Returning to O-Scale/Gauge – Decisions

Welcome back to O gauge. Great plan. The only thing I would change is the track. I love scaletrax. However, the selection available is always limited, particularly the switches.  I’d go with Atlas track and Ross custom switches. Always widely available and looks good as well. As far as control systems, I’ve seen plenty of people start out with one or the other and then along comes a must have engine with a different control system. Most people expand accordingly.  Good luck!

@Dublinjack posted:

Hi! I am returning to O-Scale/Gauge after being away 30 plus years. Recently I sold all my high-quality N-Scale Katy coupler equipment. Then I bough a L/N K-Line Hudson TMCC for display. After receiving the Hudson, it triggered my interest to get back into O-scale.

I am looking for some advice and guidance to get up to get up to speed with all the changes that have occurred in O-Scale over the years. This forum is a key resource for me with all its excellent posts.

After much research and analysis, I have made the following preliminary decisions:

O-Scale 2-Rail vs O-Gauge 3-Rail. I prefer 2-rail for realism; however, it became apparent that there are a lot more resources readily available in 3-rail.

1. To move forward now with the hobby, I am going with 3-rail scale track.
2. While using the 3-rail system, I will take the time to learn 2-rail systems and available resources. Unfortunately, I only have 3-rail local resources.

Track. Since I want as realistic as possible track system, I will choose scale rails where possible:

1. In 3-rail there appear to be 3 excellent alternatives with black center rail . . . Atlas O 3-Rail Nickel Silver, MTH 3-Rail RealTrax or MTH 3-Rail ScaleTrax. I probably will go with MTH ScaleTrax.
2. It appears that these track systems including the switches will handle both scale wheels and hi-rail wheels. I want to go with locomotives with scale wheels as noted below.

Locomotives.  I will be acquiring both steam and diesel locomotives that are of historic interest.

1. With Mike Wolf retiring and shutting down the original MTH, I have decided to concentrate on buying initially MTH Premier steam locomotives that have the 3-rail/2-rail capability . . . . . . . . . .  These are ones that I looking to buy now:   (a) 20-3471-2 (scale wheels) PRR K4, 2011,                                                                                                                           (b) 22-3714-2, 2018 or 22-3775-2, 2020 (scale wheels) UP Big-Boy,                                                                                 (c) 22-3582-2 (scale wheels) NYC Hudson, 2015 (only if my K-Line Hudson cannot be converted at a reasonable price. Understand that Joe Foehrkolb has retired.
2. I have three other 2-rail motorized steam locomotives (scale wheels), which I have on display. I built them over 30 years ago and will upgrade each to have smoke and sound.
3. If I decide to stay 3-rail, I will upgrade my K-Line Hudson with chuffing smoke, PS3 and cruise control. I would also convert my three 2-rail locomotives to 3-rail.

Rolling Stock. Fortunately, there are a lot of sources for rolling stock including passenger cars that easily can be converted from 3-rail to 2-rail by just changing the wheels of trucks.  Atlas, Lionel and MTH are all excellent sources for new and online for used.

Control Systems. Since I am coming from N-Scale, I need to get up to speed on O-Scale control systems capabilities and cost to meet my needs. Since Lionel is only 3-rail, I will not consider their TMCC control.

1. Since I will be initially going with 3-rail and then converting perhaps to 2-rail later, I will go with MTH’s DCS system, which has DCC capabilities for 2-rail systems.
2. I need to do much research to learn 2-rail DCC as well as Bluetooth system capabilities and costs. In 2-rail I want each locomotive to have its operational sound and control.

Any advice and guidance will be greatly appreciated.

Jack

If I may toot our own whistle, you may want to consider getting at least a digital subscription to OGR magazine.  It is an excellent resource and with a digital subscription, you have access to ALL issues ever published!  In addition, you get FREE access to the OGR digital library featuring many videos that will help you in your quest to learn more about O-gauge.  Finally, your subscription helps support OGR's efforts in this segment of the hobby...and no, we are not getting rich...believe me, we need as many subscribers as possible.

