Wednesday, March 18, 2009

90 Year Old Coach Receives "Modern" (well, 1950's era) Roller Bearings

Wayne Hebert operates the hoist as Charlie Pike and Bill Wolf rig the truck.

Coach 503 (built in 1914 for the Lackawanna) has been "re-wheeled" using like new roller bearing wheel sets which we recently purchased from railroad car wheel expert, Bruce Moore.
The other cars in our fleet all have friction bearings, a type of bearing commonly used from the early days of railroads up until the adoption of roller bearings in the mid-20th Century.
A friction bearing rides directly on the axle, typically lubricated via wool yarn or cotton waste packed under the axle and saturated with oil. The yarn or waste had to be carefully arranged into little bundles called "mice". These "mice" in turn had to be carefully "packed" into the journal box, making sure their "tails" (the loose ends of the yarn or waste) were carefully folded under and not dangling. If one of the "tails" were to come loose and get caught between the axle and the bearing as the axle was turning, a "waste grab" would occur, a "mouse nest" would form and an over heated bearing or "hot box" would result. In extreme cases, a "hot box" could cause the end of the axle to fail, usually resulting in a derailment. Waste became obsolete as foam rubber filled "journal pads" found favor. These pads look rather like a mop head and require less skill to install and maintain.
The roller bearing is a series of highly polished cylindrical or tapered steel rollers which run between highly polished "races" the inner of which is pressed onto the bearing end of the axle, the outer of which is in contact with the journal box. This type of bearing requires less energy to get it turning than a friction bearing. The journal box is sealed so the oil or grease used to lubricate the bearing can't run out. The roller bearing requires minimal maintenance.

Coach 503 truck, roller bearing wheel set to the right, friction bearing to the left. In the forground is a friction bearing journal box with a bearing on the tray behind it.


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