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!