@Dublinjack posted:

1. In 3-rail there appear to be 3 excellent alternatives with black center rail . . . Atlas O 3-Rail Nickel Silver, MTH 3-Rail RealTrax or MTH 3-Rail ScaleTrax. I probably will go with MTH ScaleTrax.
2. It appears that these track systems including the switches will handle both scale wheels and hi-rail wheels. I want to go with locomotives with scale wheels as noted below.

I'd consider Ross and/or Gragraves track and Ross Switches.  Both Ross and Gargraves have black center rails.  I would personally NOT recommend Atlas switches, though I do like their track.

@Dublinjack posted:

Control Systems. Since I am coming from N-Scale, I need to get up to speed on O-Scale control systems capabilities and cost to meet my needs. Since Lionel is only 3-rail, I will not consider their TMCC control.

You'll miss out on a lot of nice locomotives.

@Dublinjack posted:

Control Systems. Since I am coming from N-Scale, I need to get up to speed on O-Scale control systems capabilities and cost to meet my needs. Since Lionel is only 3-rail, I will not consider their TMCC control.

1. Since I will be initially going with 3-rail and then converting perhaps to 2-rail later, I will go with MTH’s DCS system, which has DCC capabilities for 2-rail systems.
2. I need to do much research to learn 2-rail DCC as well as Bluetooth system capabilities and costs. In 2-rail I want each locomotive to have its operational sound and control.

Note that PS/2 does NOT do DCC, so you'll want to stick to PS/3 to achieve your stated goals.

@Dublinjack posted:

O-Scale 2-Rail vs O-Gauge 3-Rail. I prefer 2-rail for realism; however, it became apparent that there are a lot more resources readily available in 3-rail.

1. To move forward now with the hobby, I am going with 3-rail scale track.
2. While using the 3-rail system, I will take the time to learn 2-rail systems and available resources. Unfortunately, I only have 3-rail local resources.

Once you make your mind up to invest in three rail, it is highly unlikely you will later  "take the time to learn 2-rail and available resources".   One recuring theme is "I would go to 2 rail because of the realism, but I already have invested too much in three rail.

I suggest you take the time to learn about two rail and three rail now, before you make a sizeable investment in either.   Visit layouts, talk to layout owners, go to shows.   If you want I can send you a talk I gave on the basics of modeling in 2 rail O scale (including resources). Just e-mail me.  Learning all this will help you make an informed decision to chose which is the best way for you to enjoy O scale railroading.

By the way:  Your statement that there are a lot more resources readily available in 3-rail, while strictly true, is a bit misleading.  Particularly IF you are after fidelity to the prototype.    I have found that I have been able to get anything I want in two rail.  I model the PRR.  But so have my fellow modelers who model the N&W, C&O, Santa Fe, WM, B&O, Southern, BNSF, DRGW, Milwaukee Road, NKP, and a host of others.   

@Dublinjack posted:

Hi! I am returning to O-Scale/Gauge after being away 30 plus years.

Track. Since I want as realistic as possible track system, I will choose scale rails where possible:

1. In 3-rail there appear to be 3 excellent alternatives with black center rail . . . Atlas O 3-Rail Nickel Silver, MTH 3-Rail RealTrax or MTH 3-Rail ScaleTrax. I probably will go with MTH ScaleTrax.
2. It appears that these track systems including the switches will handle both scale wheels and hi-rail wheels. I want to go with locomotives with scale wheels as noted below.

Any advice and guidance will be greatly appreciated.

Jack

Jack,

I think you are wise to convert from N to O-scale. In my opinion, there's just no comparison between models in those scales. I think that O-scale is much more impressive and satisfying than N, but selection of a scale is a just personal preference.

