission. Well-established VR and AR techniques allow insertion of digital controls, etc. in the view, perhaps best derived from the second available technology: video train simulators. These provide all the physics necessary to do effective momentum simulation, train dynamics, etc. to actually control DCC ‘correctly’ rather than present operators with a rat’s-nest of goofy command codes, errors, and low-level register settings.

The third available technology is computer gaming, and this is where some combination of ‘Railroad Tycoon’ and a first-person gaming engine could easily produce the appropriate context for an interactive operating session in the cab of an engine, or in a caboose or tower, or whatever. An interaction between the gaming engine and some simulator features could easily provide random emergencies (and appropriate feedback/guides for their handling, including ‘multiplayer’ crews over the Internet, as has been done quite effectively for free games on phones and cheap computers for a decade or more)

The other thing 'missing&#

RME:

The sense I get is that people who “operate” model train layouts (as opposed to relax and watch the trains roll by) don’t want that level of realism because they like what they are doing now and don’t want train handling to get in the way.

There is an awful lot of selective compression going on in addition to the proportional scaling from HO to the 87.1 times larger prototype. You have fast clocks in operating sessions, much shorter train lengths, nowhere near the amount of track in a major yard, selectively compressed route lengths and so on. An operating session on a model layout may have as much to do with actual prototype operations as the game of Monopoly does to actual real estate speculation – that is, not all that much. More realistic momentum and train dynamics would probably confuse and confound many operators, much as a more realistic game of Monopoly would involve being put in legal trouble for sharp business dealings rather than simply losing some turns for “being in jail.”

As I said, I am thinking that more realistic locomotive and train handling is more for the train sim people than the model train layout operations people’s tastes and interests.

I like your idea of the “steam engine simulator” – it could probably settle a number of arguments regarding steam-era operating practices? But again, maybe it is just you, me, and a couple other guys (plus Juniatha) who are even aware of why a person would be interested in such a thing?

Yes, and that’s certainly a big part of ‘why’ there isn’t any use of telepresence in model railroading other than the occasional staring cell-phone camera taped at cab-window level for a couple of YouTube turns around the pike. Even the crude train-sims let you change the POV, run on full-scale curves easily, model whole divisions of the PRR for a few bucks. Modern game-engine technology evolution would get you to photorealistic detail much quicker and neater than the same exercise even in the hands of the Gene Deimlings of this world…

I dusted off the old approach specifically because alloboard said he wanted the ‘full’ railroading experience running HO trains. Now he knows how it can be done, in terms that I think are much better and more appropriate than simulating the multiphysics of the diesel engine, or putting interactive engine detail behind the hood doors, on his models.

It certainly should, at the appropriate time in the 5550 development process.

Alas, yes. On the other hand, we’re going into an era in which the old steam heads are dying off without training their effective replacements (one reason for the emphasis on Bene Gesserit TQM in the recent UP Heritage operation) and I think the provision and use of simulators is likely to prove extremely valuable. How many of them could I build for the price of a set of replaced or re-turned driver tire

Thanks for the reference for this very interesting article that you posted.

I am into train simulation too. I have Train Simulator 2017

In interesting workaround might be to place a Samsung Gear VR 360 camera on an HO scale flatcar, and use the Samsung Gear VR Headset for exploration.

VR360 is still a bit large and unwieldy for HO – but making a proper mount for, say, P:48 or its Russian-gauge equivalent wouldn’t be difficult.

Problem is that deconvolving the fisheye “360-degree” pictures the thing generates is a major pain, similar to viewing the anamorphic Steeleye Span album cover without a mirrored cylinder. And doing the image correction in realtime to match the ‘viewport’ of the phone-in-the-headset as its accelerometers feed it your head orientation is not something I think the phone architecture is geared toward.

Where I think Samsung (and the others, including the MotoMods people) may be missing the boat is in providing aspheric lensing to go over the phone screen to increase the VR field past the normal human-eye field, similar to bringing your eye up close to the viewing lens on one of those old handheld slide viewers. It is astounding how quickly this puts you ‘in the experience’ of what the camera sees, and with a little remedial eye-tracking to keep actual high-resolution rendering in sync with the fovea during natural saccade it can hold the rendering bitrate to sensible levels…

I still think it’s better to have active pan and tilt (which would be comparatively simple to implement on a ball camera) and make the lens(es) less aggressively fish-eyed and provide workable telephoto capability. Then we can work on light sources to keep camera output reasonably stable when going through radical changes in illumination or color. The feedback control from the phone in the headset to the power mount might make a nifty maker project…

I thought I might return to the original post, which I found a little confusing.

