Scale vs Gauge

[Anonymous]

Hi, it's Untabubba back with another "rookie" question. Recently I visited a local museum that has a fairly nice O gauge layout. (over 2000+ feet) I was watching the "Yardmaster" as he worked some of the controls. I made an off-hand comment about how "room-intensive" O SCALE was and he (almost scoldingly) retorted...."O GAUGE"! Which, of course, immediately turned me off, and ended what COULD have been an interesting "learning experience" for ME, as I was using that as an "opening line" to ask more questions.
SO, here's the question. What IS the difference between "scale" and "gauge" and how/when is each (correctly) USED?
Thanks

[Anonymous]

Guage is the distance between the rails. Scale is well, to tell ya the truth, I don't realy know what scale means.

[Anonymous]

QUOTE: Originally posted by 4884bigboy

Guage is the distance between the rails. Scale is well, to tell ya the truth, I don't realy know what scale means.

Then why did you post , if you couldn't answer the question?

The question here is one of defintions of words vs. long-time hobbists' use of them.

In reality, used correctly:

"Scale" is the proporation a model has to the prototype. HO scale is 1/87th the size of the real thing, O is 1/48th, N is 1/160th, Z is 1/220th...and there are others, but you get the idea.

"Gauge" is how far apart the rails are. Standard gauge--what most tracks are--is 4', 8.5" in real life; narrow gauge can be any of several smaller widths. The same is true in models, but 1/87th or whatever proportion smaller.

Now. It used to be that in the old days when we were somewhat less-enlightened, those words were used interchangeably. Especially common was the phrase "N gauge," but it was used in all scales. The older the modeller is, the more likely it is that he, because he was taught this way, will call his scale of choice "gauge."

Bottom line: YOU were correct. He is using an older nomenclature and in all liklihood cannot tell you why or define the words himself; it's habit, but incorrect.

And someone at a museum should never have answered that way to a member of the public.

[IRONROOSTER]

O Gauge is frequently used in the three rail world, because not every thing that runs on three rail O gauge track is O scale. There are manufacturers, K-Line is one who make locomotives to scales other than 1:48, but run on O gauge track. Industrial Rails makes 1:55 freight cars and trolleys for O gauge track. Lionels O27 line is undersized as well. American Flyer pre WWII used to make 1:64 engines for O gauge track. And so forth.
Enjoy
Paul

[n2mopac]

I have to admit that while not usually a stickler for these kinds of things, this interchanging of these terms annoys me. Here is why. In scale modeling worlds, guage (the distance between the rails) should always be the same (4' 8.5") unless otherwise specified as some narrow or other unusual distance. Thus, technically, N "guage" and HO "guage" are the same in their respective scales. The difference in the actual distance between the rails of N and HO track is a difference in SCALE, not guage.
Ron

[fec153]

n2mopac you hit the spike right on. Very well stated.

[Jetrock]

In HO and N, however, when track isn't a scale 4'8-1/2" wide, it is because the modeler is deliberately trying to model a narrow (or wide) prototype. It makes things nice and simple.

But in some other scales, O in particular, that is often not the case. As mentioned above, many models built for O are not O scale--they run on "O gauge" track (which is typically 1.25" wide, actually 5' rather than standard gauge) but their scale can be as small as 1/64.

And then there's OO--which can mean either "American OO", 1/76 track with rails in standard gauge for that scale, and "British HO" OO, which is 1/87 track (standard HO width) with 1/76 scale engines and cars running on it (since British prototypes were too small to hold the large motors of the day in scale-sized housings.)

And then there's that bewildering array of scales, gauges and other measurements that goes into the big-scale stuff--G/H/I scale? Who can keep it all straight?

Confusing? Yes. We HO/N/S/Z people have it easy...

[RhB_HJ]

As stated gauge refers to the distance between the rails, measured inside to inside (not the centerline!).

Scale is the ratio a model is either larger 2.5:1 or smaller 1: 87 when compared to the master (prototype).

