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I recently watched a Youtube video about an extremely well-done layout in P48. Much of the equipment appeared to be scratchbuilt, so I was curious if MTH's Premier line, if equipped with scale wheels, was considered true P48 by hobbyists, or if the trucks were still not gauged correctly. 

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MTH's 3/2 locomotives are not P48.  They are what two railers call OW5 for O scale wide guage 5'.  In other words the same spacing as three rail track.

While 1:48 is the NMRA standard for Scale O in the US, most of the rest of the world uses 1:45. 

Proto 48 is a different variation that uses true spacing of track at 1:48 to get the correct 4' 8-1/2" between the rails, so the MTH trucks are not gauged for that rail spacing.  Another tenant of Proto 48 is typically much closer to scale flanges than even standard 2 rail.  Proto 48 flanges are very small.  

It's a great way to model if you have the time and the patience to do it!  I currently don't. 

Thanks for clearing that up. As a (probably unanswerable) follow-up, if O gauge tracks are scaled for 5 feet, why didn't (too late to change now, I suppose) manufacturers offer trains scaled to the same width as the track when the opportunity arose? For example, when Lionel offered its 'full-scale" Hudson, why didn't they scale it for 1:45 or similar? 

Dan,

That is a debate that goes back to the 1930's and has been discussed thoroughly.  The simple answer I think is that when Lionel offered it's scale Hudson in 1938, 1:48 was much easier to calculate than 1:45.  There was a movement among smaller manufacturers to build 17/64" in the 1930's, but as 2 Rail O has always been less popular than the more common 3 Rail, there wasn't enough momentum to make that a US standard.  If you look at MTH's European equipment it is scaled at 17/64" or 1:45.  The NJT ALP-46 is a 1:45 model as it is based on a European prototype.

I know one of the Lionel experts through my local TCA Division and we have a meeting on Saturday.  I'll ask him and see if he knows why Lionel choose 1:48 for their Hudson. 

There was some debate on here recently about "O" scale so for the sake of simplicity, it is probably safer to refer to proportion.  On30 and On3 are still O scale at 1:48, but run on 30" scale and 36" scale track respectively.

Blame it all on the Founding Fathers.  When we had our Revolution, we should have also broken from the British measurement system and followed our allies, the French, and adopted the metric system, everything down to even hundredths of a meter.  Washington could have done it by "executive order".

It sure would have made life simpler, but imagine how much less interesting discussions would have become. 

No - it would have been trivial to either change the scale or gauge.  I guess it wasn't all that important to 1938 O Scalers.

It is important to me - I model in 17/64.  I also have several strings of O Scale 1 1/8" gauge trains, and a loop to run them on.  End- on, this improves the appearance of my models.

GG1 4877 posted:

 

There was some debate on here recently about "O" scale so for the sake of simplicity, it is probably safer to refer to proportion.  On30 and On3 are still O scale at 1:48, but run on 30" scale and 36" scale track respectively.

Not to get off topic here, but are On30 and On3 both valid for narrow gauge sizes (or whatever it would be called)?  Would one be preferred over the other?  I know very little about the prototypes, just a curious 3 railer in the wrong forum?  

Woodshire Bill posted:

Blame it all on the Founding Fathers.  When we had our Revolution, we should have also broken from the British measurement system and followed our allies, the French, and adopted the metric system, everything down to even hundredths of a meter.  Washington could have done it by "executive order".

It sure would have made life simpler, but imagine how much less interesting discussions would have become. 

but the French use 1.43.5, as do the British, so no use blaming Europeans then for 1/4'' scale

ON30 and ON3 are both valid track gauges.    However, very little common carrier, if any, was built to 30 inch gauge in the USA.    I think there has been quite a bit of industrial narrow gauge at 30 inches.     3 Foot gauge (36 inches) was used a lot for common carrier shortlines in the 1870s and so.    There was a major movement to build "narrow" gauge lines because they were cheaper to build and maintain in every way.    Colorado had over 1700 miles of narrow gauge at one time.   The East Broad Top in Pennsylvania is another famous 3 ft line.    There was also the Ohio River and Western which ran from near Wheeling to Zanesville OH and the Washington and Waynesville which ran between the namesake towns.   The B&O was involved in the Pittsburgh Southern which was built to 3 ft and then standard gauged in a few years.    Maine had a small system of 2 ft gauge common carriers.   

