080

Custom but normal (standard) for the mainline is O72.

George

027

John

O72

Atlas O sectional curves......0-108.... go big or go home !

0-27

Curt

Old Realtrak layout O-82 (may it rest in pieces)

New Atlas layout will have 108 in some stretches and 72 at the end of loops

O-42, though the next one will be O-72

o 128

Mainlines - O80 in the temporary section, O90 when complete.  O72 in the yards, 054 for some spurs.

The mainline is O36, though I do have a piece of O72.

BTW, all O48 switches.

4x12 layout, so 042.

O-72 on 12'-by-8' layout.

O-54 on 10'-by-5' layout.

MELGAR

O72 on 9x14 layout

Realtrax o31

o 128

080

027

The largest curve is flex track, measured to be about 99" diameter.  The tightest curve is O54 on a couple of industry sidings, other than that, O72 is the tightest curve.

057 flex track

072

6 by 18  somewhat of a half dog bone.  Dual mainline 060/048.  In transition, space may dictate losing the 060 as I am finding some of that “ train room peace “ in building  and painting .

072

072

031 on the upper logging line with 072 and 080 on the main line.

O 54 on the lower outer mainline loop.  0 42 on the upper mountain loop.  

072

O72

O27 gauge tinplate track here, BUT O42, O54 and O72 radius curves

o-72

O54 is largest but occassionally use O60

O72

Max 122  min 096    including industrial and yard trackage. If  I have another layout those numbers will be larger.  If I have to go smaller,  I sell out.

Fastrack 036

Mainline O90 & O81,  O72 elsewhere.

Jan

060 Fastrack

O-31 on my Christmas tree layout, O-36 on my basement layout.

O72 FasTrack

027

Currently O72 for 3 rail.  Going to be 54" radius (0108) minimum when I start my 2 rail layout.

O-106 max, O-42 min

11 x 17 ft platform.

2 mainline ovals with all O54 GG curves.

Multiple through sidings off of mainline ovals all with O72 Ross turnouts.

2 curved Ross turnouts both O96/O72.

.Atlas 3R, Triple main 090, 099, 108. Yard 072. Sidings 072 and 054.

For all of my 022 switches, curves on my 4 reverse loops and most of my curves: 031.

However, I have some sections of 042, 054 and 072 curves.

O72

0-90, soon to be 0-99

Layout = 8' by 24', largest radius curve = 072.

072

11 X 14' layout; max is 0-90, min is 1/2 section of 0-72 on innermost loop.

072

On my  6-1/2' x 12',  O-72 largest.  Also a O-48 & O-36 ovals all FasTrack.

Ross 112, min 072. 054 in diesel service area where larger not needed.

042

Atlas O81 sectional, O137 flex.

Outside loop is O 72.

O-63 max - O-54 min

Some O54.  Majority is O31 on a 7 x 7 layout.

Almost all 072 or greater.

054.

O72

O54 minimum

O-60, looking to expand to O-72.

What kills me regarding curves is not the diameter itself (for minimum requirements of rolling stock/engines) but the 6" spacing that most people recommend because of overhang. It makes for a larger footprint of a layout.

O-36, but hoping to expand to O48 sometime in the future.

031 on all 16 or so square feet of it.  Better than nothing.

0-42, but hoping to expand to 0-60.

Largest on Mainline:  0-72

Tightest on Mainline: 0-42

All K-Line Super-K Shadow Rail track.

0-72 Fastrack

Mark

O-80

I have an inside loop using O-54

O-72, -63, -54, -27 (for streetcars)

O-72 Outer, O-54 Inner

089 Outside Loop

080 Inside Loop

072 Yards

from O31 to O54, O gauge

O42 to O72, standard gauge

O-72

089 largest 072 smallest maybe a single section of 054 on a siding. Gotta be able to run big scale steam and my Centipedes. Granddaughters Christmas Polar Express 031.

031 on 7x8 layout and 027 on test track.

Essentially O72 minimum.

Which is how I managed RRTrack through the design process.  There are lots of places where more generous radii were used if possible.  It's been nearly 20 years since design/construct.  RRTrack is/was on the hard drive of about 3 computers ago.  My septuagenarian memory is deserting me more each day.   I believe the largest radius used in one corner (accommodating access to the house electrical panel) was O128. 

Bigger is better, of course.  (WRT model railroading track radii and beer steins, especially!)  I'd probably still be in HO using 40" radius minimum on the mains if it weren't for the aforementioned trappings of age.  That would've given equivalent appearance of O  scale equipment on O160 curves...the stuff of dreams.   There's compromise in everything.  We do what we can with what we've got....eh?

