Re: 8.000/10.000 gallon tank car trucks [Proto 2000].


Richard Hendrickson
 

On Jan 19, 2006, at 12:12 PM, Arnold wrote:

I've just saw severall photo's of the 8.000/10.000 gallon tank cars.
The revited type by Proto 2000.
Normal and insulated.
On the photo's you can see that all the trucks of that type is having
2 springs per side on 1 truck.
The insulated types 4!!

But the Proto 2000 is having 3!!!
Is 3 correct?
Can anyone tell me the manufacturer that has the proper type for this
car in the 1947/1960 period?
Arnold, the responses from both Tim O'Connor and Tony Thompson are
essentially correct. There are more springs in a truck than are
visible from the outside of the side frame. North American freight car
trucks typically had either four or five springs per truck, arranged
(looking from the top down):

O O
O O

or

O O
O
O O

Sometimes the center spring, if any, was visible (as modeled on the
Life-Like HO scale AAR trucks); sometimes it was lost in the shadows.

Seventy ton and heavier trucks often had six springs:

O O O
O O O

The trucks with four visible springs were Dalman trucks, which were
widely used in the 1920s and early '30s, before trucks with built-in
snubbers were developed. Dalmans had more and softer springs to
provide a better ride for the same weight-carrying capacity, and their
springs were arranged:

O O O O
O O O O

Eastern Car Works offers rather crude HO scale kits for Dalman trucks
(as well as for seventy ton AAR trucks) which are all we have at
present, but a better Dalman truck is under development by another
manufacturer and should become available later in 2006.

As for the correct trucks on the Life-Like AC&F Type 21 tank cars, it
depends. Many were built with Arch Bar trucks and got some type of
Andrews or ARA/AAR truck later in life. Some, like the Texaco and
General American cars modeled by Life-Like, were delivered with Dalman
two-level trucks. Others got ARA cast steel trucks with spring planks
when new. None were built with, and very few received as replacements,
the self-aligning spring-plankless trucks introduced in the mid-1930s
which are modeled by most manufacturers of HO scale trucks (and which
are often, though incorrectly, called "Bettendorf" trucks). As usual,
you have to consult prototype photos and then find the model trucks
that most closely resemble in type and side frame configuration the
trucks on the prototype you're modeling. No easy answers here.

Richard Hendrickson

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