Regarding O gauge track, I prefer the solid nickel-silver rails of Atlas O. I have used their track and switches on both of my 3-rail layouts without problems for many years. But, I just want to caution you that some MTH Premier scale-wheeled locomotives (specifically the USRA 0-8-0 steam switcher) will not get through the curved path of Atlas O-54 switches on my layouts. MTH says that locomotive requires curves with at least 42-inch radius, although  they list O-31 curves with hi-rail wheels. Enjoy your new model railroad.

MELGAR

I did N 30 years ago only because of space limitations.  As one ages and vision challenges arise, if one has the space, larger is better, hence my own return to O.  Though my interest and collection is 3RS, my perception is that there's a lot more available in 2-rail O-scale now than there was 20 years ago (see especially 3rd Rail / Sunset / GGD), if one wants to take that route.  With DCC and the modern 2-rail offerings from Sunset and what's left of MTH, the advantage of 3RS over 2-rail is not what it was 20-30 years ago, especially if you don't have a substantial, sunk investment in 3RS.  As to track, in 3R, the Atlas product is more prototypical, but note the switch issues stated above, and it costs more.  Agree with John Sethian's comment on taking some more time to mull over the 2 vs 3 rail matter - and look at what folks have done in 2R via a digital subscription to OGR!

You will want to consider the larger area that 2-rail will require over 3-rail for a similar layout plan.

I second what Gunrunner John said I wanted to go to 2 rail coming from HO there was limited DCC decoders available at the time for O scale. You would get accustomed to seeing the third rail fairly quickly. And the ability to use smaller radii track is a major bonus.

I have a 24 x 12 layout in 3-rail.  My smallest curve with the exception of a couple of industry sidings is O72, and I can run pretty much any O-scale 3-rail locomotive or rolling stock here.  While it's a decent size, but not really expansive for 3-rail, it would be a hopelessly inadequate space for 2-rail.

If that and realistic track are your only criteria, remember it is not the number of rails that determines track radius.  If you need O-27 curves but like 2-rail track, consider battery/RC.

@bob2 posted:

If that and realistic track are your only criteria, remember it is not the number of rails that determines track radius.  If you need O-27 curves but like 2-rail track, consider battery/RC.

Or consider a streetcar or Interurban type layout.

You're not going to believe this- but (at least to me) NOW after 5 years or so in three-rail the track looks "normal"- and 2-rail looks like it is missing something.  Actually- it IS- the middle rail.

Technically, the reason 3-rail, to me,  is better is the reliability of AC vs. DC.  That debate goes back to Edison vs. Tesla.  The reasons I like the Lionel (TMCC or Legacy) system is simplicity (one wire connected to an outside rail of the track, and use of your house wiring system for the antenna).   

Also- (I have posted this before), but:

- everything in model railroading is a caricature, anyway. Real scale is unachievable indoors - the track- the minimum actual prototype curves are something like 17 feet diameter.  Anyone have O408 track for sale?

(Wikipedia: "In North America, equipment for unlimited interchange between railroad companies are built to accommodate for a 288-foot (87.8 m) radius, but normally a 410-foot (125.0 m) radius is used as a minimum, as some freight carriages (freight cars) are handled by special agreement between railroads that cannot take the sharper curvature. For the handling of long freight trains, a minimum 574-foot (175.0 m) radius is preferred.).

- and, the train length-  a 100-car O scale train - using 60-foot (common in 1950) cars, would be around 125 actual feet long in O, not counting locomotives, tenders, or couplers.  And, a model loco would be very unlikely to be capable of pulling 100 cars, say weighing 12 oz. each, or 75 lbs.

All that matters is how much space you have, and the amount of "caricature" you are willing to accept.

Relax, and have fun.  It's all a game anyway!!  .

With the uncertainties involved, and no announced plan yet to produce track in the future, choosing ScaleTrax seems to me a likely source of future frustration.   The recommendations of Ross/Gargraves or Atlas seem prudent to me. Track is important .

