Designing New Two Foot Gauge Trucks - Need Advice

[Rick Rowlands]

Due to the scarcity of available two foot gauge trucks we over at the J&L Narrow Gauge Railroad have decided to design and build our own.  Since our railroad is set up to represent heavy duty steel mill railroading, our truck design is quite heavy and is based on a standard gauge ingot mold car truck.

The truck is based upon an 18" wheel, simply because we have an 18" wheel pattern with a profile nearly identical to the profile of the drivers on the J&L 58.  The pattern is from the Wilkes Barre Iron Mfg. Co. which built narrow gauge mine cars and equipment in the 1920s.  The pattern makes a spoked wheel, which wouldn't normally be found in steel mills but I will overlook that.  

I am trying to figure out some design elements without having any other two foot gauge trucks to look at.  For a standard freight car truck, such as those found under Box Car 67, let me ask a few questions.  What is the wheel diameter?  Axle diameter?  Journal diameter and length? Wheelbase? Back to back distance of wheels?  

On our design we are of course going with the 18" wheel, 3" axle dia. turned down to 2 1/2"x 4" journals and a 36" wheelbase.  Back to back distance of 21 1/8" (this was arrived at by measuring the J&L 58 drivers. It was built to 23" gauge and had a 20 1/8" back to back.  Moving each driver tire out 1/2" to regauge to 24" gives me 21 1/8"). For springs I am using Barber B-296 springs which have a capacity of 2,060 lbs. each.  The spring window is wide enough for up to three springs, so I can build these trucks with either four or six springs, giving me either 4 or 6 tons capacity per truck.  The one part that I am unsure of is the journal diameter and if that is sufficient for the intended capacity of 6 tons per truck.   Oh that brings me to my last question.  What would a typical WW&F freight car weigh fully loaded?  

Attached is the first sketch of the truck design.  Several changes are being made today from that initial sketch.  Aside from the wheels the truck is 100% plate burnouts and structural shapes.  2" plate sideframes, 10" channel welded in a box shape for bolster plus another for a spring plank.  9" center bowl with 1" dia. center pin.  

Thanks for the help!

[Harold Downey]

I think your journal diameter is too small.  I believe all the WW&F journals are 3" dia by about 5" long.  All our wheels are 20". 

The back to back distance I have for #11 rear truck is 20 7/8".

That looks like a pretty heavy duty truck, but why no swing links?   I am also concerned about your C channel orientation -- the bending stiffness is relatively low in that horizontal orientation.   

Here is a screen shot of my drawing for #11 rear truck (not complete).   This is not a passenger car truck, nor a freight truck, but some of the design elements are similar.   Load on this truck is 10-11 tons.

[Rick Rowlands]

Thanks. With your mention of the channel it just occurred to me that I should be using structural tubing instead which would be stronger than two channels welded together.  So I'll be making a change in bolster material.

3" x 5" journals.  OK no problem.  I'll enlarge my journal diameter.

I see in my notes that Jason did tell me a while back that your back to back distance is 20 7/8".   

Thanks!

[Dave Crow]

Hi Rick,

I'm being lazy because I don't have any of my books close by...

Take a look at the Sandy River museum's web site; I seem to recall some photos of at least one of their boxcars with all of the neat boxcar stenciling, which includes empty weight, loaded weight, and capacity - or some other values that allow someone to perform really basic math to come up with what you want.

Randy Hees and the guys at Carter Brothers Preservation have similar size/loading boxcars, about 10-12 tons capacity, and I think their journals are also around 3"x5" =/-.

Dave Crow

[Philip Marshall]

I'm a little late to the conversation, but I have this Ed Bond drawing that may be useful. (See attachment.) It shows a 4'0" wheelbase.

-Philip Marshall

[Rick Rowlands]

We got our new truck designed and we are now ready for construction of the prototype.  There were a few changes made from the earlier design.  There are no provision for brakes but there is room for their later addition. 

[Rick Rowlands]

The next thing on the list is to build a flatcar and a caboose.  These will be patterned after these standard gauge cars in the attached photo.  The Monongahela Connecting Railroad was the standard gauge company owned railroad that served the J&L Pittsburgh Works.  The narrow gauge operation where the 58 operated was across the river.  So its quite fitting that our narrow gauge equipment look similar in appearance to the stuff the Mon Conn once operated.

The caboose will probably be 5' interior width by 6' 6" eave height by 14' overall length.  Flatcar will be 14' long x 54" deck width. Lots of work to do!