Tag: On18

Adventures in On18

On The Horse Thief & Never Mine Ry.

 

I've added a new engine to the roster of my On18 Horse Thief & Never Mine Ry., No. 5, the H.D. Ryman - named for one of my all time favorite Disney artists, Herb Ryman. In this week's video, I show how I scratchbuilt the engine, and get into some of the particulars of On18. Allow me to expand on things a little more below.

A Primer on On18 and Scale vs Gauge

If you are already familiar with On18, this information will not be new to you, but since it is a relatively obscure scale/gauge combination, here's a brief explainer of what it's all about for the uninitiated.

The "O" in On18 stands for O scale, which in America is understood to mean 1:48, or 1/4" = 1'. The "n" stands for narrow gauge, meaning a distance between the rails narrower than the American standard gauge of 4' 8.5". The "18" refers to a track gauge of 18". Unfortunately, the terms "scale" and "gauge" are often confused or conflated by the layman but they actually mean very different things. In the simplest terms, "scale" refers to the size of a model relative to the real thing, while "gauge" is a railroad specific term that refers to the distance between parallel rails on a track. In other words, if you say, for example, that a model is N gauge, what you are really indicating is only that it runs on 9 mm gauge track. Whereas if you say it is N scale, you are specifically stating that the model is 1:160th the size of the real thing.

The Thunder Mesa Mining Company model railroad is built in On30. Using the formula above, this translates to O scale trains running on 30" narrow gauge rails. Its wholly owned subsidiary, the Horse Thief & Never Mine Ry is built in On18. Though still the same scale, that means the equipment is somewhat smaller because it runs on a narrower gauge track.

To model On18, we often use N scale mechanisms, wheels, etc. as a starting point. Using them in O scale means we are effectively changing their size relative to the real thing. Track is a good example of this. In N scale (1:160), 9 mm gauge track represents American standard gauge, 4' 8.5". The same 9 mm gauge track used in O scale (1:48) shrinks down to become 18" industrial narrow gauge.

This is the same formula used to model On30. HO gauge track scales out to very near 30" in O scale, and so HO scale mechanisms, wheels, etc., can be repurposed for On30.

To further confuse matters, there is HOn30, used by some modelers in HO scale (1:87) to represent 2', 3', or 30" narrow gauge. Just like N scale and On18, HOn30 also uses 9 mm gauge track and components, and fortunately for the On18 modeler, many of these can be repurposed for O scale. For example, the Horse Thief & Never Mine uses Peco HOn30 track to better model On18 track. The scaled up and wider distanced ties look better than standard N scale track would.

An On18 Baby Climax

To build my On18 "Baby Climax" locomotive, I started with a smooth running and reliable Kato 11-106 N scale 4-axle mechanism. Then it was a matter of designing and building a somewhat plausible model to fit over this mechanism. I used a lot of parts from my scrapbox, particularly from old HO scale locomotives that had given their all. I never throw anything away and will sometimes buy old junkers on ebay just to use for parts in projects like this. Things like bells, whistles, and headlights translate perfectly from HO to O18 because they should look like smaller versions than one would find on the usual O scale narrow gauge equipment.  I use Micro-Trains N scale couplers with draft boxes and trim off the trip pins since these trains wouldn't have air brakes. One thing I failed to mention in the video is the extra weight added to make the model run better. During assembly, I filled the boiler with lead BBs held in place with epoxy resin.

Below are some photos from the build and of the finished model.

About the Climax Locomotive

The Climax geared locomotive was the invention of a skilled lumberjack and machinist named Charles D. Scott. He brought his drawings to the Climax Manufacturing Co. of Corry, PA, and the first locomotives of his design were built and delivered in 1888. Climax locomotives of ever improving design were manufactured until 1928 and more than 1,000 were built. Many loggers and miners considered the Climax to be superior to the similar Shay in hauling capability, stability, and performance.

My model represents one of the earliest models, known as a "Class A Climax." They had either vertical or "T" type boilers, with two vertical cylinders mounted in the center. Their construction was similar to that of a flat car or gondola, with boxy wooden sides built up to protect the crew and fuel from the elements. Most had a round water tank in the rear, though my model employs a rectangular tank to save on space. Though I've never seen a photo of a Climax locomotive this small, I'd like to think that such a critter was at least possible.


Thanks for following along, amigos. Registered users can leave questions and comments below so, please, join in the conversation!

All the best,
Dave

Adventures in On18

The Horse Thief & Never Mine Ry.