I was out of the hobby for 30 years as well and Boy did things Change!!!  I went with Atlas track and turnouts.  I have 045, 054 and 072 loops with all 072 turnouts.  I did swap out the coil switch machines for Tortoise which are rock solid performers and look GREAT... because, you cannot see them.   The Atlas switch machines worked fine... but, I would have switched any top mount coil based switch machine.

Something to think about.  Considering you are restarting with one leg fully over each side of the fence, maybe consider hiding the CC and check book for 6 months.

As Alan suggests, explore the back issues, especially the real old early issues.  Expose yourself to folks who have invested a lot of time and effort in both 2 & 3 rail.

With Joe retired the thoughts to switch different engines back and forth between 2/3 wheel style may be lacking in practicality.

In your plans I note a lack of presence of on board battery remote control.  That discipline is truly the future of model railroading. 

Wiring a RR properly can be a ginormous amount of work.  I have built quite a few large RRs and IME I have spent as many hours wiring a pike as I spent stick building the layout and laying the track.  Really!

The amount of space you have available can be somewhat of a determining factor,  however that concern, IMO, is not as cut and dry as it may  seem to be.  Paper tigers roam in that neighborhood.

Take your time, you are at the fork of the road ready to take some rather large steps of what could be a regrettable commitment.

It has been said there was a warning notice at the edge of an old West town, "Be careful of which pair of ruts in which you set your wheels, either set of ruts last for 50 miles but wind up in different towns".

One thing that seems missing in you decision making process.  Have you considered designing a RR with an unconnected installation of BOTH 2 and 3 rail?  That bug bit me after seeing the very large seasonal 0 scale RR at the Brandywine River Museum in Chadds Ford PA.  They have both 2 and 3 rail knitted together running through the same area.

For me it is not a question of either/or.  I now run both.

@Mike Wyatt posted:

Technically, the reason 3-rail, to me,  is better is the reliability of AC vs. DC.  That debate goes back to Edison vs. Tesla.  The reasons I like the Lionel (TMCC or Legacy) system is simplicity (one wire connected to an outside rail of the track, and use of your house wiring system for the antenna).   

I run 2 rail DCS and TMCC (Legacy).  All on AC.  (Lionel bricks, in fact!). The number of rails does not determine the control system and/or the type of power.

@Landsteiner posted:

With the uncertainties involved, and no announced plan yet to produce track in the future, choosing ScaleTrax seems to me a likely source of future frustration.   The recommendations of Ross/Gargraves or Atlas seem prudent to me. Track is important .

That makes sense for track choices. . I know this doesn’t apply to the OP, but if I was coming in to the the hobby now, I would  stay away from traditional sized trains and start right away with scale size freight cars and locomotives. Postwar and postwar size trains are a dead end now.  I would also stay with 3 rail for simplicity and wide variety of available trains.

I would just go 2 rail. 2 rail HO. Way better variety, cheaper, and most of the makers have very cohesive product lines. You could build a nice layout so much faster in less space. You’re also not stuck with dead end proprietary controls with limited sound options and dumbed down features.

I greatly appreciate all the feedback on my preliminary decisions of returning to O scale. Based on all the comments, I will:

1. Subscript immediately to OGR magazine as a great resource to make my decision.
2. Take the time to learn about both 2-rail and 3-rail before making any investment.
3. Change my choice of track to consider Ross/Gargraves or Atlas.
4. Include Lionel TMCC/Legacy in addition to MTH DCS and DCC 2-rail systems as I evaluated which control system to use. Understand that Lionel has many excellent 3-rail locomotives.
5. Stick with MTH’s DCS PS/3 (not PS/2) in evaluation which control system to achieve my goals.
6. Evaluate layout size as a primary two or three rail selection factor. Understand that 2-rail requires a larger size layout than 3-rail systems. My goal is to have minimum curves of 054 and prefer 060 and larger.
7. Appreciate the comment that I should consider designing an unconnected installation of both two and three rail systems. Based on layout size I may be forced to select only one system.

