In numerous railroad pictures, I see car wheelsets (two wheels on axle) stored outside, without any protection. But, in pictures from, say Strasburg, the journals are carefully protected by wood and tape.

Why would the journals on these large collections of wheelsets also not be protected?

There are 2 different types of damage that can occur to the journals: impact and rust.


The wood and tape protect from impact damage, but by themselves do little to protect from rust.


Cosmoline or other rust preventatives protect from rust, but by itself does almost nothing for impact protection, and may be used in combination with the wood and tape impact protection.


The RR will decide which type of protection is most useful for the storage or shipping conditions the wheelsets will be in.


In some cases, for example a wheelset worn beyond the limits of being reconditioned, the RR may simply set the wheelset aside without any protection, because who cares if the scrap metal gets rusty?

Jeff

I thought bearings reduced friction. I'd call them plain bearings.

Robby Peartree

Neither preceding post contained either the words "friction" or "bearing"....

Please read the title.
Robby Peartree

Au contraire, both of them do ... in the subject line. That is the part that needs to be edited from 'friction' to 'plain', this not being a topic in any way associated with Timken antifriction bearings or that company's propaganda efforts back in the day.

Etymological backformations are cute, but they really have little place in engineering applications. "Plain" is one of the right terms for a hydrodynamic bearing system like the one inherent in this topic's discussions. (And yes, in my opinion that would also apply to systems like Isothermos that use relief or circulation channels to assist the hydrodynamic tribology).

Sure, we understand what a 'friction bearing' is, and can be perfectly patient tolerating people who (mis)use the language that way.

I remember the conversation about these terms from threads years ago and I was thinking that as I wrote the post and I was just too tired to check it.

I remember reading that one of the roller bearing manufacturers, SKF, Timken, et al, came up with the term 'friction bearing' to point out the fact that their roller bearings created less friction than plain bearings. Or so the story goes....

Right or wrong, it is a mater of interpretation.

I have been around railroad equipment for over 45 years and have owned many pieces of railroad equipment with "friction bearings. RYPN is the only place I have ever seen or heard them called "plain bearings."

I have sold many new and used "friction bearings" and No one has ever ask me for a "plain bearing".

The dictionary has for friction "the rubbing of one body against another" and "resistance to relative motion between two bodies in contact".

And were this to characterize the tribology of your "friction bearing", you might have something. But it really doesn't. You'll find that once hydrodynamic issues such as establishment of the wedge are overcome at starting, the actual "friction" of a plain bearing of given engineering capacity is comparable to an equivalent rolling-element bearing, and may in fact be lower for a number of reasons. The argument is not whether the bearing will last a vastly longer time without replacement, or serve without routine checking and maintenance. Those aren't the criteria the present discussion is concerned with.

In fact, there are vast areas of practice where 'friction' construction has been repeatedly demonstrated superior to any rolling-element construction -- notably in internal-combustion engines, where roller cranks are a high-dollar, fragile, difficult-to-maintain tweak niche. I could also go into the areas, like reciprocating small-angle motion as in conjugated locomotive valve gear, where rolling-element bearings cause more issues than they solve.

If I were inclined to debate the question of fair labeling, I could bring up issues of fretting or extended line-contact deformation in, say, Timken 'antifriction' bearings, issues requiring fairly quick attention at somewhat greater cost and difficulty than machining a new brass and depitting the journal surface.

Getting back on to the original poster's question: Leave the wheelset outdoors and, sooner or later, any type of grease that you might lather on a bearing surface is going to be washed off by precipitation. Then the rusting and pitting will begin.

What I've done on wheelsets stored outdoors is to paint the bearing spools with any readily-available oil-based paint. There always seems to be a gallon can of something laying around with only one pint remaining. Put it to good use. Lather on generously so there are no pinholes in the paint surface where rust can initiate. If applicable, do the same on the axle's motor support bearing surfaces and bull gear teeth. If the wheelset is outdoors for years (or decades......) repeat the painting periodically.

When (and if) the wheelset is ever used again, the shop crew will have to strip off the paint, but that's a lot easier and cheaper than turning the axle to remove rust and pitting from the bearing surfaces.

Hopefully everybody knows to not store the wheelsets on the ground. Wheel treads and flanges in contact with the earth will become badly pitted. Sections of "snap track" for storing trucks and axles are one of the best uses of odd sections of worn rail and not-quite-relay-grade crossties.

/s/ Larry
Lawrence G. Lovejoy, P.E.

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I remember seeing a set of wheels where the bearing journals were painted with a primer gray colored paint (but more of a satin finish) that wiped off somewhat easy, but held up in the weather. I don't know what it was but would like to.


On a side note, having a thread where the first handfull of replies are bickering over the use of a term is not helping the serious tension on this board. I am from Michigan. We call soda-pop and liquor stores-party stores. Could it be that certain terms are used differently across the world for the same components? Just a thought.
E

Sounds like graphite, commonly used by the gallon to lube switch parts and the like.

A road repair car back in the day. The caption notes that the wheelsets are greased AND capped. A wheelset inside the car appears to have yellow caps/cans on both ends of the axle:

http://www.railpictures.ca/?attachment_id=29569

Another advantage of modern roller bearing and axle/truck designs is that you do not have to take apart the truck frame like this to change wheelsets:

http://www.railpictures.ca/?attachment_id=29530