Re: Truck Journals


Richard Hendrickson
 

On Aug 27, 2005, at 9:04 AM, Montford Switzer wrote:

This has been quite a lengthy thread and this may have been covered
earlier. Anyway one reason for the railroads NOT to invest in roller
bearing trucks was that the cars spent a lot of time off line benefiting
another railroad that may not have made a similar investment.
Mont is, as usual, correct. Immediately following WW II, several railroads equipped freight cars with roller bearings for on-line service (e.g., the Union Pacific's Day Livestock Service stock cars, the C&O's unit train hoppers). But none of the North American railroads were willing to spend the extra money to equip cars in interchange service with roller bearings, since other RRs would then get much of the benefit without having to spend their own capital. As 100 ton nominal capacity freight cars began to appear in growing numbers in the late 1950s, however, it was found that solid bearing trucks would not perform reliably carrying that much weight, and once the application of roller bearing trucks to 100 ton cars became common practice, the resistance to putting them on cars of lower capacity rapidly diminished, especially as their elimination of hot journals came to be increasingly appreciated by both mechanical and operating departments. By the way, this has all been covered in published sources as well as in previous discussions on the STMFC list, so the recent deluge on the list of opinion and speculation masquerading as fact on this subject is really quite unwarranted, not to say tiresome for those of us who have been paying attention to these matters for a long time.

With regard to terminology, I will say yet again what Tony Thompson has already asserted on this subject, that "friction bearing" was a term used as a promotional ploy by the roller bearing manufacturers to imply that roller bearing were "non-friction bearings," which is, of course, nonsense. That it may have gained some currency in later years with railroad employees is beside the point. During the steam/transition era, which is our concern on this list, the terms used almost universally in the railroad engineering literature for conventional bearings were "solid" or "plain" bearings, as anyone can determine by spending a little time reading that literature (e.g., Car Builders' Cyclopedias and periodicals such as Railway Mechanical Engineer). That an exception to this practice was found in a single, rather dated, publication proves nothing to the contrary.

Those of us on this list who carry out serious prototype research generally prefer to use the terms that were common to the engineering literature where different from those used by the working stiffs who ran trains and maintained rolling stock, a preference which in no way reflects any lack of respect for the working stiffs but does reflect a desire for clarity and consistency. Others on the list may, of course, use any terminology they like, but should be aware that their choices may lead others to doubt their seriousness and their credibility.

Richard Hendrickson

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