and he notes - You are correct. "Baldwin Disk" and "Box Pok" are similar, but quite different in construction. B&M's R1ds (Mountains) had Baldwin Disk drivers and except for size, were identical to the SF loco's.
However there were variations on what we call "Box Pok" drivers. Some had different shaped holes between the spokes and may be attributed to another manufacturer; as shown in the lower photos on the Soo Line locomotive: http://www.2719.com/pages/2719photo38.html The Grand Trunk Western used similar drivers on a few of their 4-8-2s. No. 6039 was reported to have received vanadium steel main frames and "boxpok" drive wheels. Technically called "box-spoke," these drivers had fewer spokes and were of box-section type, like the wheel rim, a design that provided greatly improved lateral strength and rim stiffness. Viewed from the side, the opening between the spokes was circular, rather than wedge-shaped. The variations in shape got my curiosity and I poked around the net for an answer. It appears that SP used disc drivers on many of their Mountain types but they were "Universal" type, not "Box Pok" The name "Boxpok" was a General Steel Castings (Commonwealth) trademark. Universal discs were made by Locomotive Finished Material Co. and had much larger, and fewer holes than GSC's Boxpok¹s. (Nos. 4351, 4354, and 4365 were the only Mt-4's with real "Box Pok" discs). So, do we have variations in "Box Pok" designs or a different driver type? Incidentally, I found a neat site with close up photos of the Soo loco's drivers: http://home.new.rr.com/trumpetb/loco/2714.html It also has animated drawings of the valve motion, as well as other useful information. Raleigh in Maine At 11:33 AM 8/13/2005, Bud Rindfleisch wrote: >Raleigh, > I think there has been some confusion on the difference between >"Baldwin Disk" drivers and Box Poks. I think you are right about the >disks being used on the ATSF engines, but the LV prefered the box poks. >I have many books on the LV as well as numerous photos and none show any >disk drivers. > >Tom, > Thanks for the info on driver diameter and leading and trailing >wheels also. Now I wonder if the AM model will be full scale 80" or >reduced somewhat to allow model flanges? > > Bud Rindfleisch To REPLY to the list, use REPLY ALL; to reply to the sender, use REPLY. For those of you on DIGEST mode, all REPLY messages go to the list (remember to edit the SUBJECT of your message). Change message settings, use our CALENDAR or LINKS, view shared files or photos, view the list archives, GO TO http://groups.yahoo.com/group/S-Scale/ Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/S-Scale/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