Again, thanks for the feedback and any other recommendations that you may have.

Jack

@Dublinjack posted:

1. Evaluate layout size as a primary two or three rail selection factor. Understand that 2-rail requires a larger size layout than 3-rail systems. My goal is to have minimum curves of 054 and prefer 060 and larger.

My suggestion is even for 3-rail to go with O72 curves and larger.  I've had everything from O27 and up, and I can tell you that smaller curves will always leave you wanting for larger curves. My current layout I finally decided that O72 should be the minimum, and I only violated that for a couple of industry sidings, and maybe my future freight yard.  Even for those, I'm trying to stick with O54 to limit the restrictions on what will run there.  All my mainline, and the secondary loops are at least O72 curves.

FWIW, for 2-rail, O72 would be O36 radius, something that's the bare minimum for smaller 2-rail O-scale equipment, something to consider.

@gunrunnerjohn posted:

I have a 24 x 12 layout in 3-rail.  My smallest curve with the exception of a couple of industry sidings is O72, and I can run pretty much any O-scale 3-rail locomotive or rolling stock here.  While it's a decent size, but not really expansive for 3-rail, it would be a hopelessly inadequate space for 2-rail.

Nonsense - You have double the space I have for my 2-rail layout.

@John Sethian posted:

Once you make your mind up to invest in three rail, it is highly unlikely you will later  "take the time to learn 2-rail and available resources".   One recuring theme is "I would go to 2 rail because of the realism, but I already have invested too much in three rail.

I suggest you take the time to learn about two rail and three rail now, before you make a sizeable investment in either.   Visit layouts, talk to layout owners, go to shows.   If you want I can send you a talk I gave on the basics of modeling in 2 rail O scale (including resources). Just e-mail me.  Learning all this will help you make an informed decision to chose which is the best way for you to enjoy O scale railroading.

By the way:  Your statement that there are a lot more resources readily available in 3-rail, while strictly true, is a bit misleading.  Particularly IF you are after fidelity to the prototype.    I have found that I have been able to get anything I want in two rail.  I model the PRR.  But so have my fellow modelers who model the N&W, C&O, Santa Fe, WM, B&O, Southern, BNSF, DRGW, Milwaukee Road, NKP, and a host of others.   

All good advise from John and well worth following.

@John Sethian posted:

I run 2 rail DCS and TMCC (Legacy).  All on AC.  (Lionel bricks, in fact!). The number of rails does not determine the control system and/or the type of power.

Also true. In fact, the number of rails does not even determine very much at all.

If you are already familiar with and understand how to use DCC, DO NOT SWITCH.

You will gain nothing but headaches and frustrations trying to use the proprietary 3 rail systems.

I had been 3 rail all my life, I recently started working with 2 rail. My layout is going to be 2 rail and 3 rail (completely separated). I have too much 3R stuff to give it up completely, but the allure of running stuff in scale just became too tempting to let go.  To be completely honest, trying to use scaletrax drove me to drop the center rail. I had been trending that way for a long time. Scale wheel engines, running 2 rail cars, kadee everything in sight.... the straw that broke the camel's back wasnt necessarily the center rail, it was the scale stuff slamming and wallowing through the 3 rail switches. The "standard non-standard" 3 rail and the need to make everything backward compatible to 1903 means that everything gets built to clear the old HUGE flanges (not to be confused with the newer, but still somewhat large ones), the accessory shoes and all that stuff.  The sloppy frogs were what did it. I thought i could do it. It was "almost" scale, but it ran like crap.

I basically made the minimal investment at first, a couple pieces of track, an atlas 2 rail engine (which I knew could be 3 railed if I decided to not do it), and a basic DCC set (which I presumed I could resell if necessary). Well, yeah. It took one push of Function 8 to know I wasnt gonna give this up.

