Can 3-rail be made to run 2-rail?

I'd re-think the plan.  Unless you have the switchable 2-rail/3-rail MTH locomotives, it's a major chore to make 3-rail stuff run on 2-rail track.  Also, any locomotive modified for 2-rail won't run on the 3-rail track for obvious reasons.

In a word,,,,,,,,,no.  Aside from the electrical issues, the 3-Rail wheel flanges are simply WAY too big for proper operation on scale 2-Rail track & turnouts. With the right 3-Rail track & turnouts (like Atlas or MTH ScaleTrack) 2-Rail scale rolling stock will work pretty well on 3-Rail track.

If you use Gargraves track you can run 2 rail equipment by powering only the outside rails as all three rails are connected with real wood ties which does not conduct electricity.  The issue would be turnouts if using actual "scale" 2 rail equipment as the large gaps between the frogs and guide rails being way too far out to actually guide anything may cause derailment issues.  If you have a closed loop without turnouts, Gargraves would accommodate either two or three rail trains, you just could not use non-insulated three rail cars on your 2 rail train.  Good luck!

If you want to cross from a section of 3-rail track to a 2-rail section...the center roller is your enemy.

Without center rollers you won't pickup any power from the middle rail and the sprung center rollers will hit the ties on 2-rail track as the train goes around and probably derail when they come to a switch. Plus, unless you do some internal rewiring to your engines, things will short out or simply not work.

But if you want to run 3-rail trains on 2-rail track YES!!!

All of my 3-rail engines and rolling stock still use the "pizza-cutter flanges" but have been converted to Battery-Powered, Remote Control (BPRC) and running on code 148 2-rail track.  The only derailments I have had were "pilot error", not throwing a switch, etc.  All ,my engines have a battery and a receiver installed and are run by a handheld remote on 2.4Ghz.

Here's 2 Williams/Samhongsa engines, a N&W J 4-8-4 along with a SAL Q-3 2-8-2 sitting on Micro-Engineering code 148 track, both engines still have their original 3-rail wheels on them.

And a variety of makers rolling stock:

I don't think I've ever seen a layout that will let you simply run a 3-rail train off of 3-rail track onto 2-rail track successfully, without having to stop and turn something off, then turn something else on to continue.

Thanks for all the input. To clarify, the intent is to run 2-rail equipment only and ditch the 3-rail. Here's another option...I have a smaller layout in 3-rail and one option is to just build a 2-rail layout around it with no rail connection between the two. Operationally, it would work but, yes, it would look funny with the 2 and 3-rail combined. I hate to ditch the 3-rail layout as I've spent the last five years building it for the grandsons and it's pretty well completed at this point.

If I had to start over, I would have gone 2-rail.

@Bob Delbridge posted:

...

All of my 3-rail engines and rolling stock still use the "pizza-cutter flanges" but have been converted to Battery-Powered, Remote Control (BPRC) and running on code 148 2-rail track.  The only derailments I have had were "pilot error", not throwing a switch, etc.  All ,my engines have a battery and a receiver installed and are run by a handheld remote on 2.4Ghz.

Here's 2 Williams/Samhongsa engines, a N&W J 4-8-4 along with a SAL Q-3 2-8-2 sitting on Micro-Engineering code 148 track, both engines still have their original 3-rail wheels on them.

And a variety of makers rolling stock:

I don't think I've ever seen a layout that will let you simply run a 3-rail train off of 3-rail track onto 2-rail track successfully, without having to stop and turn something off, then turn something else on to continue.

Nice work, Bob. I didn't know you had switched over to Code 148 track. What modifications do you make to turnouts to handle the gauging of 3-rail wheel sets?

The MTH switchable products are an exception to this HW, they have scale wheels and switchable 2-rail/3-rail.  However, I have to disagree that 2-rail rolling stock works well with Atlas switches.  Our club layout has a ton of Atlas switches, all are O72 or larger.   2-rail rolling stock still derails way too often on the switches.

It seems pretty apparent that 2 rail is the way you want to go. Don't try and mix the stuff, just go 2 rail and leave the 3 rail stuff you have for your grand kids.

Be aware that 2 rail requires more space, (larger radii curves) particularly if you want to run LARGE engines. I would seriously consider dead rail for power (radio control rechargeable battery). Delbridge above can tell you about that. There are piles of 2 rail stuff out there particularly on the secondary market. There are a lot of 2 rail layouts on You Tube.....you might want to get on there and figure out what you like, what you have room for, and what you can afford.