FWIW, always.

KD

Most of it: 072 GG/Ross/Curtis.

A bit in yards: Lionel tubular 042 (not much selection when I built this).

All switches are GG 0-100; except: 4 GG 0-72 and one Ross 8-way yard set.

All track and switches are painted.

While bigger is most certainly better, my layout which is 36" wide by 17 ' long had to fit into a long skinny alleyway in the room I had available.  So I am also a bit of a traditionalist and use 3 rail tubular track (I purchased all new from both Menards and MTH) .  The "outside" loop is Lionel "0 gauge" of 31" diameter but at the apex of the curve I have a single straight  of 5" to give me some extra width.  My inner loop " 0-27" and is pretty much left as is.  I use appropriate switches for each loop, 022 on outside and (i don't remember Lionel #) but 0-27 on the inside loop.  See picture view.

Best wishes and good luck with your layout.

Don

054 in an 11x11 room

Just wondering but how will this help manufactures? There are some physical requirements for scale size models that keep them from going around certain curve sizes. Maybe 50% or hobbyists have maximum curves of 031. That's fine and all, but no one is going to physically be able to make a scale size Big Boy run on 031 curves. 

120

Sure it can help.  Can see how things are trending. Should they make more big stuff ?  years ago I think this same question was asked and back then most everything was o31 027 and some 072 with  just a few larger than that. 072 was big for me, now I think that is the smallest track that should be made.

@Lou1985 posted:

Just wondering but how will this help manufactures? There are some physical requirements for scale size models that keep them from going around certain curve sizes. Maybe 50% or hobbyists have maximum curves of 031. That's fine and all, but no one is going to physically be able to make a scale size Big Boy run on 031 curves.

I know it may not be scale but my new LC+ 2.0 big boy which is 29 inches long runs wonderfully with o31. I hope Lionel will keep making larger locomotives with articulating drive wheels to accommodate o31. I have a lot of straights so it makes up for the curves but it negotiates them with ease and looks great too. It shows the real life size of the big boy so it works great.

Brad

@B rad posted:

I know it may not be scale but my new LC+ 2.0 big boy which is 29 inches long runs wonderfully with o31. I hope Lionel will keep making larger locomotives with articulating drive wheels to accommodate o31. I have a lot of straights so it makes up for the curves but it negotiates them with ease and looks great too. It shows the real life size of the big boy so it works great.

Brad

If you're interested, they made a LC+ 2.0 SP Cab Forward. Not too long ago they also had plans to release a LC+ 2.0 Allegheny, but unfortunately it didn't receive enough preorders.

Inner loop MIN is O44.5 (sectional compound curve).  Outer loop MIN is O54

042 on the main loop to loop, upper branch return loop is super o which i think is 036.  Alas space constraints made it impossible to go much bigger, 054 would have been better. 

072 on the home layout.

0106, 0102, 072,072 on the club layout.

096 is the largest mainline.  Smallest 031 turnouts for track platforms under Grand Central.

040 Gargraves flextrack

0-80

Largest 0144", smallest 031" hidden, the majority 0120"

O-96 Fastrack carpet layout to run my scale engine and passenger cars.

Jim

O 54, keeps me out of the 4-8-4 market

Lionel tubular O42 and O42 switches, which are the largest curvature I could fit on the L-shaped platforms of the lower (main) level of may layout.  The upper level has three short trolley runs with Lionel O27 tubular track with bumpers at all ends for back-and-forth travel through DEPT 56 Christmassy scenes.

I own several train sets that require O60 (better yet, O72) tracks), but those curvatures won't fit within my L-shaped train room. Track plans attached for reference.

Mike Mottler    LCCA 12394

O-48 outside loop with O-36 inside figure eight loop

Fastrack: 2 outer loops are O48 with O72 switches and 1 inner loop 036 is for storage only.

@wb47 posted:

O 54, keeps me out of the 4-8-4 market

HI wb47, maybe I misunderstand your post, but most Lionel Northern Class 4-8-4 Scale models run on O54, so shouldn't be a problem. As a matter of fact I have two scale Northern 4-8-4 SP and WP GS series running just fine on O48 (don't tell anybody) ;-) Here's a photo of them parked on a O48 curve looking good! Disclaimer: I'm not going to say that all scale Northern Class will run on O48!

Mainline #1 072

Mainline #2 036

Double main so 054 on outer main & 042 on inner main.

O-120 K-Line Super Snap on the outer loop.  The other four loops range from O-96 down to O-72.

Largest is 072, but mostly 054 and 031 to get as much railway in limited 9X14 layout with lots of spurs.

