Wooden Stringer Logging

Background

My interest in logging railroads made me aware of pole and wooden stringer logging roads that were used for hauling logs a short distance of a few miles. They were an improvement over animal power, but not as good as a road with steel rails. I have seen the occasional pictures of these roads, but not much about them in writing. The 1913 textbook "Logging" by Ralph Clement Bryant was the best technical information source I found (reprinted by the NMRA in 2008; see References, below). I also have a strong interest in geared steam locomotives and have been wanting to build a model of a Class A Climax, which is what I had in mind when I first started this project.

"Dead-rail"

These types of railroads cannot be realistically modeled except by using "dead-rail" technology. If you are not familiar with this terminology, it basically means that the model locomotive carries its own power source with it, since there may not be any electricity available to the tracks. When tracks are made of wood, this is quite obviously a problem. Thanks to mobile phone technology, re-chargeable batteries are now available in a small enough package to fit inside scale locomotives.

Locomotive

The first issue I needed to resolve was how to power the locomotive. I knew I needed space in it for the battery and the electronics, which led me down the powered-truck route. Bryant's book stated that 42" gauge was common for stringer roads, which in S-scale is the same as HO-scale track. So, I decided on using HO-scale NWSL Stanton Drive trucks with the shortest wheelbase available, which works out to 4'9" in S-scale. This is still too big for the Precision Scale Climax sideframes I wanted to use, however I had some P-B-L archbar trucks that were within a scale inch, so I used their sideframes.

Dunkirk also made some locomotives similar to the Class A Climax, so I decided to follow the general dimensions of the Class A Dunkirk plan in David Hoffman's "The Geared Locomotives of Dunkirk", which happens to be printed in S-scale. This is a very small locomotive, only 25' long with a vertical boiler. However, there are some compromises in my model. The main ones are the trucks are wrong and I enclosed the cab to hide the electronics.

The main frame is a brass sheet. The visible side frames, end beams, and deck are stripwood. The superstructure is some scribed siding and more stripwood, with cardstock as the roof base. The water tank and the stack castings are from a Boulder Valley Models On30 Dunkirk conversion kit. Modified dummy HO-scale couplers are used in modified P-B-L Shay coupler pockets. The whistle is a Precision Scale casting. Grandt Line stirrup steps and nut-bolt-washer castings were used. The superstructure is easily removable so I can remove and re-charge the battery.

I have a DCC-controlled layout and there is no way to charge through wooden rails, so I used the Tam Valley Depot wireless system. The locomotive contains a 400mAH, 11.1 volt Li-Po battery, a Tam Valley DRS-1 Receiver, a Zimo MX646 DCC sound decoder, and a small "ice-cube" speaker with an enclosure. All are located within the superstructure. The Tam Valley transmitter ties into the DCC bus of my layout and I can use my regular throttles to control this locomotive.

Rolling Stock

I needed some log cars for this loco to do some work, and I wanted to do something quick and easy. I chose to build some HO-scale Kadee disconnect kits. Even the brakewheel was the same size as some of my S-scale ones, so the only thing I changed was to use Sergent HO-scale couplers.

Track

I needed a small test track so I could run it some place other than on the top of a table, so I made a 1'x3' wooden base with an aluminum angle frame. I also needed to model some stringer track. I used 5"x7" 7' scale wooden ties. Stringer rails are scale 6"x6" stripwood. I used a pneumatic 23-gauge pin nailer to pin the stringer rails to the ties.

I did some tests and I can bend the stringer rails to a reasonable curve. Also, stub-style turnouts will work.

References

"Logging" by Ralph Clement Bryant
"The Geared Locomotives of Dunkirk" by David Hoffman
NWSL HO-scale Stanton Drive (with shortest wheelbase)
Zimo MX646 DCC decoder (as sold by Foothill Model Works in the U.S.)
Kadee HO-scale Disconnect Cars
Sergent HO-scale couplers