Take your time, enjoy the trip, Just have fun!

Simon

@gunrunnerjohn posted:

The MTH switchable products are an exception to this HW, they have scale wheels and switchable 2-rail/3-rail.  However, I have to disagree that 2-rail rolling stock works well with Atlas switches.  Our club layout has a ton of Atlas switches, all are O72 or larger.   2-rail rolling stock still derails way too often on the switches.

I used to have the same issue with my Atlas turnouts, until I learned "the trick"! Simply glue a strip of thin styrene on top of each & every turnout guard-rail, in oder to make the guard-rails the same height as the running rails. Didn't have any more derailments after that.

Interesting mod, that kinda' makes sense looking at an Atlas switch.  I just chalked it up to providence, there were only a handful of 2-rail cars that we wanted to run.  The final solution was to swap out the wheelsets for standard pizza cutter wheels.

@AGHRMatt posted:

Nice work, Bob. I didn't know you had switched over to Code 148 track. What modifications do you make to turnouts to handle the gauging of 3-rail wheel sets?

Hey Matt.  3 or 4 years ago I decided I didn't like what I had done, that is pulled up the center rail.  I ended up tearing the whole layout down and redesigning it using Mianne benchwork and code 148 2-rail track from ME, Atlas, and Signature Switch.  Add in the gutting of my 24 steam and diesel engines and converting them to BPRC and it's obvious I spent my kids inheritance, but I got what I wanted.

I tried making 2-rail turnouts, miserable failure.  I contact Brad Strong at Signature Switch and told him what I wanted to do (run 3-rail wheels on 2-rail track) and he fixed me right up.  His switches/turnouts are the stuff!!!  It took me 2 years but I managed to get approx 20 switches from him, I'd have to go back and count.  Here's my (kinda) present layout, I've made a few changes but it's 95% accurate.  Gives me a 3/4 mile loop to run on and a lot of switching:

The 2 thick black lines are a wall and a knee wall at the top of the stairs, I ended up making a piece of benchwork to go where the 2 walls connect (at the top of the stairs) from a 1x8 board with a spine underneath for support.  It attaches to the horizontal wall and the end of the Mianne workbench.  The horizontal wall goes all the way from downstairs to the ceiling upstairs, but it can be cut down so it's even with the height of the layout.  Right now I have a "tunnelette" about 6" long thru the wall.  When we bought the house the stairs were very narrow and steep, my dad widened them to 36" and made them less steep, in doing so he also built that wall, so I know I can cut it down if I want.

I told myself I would run trains for at least a year before I did any scenery, it's been longer than that but I'm at the point where I've started gathering supplies.  It won't be Ed Rappe caliber scenery , but at least some trees will be "planted" and some people populating the buildings/businesses.

@Bob Delbridge posted:

Hey Matt.  3 or 4 years ago I decided I didn't like what I had done, that is pulled up the center rail.  I ended up tearing the whole layout down and redesigning it using Mianne benchwork and code 148 2-rail track from ME, Atlas, and Signature Switch.  Add in the gutting of my 24 steam and diesel engines and converting them to BPRC and it's obvious I spent my kids inheritance, but I got what I wanted.

I tried making 2-rail turnouts, miserable failure.  I contact Brad Strong at Signature Switch and told him what I wanted to do (run 3-rail wheels on 2-rail track) and he fixed me right up.  His switches/turnouts are the stuff!!!  It took me 2 years but I managed to get approx 20 switches from him, I'd have to go back and count.  Here's my (kinda) present layout, I've made a few changes but it's 95% accurate.  Gives me a 3/4 mile loop to run on and a lot of switching:

The 2 thick black lines are a wall and a knee wall at the top of the stairs, I ended up making a piece of benchwork to go where the 2 walls connect (at the top of the stairs) from a 1x8 board with a spine underneath for support.  It attaches to the horizontal wall and the end of the Mianne workbench.  The horizontal wall goes all the way from downstairs to the ceiling upstairs, but it can be cut down so it's even with the height of the layout.  Right now I have a "tunnelette" about 6" long thru the wall.  When we bought the house the stairs were very narrow and steep, my dad widened them to 36" and made them less steep, in doing so he also built that wall, so I know I can cut it down if I want.

