Why is the center rail so much more grimy?

I'm curious if you run command. Best guees is the center rails field from carrying more electron movement is stonger so attracts more airborn particles...? Which rails build gunk varies for me at times.

You didn't mention whether or not the center rail is actually blackened.  I know that when I first started using Atlas track, I had to take a bright-boy to the center rail and take the coating off of it due to conduction issues.

Fred

yes, it would be from over-lubrication of the collector rollers. The concept of sparingly or a small drop is not well understood.

Sanding or abrading the rails at some point will increase the chance of crud build up.

and, yes, Adriatic is correct - the electrical effect does play a part

Cleaning the wheels and collector rollers should be part of the maintenance routine.

I run old pre and post war Lionel, conventional, and do not lube my center rollers and my center rail gets much dirtier than the outer rails. Sometimes I just clean the center rail and live with it. I have attributed it to the electrical charge until proven wrong.

There are a lot more wheels than collector rollers. I think the wheels collecting a lot of the dirt is a factor. How many of us have run across wheels with a band of crud stuck to them?

Yes we do run command on all tracks and the buildup seems to occur equally on the tinplate track as well as Gargraves with blackened center rail.   My guess is the vast majority of operators seldom if ever clean the wheels and rollers.   If the grime was slinging off the wheels ending up on the center rail, I think it would be noticeable on the ballast as well.   There is no such evidence.   That said, I'm thinking it is more an electical related problem, but curious how that works.

You didn’t say if you were running smoke. When RC3R runs displays we clean the track at the beginning of each shift. Smoke fluid use leaves a noticeable increase in black gunk on the center rail.

We use Atlas track for most of the layout. On the stone bridge, I used stainless steel 5 rail GarGraves. The stainless track is always much cleaner than everything else.

I have suspected that the black deposit is carbon on the center rail. I think the carbon tracking may be the result of passing power from that rail through the roller pick-up. Since the stainless has a lower carbon content, this seems to support my theory.

If the grime was slinging off the wheels ending up on the center rail, I think it would be noticeable on the ballast as well.   There is no such evidence.

I am not certain whether this is in response to my comment.
If so, I meant that the wheels collect the dirt, not that they sling it about.
Many people find that they have to clean their wheels from time to time, otherwise they get a band of crud on them that can get rather thick.

Gilly@N&W posted:

You didn’t say if you were running smoke. When RC3R runs displays we clean the track at the beginning of each shift. Smoke fluid use leaves a noticeable increase in black gunk on the center rail.

You may be on to something, there.  And I suspect that "cylinder steam smoke" may well be adding to the effect.

I've had excess smoke fluid accumulate on the underside of engines and suspect it drips onto the center rail.

This in turn would cause the center roller to pickup dust and so forth from the center rail.

I have suspected that the black deposit is carbon on the center rail. I think the carbon tracking may be the result of passing power from that rail through the roller pick-up. Since the stainless has a lower carbon content, this seems to support my theory.

With most operators, no smoke on while running.  I would find it hard to believe enough smoke is in the air once a train 10  cars or longer passes, and we do not see a buildup from smoke on any trackside scenery.    I find the carbon theory possible.   Maybe someone who never runs smoke is seeing this same effect?  Maybe running engines that really spark on the center rail (like Marx) can cause the center rail build up?  Might create carbon, but does not explain the tackiness.

All 3 rail get just about equally dirty, like CW said, the car wheels 'clean' the outside rails. Many times in cleaning customers trains I have had to use a screwdriver like a chisel to get the built up crud off, like a traction tire thickness! The rollers don't 'clean' the center rail well, that's why more build up. Since it is AC current to the track, I'm not so sure if electrically charged particles applies in this instance. Remember in the 1950's operators booklets on the bottom of the page it states 'wipe your track regularly.' 

Railgon posted:

I was running at the club last weekend and slowdowns caused by dirty track started to show up.   What I have consistently noticed is that the center rail is much more grimy than the outer rails.  Why does this happen?   I run my finger on the outside rails a couple of inches and very little black grime.   Run my finger and inch or two on the center rail and it feels tacky and leaves a heavy black line.  I can't believe this would be from over lubrication of the center rail pickup rollers or locomotive gears.   Most operators run modern equipment and no smoke.   We do a thorough track cleaning twice a year, and it seems to only take about 3 months for the dirty center rail to start appearing again.

Thanks for your replies.

the reason is you only clean your track twice a year...

 

we clean our track before every run, every day.

The easiest way to keep the track clean is to regularly run a track cleaning car in a train.  This will generally keep the frequently used tracks clean.  You won't even notice a track cleaning car in a freight consist.

NH Joe 

 

Funny, I didn't clean my track for near half a century. It was used for at least 3 and up to 6 months after each Christmas, and on the floor to boot.