Plans for an On18 mining tram to feed the Thunder Mesa mainline have gone through several evolutions over the years. Most recently, I've settled on a simple point to point design that operates between Never Mine tunnel through Baxter's Butte, and some as-yet-to-be-built ore bins at Horse Thief Canyon. In between, the tram will serve the richest diggings in the territory; Big Thunder Mine and the camp of shacks and outbuildings that have sprung up around it. Earlier versions had the tram extending all the way to Calico, and even included a portable On18 module at Calico Mountain. This plan was scrapped, mostly due to esthetic reasons since I decided a long On18 trestle in front of the backdrop would detract from other scenic features there like Horse Thief Canyon and the balancing rocks beyond.

An On18 Primer

Simply stated, On18 is O scale trains running on N gauge track. The "N" in N gauge stands for 9mm, and that scales out to about 18" in 1/4" O scale. 18" was a common track gauge for mining trams in the American West so the result of this scale/gauge alchemy is On18. I'm sure that readers of this blog don't need reminding about the esoteric differences between scale and gauge, but just in case you do, there's a post on it here.

To make things just a little more complicated, On18 trackage on the Thunder Mesa layout is represented using Peco HOn30 flextrack and turnouts which are, of course, also 9mm gauge. HOn30 uses N gauge track and mechanisms to model 2' gauge or 30" prototypes in 1:87 scale - but that's a story for another day. Suffice to say that this Peco track also has the perfect look for a light On18 mining tram.

On18 uses parts and materials from N, HO, S, and O scales to represent 18" gauge equipment in 1:48. Vertical boiler engine #2, the Walter Knott uses a 3D printed shell from Shapeways atop an N scale Kato 11-103 mechanism. 


Earlier Track Plans

As mentioned above, fitting an On18 line into the world of Thunder Mesa has been an ongoing process. Several plans were created and then later set aside as the line as it currently exists evolved somewhat organically on its own. Here are a few of those On18 plans, all of which incorporate Calico in some form or another. Though none of these are presently being built, each could work on their own in some future project.

Building the Horse Thief & Never Mine

The point to point On18 HT&NM Ry runs on a level between 5 and 6 inches above the On30 tracks of the TMMC. It starts at some ore bins at Horse Thief Canyon before quickly ducking into a tunnel and emerging at Natural Arch Bridge where it crosses the TMMC mainline. From there it's on to Big Thunder Camp, which sits directly above Rainbow Caverns, and into Never Mine Tunnel which passes through the heart of Baxter's Butte. The line terminates at the combination dump trestle and loading dock above Saguaro Siding. The sharpest curve on the line is about a 12" radius and control is standard DC. In the future, point to point operations may be automated using photic detection and a Circuitron AR-2 unit.

Track and roadbed being laid through Big Thunder Camp and across Natural Arch Bridge. Midwest products HO scale cork roadbed and Peco HOn30 track were the products used.

Track was primed and painted with artists acrylics. The trestle above Saguaro Siding was originally built for On30 rails, but it works just fine for On18. The scratchbuilt jib crane is used to bring supplies up to the mines from the TMMC siding below.

Ground cover is Polyblend sanded grout, and the ballast is red dirt collected near Sedona, AZ. Plants, weeds and bushes come from Scenic Express and Woodland Scenics. Cacti are from Pegasus Scale Models. 

The miner's shack was scratchbuilt from wood and Illustration board and features flickering lantern lights.

At least two more locomotives will join the HT&NM Ry roster, a tiny Shay, and a Porter-like 0-6-0, both currently under construction. The 0-6-0 is mostly being built from scrapbox parts, but the Shay has a 3D printed shell  from Marsh Creek Miniatures and runs on a Kato 11-103 chassis.

What's Next

Most of the track for the On18 line has now been completed and the rest is details and structures. One of the main features will be the Big Thunder Mine complex. This will be a combination of kit-bashed and scratchbuilt structures sitting on a high ledge above Rainbow Caverns. A below ground view into the caverns will also reveal the main shaft of the mine and an animated lift beneath the headframe. At the Horse Thief Canyon end, ore bins and a short trestle need to be built for the transfer of ore to TMMC trains. Also, if I can find the room, there may be a small turntable and engine shops in Big Thunder Camp. 

Summing up, I was a little sad to let go of the whole Calico mini-layout idea, but part of the creative process is knowing when things just aren't going to work and making the proper adjustments. I haven' given up on Calico Mountain, far from it, it just won't be a part of the On18 layout. But there'll be much more on that in an upcoming post. 

As always, I'll do my best to answer any questions in the comments below - so ask away! Just keep in mind that the WordPress platform is a spam magnet so it may take a little while for me to weed through and get to an answer. Thanks for checking in, amigos. Adios for now!