O27 verses 0 Gauge

There's no difference in the trains, the difference is in the track.

At the very bacic level, from the traditional tubular track viewpoint, O27 track is lighter and the curves are sharper, making a 27" diameter circle.  Hence the name "O27."

"O" gauge track is heavier material, a little taller and a slightly larger circle, being 31" in diameter. 

The track gauge (width between the rails) is the same.  The limiting factor of O27 is that some locomotives that will run on O31 curves will not run or not run well on O27 curves.

Rusty

Rusty is correct. Here's a good explanation, with pics, from Thor Shiel's website:

http://thortrains.net/manual5.htm

O27 refers to the sharpest and most commonly available curves for the "lightweight" version of conventional 3-rail track. However it is also possible to get O42 and O54 curves in the "O27 profile" track, and some older compatible Marx track is "O34".

The sharpest curves in "Standard O" conventional 3-rail track are O31, but O42, O54 and O72 curves are also avaliable.

The two-digit numbers generally refer to the overall diameter of a circle of those track pieces, in inches.

In another post, I discuss use of different curve radii for good effect.

https://ogrforum.com/d...56#11285375717620756

Hi all,

Any idea if a Lionel U30C Diesel Engine (6-18276) will work on O-27 curves? No switches are used in the layout. Thanks for your help!

I believe that O27 track looks better than O gauge track because the rails and ties aren't as tall.

I agree.  I have always liked the look of O27 track better...even the ties are more realistic looking.

What he said!

John,

Welcome to Model Railroading, the Worlds Greatest Hobby.

You original question mentioned collecting, which leans me to think you are looking at train items, perhaps on ebay or somewhere where they list it as "027" or O gauge.

It'll take a bit to grasp the difference, especially when at times there wasn't. Best advise would be to attend a local train show and ask the simple questions. Most train guys are more than willing to help when asked. At just one show, you'll be able to grasped not only the 027/O gauge question, but also the "Scale", HO, S, N, Z and Large Scale. 

Seeing in person always helped me.

Good luck and welcome!

If you're new to the hobby and unfamiliar with items you're bidding on or planning to buy via mail order or such, NEVER, NEVER, NEVER pay attention to the "O", "O27", "scale" descriptions/designations until AFTER you have thoroughly researched the precise item you're thinking of buying.

I imagine 90% of the people selling this stuff--and especially on eBay and other such sites--have no idea of the meaning--past or present--of these designations.

Hey Alan;

Not to sidetrack this thread, but if you like smaller rails and such, Take a look at MTH's ScaleTrax. You may find a new track preference ! I sure did.

In the early Lionel catalogs O27 was a marketing term for "cheaper" sets. The engine was often exactly the same as the "O" version, but with different cab numbers: the K4 O27 was 2025, the O was 675. The price difference for the engine and tender alone was 50 cents...$24.50 vs $25.! Set-wise, the O27 came with a stipped-down caboose (no lighting and less details). The Turbine was similar. The Berkshire only came in O. I assume it was too long for O27 curves.

Today many new trains need a curve wider than O31...some MUCH wider. Even O36 is now minimum for many new trains.

I like the lower profile rail of 027 myself.  Wish 'L' would expand it to all the

diameters and switches that their O gauge has. Oh well  .  .  .

     Hoppy

My original layout was 027 and I too liked the lower profile of the rails but I could not run O gauge engines until I found the same profile track with 031 curves. I believe that Lionel made this wide curve 027 track back in the Late 70'S /Early 80'S. My current layout uses Gargraves track, Ross and Gargraves switches as it looks more realistic to me and I like to form my own curves.

I believe the source of source of confusion comes from referring to O and O27 as if they are two different gauges (O gauge vs. O27 gauge).  They are actually the exact same gauge - 1-1/4" between the inside edges of the rails.  The differences are in the rail height and the traditional minimum diameters (27" outer diameter vs. 31" outer diameter).  It would be more appropriate call it O size or 027 size track.

[quote]Any idea if a Lionel U30C Diesel Engine (6-18276) will work on O-27 curves? No switches are used in the layout. Thanks for your help![\quote]

No, minimum curve is 31 (it's listed in the catalog).  Flanges will work on O-27 style track but you need O-31 diameter curves or larger.   At 18" long the model is scale or very close.  On an O-27 curve the overhang will be really, really, really bad and that's assuming the three axle trucks wont bind on a curve that tight.

Allan Miller makes a very valid point !

All good replies though, especially from Jumijo a concerning track height versus

relaisticity.

Jumijo, I didn't see your O27 switches for sale @ $3 but would certainly buy some if they're still available. I like O27 and I like $3 even better!

Sorry, Bill. They went to the landfill about a month ago.