As for the different scales one can look up the NMRA Standards and/or the NEM-MOROP Standards. The NEM Standards are considerably closer as well as better organized when compared to what NMRA specifies.

A comment regarding Large Scale (yes, I model that): "G scale" is the craziest misnomer ever, regardless of who coined the term.
I model 1:22.5 which for the 45mm track gauge is close to Meter gauge.
Standard gauge items running on 45mm track scale to 1:32. That scale is referred to as No1
Standard gauge that is scale 1:22.5 runs on 64mm track.

Sooooooooooooo if it is somwhere between 1:23 and 1:31 i.e 1:24; 1:26; 1:27; 1:29 etc. etc. and running on 45mm track it may be large but it most certainly isn't to scale!

[RhB_HJ]

QUOTE: Originally posted by ACL Fan

Then why did you post , if you couldn't answer the question?

...........snip

Now. It used to be that in the old days when we were somewhat less-enlightened, those words were used interchangeably. Especially common was the phrase "N gauge," but it was used in all scales. The older the modeller is, the more likely it is that he, because he was taught this way, will call his scale of choice "gauge."

Bottom line: YOU were correct. He is using an older nomenclature and in all liklihood cannot tell you why or define the words himself; it's habit, but incorrect.

And someone at a museum should never have answered that way to a member of the public.

Ooooooooooooops,

Meow, meow........

Well in olden days anyone who ever looked at a technical drawing and had to produce any parts from that knew what scale meant!

Now to the "gauge" moniker as applied by the museum "yardmaster", he was only half off the mark. As it happens the track gauge for O is 32mm, however the "scale" is 1:48! Now if one multiplies 32 by 48 one arrives at 1536mm! Standard gauge is 1435mm (4ft 8.5").
So the yardmaster calling it "O gauge" has a point, whatever it is is certainly not to scale. OTOH I very much doubt that he was aware of that, or for that matter cared.

BTW much of this utter scale confusion i.e dumb ratios and compromises here and there, stems from the fact that some "jokers" way back when mixed metric and imperial measures to arrive at whatever ratios. For instance HO's 1:87 is 3.5mm/1 foot.
OTOH considering that they started out with 4ft 8.5inch it isn't much of a surprise.

[CNJ831]

A point lost on most modern model railroaders is that the term "gauge", when used in conjunction with model trains of all kinds, refers to the rail separation for that particular model's size, not to propotions, nor to track of standard vs. narrow gauge. It was originally based on a set of standard size track spacings established by toy manufacturers in Europe more than a century ago. O gauge is really "zero" gauge, the smallest size at that time, and you went up from there through #1 gauge, #2 gauge and so on, in increasing standard model size/track spacing. Gauge, in terms of its original usage regarding models, does NOT refer to the 4' 8 1/2" track spacing of the prototype. Thus, HO trains, at their inception, had a rail spacing of roughly half of that of zero gauge trains. It did not orginally mean that everything was to be to 1:87 scale - and none of the early ones were! When N and Z came along later, naming was created less logically (however, there was once an N-like triple zero or "treble O" gauge!).

Most of today's modelers like to deny these facts but it nevertheless is the true meaning of the term "gauge" as applicable to toy and model trains. The Yardmaster in question was probably an oldtimer. Prior to about 1960 hobby magazines typically spoke of models by their "gauge" and not necessarily by "scale". Most older guys I know today that model in 1:43 or 1:48 still call it O-gauge. The exclusive use of the term "scale" in our hobby largely arose when HO modelers put on airs and tried to separate themselves from the looked-down-upon tinplate hi-railers in the latter half of the 1950's. You'll find bits and pieces of this story in the editorials of MR and RMC of the period. Believe me, the history of our hobby is at once very interesting, yet bizarre!

CNJ831

[Big_Boy_4005]

As one who does 3 rail O, I like Ironrooster's explanation best, but just about all of the responses are on the right track.[:p]

In order to avoid confusion the term "O SCALE" should only be used to talk about 2 rail DC powered trains.