Michael

O-128

Mainline - inner loop O-80, outer loop O-92
Secondary - O-72
Yards and Sidings - O-72

Atlas O-81

O27 at home. Large custom curves at the club.

042

Mainline tracks are 072 or 080 GG track.  All mainline turnouts are 100" GG.

Siding tracks are 054 plus, with 054 on the two 054 turnouts GG.

O-72 - outside loop

O-27 and O-48 at home!!!

Inner loop is O-54 and outer loop is O-72.

Both loops are tubular.

Inner loop O-31, middle loop O-31, outer loop O-72.

Ron

Three main Loops 096 with Ross 096 switches

Mikey

The most interesting aspect of this survey is to reveal the large numbers of forum members who actually have operating layouts....and thus enormous wealth of hands-on experience to help others.

@Bruce Brown posted:

The most interesting aspect of this survey is to reveal the large numbers of forum members who actually have operating layouts....and thus enormous wealth of hands-on experience to help others.

Some of us anyway.  I'm still in the early stages of my layout and haven't got to wiring, scenery, or signaling, so I'm still learning.  That said, this forum is a wealth of information and I appreciate those who contribute to it.

0-80 Gargraves track an Ross switches

O-72... that way I can run almost anything on the track

072

@rplst8 posted:

Some of us anyway.  I'm still in the early stages of my layout and haven't got to wiring, scenery, or signaling, so I'm still learning.  That said, this forum is a wealth of information and I appreciate those who contribute to it.

Don't sell yourself short.  You do contribute!!  I don't want to elaborate and hijack this topic, but even asking questions is a contribution, because others are wondering the same thing.

@John A posted:

This information may help manufacturers in the real world.

Good participation for your requested survey,

...but after 3 pages of responses I'll admit to not knowing what it's all worth to a manufacturer...in the real world. 

All Fastrack in my 9' x 12' layout. Inner loop is 048 min, outer loop is 060 min. Crossovers are 072 switches, sidings are 060 and 072 wye switches. No issues running my Legacy DD35A, LC+2.0 Big Boy, MTH smooth sided 19" passenger cars, or Williams 20" superliners on this layout!

Thanks to everyone who responded. I was surprised at how the majority of layouts (who responded) have 072 as the minimum. I was hoping more operators would have smaller radii, possibly influencing manufacturers to make more smaller rolling stock offerings. Interesting results! JohnA

O-72, for me, I  want to be able to run just about anything with a decent length train behind the locomotive.

I have nothing tighter than 0-72.  Lionel/MTH give me fixed pilots on diesels.  I would have more diesels if they did.  I hate the look of the swinging pilot.  Understand why you would need it on tighter curves but that's not a issue on my pike.

Widest curve is one small section of O-54.  But all switches are O-31… so that’s the limiting factor.

Jon

O72 and o42 set up long term.   Holiday and temp layouts may go down as low as 031.

I decided to use some of all available FasTrack Curves and Switches.  So the curves range from O31, 36, 48, 60, 72, 84, and 96.

“O” profile:  O42 loop, O31 loops, O31 switches

”O27” profile:  O42 loop, O34 loop, O27 loop, O27 switches

@John_A, time for a tabulation of the responses to your survey?

@Lou1985 posted:

Just wondering but how will this help manufactures? There are some physical requirements for scale size models that keep them from going around certain curve sizes. Maybe 50% or hobbyists have maximum curves of 031. That's fine and all, but no one is going to physically be able to make a scale size Big Boy run on 031 curves.

I Agree. Its pretty well established if you want the scale 3 rail and two rail target market, your loco/ rolling stock product needs to make 072 curves as a minimum.

For traditional 0 gauge market, the loco/rolling stock needs to meet 031/036 as a minimum.

Inner loop is O-48 and outer loop is O-54

I currently have one shelf layout and ten (!) portable table layouts. The shelf layout features an O36 FasTrack  kidney. The largest table layout is 45" x 55" and hosts an MTH O42 oval. Others include postwar Lionel O27 tubular, O31 FasTrack, and O31 MTH solid rail.

Three of the table layouts are dedicated holiday layouts, but the others each feature a particular theme and era. Only one of the others (32" x 64") features traditional equipment; others run scale. I had to modify the pilot of a Sunset ATSF 2-8-0 to handle O36; otherwise I usually stick with Lionel motive power since it is usually engineered for toy-train radii. The O42 layout is dictated by Lionel's Reading T-1 (6-18006). The shelf layout can mechanically handle Lionel's Frisco Mikado (6-18030) and ATSF PA (6-18952), but the latter looks especially bad coming out of a curve towards the viewer. I mostly run a Lionel FT set (6-24568 and 6-24570).

