Re: RGS #36 Pictures?

James,

I decided to compare the spec sheets of the "standard" 8-18C plan 4 (NPC "Sonoma") and the D&RG 8-18.5C plan 2 and there aren't as many differences that stand out.
For example: The wheel base of both locomotives is the same and the fireboxes are similar in size, except the plan 2 has a shorter firebox (this makes sense as a coal burner). I seem to recall the only major differences in the plan 2 and 4 was this difference in firebox design. The D&RG locomotive being an 8-18.5C doesn't really make it unique, if they were truly unique Baldwin would have assigned them their own plan number. In Baldwin parlance, the .5 or 1/2 nomenclature indicates the cylinder has more stroke than the standard plan. True to form that is the case with the D&RG locomotives, they have cylinders that are 12x18 instead of the 12x16 the standard plan would have had. This same difference in cylinder dimension exists on the "Santa Cruz" at the Smithsonian which is a 8-18.5C plan 4. Both the plan 4 and D&RG's plan 2 had the same internal dimensions for the steam ports. That will simplify the process of recreating the cylinders slightly, since the drawing for the plan 4 cylinders exists in the California State Railroad Museum Library.

Here are the biggest items that differ between the plan 2 and the plan 4 that I see at quick glance:
Boiler diameter and material is different on the D&RG locos, they are 40" diameter boiler made from 5/16" thick steel. The plan 4 (NPC "Sonoma") has a 42" of 3/8" thick iron.
The driver diameter on the D&RG locomotive is 2" larger, having a 45" driver.
Jacket was American Iron, not Russia like "Sonoma".
The tender for the D&RG locomotive was 1200 gal capacity vs 1000 gal on the Sonoma. The "Glenbrook" has a 1200 gal tender however.

As far as I can see, everything else that differs is internal like the number of flues and such.
Every other component, being a Baldwin part, can be replicated from the original Baldwin drawings. Here is a list of the surviving 8-18C drawings and where they are located: http://www.pacificng.com/ref/locobuilders/blw/818C/blw-818c-survivingdrawings.pdf
Though the drawings for domes and other components are listed as being for 8-18C locomotives, they are standard Baldwin parts that include the different card numbers and the adjusted dimensions to match.
For D&RG specific 4-4-0s, the full cab drawings are at the Denver Public Library, I photographed them back in February but I don't have the finding aid information handy at this exact moment.







Edited 1 time(s). Last edit at 08/07/2018 06:24PM by Andrew Brandon.