Actually, the distance between the rails (guage) for 2 rail and 3 rail is about the same, and 2 rail cars will work on 3 rail track, but not very well through the switches. Conversly, 3 rail cars will not work on 2 rail track because of the oversized flanges, and their all metal wheel sets.

In order to further confuse every one, some of us now do scale sized equipment on 3 rail track. Atlas and Weaver make really nice stuff that is all scale sized and marketed to both guoups. Loinel and MTH both make some scale pieces in addition to the non scale "O GUAGE" trains.

Did everyone get that? [:D]

[RhB_HJ]

Hmmmmmmmm

OK let's try this once more.
Gauge is the distance between railheads (inside). It doesn't matter if it's proto or model.
Therefore if a model is a certain scale (easily determined by comparing the prototype measurements to the dimensions of the model) and that scale multiplied by the track gauge does not match up to the proto track gauge (either narrow, standard or broad gauge) then that model is not to scale.
Straight forward and simple.

BTW the best analogy are the standards that are employed in industry. When the ISO standards first took hold in countries that up to that time used Imperial measures, there was much confusion for one simple reason: The metric system and the standards that ISO is based on was so logical that it confused all those who were used to fractions and other such "esoteric" methods.[}:)][}:)][;)] Don't even start me on tolerance rules and tolerance spreads!
For some strange reason it always seemed easier for Europeans to adapt to the archaic Imperial system than the other way around (this is first hand experience). There are one or two theories I could advance on the reasons, but we'll leave that for the moment.[;)][;)][:)]

[CNJ831]

Perhaps I should make an addendum to my earlier post since I think I can hear the approaching shrieks of, "No, no, it can't be so!" from some of the current generation of modelers.

Except by convention initiated over the past 35 years or so, the terms O, HO, N, and G do not, and have not, represented singularly specific scale sizes. The term "O" is claimed by at least 3 slightly differing "scales", HO today consists of 2 distinct "scales", while N started out with 3, and G currently has no less than 3 or 4 all running on one size of track! All are technically "gauges", as outlined in my earlier post. I believe that only the now largely defunct TT Scale, at 1:120 the prototype, ever intentionally started out from a scale-specific, not a "gauge", standpoint. I'll leave it to others to have the fun of sorting out the original and current states of OO and S (CD-gauge) !

While I'd certainly never condem anyone for today saying that it's "HO scale", I would ask that they at least understand and appreciate that "gauge" is just as proper and historically probably the more appropriate term.

CNJ831

[Anonymous]

QUOTE: Originally posted by CNJ831

Perhaps I should make an addendum to my earlier post since I think I can hear the approaching shrieks of, "No, no, it can't be so!" from some of the current generation of modelers.

Except by convention initiated over the past 35 years or so, the terms O, HO, N, and G do not, and have not, represented singularly specific scale sizes. The term "O" is claimed by at least 3 slightly differing "scales", HO today consists of 2 distinct "scales", while N started out with 3, and G currently has no less than 3 or 4 all running on one size of track! All are technically "gauges", as outlined in my earlier post. I believe that only the now largely defunct TT Scale, at 1:120 the prototype, ever intentionally started out from a scale-specific, not a "gauge", standpoint. I'll leave it to others to have the fun of sorting out the original and current states of OO and S (CD-gauge) !

While I'd certainly never condem anyone for today saying that it's "HO scale", I would ask that they at least understand and appreciate that "gauge" is just as proper and historically probably the more appropriate term.

CNJ831

Well stated, and totally correct ![:D][:D]
There's quite a bit of BS on this thread, as is usual on the "scale vs. gauge" debate.
One thing though.....if some of those who have an opinion could learn to spell "gauge" correctly, I might fini***heir posts....as soon as I see "guage", that Post is Toast ![:(]
regards
Mike

[Anonymous]

QUOTE: Originally posted by n2mopac

I have to admit that while not usually a stickler for these kinds of things, this interchanging of these terms annoys me. Here is why. In scale modeling worlds, guage (the distance between the rails) should always be the same (4' 8.5") unless otherwise specified as some narrow or other unusual distance. Thus, technically, N "guage" and HO "guage" are the same in their respective scales. The difference in the actual distance between the rails of N and HO track is a difference in SCALE, not guage.
Ron

I think you and I may on the same page, but here is a simpler explaination, GAUGE refers strictly to the track gauge and only the track gauge. The term SCALE refers to the relationship in size between the model and the prototype.

