Anthony Thompson <thompson@...>
Paul Lyons said:
I asked about "best model truck" in hopes of short cutting theNot necessarily, though there were not many variations for a given tonnage capacity.
If I know it is an ARA truck I know thereNo. If you look in a Cyc for ARA or AAR truck specifications (at the front of the truck section) you will find a set of dimensional parameters to permit interchangeable parts, but NOT a particular truck side frame pattern. Different truck manufacturers DID offer their own (modest) variations on side frame shapes, with different degrees of top curvature, etc. But since many car owners changed out trucks as needed, after a time in service, cars of a particular group (class or part of a class) often would have different trucks from each other.
Big roads (SP is one example) had a list of "okay" or approved truck patterns, called out by pattern number or drawing number (often a supplier drawing), and suppliers of trucks on a car order could supply anything that was approved. There are instances of truck orders being spread over six truck makers for a single boxcar class, with the only proviso being "ARA trucks" or "AAR trucks" to be supplied.
As Richard Hendrickson pointed out in his two articles on freight trucks, we are a long way from having a very full set of model trucks from which to match particular prototypes. But nowadays we can usually come close on sideframe pattern and presence or absence of spring planks, along with some spring package patterns.
Tony Thompson Editor, Signature Press, Berkeley, CA
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