Toy train operating and collecting

There is no difference as far as structures go, Tex. O27 track is O gauge track with a tighter turning radius and shorter track height. O27 trains are O gauge that run on the tighter radius track. Any O gauge structure works well with both O and O27.

Jim 

Mainly O gauge and 027 refers to track size, there are little differances except for track radius and what will operate on the track. 027 track being a little lower in heighth than O gauge tubular and lower in price when you buy it new. If using 027 switches you will run into trouble with long frieght and long passenger cars.

Lee F.

If you get any Plasticville, or copies i.e. K-Line, they tend to be a bit less than true 1/4 scale, maybe closer to S scale.

Tex, the way I read your question, your are equating "gauge" with "scale".  It's a very common question, since even the manufacturers don't separate the two terms very well.

Gauge is the distance between the inside running rails.  For the real (prototype) railroads, the usual gauge is 56.5".  For both O-gauge and O-27 gauge, the distance is 1-1/4".  The ratio of O-gauge to the prototype gauge is approximately 1:48.

This ratio is O-scale.  Although the ratio isn't quite exact, it allows us to equate 1/4" in O-scale to 1' in the real world.  A forty-foot boxcar should be 40/4, or 10" long in O-scale.  A six-foot man would be 6/4, or 1.5" tall in O-scale.  In order for anything to be O-scale, all its dimensions should be 1/48th as big as the prototype.

BTW, Lionel O-gauge track is 11/16" high (2.75-foot prototype), and Lionel O-27 track is 7/16" high (1.75-foot prototype).  Prototype track isn't that high; that's why we use the term "hi-rail" to represent scale modeling when just about everything except the track is 1:48 scale height.

O-scale trains (Lionel's "Standard O", MTH's "Premier") and structures labeled "O-scale" generally conform to the 1:48 ratio.

O-27 trains (Lionel "Traditional", MTH "Railking") do not conform to any scale - they could be smaller, the same size, or even larger than O-scale.  They are designed to negotiate smaller curves, so often their length is shorter and the height and width may have been changed to make them "look right" (called "selective compression").  OTOH, the engines can't be too small or the motor and circuitry would not fit inside.

In order to determine if an item is O-scale, you would have to determine what its prototype is and then determine whether or not all the model's dimensions (at least length, height, and width) conform with the 1:48 standard.  This can be difficult for trains if you don't have reference books giving the prototype measurements.  It's a little bit easier for structures, since they don't necessarily have a prototype counterpart.  However, the doors would need to be of the proper height and width, and you wouldn't want to model a WallyWorldSuperCenter in a 4" x6" space (!).

One final note - there is a modeling technique called "forced perspective" in which smaller-than-scale structures (or trains) are located farther away from the viewer than the larger structures and trains.  The technique tricks the eye into thinking the layout has greater depth.  Lionel Trains, Inc. runs an S-scale (1:64) train in the middle of their showroom layout.  Dennis Brennan has an excellent article in the March issue of Classic Toy Trains that shows how HO-scale (1:87) structures can be used in the background to produce this effect.

It does get rather confusing. Yes, as others say, 027 and O gauge are the same distance between the rails: 1 1/4". In the 50's, Lionel called their regular line of trains O gauge. They ran on 031 track. Engines such as NW switchers, GP-7's, F-3's, and Trainmasters were close to O scale (1/48) but the rolling stock was scaled down a little. Lionel also made a budget starter set line and called it 027. It ran on the smaller diameter 027 track. The engines in these sets such as Alco's, 2037 steamers, etc were scaled down from O scale and the cars were scaled down even more than the regular O gauge cars. Engines such as GP-7's and NW switchers worked on 027 switches as well as 031 switches (022). These engines were included in 027 sets as well as O gauge. Sometimes identical engines got a different number such as the ATSF switcher. It was a 622 for O gauge and 6220 for O27. There was 671 Turbines for O gauge and 2020 Turbines for 027.

Nowadays it's called Standard O, Traditional Line, Premier Line, Railking, Railking Scale, Railking Imperial,.....Good grief, I'm getting a headache. I'll shut up.