[RhB_HJ]

QUOTE: Originally posted by CNJ831

Perhaps I should make an addendum to my earlier post since I think I can hear the approaching shrieks of, "No, no, it can't be so!" from some of the current generation of modelers.

Except by convention initiated over the past 35 years or so, the terms O, HO, N, and G do not, and have not, represented singularly specific scale sizes. The term "O" is claimed by at least 3 slightly differing "scales", HO today consists of 2 distinct "scales", while N started out with 3, and G currently has no less than 3 or 4 all running on one size of track! All are technically "gauges", as outlined in my earlier post. I believe that only the now largely defunct TT Scale, at 1:120 the prototype, ever intentionally started out from a scale-specific, not a "gauge", standpoint. I'll leave it to others to have the fun of sorting out the original and current states of OO and S (CD-gauge) !

While I'd certainly never condem anyone for today saying that it's "HO scale", I would ask that they at least understand and appreciate that "gauge" is just as proper and historically probably the more appropriate term.

CNJ831

Hmmmmmmm, let's see once more. On the example of O scale. Three different versions all running on the same trackgauge (32mm); 1:48; 1:45; 1:43.5
The 32mm represents standard gauge 1435mm (4ft 8.5"),
Therefore 1:48 should be running on 29.89mm track i.e. it is 6.6% too small!

1:45 should be running on 31.88mm track so 32mm is very close i.e. it is 0.35% too small!

1:43.5 should be running on 32.98mm track IOW it is 3.08% too large!

Now whatever one may believe, this routine can be repeated with every scale mentioned and compared to the track gauge used.

If it has less than a 1 or 2% error and, preferably, rounds to a one digit after the point figure for the track gauge in the metric system I can live with that.

Some of the other stuff; well I admire some of the highly detailed 1:48 models, it's just too bad that they couldn't get the track gauge right. Why have all the super detailing when the very basics i.e. track gauge to scale ratio is out of wack?

Some of the "weird" scales are hard to explain, apart from the fact that existing motors needed to be fitted (OO) etc. etc.

[RhB_HJ]

QUOTE: Originally posted by robmik

Well stated, and totally correct ![:D][:D]
There's quite a bit of BS on this thread, as is usual on the "scale vs. gauge" debate.
One thing though.....if some of those who have an opinion could learn to spell "gauge" correctly, I might fini***heir posts....as soon as I see "guage", that Post is Toast ![:(]
regards
Mike

Since guage is gauche,
this post is toast.
[;)][:)][:)]

[Big_Boy_4005]

I don't care about the dimension between the rails, and neither does the person who started the topic! Although the topic heading may imply that that is what this discussion is about, when you read the question, it becomes clear that it is about the difference between O scale trains(2 rail) , and TOY trains(3 rail), commonly called O guage.

Untabubba was "told off" by someone for using the wrong term when talking about the trains. In Untabubba's defense, I think the other guy was being rude, and what he should have done was politely explain the difference in terminology.

[vsmith]

Time to show you the meaning of the term: CONFUSION....

and a little lesson in SCALE vs GUAGE...

1st. Switch to Large Scale...

2nd. Time to become C-O-N-F-U-S-E-D...!!!!!