Do yourself a huge favor. If you already speak DCC, and know the likes of ESU and Tsunami sounds... dont switch. I really dont think you gain anything. Either way, if your plan is to go SCALE, with 2 rails or 3, the space it takes up is roughly the same. There's no place for O36 switches in scale.

BTW, contrary to popular belief, my 2 rail layout is 36" min radius and stuff runs fine, even 60 foot cars. You do have to know your limits. I had no plans to run steam engines, but 4 axle diesels are no sweat (even some of the big MTH diesels clear 36" in spite of the box label... ES44AC for example). Even though 2 railers hate vertical can motors... they do help when it comes to traversing small curves.

If you decide to go 3 rail, Atlas or Ross Track. Either way Ross switches, for the reliability and the variety (and they mate directly to atlas track using atlas joiners).

For 2 Rail, Micro Engineering over Atlas, but they both play nicely together if you go with code 148. I made my own switches with Fastrack jigs, and there's a variety of cottage switch makers who will make you switches. Commercial switches... Atlas is the only game in town right now. The wyes are good because they're space savers, but the 5s and 7.5s are better done as roll your own.

Keep in mind: Just about any car that is 3 rail can be 2 railed, Either by swapping the trucks or using NWSL wheelsets and adding Kadees (which most recent production cars are built kadee capable).

The MTH scale wheel engines are obviously 2 rail ready, but as a decoder PS3 is screwy and if you want to change it requires a total re-wire because again... standard non-standard. Unlike DCC which is common positive, PS3 is common negative.

Atlas diesels in 2 rail can be hard to find and/or spendy, but they're around depending upon what you want. Some of the newer ones are ESU ready or ESU equipped. The older ones are either DC (rip out the board and install from scratch) or had a QSI decoder (IMO, also rip out the board and install from scratch) which would at least get you going.

An around-the-walls layout will usually allow larger-radius curves than an island-type layout - 2-rail or 3-rail.

MELGAR

Jack,

As someone who is "in too far to turn back", I run 3-rail.  Regardless, I attempt to model the PRR prototypically.  The layout is 47' x 11' and mainline curves are a minimum of 72" diameter.  I use GarGraves, Ross, and Curtis track (it's all physically and visually compatible).  I also use both Curtis HiRail and Ross switches with Z-Stuff DZ-2500 switch machines.  The layout (including the switch machines) is all command control using TMCC.  Very reliable.

My only recommendation to you is to take much more time investigating your options.  You have many and as someone noted, once you make a decision you are pretty much committed.

That said, you may want to edit your profile to include your e-mail address.  That lets people send you documents and info.

Welcome and best wishes.

George

@mwb posted:

Nonsense - You have double the space I have for my 2-rail layout.

I can only say you are pretty limited with half that space running O-scale 2-rail!  If you're happy, so be it.

However, I call you on your "nonsense" claim.  I still maintain that 12 x 24 is a fairly small O-scale 2-rail layout and half that would be a VERY small O-scale 2-rail layout. I say it's Nonsense that you would claim that's plenty for a O-scale 2-rail layout and quite frankly, bad advice to a new user!

I'd like more space for my 3-rail, but I ran out of basement.

My opinion is please look at both 3 rail and 2 rail carefully before you make a decision. It took me almost a year to decide to switch to 2 rail and I am glad I did. I will always like PW trains and will always feel they have a charm to them but on a scale layout the center rail just bothered me too much.

I think John Sethian has made some very good points above.

My basement space for my layout isn’t much bigger than 12x24 but I will be happy if I can get the layout built. My space is 17x31. Its all I got and it’s going to have to do. I am a steam guy. I love steam. I haven’t totally decided on a minimum radius but at this point it looks like 54” R with easements. I will not running any fully flanged locomotives with 10 drivers as more than likely they will not make it around those curves. I can live with that and since the NYC has very few of these type of locomotives (not to mention models of them are not available) I don’t need them. There was a forum member here named Mike Pitogo who routinely posted that his MTH Big Boy (2R) could handle 36” R curves so if I want to run a BB I can.

