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The general answer is NO with hi-rail wheels. The reason being is that to accommodate the sharp curves, the treads are wider and the back-to-back spacing on the wheels is too narrow for the guard rails/frogs on 2-rail turnouts. If you can swap out the axles for the scale ones, they will work just fine. The other alternative is to modify the turnouts to increase the guard rail gap (the hi-rail flanges should squeak through the frog on the Atlas turnout (at least it did in some tests we ran years ago). On the regular track, it should work fine as the flanges seem to clear Code 148 rail.

In reverse order:

The rail used on AtlasO 2 rail track made since the 1990's is code 148.  This product line is made in China and has brown plastic ties.  Back in the 1970-80's Atlas imported 2 rail O scale track made in Austria by Roco.  The rail was nominally code 152 and can be spotted by the black plastic ties.   Heads up - early production Atlas-Roco track used nickel plated brass rail and under heavy use (or cleaning)  the plating will wear off leaving a brass rail top.  Late production Atlas-Roco and all Atlas-China track featured solid nickel silver rail.  

Atlas 2 rail turnouts have frog and guard rail flangeways formed to NMRA standards which do not provide clearance for the deep and thick MTH 3 rail wheel profiles.   If you are going to go 2 rail my recommendation is to lay your track to NMRA standards for brand independent smooth operation.    

Thank you Matt!  I have been studying 2 rail this past week.  The more I learn the more I'm amazed at the huge differences in the same gauge.

I believe that most people, including me, assume that either 2 rail O or 3 rail O are pretty much the same less the number rails and polarity issue when using 2 rail track.

Those things just scratch the surface.

I have a HUGE investment in 3 rail and still enjoy it.  However, I desire to create and have an O scale 2 rail portable layout that I may display at different NMRA events.  I thought I could use my 3 rail equipment on this portable 2 rail.

I learned I can use DCS and AC power on 2 rails.  I have MTH locos where I only need to flip the switch for 2 rail.  I thought all I needed was track.  Then the issue came to my attention about hi-rail wheels have issues on 2 rail track turnouts.

Option #1

I could simply remove the center rail on my Ross turnouts and Gargraves track.  However, I wanted a highly realistic track with much lower rail.  It is rare to see O scale 2 rail at NMRA events; at least in Central Indiana.

I really want to save money and not buy 2 rail engines and cars for my possible future portable 2 rail O.

I am considering modifying 2 rail turnouts to accommodate hi-rail wheels.

However, if someone in the future buys the layout or switches, or wants to run 2 rail equipment on my 2 rail track, there is going to be an issue at turnouts.

I have even went so far as Proto 48, but I'm simple not going to adjust cars and engines wheel sets that little bit, which will restrict them solely to P48 track.

Don't get me wrong, I think Proto 48 is awesome!  If this was day 1, and I had a clean slate, I would consider it.  I just have way too much invested in 3 rail.

11 years ago when I began planning The Glacier Line, I wanted something very different.  That is why I choose 3 rail O and put it in a highly realistic setting.  I have no regrets.

The Glacier Line has been professionally videotaped twice by two different companies and has appeared in four other national publications including OGR and the NMRA Magazine.  It isn't easy getting 3 rail in the NMRA National magazine.

I really like the look of Code 148 2 rail O scale track.  And I learned very recently about the Signature Switch Company owned by Brad Strong.  I have read a number of reviews on this Forum attesting to the high quality of Brad's products.

All that remains to be seen is what I'm going to do as far as building a 2 rail portable layout.

It is a shame that I'm so attracted to a different number of scales.  I'm just finishing my scenery module in N scale.  This is what got me thinking about super realistic 2 rail O scale.

It's a shame I'm not rich.


Seems to me if you indeed want (and I quote) "super realistic 2 rail O scale", then it sounds like you will have to bite the bullet and get some equally "super realistic 2 rail O scale" rolling stock. Is 2 rail stuff THAT much more expensive than higher quality 3 rail? You never know; you might be surprised... 

Mark in Oregon

Good point Mark!

However, I'm just trying to more effectively and efficiently use the wealth of material which I already possess.

I have over 30 some odd engines with some having the 2 / 3 rail switch.

I have somewhere in the neighborhood of 400 cars.  Several have plastic wheels which I can swap out to use on the 2 rail.

I already have two DCS systems and multiple extra remotes--and transformers.

Many of my cars are already highly detailed highly realistic and prototypical Atlas cars that I have weathered.

Really, all I desire is 2 rail track.

I want an O scale 2 rail layout that is super easily portable, exactly like my 3 rail Timesaver, so I may display it at NMRA and other sponsored train shows.

I have communicated with Brad from Signature Switches who can build Code 148 turnouts in a way that provides clearance for hi-rail wheel engines and cars.

