Re: Solid, Roller & Friction Bearing Journals


Message: 8
Date: Fri, 26 Aug 2005 11:14:42 -0500
From: "Tom Jones III" <>
Subject: Re: Re: Solid, Roller & Friction Bearing Journals

More like the application of fuel prices and safety issues (i.e.,
liability claims) that moved railroads to roller bearings.
Except for their catastrophic failure mode roller bearings are better than friction bearings. Friction bearings advertise their pending failure for a long time. As friction bearings heat up they emit smoke from the overheated journal box that an alert train crew could often spot in time.

Roller bearing run until they fail, then they fail Right Now with little or no advance notice. They can run by a hot box detector with no problem and then fail in the next few miles. Because of this failure mode it is always a catastrophic failure. The blessing is that with the improved bearings we have today, the failure rate is very very low.

Although roller bearings we developed quite early I don't think the metallurgical technology was up to producing the type of metals needed for railway quality bearings until around WW II. War is a great technology accelerator and by the end of the war the metallurgical technology and production facilities were in place to produce the quality of bearings needed for railway use.

Bill Dixon

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