so could you use ON30 track to model ON3?    Probably that would work as well as using 5 ft gauge to model 4 ft 8 1/2.    Some people will not like it and some wouldn't do it.  

but the French use 1.43.5, as do the British, so no use blaming Europeans then for 1/4'' scale

 

Ah, but I didn't say the French did it right; but merely that the metric system would have empowered the U.S. to do it better.  And you Brits get a lot of the blame for adopting the Roman standard of the width of a horse's a**.  

from the Wik "The United States standard railroad gauge of 4 feet, 8.5 inches is derived from the original specifications for an Imperial Roman war chariot. And bureaucracies live forever"

During the presidency of George Washington, he should have ordered that the width of all future main transportation ways shall be a minimum of 2 meters.  He would have made the ride on coaches more comfortable and model railroading easier and less contentious by miles.

And don't get me started on the mess that the British standard has caused in the aerospace industry, although it probably led to the employment of thousands of additional engineers and checkers.  Even at that, we missed Mars because someone failed to check the conversion from miles to kilometers.

I will say that being brought up on British has probably made it easier to count by twos which has more relevance when moving from the abacus to the chip.  Now up to RFC3548 (base 16, 32, 64) rather than the hexadecimal of yesteryear.

Anyway, I'll take my O scale at 30mm, no exceptions, and that's by executive order.   The next CEO can do as she wishes.  

Last edited by Woodshire Bill

30 mm is really close.  If I had my druthers it would always be narrower rather than wider.  I have always been intrigued with the idea that, with a window seat, my arse was outside the rail head - outside the outermost point of the crossties.  Fun thought, going over trestles.

But we are, as a hobby, moving ever more toward accuracy, especially our 3-rail scale buddies.  We shall have to fix this scale/gauge problem.  I vote for 17/64 scale.  I admire the Proto-48 crowd.

prrjim posted:

ON30 and ON3 are both valid track gauges.    However, very little common carrier, if any, was built to 30 inch gauge in the USA.    I think there has been quite a bit of industrial narrow gauge at 30 inches.     3 Foot gauge (36 inches) was used a lot for common carrier shortlines in the 1870s and so.    There was a major movement to build "narrow" gauge lines because they were cheaper to build and maintain in every way.    Colorado had over 1700 miles of narrow gauge at one time.   The East Broad Top in Pennsylvania is another famous 3 ft line.    There was also the Ohio River and Western which ran from near Wheeling to Zanesville OH and the Washington and Waynesville which ran between the namesake towns.   The B&O was involved in the Pittsburgh Southern which was built to 3 ft and then standard gauged in a few years.    Maine had a small system of 2 ft gauge common carriers.   

so could you use ON30 track to model ON3?    Probably that would work as well as using 5 ft gauge to model 4 ft 8 1/2.    Some people will not like it and some wouldn't do it.  

Thanks for the explanation. I knew Colorado had narrow gauge, but I didn't know which size it was. I've heard of the Broad Top, but did not know it was narrow gauge. Also didn't know about any of the others you mentioned. My LHS has some On30, but I am not sure I have ever even seen any On3? (Pretty sure I have those correct here?). Maybe I'll ask them about that one.

I really am 'prototypically challenged', wasn't kidding about that.   If it looks like a train and runs well on my Atlas track I am happy. I do like the more detailed models they have these days and also command control, but have no idea if they are correct or not. The correctness doesn't bother me as I don't know the differences. I started out with RailKing when I got back in the hobby in 2011, but have now moved up to to the actual O-scale sized trains. I like the looks of the larger, actual correctly sized items over the smaller ones available. I actually like 3 rails though, from what I had as a kid it just looks right to me. The postwar trains I had as a kid really look small to me these days. 

