Re: Type C/UP trucks

Posted by Jim Courtney on Apr 18, 2020; 8:15pm
URL: http://c-sng-discussion-forum.254.s1.nabble.com/Type-C-UP-trucks-tp15497p15499.html

Wow, a timely thread, Michael.

I'm about to take on modifying some of Eric's Rio Grande Models Carter Bros. trucks (4 foot wheelbase) in Sn3 to try to match the details of the "type C" UP 14 ton trucks. Printed trucks would be even better.

This is what I'm using so far:




My first impression of your drawing is that the transoms are too tall, too close togethere and the circular cut out too small. I see a single spring thru the circular cut out. These are the best photos I have of the side frames:


Courtesy of Todd Hacket. 1901, Washington Spur wreck.



About 1902. UP 14 ton truck on left, Litchfield 12 ton truck on right.



Courtesy Doug Heitkamp. 14 ton truck on flanger in Leadville, 1930s


To my eye, the center plate with the circular cutout has a metal ridge, horizontally placed at the top and near the the bottom of the plate. Two tie rods are run through the transoms just above and below the circular cut out, with bolt heads visible on the outside of the transoms.

For an Sn3 version, I am using PBL's wheel sets:

Axle diameter = 0.100 inches, pointed ends.
Axle length (to end of point) = 0.900 inches.
Wheel thickness = 0.095 inches.
Wheel diameter = 0.400 inches.
Flange diameter = 0.440 inches.
Axle end (point) to wheel face =0.11 inches.

If you can't tell, I would love to have 15-20 pair of these trucks, printed in Sn3, as it would save a lot of time in modifying the white metal truck assemblies that I have now.

I now believe these trucks were ubiquitous, used under both the 26' and 27' Tiffany reefers, the 27' UP built boxcars and both classes of  27' coal cars. The more familiar 20 ton "type B" trucks were pretty much confined to the 30' Peninsular boxcars, coal cars and flat cars, also used under locomotive tenders in the 1890's.

While you're making drawings for printed trucks, how about re-scaling the 12 ton Litchfield "type A" trucks that you produced in On3 to Sn3 as well, like the ones under the flat car above? The only Sn3 version is by the Leadville Shops as brass castings and are difficult to fit and solder together.

I have a couple of sets of your S scale South Park early under frames, destined to be installed under an Overland brass way car. They are exquisite parts. I look forward to seeing your progress on this project.