Almost all trains in Large Scale operate using LGB type 45mm GUAGE track. This is ment to represent European meter gauge railroads at a SCALE of 1:22.5. NowLGB comes to America and they start making US type trains that dont run on meter gauge but did on 3' guage, so they make the US style trains but keep the scale at 1:22.5, even though at this SCALE the GAUGE is now 3'-3". Some modelers complain that they 45mm track used for a 3' narrow gauge track would yield a scale of 1:20.3, but only a few makers cater to this group. Now other makers get into the act, and produce trains that represent standard gauge 4- 8 1/2" gauge track on the same 45 mm track, giving an actual scale of 1:32 but some makers think the trains are too diminuative and "dont quite look right" at 1:32 scale so they bump up the scale of their standard guage trains to 1:29 scale so now the 1:29 SCALE trains trainslate into a roughly 4' scale GAUGE but are expected to be accepted at standard guage 4'-81/2". Now other manufacturers are at the same time making products at 1:24 scale at a scale gauge of 3'-6". Then Bachmann who was making things at 1:22.5 decides that it will make all new products at a scale 1:20.3 but they dont retool and redo their older 1:22.5 offerings, they simply "call them" 1:20.3 which leads to real confusion when you actually put a scale to the older now "upscaled" items. Now add that LGB is also producing standard gauge items at somewhere between 1:22.5 and 1:29 scale, they wont specify a "scale".

And all this runs on the same 45mm track...

Are we C-ON-F-U-S-E-D yet ????????????

[Roadtrp]

Wow -- what a thread! [(-D]

While we're at it, anyone know how many angels fit on the head of a pin?

I know the kind of trains I run. They're N SIZED. [;)]

[Anonymous]

QUOTE: Originally posted by vsmith

Time to show you the meaning of the term: CONFUSION....

and a little lesson in SCALE vs GUAGE...

1st. Switch to Large Scale...

2nd. Time to become C-O-N-F-U-S-E-D...!!!!!

Almost all trains in Large Scale operate using LGB type 45mm GUAGE track. This is ment to represent European meter gauge railroads at a SCALE of 1:22.5. NowLGB comes to America and they start making US type trains that dont run on meter gauge but did on 3' guage, so they make the US style trains but keep the scale at 1:22.5, even though at this SCALE the GAUGE is now 3'-3". Some modelers complain that they 45mm track used for a 3' narrow gauge track would yield a scale of 1:20.3, but only a few makers cater to this group. Now other makers get into the act, and produce trains that represent standard gauge 4- 8 1/2" gauge track on the same 45 mm track, giving an actual scale of 1:32 but some makers think the trains are too diminuative and "dont quite look right" at 1:32 scale so they bump up the scale of their standard guage trains to 1:29 scale so now the 1:29 SCALE trains trainslate into a roughly 4' scale GAUGE but are expected to be accepted at standard guage 4'-81/2". Now other manufacturers are at the same time making products at 1:24 scale at a scale gauge of 3'-6". Then Bachmann who was making things at 1:22.5 decides that it will make all new products at a scale 1:20.3 but they dont retool and redo their older 1:22.5 offerings, they simply "call them" 1:20.3 which leads to real confusion when you actually put a scale to the older now "upscaled" items. Now add that LGB is also producing standard gauge items at somewhere between 1:22.5 and 1:29 scale, they wont specify a "scale".

And all this runs on the same 45mm track...

Are we C-ON-F-U-S-E-D yet ????????????

I agree with you there. When I first dabbled in "Large Scale" trains (often called G-Scale), I was a little confused by how the LGB stock represented both narrow gauge (Their small German steamers, coaches, etc) and standard gauge (The F7, their US freight and passenger cars...). Aristo-Craft also make stock that appears standard gauge but runs on 45mm track. To add to this, there is a scale known as "Gauge 1" from the really early days of model trains - though some manufacturers still produce kits for it - that also uses 45mm gauge track...

As I understand it, "gauge" refers to the distance between the rails, while "scale" refers to the scale at which the model is constructed (3.5mm/1ft for HO, for example). I've heard the two used interchangably for a while - can't say it really annoys me. I certainly wouldn't give the response recieved by untabubba if someone used the wrong term - that kind of attitude doesn't help the hobby at all IMO.

