Model Railroading > Question, passenger car truck nomenclature

Greetings
Can anyone explain what is the nomenclature 41-CUDO means? I know this is an outside swing hanger truck and I know what most of the truck parts are called but I have found nothing to explain what the terms 41 and CUDO stands for.

Thanks
KR

4= 4 wheels
1= 1 bolster
C= 9-foot wheelbase
U= Union Pacific variant
D= disk brake
O= outside swing hanger

As I recall, anyway!

~ BZ

From "Mainline Modeler", Jan/Feb 1982, by the late Bill/Wil/W. Gordon Anderson:

PULLMAN PREWAR CODE:

A - Any truck used at an articulation
U - Truck used under specific Union Pacific-assigned cars
41 - Four wheels, one bolster
43 - Four wheels, triple bolster (SP, UP, PRR, etc)
62 - Six wheels, double bolster
63 - Six wheels, triple bolster
E - Elliptical (leaf-style) bolster spring
H - Helical ("coil"-style) bolster spring
R - Equipped with roller bearings
X - Experimental
11 - 6"x11" journals (5.5"x10" were standard)

PULLMAN POSTWAR CODE:

No designating letter indicates standard 8-foot six-inch wheelbase
A = 7'0"
B = 8'0"
C = 9'0"

No designating letter indicates clasp brakes
D = disk (rotor) brakes

No designating letter indicates 15-1/16" pedestal liner openings (jaws)
N = 13-3/8"
M = 13-7/8" (Milwaukee Road)
U = 14-1/16" (Union Pacific)

No designating letter indicates helical ("coil") bolster springs
E indicates elliptical
P indicates combination of helical and elliptical (Pennsylvania, as on new Walthers "Broadway Limited" cars)

No designating letter indicates no roll stabilization
S = roll stabilizer

No designating number indicates 5.5"x10" bearings
11 (as suffix) indicates 6"x11" bearings

No designation indicates inside swing hangers
O = Outside swing hanger

Typical passenger trucks include the 41-N and 41-N-11, with the 41-ND being similar, except the sideframe-mounted brake cylinders and clasp brake rigging are removed in favor of disk assemblies within the sideframe. This is notable by the remaining bracket for the brake cylinder cast into the sideframe.

The prewar and postwar codes are a little confusing in the overlap, and some designations like 'H' for helical and 'R' for roller bearing were dropped, since postwar trucks pretty much dropped the use of elliptical springs and solid bearings. (It's a minor point, but spring professionals don't use the word "coil" to describe a helical spring, even though most of us still do -- and incorrectly! A "helical" spring winds around a central axis, while a "coil" spring winds on a single plane and outward from center, like a clock or watch spring. Aha!)

Go forth and identify -- and good luck measuring those pedestal liners!

~ BZ



Edited 1 time(s). Last edit at 07/11/11 14:01 by Notch16.

Notch,
Thank you. This is very informative and I will file this data away for future reference. I am sure others will too.

KR

It was a good question, and yes, I think lots of folks can file this away for reference. Thanks!

~ BZ