I told myself I would run trains for at least a year before I did any scenery, it's been longer than that but I'm at the point where I've started gathering supplies.  It won't be Ed Rappe caliber scenery , but at least some trees will be "planted" and some people populating the buildings/businesses.

Thanks Bob. Nice layout design. I have a collection of ScaleTrax, but the more I think about things, the more I'm inclined to go with Code 148 ME track. I'll probably drop in a Code 100 center rail for my older 3-rail equipment and pull the rollers on my scale-wheel equipment.

It can be done.  With all of the work involved and the limitations it would impose I don't know why you would want to do it.

Opinion here - mixed two and three rail is a lot better than sticking exclusively with 3 rail.  Gives you a chance to see the advantages and disadvantages of both.

And again opinion - having a loop of 2-rail outside a loop of 3-rail will not make the 3-rail look any worse than it already does.

The 3-rail has 54" curves. I want larger diameter to run those longer locos. So, the only way to get there is to create more track. I have a fair amount of structures (and $) on the existing layout that I would hate to ignore. I would run shorter locos like a 2-8-0 Consolidation on the 54" 3-rail track and run the larger stuff on the 2-rail located outside of the existing 3-rail.

@HudsonORailRoader posted:

The 3-rail has 54" curves. I want larger diameter to run those longer locos. So, the only way to get there is to create more track. I have a fair amount of structures (and $) on the existing layout that I would hate to ignore. I would run shorter locos like a 2-8-0 Consolidation on the 54" 3-rail track and run the larger stuff on the 2-rail located outside of the existing 3-rail.

Is it 54" curves or 054 3-rail track???  054 is 27" radius, 54" 2-rail track is 54" radius.

@Bob Delbridge posted:

Is it 54" curves or 054 3-rail track???  054 is 27" radius, 54" 2-rail track is 54" radius.

Its Gargraves 3-rail 54" curves. I guess that would make it 27" radius or 54" diameter.

@HudsonORailRoader posted:

Its Gargraves 3-rail 54" curves. I guess that would make it 27" radius or 54" diameter.

Correct.

If you did what Bob2 said you could run your 3-rail freight cars on 2-rail track, but you'd have to have 2-rail locos or the MTH 3-2 rail types where there's a switch underneath(?) to go back and forth between 2 and 3 rail.  Never thought of running both 3 rail AND 2 rail on separate track on the same layout.

Yeah, you need O-96, or 48” radius, to even consider 2-rail accuracy.  Either that, or serious modifications to couplers and wheel clearances will be required.

@bob2 posted:

Yeah, you need O-96, or 48” radius, to even consider 2-rail accuracy.  Either that, or serious modifications to couplers and wheel clearances will be required.

Pretty much. There are engines that will sneak through a 36" radius, but they need to be short with good coupler swing and/or have a short truck wheelbase and "China Drive" vertical motors. Every MTH scale-wheel diesel I have can get through 36" radius, plus a Hudson and my Big Boy (centipede tender and all).

@Bob Delbridge posted:

Never thought of running both 3 rail AND 2 rail on separate track on the same layout.

It’s been done before. I saw a layout many years ago in OGR that a gentleman had one or two loops of 2 rail around the 3 rail layout and there is a club in Eastern PA that has a loop of 2 rail along side their 3 rail. They also have S scale inside the 3 rail layout. It doesn’t look bad at all. I considered it but I decided I would rather have an all 2 rail layout.

Good luck HudsonORailRoader and keep us posted on what you decide to do.

One of the issues not mentioned was the un-insulated wheelsets on 3 rail cars.    Unless you change the wheelsets, or have some with one wheel insulated, 3-rail wheelsets will SHORT out on 2 rail track.

I disagree with the statement that you need to make major modifications to use 48 in radius with 2 rail equipment.    I have about 500 freight cars, and I have NO problems with any of them on 48 inch radius curves.    Now, The longest are 50 ft models.    I don't have any big auto racks or 80 foot models.    I do have a bunch of 52 gondolas and flats.      I have tested this and most if not all will get down to 40 inch radius and most 40ft models will get down to 36 inch.    I use all body mounted kadee couplers, not talgo style.    Also I have about 1 z dozen GGD 80 ft (20 inch) passenger car models and they also work on 48 inch radius - although my main line is 52 inch.    Again all have body mount couplers.    None of these cars have had to be modified to do this.   I also have a bunch of PRR model steamers and diesels and most except the 2-10-4 will handle 48 inch.  The steamers include mikados and mountains.    You have to decide how all this stuff looks, but they don't look as bad as "072" curves.