[RhB_HJ]

QUOTE: Originally posted by Big_Boy_4005

I don't care about the dimension between the rails, and neither does the person who started the topic! Although the topic heading may imply that that is what this discussion is about, when you read the question, it becomes clear that it is about the difference between O scale trains(2 rail) , and TOY trains(3 rail), commonly called O guage.

Untabubba was "told off" by someone for using the wrong term when talking about the trains. In Untabubba's defense, I think the other guy was being rude, and what he should have done was politely explain the difference in terminology.

Elliot,

Point taken.
OTOH clarifying the difference between gauge and scale never hurts.
Judging by the response the basics are still a bit fuzzy in some peoples' heads.
Perhaps those angels on the head of a pin need larger than scale size wings in order for the concept to take flight.


BTW I used to teach "The Basics of model railroading" as an extension course. Not one of the people in the course ever had this "ongoing problem" about not being able to tell the difference. Youngest in any of the classes was 11, oldest was 65.

Did the "Yard master" really know the difference between the terms, as a matter of fact do we even know that it was a three-rail layout ? (I also remember some 1:48 scale 3-rail layouts)

[Anonymous]

QUOTE:

.....commonly called O guage.

Actually, BigBoy, it's commonly called "gauge".

I believe "guage" is where Elmer Fudd keeps his automobile.[:o)]

and ...please don't shout.[xx(]
regards
Mike

[Big_Boy_4005]

Sorry for "shouting " gang, but I was getting a little frustrated with how things had drifted away from the original issue of Untabubba's post. I don't usually complain when a topic's responses go astray, but I take this one somewhat personally, since I do 3 rail O trains, and was once a member of a 2 rail O club.

I have extensive experience answering the questions of the "Untabubbas of the world", and have a special understanding when it comes to the specifics of his question.

By the way HJ, I have also spent a lot of time educating people on the subject of model railroading, though not in as formal a setting as you. You are right, when you say that people are "fuzzy" about their understanding of the terms scale and gauge, and it is a very basic concept that every modeler should have a clear grasp of.

Over my 30 plus years in this hobby, I have worked with trains of every major scale, but always in standard gauge.[:)]

OOPS, after all these years I should know how to spell it, I subscribe to a magazine with the word in its title, and I know what it means, I guess I just haven't written the word GAUGE enough. I won't forget how to spell it now.[:I]

[Anonymous]

QUOTE: Originally posted by Big_Boy_4005

I don't care about the dimension between the rails, and neither does the person who started the topic! Although the topic heading may imply that that is what this discussion is about, when you read the question, it becomes clear that it is about the difference between O scale trains(2 rail) , and TOY trains(3 rail), commonly called O guage.

Untabubba was "told off" by someone for using the wrong term when talking about the trains. In Untabubba's defense, I think the other guy was being rude, and what he should have done was politely explain the difference in terminology.

SO, here's the question. What IS the difference between "scale" and "gauge" and how/when is each (correctly) USED?



Well lets see here, this surely does look like a question about the differance betwwen scale and guage to me. If these old eyes don't decieve me, it even says so.

[RhB_HJ]

QUOTE: Originally posted by emeraldisle

QUOTE: Originally posted by Big_Boy_4005

I don't care about the dimension between the rails, and neither does the person who started the topic! Although the topic heading may imply that that is what this discussion is about, when you read the question, it becomes clear that it is about the difference between O scale trains(2 rail) , and TOY trains(3 rail), commonly called O guage.

Untabubba was "told off" by someone for using the wrong term when talking about the trains. In Untabubba's defense, I think the other guy was being rude, and what he should have done was politely explain the difference in terminology.

QUOTE: SO, here's the question. What IS the difference between "scale" and "gauge" and how/when is each (correctly) USED?

Well lets see here, this surely does look like a question about the differance betwwen scale and guage to me. If these old eyes don't decieve me, it even says so.

Yep, was plain Engli***o me! No ifs or buts!