As mentioned above in 3 rail you could get away 36”R curves and run every locomotive. This is true. The way I look at it is I am trading 3 foot of space on a 180 degree turn to get rid of the center rail since 54” is 18” larger than 36”. This is a trade I will make every day of the week.

I am not knocking 3 rail. I love to see a really well done scale 3 rail layout or traditional 3R layout. O scale done well is awesome whether 3 rail or 2 rail but I just want you to get the facts about both choices.

"1.  Subscribe immediately to OGR magazine as a great resource to make my decision."

I would strongly suggest that you ALSO subscribe to "Classic Toy Trains" (CTT) from Kalmbach.  You can never have too much information - or stuff to read for that matter.

This has been an interesting discussion and even though I didn't have a lengthy break from the hobby it does reflect the one I had with myself when I made the switch from HO several years ago. Focusing on 2 rail, I attended several shows and quickly figured out that to get what I wanted in 2 rail was going to require me to become a machinist, or at least hire one, to covert 3 rail locomotives to 2 rail. Nor did I want to become an eBay detective watching and waiting for what I wanted to come up for bid.

Coming from HO scale I was pretty convinced that I would never be able to live with a 3 rail layout. After all, that center rail was a dead giveaway of "toy trains" and no serious modeler would even consider 3 rail. Then I looked around on YouTube and found videos of the layouts built by Norm Charbonneau and Dave Minarik and Train TV had a feature on Bob Bartizek's Pennsy layout. These layouts weren't just only 3 rail, they are among the finest layouts I had ever seen in any scale and are largely responsible for me deciding "that third rail ain't all that bad."

I do consider myself a "3 Rail Scale" guy and my locomotives are equipped with fixed pilots and both locos and rolling stock have Kadee couplers. My 14 1/2' x 25' layout is built for prototypical operation and is built to the same track standards that I would have used with a 2 rail layout. It's not large by any standard but it meets my needs for replicating a small short line servicing a few industries. I have both DCS and Legacy controls and have also added my Digitrax DCC system. My intent is to convert everything to DCC in the next few years.

I still get the 2 rail bug every now and then and have a couple cases of Atlas O scale flex track and some Fasttracks turnout jigs and templates squirreled away in case I can't resist.

Joe Shipbaugh

@gunrunnerjohn posted:

My suggestion is even for 3-rail to go with O72 curves and larger.  I've had everything from O27 and up, and I can tell you that smaller curves will always leave you wanting for larger curves.

John and I have been down this road before.  Curves of O72 or larger fall into that big category of things you should do if you can pull it off.  The reality is that such wide curves will come at a significant cost if space is at a premium, and for some of us that cost is way too high.   If you have a modest space for a train layout a few minutes of doodling will show you how much space those O72 curves will take up.

If you see yourself operating scale articulated steam locomotives then O72 is a must.  However there are a large number of scale steam locos that can operate on less than 72" diameter track, including some that can operate on O-36.  If you want scale sized passenger cars you can get by with O-54.  If shortened passenger cars are OK you can get by with even less.  If you anticipate freight only operations, which era do you plan on doing and how long will your trains be?  Shorter freights of steam or transition cars can frequently operate well on curves as tight as O-36.

The good thing about getting into O today is that even though we don't know what may be made in the future, we do have some idea of what its requirements will be when it comes to curves.  When some of us got into it, articulated locos were rare and passenger cars were mostly shortened models that could operate on O-42.  Today you can more realistically plan for what you might need or want tomorrow.  So start out making a list of what you require and what would be nice to have.  Map out your future layout space, doodle some layout designs and then "operate trains" on those designs to see if they will hold your interest.  Many of us feel that the third rail is no big deal, but that doesn't matter.  What is important is whether you can tolerate it.  Moving from a 3 rail layout to a 2 rail layout will be a big deal, so make that decision up front.

