tag:blogger.com,1999:blog-717574802343934574.post7557378129039182102..comments2024-03-24T04:30:37.015-07:00Comments on Prototype Railroad Topics: The enigmatic PRR 2D-F8 truckTed Culottahttp://www.blogger.com/profile/13464177949755591200noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-717574802343934574.post-11988838130715621302020-07-10T03:34:39.486-07:002020-07-10T03:34:39.486-07:00Please consider that you might be referring to dif...Please consider that you might be referring to differing PRR classes of trucks and not variations of the 2D-F8. See http://prr.railfan.net/freight/PRRTruckTypes-C422800.html which links to diagrams of most of the freight trucks the PRR used. According to this document, the X29 and its various sub-classes, used eleven different 2D-f* classes of trucks. <br /><br />In particular the last image in your post is really a PRR class 2D-F22 truck. http://prr.railfan.net/diagrams/PRRdiagrams.html?diag=2D-F22-E418960A.gif&sel=ftk&sz=sm&fr=John LeMerisehttps://www.blogger.com/profile/00463264116948008031noreply@blogger.comtag:blogger.com,1999:blog-717574802343934574.post-63538948332128778802020-06-28T08:45:49.568-07:002020-06-28T08:45:49.568-07:00Ted, I agree the variation in the bolster ends is ...Ted, I agree the variation in the bolster ends is interesting, but also note the variation in the shape of the side-frame. The 2D-F8s that came on the 1924-25 X29s had that distinctive "droop" above the journal boxes, and the Red Caboose trucks are an exact match. All subsequent PRR 2D-F8s are flatter along the top, and the Bowser trucks are closer (but maybe not perfect).<br /><br />The former are often termed "ARA Type Y" trucks because the sideframe shape matches some ARA drawings from the 1920s. But two points: (i)the ARA standard was for dimensions and engineering standards, NOT the exact shape of the sideframe, and (ii) the exact shape seems to vary a bit from the earliest 1923 drawings to those published into the 1930s.<br /><br />Thanks for the interesting post, and best regards.Dave Parkernoreply@blogger.com