Andews vs Crown Trucks

[Anonymous]

Does anyone know the difference between Andrews and "Crown" trucks. I suspect that "Andrews" refers to a design originating about 1898 and that "Crown" refers to the manufacturer of sideframe castings used in a truck of "Andrews" design. But I have never been able to confirm this. On the PRR the conventional terminology was "Andrews" trucks.

Patrick Nixon
Canton, MI
[e-mail]

[Anonymous]

The Andrews truck was designed to replace the archbar truck by allowing use of the old journal boxes, etc. in a new cast frame. The journal boxes were attached to the Andrews frame in the same manner as they were attached to the archbar - with vertical bolts on each side of the journal box. This necessitated the frame member underneath the journal box. I suspect the Crown truck was the designation of the 70-ton Andrews truck used under the Pennsy H21 and H25 cars. N&W had 70-ton Andrews trucks under class HU (later H3) hoppers with "Andrews Floyd" cast into the side frames above the bolster opening. Were Crown and Floyd the designers of their respective trucks?

[kenneo]

I had never thought of this until now, but the Bettendorf replaced the Andrews with the journal boxes cast into the side frame. Now we have gone back to a cross between the Andrews design and the Bettendorf design with the roller bearing journal held in place similar to the Andrews, but by gravity instead of bolts and the bolts being replaced by the cast-in "forks" that the roller bearing sits it.