Small But Mighty - 30" Power

This article expands on the locomotives that hauled the trains on 30" lines, and offers some suggestions for modeling them.

Small is Big

Two major types were especially common:

Porters - These "teakettles" were made by the H.K. Porter company, who would build them in any gauge you needed. The most common Porters were their "tank" engines, indicated by a T at the end of their designation. This meant that they carried their own water in a tank instead of having a trailing tender (coal and water car). Water was stored in tanks on the side or in "saddle tanks" that wrapped over the top of the boiler. For fuel, the firemen would dump a pile of wood or coal (whichever was cheaply and easily available) in a bin at the back of the cab.

• The smallest tank engines were 0-4-0Ts. The designation 0-4-0T means that there were four drive wheels ("drivers") and no pilot (front) or trailing (back) wheels. The 0-4-0T in the title photo was a fully-functional steam locomotive a little smaller than a minivan. Some were bigger, but none were more affordable or useful in tight spaces or on hastily-laid tracks.
• The next most common Porter was the 0-4-2T. This had the same "fixed" wheelbase as the 0-4-0T, but it had a pair of trailing wheels that supported a larger fuel bin.

Shays - In the earliest days of railroads, most steam engines were built by "tinkerers," inventors who had little math or science background and just kept trying different combinations of things to see what worked. It is no wonder that the driver was called an "engineer," because he usually had to be pretty sharp to keep the things going without blowing up.

Ephraim Shay, however, was a scholar who had studied math and science, and brought a new perspective to a decades-old problem: how do you build a small, but powerful steam engine that doesn't literally pound the rails (a real problem on light, hastily-laid trackage)? The answer was to move the pistons to the side and use gear shafts to drive the wheels. This not only spread out the force of the pistons, but it "geared down" the torque, allowing a relatively small boiler to provide a great deal of pulling power. Yes, you couldn't go very fast, but it wasn't safe to go more than a few miles an hour on most industrial railroads anyway.

Like the Porters, a Shay could be ordered in almost any track gauge. They were favorites on 30" railroads in hilly regions.

The drawing above shows a "two truck" Shay, the most common configuration, although a few Shays were built with three trucks and a sort of mini-tender that held the water and fuel.

Less Common Types

Moguls - One of the most popular 36" locomotives, the Mogul was not so common on 30" railroads. We did track down a photo of a Baldwin-looking Mogul on a Mexican Narrow Gauge railroad that was mostly 30". But, unfortunately we can't be sure of the gauge - the size of the boiler and some details in the original photo make it look more like a 36" or larger locomotive. (The photo's owner, whose grandfather took the picture, thinks it may be standard gauge).

Moguls were 2-6-0 locomotives, which means that they had two "pilot" wheels (to help steer the locomotive into tight curves), six drivers, and no trailing wheels. Pulling faster and longer trains than Porters or Shays, they were popular on U.S. 36" railroads well into the 20th century, but much less popular on U.S. 30" railroads, where the track wouldn't always support their weight and tractive effort was more important than speed.

Outside Frame Engines - Some of the biggest and most unusual locomotives ever to run on 30" track were the "outside frame" engines, so named because the frame of the locomotive encompassed the drivers (instead of fitting inside them like most locomotives.) This allowed their builder (usually Baldwin) to put a relatively large boiler on a very small "footprint." To conserve space between the frame and the drivers, the axles were extended and the counterweights were placed outside of the frame.

These were more popular in Mexico than in the U.S., because Mexican 30" railroads, even the industrial ones, tended to haul more kinds of freight and more passengers than the U.S. 30" railroads. To the right is an early 1900s photo of an Outside Frame Prairie (2-6-2) locomotive near Mapimí.

An Outside Frame Consolidation (2-8-0) that was originally manufactured for a railroad in Mexico is running in Montana on the Alder Gulch Shortline. In the photo to the right you can see that #12 has Walshaert's valve gear (identifiable by the extra rods and the little spinning "eccentric" attached to the main drive wheel). Together with the outside counterweights, this makes this locomotive look like an eggbeater going down the track, especially when it's going slow enough to see what's going on.

You can't see a lot of detail, but if you want to see the Alder Gulch 2-8-0 in action, check out this video made by one of the folks who tends her.

Outside the scope of this article, but eye-popping, are the articulated outside-frame 30" locomotives built for the railroads of the region that used to be called Yugoslavia. There, the 30" railroads provided all of the same functions as standard gauge (56.6") railroads in the U.S., so they were constantly "pushing the envelope" of what was possible on 30" rails. More information about those is provided on Bruce Pryor's page "Narrow Gauge From Off the Beaten Path."

Diesel-Electric, Gasoline, and Electric

Although there are very few photos of diesel-electric, gasoline, and electric 30" power, these units were virtually identical to the smaller examples that ran on 36" rails. So it's not too hard to figure out what they looked like. One electric locomotive photo that is 30" for sure is to the right - it's a Baldwin-Westinghouse Electric that, in 1903, was working in the smelter facilities for the Peñoles in Mexico. And, yes, the trolley pole is missing in the photo.

Models of 30" Locomotives

On30 Models

Bachmann's On30 trains are in O scale (hence the "O"), which is the scale that Lionel trains are supposed to be. But these are mostly models of very dinky trains, so they're usually a little smaller than similar Lionel trains. A few of their On30 locomotives are shown in the following table. For a longer list and description, check out the BIG Train Store On30 Locomotives page.

0-4-0T Porter	0-4-0T Porter	Baldwin 2-6-0 Mogul

Outside Frame Consolidation	Climax

Early 4-wheel Diesel-Electric Switcher	Rail Truck	Streetcar

Most Collectible Trains, by "Hawthorne Village" fall into the On30 designation as well (except for the Hawthorne Village Sports Trains). As a result, many people who start with a Thomas Kinkade(tm) or other collectible train find themselves adding Bachmann On30 trains, or vice versa - they all play together very nicely (in fact the mechanism for most of them is built in the same factory).

Large Scale Models - (Mostly Outdoor Use) - Most garden trains run on 45mm track (about 1 3/4"). The newest narrow gauge models tend to model 36" railroads in 1:20.3 scale. To model a 30" railroad on 45mm track, your models would have to be in about 17:1 scale, about 16% larger than most commercially available models.

On the other hand, boiler and driver sizes were almost unique to each 30" railroad, and most 30" railroads had cars that were narrower and shorter (lengthwise) than cars on 36" railroads. You could "borrow" most 1:20.3 ore cars. You could give your other equipment a 30" look by going up. For example, using high-sided gondolas when possible, increasing the door heights by 16% if possible, putting slightly taller cabs and smokestacks on 1:20.3 locomotives, and so on.

A Bachmann Large Scale Porter model as supplied.	What the same Porter might look like with a cab and smokestack that are about 17% taller, suitable for modeling 30" railroads.

Ironically, Bachmann's 1:20.3 outside frame Consolidation was actually based on a real 30" locomotive, the one at Alder Gulch, Montana. But judging by the photos (they haven't given me a locomotive to try out on my railroad), it is probably 1:20.3 scale and would still need the cab and smokestack to be a little taller to look quite right for 1:17.

If you think lengthening the cab sides, front and roof, and adding a larger smokestack makes a locomotive look a little "unrealistic," take a close look at the Outside Frame Mikado (found on Bruce Pryor's page "Narrow Gauge From Off the Beaten Path.")