Gargraves does make 2 rail track that would work with lionel size flanges, but you still have the short problem unless you go to battery power.

A friend of mine has an Overland WM 2-8-0 which is a large one, and it has not problems on his 36 inch radius curves.    Most brass steamers have the side rods (connecting the drivers to each) jointed at each driver to allow them to adjust some to curves.     Most 3 rail steamers have solid side rods, and blind center drivers.    They generally only have flanges on the end ddrivers, so they do not need to adjust to curves.    The 2 rail locos made by the same mfg unfortunately put flanges on the drivers but did not allow for curver adjustment by articulating the side rods.

Seems the focus strictly on steam here?  Most first generation O scale 2 rail diesels will navigate 24" radius with little or no modification. My own 2 rail pike grew from a 3 rail beginning and I was limited to 52" wide.  I could not put the layout in a different room as I literally built the thing into the walls so I had to go with 24" Atlas track (the old Austrian stuff). With very little modification to my #5 turnouts, I am able to run 5 MTH 3/2 "convertible" steam locos with hi-rail wheels, none of which is bigger than a Russian decapod but all my diesels are Atlas O, Weaver or P&D hobby and all I had to change was the front couplers on any dummy A units running backwards. I installed Kadee "long shank" couplers so the freight cars did not strike the pilots and that was the ticket.  I am sure the "purists" would frown but it works well and I retain the scale feel of things.  You can have a GREAT 2 rail pike in a small space.  Mine is only 12' long but serves my needs.   I had both 2 and 3 rail on the same pike for a couple of years until I converted the whole shebang and sold off any of the 3 rail stuff that was either pure tinplate or could not be converted.

Yes, 4 axle diesels especially will readily run on sharper curves.    I have tested my Weaver RS3 on 24 inch radius and it run fine and this is the original (which I like) single motor drive.    The problem with it is that the pilots swing out so far, that the kadee couplers cannot mate.    that can be fixed if I want to use curves like that.    I a friend who uses 36 inch radius and does not even have that problem.

@bob2 posted:

Yeah, you need O-96, or 48” radius, to even consider 2-rail accuracy.  Either that, or serious modifications to couplers and wheel clearances will be required.

Well, you really need to qualify that statement. This is the kind of statement that turns people away from O scale thinking that they need to have a barn and endless funds.

So, maybe it's true to some extent if you're running large steam engines, but 4 coupled diesels, small steam, freight cars 36-40', you can go quite a lot tighter on radius.  And, if you model traction and trolleys, you can go tighter yet.

Geez Martin...I can't think of everything   Does that count as a qualification???

I have a MTH 4-8-4 that I recently got up and running.  It does not like my 45" radius curves, it goes around them but I can tell there's a bit of friction.  I don't notice it running my Williams brass 4-8-4, 2-8-2 and 4-6-2 or my Lionel 4-8-2.  Biggest diesels I have are a Williams and a 3rd Rail E7 and they run fine.

I'll add to Matt's larger MTH engines that will negotiate 36" radius curves. My N&W Class A 2-6-6-4 will negotiate 36" radius since the driver wheelbases are not too long. You have to figure out what you want to run and what you can run and make your determination from there.

Bob Delbridge looks like he is doing some really good stuff with his conversion and a really nice layout design.

@Bob Delbridge posted:

Geez Martin...I can't think of everything

No worries, Bob. Every time I try to think, nothing happens.

Here's my chime in without bias. I currently have a "2-rail" addition because I was unaware of 2 rail when I got back into the hobby. With that being said I am enjoying both 2-rail and 3-rail layouts. Though I wish I had more "real estate" for my 2 rail addition I get to enjoy both of the O Scale subgroups.  I believe I have integrated them in a way that highlights both. As stated above I also get to regularly see the pros and cons of both and that will help me decided what the future holds.

My opinion would be to "dabble" in two rail unless you have your mind set that you no longer have an interest in 3-rail. The easiest way would be simply to add a two rail section separate from your 3-rail and run 2 rail equipment. From that you can decide if you want one, the other, or both.

