The C-25 tender trucks.

The tender trucks turned out to be much more difficult than I expected.  Why?  No plans!

Tender trucks tend not to show much in photographs, and Al Armitage's plans from the Gazette omitted all details below the running boards. So I had to try different methods.

First, I studied all the details which did show in photographs.  This gave me the basic dimensions: wheelbase, height, springs, journals, etc.  From these basic data and drawings in the the Locomotive Cyclopedia and Car Builder's Dictionary, I was able to design a reasonably accurate sideframe.  (The bolster and spring plank need refinement, though.)

I also got an idea of what distinguishing marks to look for on other trucks, to help me design the bolster and spring plank.  Then, I searched other places for that type truck.  I found a preserved 1912 Baldwin engine (standard gauge) in Chattanooga, which had trucks that appear to be almost identical, to judge from the bolster end, journals, etc.  I sketched it carefully.

Next, I looked through the 1906 Car Builder's Dictionary, and found truck plans which corresponded almost exactly with the photo evidence and the Chattanooga trucks.  That plan allowed me to revise my plans for the bolster and spring plank, so I can now start on those parts and on the springs.

Having sideframes I thought to be accurate, I began working on casting patterns in brass.  My master pattern for the sideframes showed me just how fine an art it is to make such things.  I made three attempts at it, and only the second actually got soldered up into a pattern.  That pattern looked fairly good to me -- all the dimensions were very close to perfect scale.  However, you can't cast all things which are perfectly to scale, and the caster had a very hard time getting the castings to come out because the lower straps on the truck were too thin.  I did get a handful of castings in a tin/lead/antimony alloy.

So, I have good data on the "internal" parts of the truck, and sideframe castings to work to.  I hope to have the trucks completed and ready to mount by the end of the year.

© copyright 1997, 1998 by: Vance R. Bass .
Back to Drawings for Small-Scale Live Steamers.

Updated on 13 October, 1998.