However, it allows me to relate a story which at least touches on the points mentioned.

As a student, I had a lecturer named Arthur Sherwood, who had a special interest in miniature devices. One of his tasks was to manufacture specialised medical equipment such as metal braces for damaged or defective human backbones and spinal cords.

However his hobbies involved similar miniature items. He had built an O scale live steam Norfolk and Western 2-8-8-2, probably a Y6b, but also an British OO scale Great Western 2-8-0 tank locomotive. But he became more interested in much smaller locomotives, and built a series of steam locomotives in 1/240th scale, Z scale being the somewhat larger 1/220th.

I think the first of these was the Delaware and Hudson triple expansion 4-8-0, selected because the casing over the water tube boiler and the wide firebox allowed a large boiler for the scale.

He had to develop special techniques for the mechanism of these locomotives. he had to use trunk type pistons with spherical connections to the piston rods since he could not machine pistons and cylinders to sufficient accuracy in the small scale.

He had built a series of increasingly smaller single cylinder model aircraft engines, all of which worked, but the smallest had to be heated to fire since scale effects meant that the heat generated by combustion was not enough to maintain the temperature in the relatively thicker cylinder body. Despite this, he had machined shallow rings in the cylinder body so it would appear to have cooling fins like the largest (which was a “normal” sized model engine of the period.)

He built electric models as well, and one day I recall him showing me a small chemical test tube. Inside was a tiny piece of brass. When I looked more closely, I realised it was a 1/480th scale Reading Class G-1 Pacific and tender. The Wooten firebox provided more room for the tiny m

There were similar tours-de-force from Sandia and Livermore, from a couple of the guys who designed and built some of the PAL devices before etched MEMS came in.

I was fascinated by one man’s hot rod at this tiny scale that was complete with working hydraulic brakes and Bowden-cable speedometer. In order to work on some of these he used a blowup device like a light table that was modeled on the machine the Hamilton watch company used to inspect escape-wheel tooth contour and finish, just to be able to see some of the components.

We can do much smaller now, but much of the fun of the hand-craftsmanship era goes out when seeing some of the design details now requires an AFM…

OK, I’m a model railroader, and I am into “operation”, and I have been at the model railroading thing pretty serious for about 47 years now.

I found the OP’s question a bit confusing, but I can provide some more insights into the behavors of a great many HO modelers.

First rule of model trains, there are no rules, other than the ones each model sets up for his layout.

Some modelers want to be the “engineer”, some have build full scale cab mockups to that end. There have been any number of electrical simulations of actual train handling, momentum, braking, etc. Some like that sort of thing, most don’t.

As mentioned above, most of it does not scale down well.

Long before DCC, any number of control schemes and throttle designs have been developed to better simulate the activities of the engineer and the dispatcher.

Some modelers want to be the dispatcher. Many operation oriented layouts have full scale CTC machines, often in a seperate room from the layout, and someone sits there and “plays” dispatcher while others run the trains.

Some people choose to simplify or stream line all the steps and processes of real operation, while still providing some “sense” of the actions necessary to move a train over the road.

Some built layouts with signal systems, some very complete, others simlified.

Most actually do not build signal systems…cost, complexity, learning curve…

Generally, groups of modelers with similar interest in this area will help each other develop suitable systems, many of which have been documented in the model press over the last 50-60 years.

The one thing that obviously works agains full simulation is selective compression. Even a very large home layout is likely only representing 8-15 scale miles of trackage…not exactly a subdivision…

Many like to just do car switching. Local trains go out with train orders and pickup/set out lists.

That video was so awesome.

Agreed, but that is a seperate hobby from anything commonly associated with model trains.

I have built my share of real automobile engines, hot rod cars, etc. I can watch that video and say that is cool. But I have no desire to own one or do that.

My view is likely typical of those who are currently in the model train hobby.

Small scales like HO are about the “big picture”, trying to simulate a small part of a complete working railroad, not focusing in on what makes one locomotive move.

To do that I would work in a larger scale…one I could ride on.

Sheldon

Remember that HO scale locomotives are powerfull as hell though.