I run no passenger cars, but I do have a dozen brass cabooses that I've modified for small-radius three-rail where necessary.

If manufacturers wanted to sell more equipment to those of us without expansive basements or spare barns, they would do well to follow the example of Lionel's 2-6-0 (6-38019 etc.): small radius, great sound, and fidelity to several surviving museum prototypes. Unless the hobby is irreparably atrophying, I would think that offering a thousand scale moguls would be better for us all than offering a hundred Yellowstones or soulless modern diesel behemoths.

Of course, if you model the Pennsy (three of my table layouts) you have your choice of whatever you want and if you're modest (the switchers, 4-4-2, 4-6-0) they'll run on O42 or less even in brass. Prolific cabin choices, too. But we don't NEED more Pennsy: we do need classic small locomotives especially for western roads with waycars to match.

My two cents.

Bob M.

O-27 gauge tubular, with O-27 and O-42 curves.

@RDM posted:

Unless the hobby is irreparably atrophying, I would think that offering a thousand scale moguls would be better for us all than offering a hundred Yellowstones or soulless modern diesel behemoths.

Well Bob, Lionel did offer a really nice Legacy Mogul, but they screwed it up and had to take most of them back!   I rescued one of the surviving examples and fixed it.

@Keith L posted:

@John_A, time for a tabulation of the responses to your survey?

I was just thinking the same thing

Yup. Got one of those B&M bodies a fellow New Englander put on a Wabash mechanism.  I wanted to use it as a stand-in until I found the CN version. I don't know much about the original run, but I began to be suspicious when I saw the rarity of these locos showing up. Too bad: they really are the best answer to mainline steam for a small layout. In my dreams Lionel will offer them again in an affordable, reliable conventional version with great sound . . .

8 X 20    with 0-72 and some 0-84 as easements.

Main outside turns are 072, with a few 060 leading to 046 under a mountain and therefore not visible.

O-81 Atlas

Thanks to all who have responded.  It looks like the majority of respondents use 072 or larger, which scale sized engines require, so the market for large engines is well established. However, I too hope for more smaller scale engines (and continued semi scale units). I was surprised to learn of the number of large radius layouts being built. JohnA

John, I suspect the preponderance of O72 and larger is because many of us have had smaller layouts and realized that they limited what we could run.  I'll admit it, I'm a sucker for big steam, so O72 or larger was mandatory on my new layout.

@John A posted:

Thanks to everyone who responded. I was surprised at how the majority of layouts (who responded) have 072 as the minimum. I was hoping more operators would have smaller radii, possibly influencing manufacturers to make more smaller rolling stock offerings. Interesting results! JohnA

It's a Big Boy World John.

John

So I see!  My layout (49 x 4) with 042 curves limits me to smaller engines. I’m happy many others can utilize bigger curves/engines.  I remain satisfied with my semi scale trains.  Something for everyone! JohnA (living in the little boy world)

So far I've put together O72 and O96 loops. I plan on using no smaller than O72.

Here’s a re-post of my now re-named

Buffal-O31 Terminal

JohnA

I could certainly live with O42 if I had to, but I didn't have to, so I didn't.

@Craftech posted:

It's a Big Boy World John.

As long as you’re pushing it around with a diesel it is!

0-42 curves and switches.  I've always used 0-42 because they seem to work best with my room sizes (medium) and most everything I buy that's 0-42 fits the limit of what I am willing to pay for a new engine ($750 max; average, $350-$550).  I admit, some of my engines (i.e. MTH Premier E8's) hang over quite a bit on curves, but it's the limitation I've accepted.  My new train room is much longer than wide so it isn't a problem.  I can see why 0-72 is the most popular here because that is the sweet spot for a quality layout if you have the space.

O-42.  Fits the room and keeps the budget in check.

Tom

Typically O-90, a few O-72.

some flextrack but mostly sectional.  I use Atlas track

@Craftech posted:

It's a Big Boy World John.

John

Unfortunately the UP Challenger and Big Boy both seem to have such exaggerated overhang on curves they "clean off" a wide swath of scenery on the layouts I've seen them running on even with O108 curves.

O-36 and that was a big step up for me to graduate from O-27 in high school.  I finally got access to all the fun O-31 trains.  This was before Lionel made Fastrack in O-31, so I went straight from O-27 to O-36.  I have an O-72 wye switch for sidings.  I'm a fan of the big steam but unless it comes in Lionmaster, it's not much use to me.

Though most of my curves are O-31, I am in the process of installing and O-42 loop around our city scene.

