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the Pennsylvania Railroad's 2DF8 truck. The American Railway
Association adopted what was essentially the Pennsylvania
design as its Type Y truck (17). (There was also a similar Type
W truck which, like the Vulcan truck, had separate bolted-in
journal boxes, but it was little used.) Equally important, the
ARA established revised standard specifications for freight car
trucks, including such key dimensions as wheelbase, center
plate height, and side bearing height.
It was soon found that the Type Y trucks were prone to crack-
ing at the lower corners of the spring box, so the Type Y side
frame design was short-lived except on the Pennsylvania
Railroad, which continued to employ 2DF8-style trucks until
the late 1930s. However, other truck manufacturers quickly
developed alternative side frame designs of varying configu-
rations which reduced the cracking problem. All had integral
16
16: Following the end of World War I, Bettendorf
redesigned its integral journal box truck to incorporate U
section rather than T-section side frames, and this was the
forerunner of many similar trucks in the 1920s conforming
to ARA specifications.
Freight Car Trucks - 8
index contents
MRH-May 2013