Railroad Forums 

  • How did 'waste' wick oil onto Friction Bearings?

  • General discussion about locomotives, rolling stock, and equipment
General discussion about locomotives, rolling stock, and equipment

Moderator: John_Perkowski

 #781803  by Sir Ray
 
From time to time I have seen images (cut-away) of friction bearings in their journal boxes, but I don't recall seeing any diagrams or images of the waste/rags (cotton strips?) in-situ showing how they wicked lubricant onto the bearings.

I have read that:
Hobos used to open up the journal box cover, steal a strip of oil-soaked waste, and use that as tinder to start fires (being careful to leave some waste to continue to lube the bearing) - hence I guess in general a bunch of waste must have been stuffed into each journal, but I'm not sure.
Also, I read that sometimes strings from the waste would get caught between the bearing and the brass[?], tangling the waste up with the bearing and potentially causing a hot-box (this sound like a design flaw, to say the least).

So, are there any such images around showing how the waste/lube was packed in the journal box, and how it functioned? Also, was there any different friction bearing lubication system in general usage (as opposed to experimental one-offs) before roller bearings took off in a big way?
 #781858  by John_Perkowski
 
A long time ago, I was at Fort Knox, and volunteered on the weekends at the Kentucky Railway Museum. This was when it was just out of downtown Louisville (1979).

I remember getting taught about plain bearings (the use of the word "friction" was advertising by the early Timken folks IIRC. All bearings have the role in life of reducing friction. The waste was packed up basically to the level of the bearing, and soaked in heavy gear old (really thick stuff). Capillary action drew it up to the top, so the bearing surface had a film of lube.

I'll try google imaging on railcar truck plain bearing and see what I get.
 #781969  by Sir Ray
 
John_Perkowski wrote:the use of the word "friction" was advertising by the early Timken folks
I guess anti-friction bearing is a better term, but googling on 'friction bearing' does turn up plenty of hits - I guess the term just stuck w/ model railroads to distinguish from roller bearings - I do know 'journal bearing', while also used by model railroaders, is not really an accurate term for plain railroad truck bearings.
The waste was packed up basically to the level of the bearing, and soaked in heavy gear old (really thick stuff). Capillary action drew it up to the top, so the bearing surface had a film of lube.
That's what I thought, but I'd still like to see a picture or diagram.
I'll try google imaging on railcar truck plain bearing and see what I get.
I had little luck - hopefully your google-fu will be better than mine... :P

ETA:
I took John's suggested terms for google search, and the 6th or so linkwas more or less what I wanted - Good Show, Sir! Thanks :-D
 #782556  by ex Budd man
 
The Reading Blue cars had plain bearings and were repacked on a yearly basis. The packing came prepackaged and soaked in oil, ready to be used. To repack the journal boxes we lifted one end of the car high enough to free the brasses then lowered it enough to pull the old packing with a packing hook. Then the journal was inspected for wear and the axle collar was gauged to be sure it wasn't below minimum thickness. New packing was placed into the journal box and a new brass was set on the axle. Once the car was lowered it was checked for alignment and the journal box was topped off with oil up to the underside of the axle journal. As the axle rotated it carried the oil to the brass (which had a babbit lining) and kept the bearing lubricated.
 #793388  by GSC
 
Another reason for the cotton waste is to keep the oil in the journal box, as a car knocker explained to me once. A wet wick is far better than just a reservoir of oil, prone to moving around and possibly sloshing and spilling. Thick journal oil gets thin when it gets heated in regular service.
 #793400  by Sir Ray
 
The confusion I had pre-these responses is that I though the 'brass' of the bearing encircled the axle (like roller bearing and many other types of bearings) - therefore, how did the lube get to the bearing surface.
The answer is that the brass did NOT encircle the axle, only the topmost portion, and so the bottom portion of the axle was immersed in the lube (via the wicking action of the waste). And I can see how the waste would act as a baffle or barrier to prevent the lube oil from sloshing around, as GSC mentioned. And finally I can understand a few threads of the waste getting stuck to a moving axle (lube is sticky, after all), being pulled up and jammed under the brass at the top, and then friction & heat doing their thing to oily, flammable cloth and bam - hot box!
 #793776  by GSC
 
The brasses have shallow grooves cut into them to allow oil to get inside, not unlike an automotive crankshaft and piston rod journal.

I've hand-scraped brasses, so I've seen these grooves firsthand.
 #794291  by ex Budd man
 
All of the bearings I worked with had no grooves for oil. We used a light grade, clear oil in our cars. The journal boxes had a rubber dust shield in the opening for the journal, while not a complete seal, it went a long way preventing dirt from contaminating the oil. The seal slid in to a slot at the rear and was replaced when the wheels were replaced. We never had "waste grabs" since the packing was not loose but pre-assembled in a single unit.
 #795586  by GSC
 
I worked on journals from 100 year old cars and almost as-old locomotives in museum rail service. I've heard of more "modern" journal assemblies but we didn't have such "luxuries". Two-piece brass bearings, a wad of clean cotton waste, and thick gooey journal oil.
 #803089  by David Benton
 
interesting stuff .
So if the bearing was only on the top 1/2 , what happened when the wheel when over a bump , or more likely a hollow , and briefly became airborne or light ??? . perhaps the cotton waste was also there to act as a kind of shock absorber in this kind of situation . or perhaps the wagons were heavy enough to not do this .
 #803532  by ex Budd man
 
One of a car knocker's daily jobs was to open each journal box lid and check the oil level and ensure the brasses and wedges were not out of place. A bottle jack would be placed under the journal box and raised enough to re-seat the displaced part. A soft iron or brass 'grab hook' was used to feel for waste 'grabs' by running it along the journal surface near the bearing. Being a soft material it didn't damage the surface of the journal.
Packing irons were used to adjust the waste or preformed packing in the box. If the journal collar looked suspect he could use his knuckle gauge to check if it were serviceable. The flat end was used to seat the waste or packing and the double hook on the side of the iron was used to open or close the box lid.
1006.jpg