Dave

I have Pacific types that needed slight modification in both the cylinder area and the tail beam to make it around 64" radius.  I added a 74" radius loop to test the ten-coupled locomotives, and even then the tail beams get narrowed.  My SP articulated chair car needed 1/8" extra space over the common truck for 74" radius, and those are shorties in comparison to the 21" cars.

@bob2 posted:

I have Pacific types that needed slight modification in both the cylinder area and the tail beam to make it around 64" radius.  I added a 74" radius loop to test the ten-coupled locomotives, and even then the tail beams get narrowed.  My SP articulated chair car needed 1/8" extra space over the common truck for 74" radius, and those are shorties in comparison to the 21" cars.

I remember you mentioning something about that a few years ago. There are scale models then there are SCALE models (Kohs locomotives come to mind). There's little truck swing and chassis clearance. My MTH 2-rail steam can make it through 36" centerline radius because they're 2-rail axles built into a 3-rail platform -- cylinders shaved and no tail beam.

Now that I'm living in both worlds, all of the designs for my future layout have a minimum 42" radius (O-84), but If I build outside I'm pushing it up to 84" radius (O-168). Even though everything I own will work on the smaller curves, there's that "look" of equipment rounding broader curves.

MTH makes the cylinders smaller!  Most just eliminate the tail beam, including 3rd Rail/Sunset.   My cure for the excellent scale Lionel and MTH steamers is a new frame, new drivers, and new cylinder block.  Usually the rods and gear are ok - on the FEF I had to replace the GS-4 rods with proper tapered castings.

I admit - I did get the Rivarossi FM Diesel and talgo cars around whatever radius the Austrians provided - 24"?  But O scale in general needs 48" minimum.  An 0-4-0 might look good on 24" with ore cars, but we are going for scale appearance, right?

@bob2 posted:

But O scale in general needs 48" minimum.  An 0-4-0 might look good on 24" with ore cars, but we are going for scale appearance, right?

There is a difference between what a train CAN do and what the ideal would be. The only way to know what a train can do is to test it. Whether that is 48" minimum, who knows? It could be 60", 64", 72" for some and 40" and 36" for others. I think that is why people have been going through this exercise. I don't have to plan for a UP 9000 because I don't have an interest in ever running a UP 9000 on the layout.

I consider anything I can make work in 2 rail as a step beyond anything I was doing in 3 rail. Sure I'd rather have 72" radius everywhere but I can make the trains I have work on much less. If that is a detriment to scale appearance then I'm still ahead of where I was with 3 rail. Otherwise I would be out of the hobby and my golf game would be much better.

I haven't touched a golf club since December 2019 (which did improved my game), my target shooting benefitted for a while, until the price of ammo went 4X the norm.  I would have thought my trains would benefit but their doing no better either.  I'm blaming my lack of improvement on the Covid!!! (I have improved my Youtube surfing abilities)

@christopher N&W posted:

I consider anything I can make work in 2 rail as a step beyond anything I was doing in 3 rail. Sure I'd rather have 72" radius everywhere but I can make the trains I have work on much less. If that is a detriment to scale appearance then I'm still ahead of where I was with 3 rail. Otherwise I would be out of the hobby and my golf game would be much better.

If I was out of 3 rail, then I would be out of O entirely.   Its not that I am a huge fan of 3 rail, but in the late 1980s I already had some to start out.  The transition to 3 Rail Scale was easy.  I could even use a number of my Postwar items with the scale cars.  Moving to 2 rail would be a bigger transition.  The alternative would be to do a 19th century road in HO in the same space I am currently using.  22" radius curves look more realistic in HO than 36" radius curves look in O.

@Bill N posted:

If I was out of 3 rail, then I would be out of O entirely.   Its not that I am a huge fan of 3 rail, but in the late 1980s I already had some to start out.  The transition to 3 Rail Scale was easy.  I could even use a number of my Postwar items with the scale cars.  Moving to 2 rail would be a bigger transition.  The alternative would be to do a 19th century road in HO in the same space I am currently using.  22" radius curves look more realistic in HO than 36" radius curves look in O.

And that brings me to option #3. I have a bunch of HO stuff in storage but I have come to appreciate the size of O scale. It comes down to amount of available real estate and how much I want to spend. 30" radius in HO looks pretty good. And, 48" looks even better. To get the same effect in O scale we need 60" and 96". That takes up a lot of basement not to mention the work involved to landscape all that area. I try to model for realism so wide curves and big steamers with lots of detail are desirable.