Im confused about scale vs gauge??

OK, I know the difference between O-27 track and O31, O42 ect is the size of the curves, the larger the number the wider the curve. But when I read that freight, and passenger cars are O27, or O scale what do they mean? Is O27 cars smaller that O scale cars, and if so how much smaller? Will an O27 car look out of place with another car or engine that is O scale? Would some of you guys set me straight. I know this is a very basic question, and I apologize for my ignorance.

Paul

O scale cars are 1/48 scale and, depending on what car it is, can require significantly larger curves. Usually the cars/engines are cataloged with the minimum required curve. For example, a scale passenger car may require O42 curves (or even larger). A scale scale steam engine may require up to O72 curves. Again, the catalog always indicates the minimum curve required.

O27 and O31 cars and engines are designed to negotiate O27 and O31 curves. As such, they are smaller in size (sometimes as small as 1/64). Lionel refers to these cars as ‘traditional’ size and their relative scale can vary widely. Does it look odd mixing traditional and scale? Sometimes, but not always. I have some of both and tend to place the scale cars in the front and the traditional sized cars in the rear of a train. You hardly notice the difference as the train goes by.

As time goes on, you may want to concentrate on one or other (traditional or scale). But there are no hard and fast rules.

O-27 track is also made of a lighter gauge steel and has a lower rail height or “profile”.

O scale in US terms is 1/48 or 1/4". This fudges the track width (O gauge track scales out to 5 feet). European O scale models were usually 1/43 (track gauge works out to 4’ 8 1/2"). Much of the “traditional” or O-27 products are smaller than true O-Scale but occasionaly items are larger (many of the Civil War era or late 1800 items are oversized. Some of the O-27 products are actually scale for late 1920 to pre war era but have been painted to match modern era equipment. Most O-27/traditional models use selective compression to allow equipment to run on extremely tight radius curves. A real railroad would rarely use a track diameter of less than 1000’ which works out to something like O-250. Some manufacturers elected to use scaled down equipment running on O gauge track (e.g. K-Lines Big Boy and Allegheny). These models would have worked out to something more like S scale train running on O gauge track. Here is a link to a review by CTT:

http://trains.com/ctt/default.aspx?c=a&id=147

Look at G gauge track for a minute. There are 1:22.5 scale (LGB) trains that run on it and there are 1:31 scale trains that run on the same track. So you can see that while the gauge remains the same the scale changes. Scale means that if you take any train car and make a scale model, it would take 22.5 of the (LGB) models cars to be the same length as the original and 31 of the other brands. Lionel being 1:48 (mostly) they are smaller than LGB and larger than HO at 1:87 scale.

There are variations on the scale (such as narrow gauge) but the basic principle is, larger the scale number, the smaller the model.

Gauge is referring to the track width.

Scale refers to the proportion of something, or its size. O scale trains are 1:48, which means they are 48 times smaller than the real thing. So, the smaller the number, the larger the train, and the larger the number, the smaller the train. HO scale trains are 1:87, so they are 87 times smaller than the real trains.

Gauge refers to the distance between the two outside rails on the track. Usually, trains of different scale cannot run on the same gauge track, because they are proportioned differently. Thus, you won’t find an HO scale train running on O gauge track.

Many manufacturers have scaled down some of their trains so they can look better going through sharper curves of track - this is what O27 scale and O scale is all about. O27 and O scale trains run on the exact same gauge of track, and the only difference is their size. O scale cars are full 1:48 models. Because of this, they often larger curves in excess of O27, usually anywhere from O31 to O72. All O27 scale trains can usually negotiate O27 or O31 curves, because they are in fact a little smaller than 1:48 proportions so they can get through the sharper curves. Lionel and MTH have cleverly sized down many of their trains so even the largest seeming locomotives can get through the sharpest curves possible.

Can you mix O27 and O scale trains on a layout? Sure you can. Since they can both run on O gauge track, you can even mix O27 and O scale cars into the same train. This sometimes makes the O scale cars look giant, so I tend to run strict O scale and O27 scale trains. Can you run an O27 scale train and an O scale train at the same time without it looking weird? You bet, I do all of the time (actually I only have one train’s worth of O scale cars, so I don’t really have a choice…[:D]). Since each train has the same proportioned cars, they really do not look bad run next to each other at all.