@Nortonville Phil posted:

Or consider a streetcar or Interurban type layout.

Needing a barn for O two-rail is a myth, and always has been.

This is an approximate ten-inch radius curve, my two-car train of fifty-foot interurbans will negotiate this with no problem.

Another option would be On2½ (O on HO track).

The above works just fine if you can forego hauling iron ore out of the Missabe or hundred-car+ trains of double-stacks.

chiming in. Go with the largest radii you can fit but no smaller than 072. There is a lot more to find in O-gauge today and OGRR is the best place to find it; but still not as much as you'd find with HO.

Atlas track   ---OK -solid rails

Gargraves/Ross  trackage ----better, more turnout selections.

MTH - may be in short supply. not dead yet!

LIONEL - always a winner, better train control that hasn't stopped advancing.

@PRRMP54 posted:

Needing a barn for O two-rail is a myth, and always has been.

This is an approximate ten-inch radius curve, my two-car train of fifty-foot interurbans will negotiate this with no problem.

As long as you don't have any articulated locomotives, fixed pilots on your diesels, decapod locomotives, etc.  A ten inch radius curve is O20 in 3-rail speak, 3-rail track isn't even made with that tight a radius, and I'm sure it's absurd to consider 2-rail track with that radius!  None of my 3-rail steam would make it around a 10-inch radius curve, AAMOF, very few 3-rail locomotives will!

I suspect many people don't want to be limited to 50 foot interurban transport.

I posted this on the 2 rail forum, but it is relevant for this discussion:

This is my experience running two rail trains on my layout.   A

36" Radius (this is my minium, a lot of these can go around narrower)

MTH 2-10-0 consolidation

Sunset GP7  (fixed pilots)

Sunset GP9 (fixed pilots)

Sunset SD9 (Fixed pilots, six axle)

MTH F7 ABBA  (Fixed pilots, Factory Spacing)

Atlas RSD7 (Fixed pilots, six axle)

Weaver RSD 12 (Fixed pilots, six axle)

Atlas RS1 (fixed pilots)

MTH Aerotrain (Fixed pilot, prototypically close coupling locos and all coaches, converted to 2 rail)

All GGD 21" passenger cars  (Factory Spacing)

MTH GG1 (converted to 2 rail)

MTH L1 2-8-2

40" Radius

MTH F7 ABBA (Prototypical close coupling)

Lionel ABBA Sharks (fixed pilots, prototypically close coupling, converted to 2 rail)

48" Radius

Sunset GG1 (widened slots in four wheel trucks)

MTH P5a and P5a Modified (Fixed pilots, converted to 2 rail)

All GGD 21" passenger cars (prototytpical close coupling, diaphragms touching)

Sunset M1b 4-8-2.

Sunset B70m baggage car

MTH I1 Decapods 2-10-0  (Double headed, I might add)

All of the above curves are hidden for asthetic reasons.   Which means equipment has to be super reliable

All of the above curves have easements

One more note: Awhile back I had a Westside J1a (2-10-4). A massive locomotive that had been reworked by Ed Rappe to go around tighter radius curves.  I set up a test track, and with easements it could easily go around 44" radius curves,  going forward and backwards. It looked a bit silly with all that overhang, but that had nothing to do with the number of rails

Good info, John!

I’ve had many layouts in my life. Mostly HO scale. When I went to O scale, I went to 2 rails. I hand led the tracks and scratched built the turnouts. And yet it was the smallest layout that I ever built. A shelf layout. 16 feet by 18 inches deep. And it was the layout that ran the most !!! Then I bit the bullet and my best friend convinced me to go 3 rails. So I built my 3 rail layout in my 2 car garage, modeling FEC RR. Using 42 inch radius  I started the layout on the 1st of January 2020. By the 18th all the tracks were laid and I had two engines to run. I never regretted. As of now I am still working on it and running my trains more than ever.

I'm more of an "operator" than a "modeler", so 3-rails suit me.