OTOH look at all the fun we've been having in the meantime[;)][;)], some even started to TALK LOUDER because as everyone knows, the natives of any country will understand perfect English, just as long as it is spoken loud enough.[}:)][;)][:D] Hmmmmmmmm what am I saying, we all wrote in Engli***o start with.[}:)][:D][:D][:o)]

[BR60103]

I suspect that use of this "scale" term started when someone wondered how a building could be "O gauge". Gauge was important originally (about 75 years ago) because you needed to know that to get cars that would run on your track. Then manufacturers began to claim they made "scale" models.

[Big_Boy_4005]

I have been dragging my feet on further response to this one, but BR60183 is onto something here and I guess its time to pick up the ball and run for the end zone (he didn't fumble he's just handing off).

The continued use of the term O gauge (I finally learned how to spell it) meaning 3 rail trains comes directly from Lionel.

Back in the 30's when the NMRA and Model Railroader started, the concept of scale was just beginning, and yes gauge did refer to the distance between the rails, and it still does today. The confusion comes from the introduction of scale to the equation.

In the old days trains were not made to a set scale, they were toys. Lionel has always made trains that were incorectly proportioned for the track that they ran on, but people don't like to call them toys anymore, so they refer to them by the type of track that they run on.

People still say Xerox when they make copies, even though the machine producing the copy wasn't made by that company at all. Same with Crecent wrenchs, and a lot of other things we use every day. Old names just sitck to some items.

All track is O gauge, but only 2 rail track can be O scale. Trains of many proportions, have been made for O gauge track, only correctly proportioned trains have been made for O scale.

If the trains that Untabubba saw ran on 3 rail track, they are commonly known as O gauge, and if he called them O scale, he was tehcnically wrong, but there was no reason for the person at the display to take a condesending tone or be rude to him.

Sometimes people get tired from working long hours, or answering the same question over and over. I suspect that Untabubba was the victim of just such a situation. I have been in situations like that, and I am embarrassed to say that I have, on occasion, snapped in a similar fashion.

Perhaps my large text reply was my own way of snapping. I hope this reply settles this issue.

[CNJ831]

"I hope this reply settles this issue." (Big_Boy_4005)

And pray tell, Big_Boy_4005, just what scale is two rail "O scale", 1:43.5 ; 1:45 ; 1:48 (even 1:55, so I hear)? They are all O-gauge but of differing scales. You can't just blindly call it O scale.

No hostility here, just pointing out a fact.

CNJ831

[Big_Boy_4005]

In the US, O scale is 1:48, other countries may have other proportions, but consult the NMRA on that. That has been my understanding, and that's what every scale rule that I have ever seen says, simple 1/4" to the foot. There is also Proto 48 for fine scale. The others exist, but are not the standard. I know this because I have worked with 1:48 trains in both 2 and 3 rails.

Weaver and Atlas are two of the best when it comes to making properly sized trains for O scale, and the exact same models are marketed to O gauge (3 rail) modelers like myself, simply by placing different trucks on them. When shopping on eBay I have to be careful to make sure that I get only 3 rail trucks, since two rail versoins of the same car won't work without changing the trucks.

There are 3 major differences, flanges, axles, and couplers that basicly prohibit the mixing of 2 rail equipment and 3 rail equipment. 3 rail wheels have grossly oversized flanges, a feature which can be directly traced back to the toy trains of long ago. They ride the ties on 2 rail track, conversly, 2 rail wheels would fall in, passing through a 3 rail switch, since the flangeways through the frog are so large.

The only thing about axles is, that when combined with the metal wheels of 3 rail, if they didn't ride the ties, the would short the rails together. With 3 rail track, this is a very useful feature, which allows the train to be detected or control accessories.

Scale (2 rail ) operators mount Kadee couplers to the body of the car. O gauge (3 rail) operators couplers are part of the truck. This combined with the fact that they are also way oversized allows them to handle the sharp curves of O gauge (toy type) track, where body mounted couplers would bind, and cause derailments.

So, ignoring all of the other sizes of train, and only talking about 2 rail O vs 3 rail O, O scale vs O gauge, which was actually the focus of Untabubba's question, I think we have pretty thouroughly covered the topic.