Maybe I am being slowly converted to the more prototypical items as I go along?  Anyway, thanks for the info, it was interesting and I always learn something! However, remembering it all is the tricky part these days, as I get older.

Regarding MTH Steam locos to be "true to scale" MTH takes liberties with their models to get them to operate on 3 rail with wide tires.  I have a very nice MTH WM Challenger that I converted to 2 rail several years ago and I use it as a display model when I give a talk on 2 rail conversions.  Looking closely at the model you will notice that the piston rods do not go into the center of the cylinder heads but are somewhat outboard so the side rods on the wide 3 rail drivers will clear the crossheads.  If you are a purest insisting on P-48 fidelity you may not want an MTH "2 rail" model.  I have had many modelers see my Challenger on my table at various shows and think it is a C&LS model.  I am quite satisfied with my standard O gauge models and all of the MTH locos I have converted to 2 rail (many) perform smoothly and will probably outlast a brass import in operation.  BUT P-48 fidelity? No!

Joe Foehrkolb

Baldwin Forge & Machine

 

rrjjf posted:

Regarding MTH Steam locos to be "true to scale" MTH takes liberties with their models to get them to operate on 3 rail with wide tires.  I have a very nice MTH WM Challenger that I converted to 2 rail several years ago and I use it as a display model when I give a talk on 2 rail conversions.  Looking closely at the model you will notice that the piston rods do not go into the center of the cylinder heads but are somewhat outboard so the side rods on the wide 3 rail drivers will clear the crossheads.  If you are a purest insisting on P-48 fidelity you may not want an MTH "2 rail" model.  I have had many modelers see my Challenger on my table at various shows and think it is a C&LS model.  I am quite satisfied with my standard O gauge models and all of the MTH locos I have converted to 2 rail (many) perform smoothly and will probably outlast a brass import in operation.  BUT P-48 fidelity? No!

Joe Foehrkolb

Baldwin Forge & Machine

 

Greetings Joe,

I'm NOT a purist to the extent that I want to go the P48 route, but your post poses a question: Assume we start with the C&LS Challenger and convert it to P48. That done, how close (other than gauge) would THAT model be to one that was originally built directly to P48 specs?

I'm guessing that most OW5 stuff is pretty much similar apart from the width of the wheel sets and sometimes, the profile of the wheels. I'm also guessing if i took a PSC boxcar and put OW5 115 profile wheel sets on it that some of our P48 friends might have difficulty knowing the gauge if it were sitting alone on a piece of hand laid track.

Thanks,

Simon

bob2 posted:

30 mm is really close.  If I had my druthers it would always be narrower rather than wider.  I have always been intrigued with the idea that, with a window seat, my arse was outside the rail head - outside the outermost point of the crossties.  Fun thought, going over trestles.

 

Seems a bit of a silly statement for someone that flies!

Simon

Not sure why that is silly.

I can easily tell an Ow5 truck, even with .115 wheelsets.  It is not a good example, since the car is a model of an older, narrower boxcar, but check out the end-on photo in the LaBelle box car thread.  Our 3-rail scale friends actually have truck sideframes that go all the way out to the outside edge of the car body.  .115 wheelsets would help that.

I should note that I tried .115 wheels.  My track was not good enough.  I can go down to maybe .158 or so without suffering derailments.

pittsburghrailfan posted:

Another quick question. I realize that the trucks and wheelsets are gauged for OW5. However, MTH and Lionel both insist that their engines and rolling stock (at least in the Premier and Lionscale lines) are built to 1:48 scale proportions. Are the shells and frames P48? Or are they scaled for OW5 as well? 

This is a confusing part about O scale in general.  1:48 is the proportion of the model and is not at all related to the gauge of the track.  OW5 refers to track gauged at 5' between the rails, Proto 48 refers to 4'-8 1/2" between the rails. 

A model can be ON3 (O scale narrow gauge 3') and it is still a 1:48 proportioned model.  The rail spacing is simply scaled for 3' between the rails.

Once you make the mental separation between proportion and track gauge, it is much easier to sort it all out.  Not always an easy thing to grasp at first.