I would love to create / build a super detailed highly realistic super easily transportable 2 rail O scale switching layout.







Thank you Dave!

 In addition to keeping you and others on the board posted, I will keep myself posted.  LOL

It will be a real Wonder to see what I will actually end up doing.

This morning, I'm leaning TOWARD the side of doing 2 rail except using 3 rail equipment on 2 rail track. That is primarily because of my sizeable sizeable sizable investment in 3 rail equipment.

I'm thinking about doing a portable layout for the future. And as most of us know now, it takes a lot larger curve to accommodate a 2 rail engine vs.  a 3 rail engine generally speaking.

Since all of our spaces are fairly limited, and especially if I want to make a layout that is easily portable, if I have any curves these are going to have to be relatively tight. That would mean either an extremely small 2 rail engine or a 3 rail engine small to a medium size.

I really love the look of the lower profile track that I'm seeing.  Code 148 from Micro Mark.

I also love the look of the signature switches that Brad makes! My next portable layout will definitely have these things.

I guess I'm going to have to compromise on the signature switches by having them made in such a manner they will accommodate 3 rail equipment.



@Strummer posted:

Seems to me if you indeed want (and I quote) "super realistic 2 rail O scale", then it sounds like you will have to bite the bullet and get some equally "super realistic 2 rail O scale" rolling stock. Is 2 rail stuff THAT much more expensive than higher quality 3 rail? You never know; you might be surprised... 

Mark in Oregon

Surprised for sure.  I have bought equivalent Atlas 2R rolling stock on Ebay sometimes half the price it is selling for in 3R.  Their are some great 2R deals to be had for sure.


I have really enjoyed your and your wife's articles and videos of the Glacier Lines.  It is the type of layout that I would build if I had the space.  

There are several 2-rail shows scheduled for 2021.  The one nearest you is probably the Chicago March meet.  I have never been to this show but I have attended O Scale West many times.  If the March meet is anything like O Scale West, there will be tables full of very nice 2ROS rolling stock at clearance prices.  I am talking about box cars at $1O each, etc.  Buying used 2-rail equipment could cost less than buying new wheel sets to convert your 3-rail equipment.

The biggest issue with running 3-rail equipment on 2-rail track is that the 3-rail wheels and axels are not insulated.  This means that standard 3-rail equipment will always short out when placed on powered 2-rail track.  It has nothing to do with track polarity.  You must change the wheels to avoid this.  Also, you usually need to modify the 3-rail car height so that it will match with 2-rail Kadee couplers NMRA standard height.  I can't see staying with claw couplers if you are making everything else scale.  

I have several MTH PS-3 2-rail engines that run fine on 2-rail track using DCC for command control. (I bought the 2-rail version.  As you probably know, MTH has a kit to convert 3 rail to 2 rail for their 3/2 diesels.)  These engines in the 2-rail version come with insulated wheels.  I also have two MTH PS-2 2-rail steam engines that I had converted to PS-3 so I could use the DCC feature that comes with PS-3.   This eliminates the polarity issues that comes with the PS-2 3/2 engines.  I would think that if you are going scale that you will want to use DCC on your modular layout.  

You might want to check out Rich Batista's Black Diamond Lines videos.  He describes how he converted 3-rail to 2-rail in one video.  Another source is O Scale Resource magazine.  This magazine is only online line and it only deals with 2-rail.  The current issue has a very good article on converting a MTH car from 3 to 2-rail.  Another source for information is the O Scale Kings organization.  

Thanks again for sharing the Glacier Lines with the model railroad community.  

I hope that this helps.  NH Joe




John C.,  You mentioned central Indiana in your post. Be sure to attend the O and S scale show this September 18 through the 20 on the south side of Indy. Always a great selection of $5 to $20 two rail cars, track and structures. I gave up a 40 year collection of HO to go into O scale 2 rail several years ago and have never regretted the change (except not doing it sooner)!   Good luck, Doug


For now, I'm living in both worlds. I buy MTH locomotives with scale wheels and all new rolling stock is equipped with scale wheels (I'm converting some 3-rail equipment to 2-rail). However, I've been a member of a 3-rail club for more than 20 years and currently run the scale-wheeled equipment on 3-rail track (a lot of YouTube videos on this). I also ran on a 2-rail modular layout at a show to demonstrate MTH's GE Hybrid running under DCC. I've run DCS on 3-rail, 2-rail, AC power and DC power (for testing purposes).

What I'd recommend is to choose one or the other and stick with it. The only advantage 3-rail has at this juncture is you can get away with running sharper curves (as small as 18" radius/O-36) but that comes at the cost of appearances and the loss of the ability to run longer trains. There is plenty of 2-rail equipment that can run on 36" radius/O-72 but in some cases it compromises appearance (think Big Boy or long rolling stock).

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