FWIW, I started a spin-off thread entitled "Traditional passenger cars on curves", so that we don't get too far off the original intent of this thread

063 outer and 054 inner at home and the club uses 072 and 081 Gargraves.

I have 036, 031 and 027. But then again, I don't run scale--I run toy trains.

You should see how great traditional size trains look on 120 super elevated curves.

I had wanted to build 3 4'x 8' tables for a total of 12' x 8' which would have allowed 0-72 or 0-84.

Unfortunately, size limitations held me to 12' x 6' so my widest is 0-60.

Since most of my trains are traditional Lionel or MTH Railking they look just fine on 0-60.

042 plus one loop of 072. I run mostly PW/traditional plus a Lionmaster Big Boy/ Challenger/Cab Forward with a few scale freight cars. My passenger cars are 12/15/18 inches. Switches are PW 022

The table layout allows for 60" width.  O54/O45 worked a double loop.  Each faint black line mark is 12".   A small bedroom and closet bottom of picture.

Camera walk-around.  Click on the underlined phrase.  There has been two additions.  One was a turntable.  The second was a remote section coal tipple, accessed with an Atlas double track Pratt truss bridge.

I am almost all O31 with a little O42.

one 072 oval and the rest is 036.  
For research purposes An 036 visionline steamer would be cool and I assume it would be a hot seller given it could run on almost every layout.  

I use both 072 and 096 from Menards.  The trains look really good on the extra wide radius curves.  Track is made really well although I did add more ties to the 096 stuff.

Rolland

O72, O96, & O120

36, 48, 60, 72

O-36, O-31

Now that I'm retired and in a new place, I've been furiously designing [again] for a 10x20+ third garage bay. The minimum radius is 42" (O-84) but I'm tinkering around with the idea of going to 48" radius (O-96). The largest locomotive I have with scale wheels is an MTH Big Boy 4014 and it can make it around 36" radius (O-72) but doesn't look right. And, yes, it has a street run.

long ago I decided on 072 so I could run a 700E I was restoring at the time.

The 072 worked out well and the gradual look of curves was appealing.

I still managed to make 2 mistakes that did not reveal themselves until many years later:

1) As I had a 2 track mainline, some curves were too close together

2) some scenery was too close to the curves.

These things did not emerge until I bought a Lionel   B&O 2-8-8-4.   The engine ran extremely well on the track but there were a half dozen or more issues due to points 1) and 2).  I eventually sold it.    In 1990 when I built the layout I could not envision owning such an engine.  Way too much overhang in front!

John

I'm not sure why people make such a big deal about overhang with articulated locomotives.  It happens in the prototype too!

The largest diameter on my floor layout is 0-81. The majority is O72.

The 81 is not really 81" center rail  to center rail, and the O72 isn't either. Found this out by things 'just not working' using an AutoCad knockoff to design the layout, and things just not coming up right. At some point I made a ring of both, measured center to center, then another 90°, then used the average for my drawings. I had to adjust the ring several times to get it as close to a circle as I could with the tape measure. Tubular track is just, will, yeah, close enough.

Further to Michael T's post, tinplate track sizes differ from one manufacturer to the next.

For those using O27 height wider radius track, even small differences can have one scratching their head when things just don't seem to line up. So you don't go nuts:

When using O54's, please note that the K-line version is 1/4 inch longer than Lionel's.

When using O42's , please note that the K-line version is 1/2 inch longer than Lionel's.  Also K-line's O42 track has 5 ties, Lionel's  have 3.

027

@rplst8 posted:

I'm not sure why people make such a big deal about overhang with articulated locomotives.  It happens in the prototype too!

I sure hope so, otherwise they made a huge financial mistake going to all the trouble to make them articulated in the first place!

O84 for my large loop, O72 inner loop. O54 on elevated loop

Joe Gozzo

I have a 5x8 board, so all my curves are O31.

Plus, I am 18, so my layout is still not really a professional layout. But honestly, I don't really see the point of getting anything that needs really big curves other than the Big Boy, the smaller versions usually look just fine.

~O72

This is only on one corner though. Most are O54.

Remember in toy trains track 027 for instance is the diameter of a circle measured at the outside of the ties, not at the center rail as engineering drawings for circles always are.

082 and 072 all Gargraves on home layout.

082 and 072 on modular layout  all MTH

O-31

As much as I love the look of a larger engine running on a big curve , it just takes up too much room. I understand engines require a min curve and thanks ok  but SIZE MATTERS . I am happy for the guys and gals that can support 060 and larger. Almost all of what I have down is 048 and that covers a vast majority of my stuff.

A vision line engine that could be used on 036 would be wildly popular in my opinion.
That’s my two cents worth