Does that help?

GG1 4877 posted:
pittsburghrailfan posted:

Another quick question. I realize that the trucks and wheelsets are gauged for OW5. However, MTH and Lionel both insist that their engines and rolling stock (at least in the Premier and Lionscale lines) are built to 1:48 scale proportions. Are the shells and frames P48? Or are they scaled for OW5 as well? 

This is a confusing part about O scale in general.  1:48 is the proportion of the model and is not at all related to the gauge of the track.  OW5 refers to track gauged at 5' between the rails, Proto 48 refers to 4'-8 1/2" between the rails. 

A model can be ON3 (O scale narrow gauge 3') and it is still a 1:48 proportioned model.  The rail spacing is simply scaled for 3' between the rails.

Once you make the mental separation between proportion and track gauge, it is much easier to sort it all out.  Not always an easy thing to grasp at first.

Does that help?

Very much so. Thank you. 

Simon and all,

I would guess that all O scale steam loco models built to operate on standard 5' gauge track would have to have some compromises built into their design so converting one to P-48 does nothing except changes the gauge.  Look at Eric's photos of his work on this forum.  I believe those beautiful models are built with P-48 track gauge and wheel profiles but can you really see a difference when viewing them out on a model railroad from standard O scale?  I cannot.

Not all compromises are due to track gauge.  I measure many drivers over the course of a year.  Do O scale modelers realize that most models of the O Scale PRR K-4s are operating with 78" drivers instead of the correct 80" diameter?  The real K-4s has closely spaced drivers and even with our "scale flanges" the model builder has to either leave the flanges off of the center drivers (obvious to the eye) or reduce the diameter of the drivers by about twenty thou on the radius.

When I give a clinic on 3 rail to 2 rail conversions, the question of P-48 comes up at times.  I refuse to convert any models to P-48 as I see no real point in it and, in my opinion,  it has created a rift in an already too small segment of our hobby known as O scale 2 rail.

 At my clinic, I bring along two pieces of pine wood cut to lengths to match 5' gauge and P-48 but 20 times larger than the size of the actual track gauge.  I hold them up side by side so the audience can see the difference in length.  Then I put them behind my back and pull out one length of pine and ask which one I am holding up.   No one can tell me without a frame of reference.

I was an O scale modeler for a few years before I found out that my models were operating on 5 foot gauge.  It does not bother me at all.  There are plenty of things going on in this world to get worked up over.  This is not one of them!

Just my thoughts...

Joe Foehrkolb

I respectJoe's opinions, and agree that worrying about track gauge, boiler bellies, and brake shoes ought to rank extremely low in the global scheme of things, but:

Joe is correct that one cannot simply look at the track and see whether or not it is the correct width.  He is also correct that you need a reference - like the end-on view of a caboose or locomotive - to tell whether the fat Russian gauge bothers you.

It bothers me, but just enough for me to do something about it.  That is why I have 1 1/8" gauge O Scale stuff, and why mostly I model in 17/64.  I simply take action, and let the rest of the world enjoy whatever they want.  Do I wish they had fixed it in 1935? Sure.  Do I lose sleep over it? Nah . . .

rrjjf posted:

Simon and all,

When I give a clinic on 3 rail to 2 rail conversions, the question of P-48 comes up at times.  I refuse to convert any models to P-48 as I see no real point in it and, in my opinion,  it has created a rift in an already too small segment of our hobby known as O scale 2 rail.

 

Just my thoughts...

Joe Foehrkolb

You do really great work Joe, and I've always admired your craftsmanship.  Your machine work is second to none.

I've always presumed, from the tone of your comments that you did not do P:48 conversions for personal/philosophical reasons,  not because they were any more difficult to do.

Unfortunately for me I admired Bob Hegge's Crooked Mountain Lines enough to make a decision that if  I ever did O scale it would be "finescale".

For me the beauty of this hobby is well detailed track and prototype profile wheelsets rolling on it.

And I appreciate craftsmanship, regardless of track gauge OR number of rails.

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