The bottom line is how much space you have on your layout, which usually tends to so

As others say, gauge is the distance between the outside rails. With O gauge, it’s 1 1/4" which is what all O gauge track is manufactured to. Scale of course is the scale and with O scale it is 1/48. 027 cars in most cases are not O scale. They are selectively compressed for small layouts with no set scale at all. They may work out to one scale in length and another in width. Postwar Lionel 6464 boxcars work out to around 1/55 scale. Often times, small 4 axle diesels such as postwar Lionel NW-2 switchers and GP-9’s work out close to 1/48 scale. Some MTH Railking equipment works out to 1/48 scale and MTH calls it “Railking Scale”. The non scale Railking is just called “Railking”. To add to the confusion, there are many pieces of equipment that run on 027 curves but hit the switch machines on 027 switches.

The origional question of the post was, "scale V guage.

Simple answer,

Scale relates to the size of the model as it relates to full size. HO = 1/87th scale, N = 1/160th scale, O scale = 1/48th scale.

Guage relates to the distance between the rail heads. Thus the term, “Narrow Guage”, which as the term implies is narrower than the “Standard Guage” which is what you normally see in Canada and the rest of North America.

I hope this helps.

Blue Flamer.

There are at least 3 “O” scales:

1/48 (America), 7 millimeters/foot (about 1/43.5, Britain), 1/45 (Continental Europe)

And 5 “O” gauges:

56.5/48 inches (Proto48, about 1.177 inches, 29.9 millimeters, America), 1 3/16 inches (“Q”, America), 1 1/4 inches (31.75 millimeters, virtually the same as 32 millimeters, toy trains), 32 millimeters (Europe, including Britain), and 33 millimeters (Britain)

WHAT???[:D] Only kidding, I got it now, but I must confess I had to read all your post a few times, but yeah I understand now, thanks for clearing that up for me.

Paul

Hi, as I understand it scale is usually used for trains that come close to the prototype or original train they are made to resemble. so when someone refers to a scale hudson they mean it is more accurate to the original train than the regular O gauge Hudsons. gauge is usually the track size. HO is Half O and S is between HO and O. Z and N gauge are smaller than HO. G gauge and Standard gauge are larger than O. within O gauge the numbers denote the diameter of the circle of the track. O gauge is 31". all the explanations are accurate but sometimes things are referred to by these terms and it’s not clear just what they are getting at. almost always in toy trains scale is the accuracy while gauge is the track size. hope this helps.

Scott

Yes with one clarification:

It’s the diameter of a half circle of track and there is no standard on what part of the track the diameter is referencing to except for original Lionel O-27 and O-31. These were measured from outside edge of tie to outside edge of tie. Some vendors measured to outside rail, some center rail to center rail.

Lionel FasTrack is one type that is measured center-rail to center-rail.

And a further clarification, to Chuck’s post: Those diameters are only approximate, except for O27. For example, the actual diameter of O31 (to the ends of the ties) is 30.534 inches, which is why you occasionally see it referred to as “O30”. Lionel called it simply “O”.

You’re right I don’t know why I put circumference, it is the diameter. I edited it to be correct so people reading wouldn’t get thrown off.

Thanx.[:I]

Scott

That’s OK, almost all of us refer to it as the radius even when we realize it is the diameter! e.g. question: What radius track are you using? Answer: O-54

Chuck,

You are certainly right in noting that the “in-group members” of the hobby often use radius and diameter interchangeably. It is correct to refer to curves as “tight-radius” or 'wide-radius," even citing dimensions in inches; but when trying to answer questions for “newbies” it pays to be very specific. For someone who is contemplating buying locos or passenger cars to run on FasTrack (for example) it is important to know that the 036 refers to the diameter of a circle, in inches, measured from center-rail to center-rail.

For someone planning to build a layout, again in FasTrack 036, it is essential to know that the overall diameter of a circle of track (counting the built-in ballast) is about 39.5 inches.

Subtracting 36 inches from 39.5 inches yields 3.5 inches. This number is useful because it “works” whether the FasTrack is nominally 036, 060, 072 or whatever. Thus, a circle of FasTrack that is 60 inches in diameter, center-rail to center-rail, is about 63.5 inches in diameter overall. One may even have to allow a bit more for the overhang of some of the longer locos. Other brands or types of track have their own geometry and their own rules.

I hope this is both accurate and helpful.