  But put it on a table and the next thing you know I'm cleaning track and wheels three times a year, plus spot cleanings. 300 lbs of Mastiff doesn't help either.

  I hadn't considered the cars being the cause when outer rail gunk is worse than inner. I guess all those extra wheels and their oils are at fault, I don't run light.

Nor had I considered carbon content in the gunk as dust alone(much of which is you own dead skin according to household allergen reads of the past) ...is so affected by static fields, I assumed it was attracted to just about any field.  I just thought of "metal dust" without thought of the actual carbon content of the various metal dusts in play here.

Interesting theories. To bad it's more or less easier to clean than actually chase the phantoms behind it all   There's always nickel silver or stainless for an edge on cutting out rail cleanings needed There is a slight traction loss and better buses are needed to overcome the slightly higher power resistance in the rails; but the smaller scales use it a lot. Being more susceptible to dirty track "ruining" a run day makes the slightly higher cost of NS&SS worth it to many.

The fact the gunk can be rock hard isn't suprising. The process used in making engine components like rods has involved high carbon metal dust and magnetic fields to align metal graining molecularly for decades. No more red hot ingots and forge poundings in a traditional sense for mass production there.

Two of my micro layouts seldom see a smoker at all but need cleaning just as often. Though I get the point no fluid is "best" in some ways, I wouldn't blame the smoke fluids too much here beyond that any wetness is likely to hold dusts. It takes heat and lots of accumulation to get a thick varnish out of them; they're thin. Thicker oil's are a more likely gunk source imo. Even how and what we cook could be a BIG difference. Lots of deep fried foods can do a real number on internally varnishing a home fast. (Lucky me fried, deep fried esp., is not really a fav.)  Aroma is often oily and usually warm and moist too; and therefore looking to condensate on cooler items, even in trace amounts that build up to...!!! ..yuck

I suspect it is a combination of things, I am not so sure of the electrostatic theory (ie that  the  current running through the middle rail and/or command control signals that DCS sends, are responsible all that much. It might cause small metal particles to accumulate, but  not sure it would affect general "crud" all that much).

I would guess as others have, that it is likely excess lubricant getting on the tracks, and perhaps smoke fluid if you are using it. I suspect the outer rails get as dirty, but as others have said, the outer wheels are better at 'cleaning it' ie they have a larger capacity to 'store' crud. Thing about it, the roller on the third rail is this small cylinder, maybe 3/8ths diameter, and its  rolling circumference is roughly 1 1/8th "....the wheels on a typical car are close 3/4", which is over 2" rolling circumference..and if running a single engine, you have a couple of rollers, if running a train you have the wheels on the engine, plus the wheels on the cars you are pulling, the ratio of wheels to rollers is going to be huge, likely 30 to 1 or more with a simple train (1 engine, 12 wheels  (assuming 3 wheel trucks),plus the wheels on the cars that will vary between 8 and 12 depending on the truck type,it is going to be a lot). They can accumulate a lot more crud and/or cause it to 'fall away' then rollers. 

 

Can't speak of the center rail (cause I ain't got one anymore) but...

I swore after converting to BPRC I would never have to clean track and/or wheels again.  Well, my non-electrified code 148 2-rail track gets just as dirty as before and so do the wheels, it just takes longer.  I've seen enough crud on the wheels that I swear it has caused a few derailments.  Now I don't clean them often, maybe twice/yr, but I still need to clean them.  I cleaned the wheels on a caboose the other night and the crud looked like it was 1/32" thick!!!  Even if it was 1/64" thick that's still a 3/4" scale buildup of crud.

I suspect the center rail sees more crud due to the light loading (contact) of the center rollers.  The weight of the engine is on the drive wheels and I believe that weight pushes away the crud more than the center rollers push it away.

I've been cleaning my wheels using a foam-tipped applicator dipped in MEK, gets them clean quick (just don't get the MEK on any paint), here's the applicators:

https://www.amazon.com/100pcs-...rds=foam+tipped+swab

We used them when cleaning read/write heads on the Navy tape drives back in the day.  I used them now to clean my firearms and my trains!

It's not the oil or the smoke fluid. It's no mystery either.

The"black stuff" is a result of the electrolysis that occurs from electricity passing through dissimilar metals.

Run your trains and clean the track when it's dirty. 

From Dick Webster of Centerline Products:

1. The number-one producer of rail & wheel crud is the electrolysis effect of passing current through dissimilar metals. Where our current-drawing locomotive wheels (of one metal) meet the rails (of another metal), a very fine powdery oxide is formed. In "a Perfect World", this oxide would just powder over the edge of the rails and never be a bother to anyone. These days, most of our rails are made from nickel-silver because the oxides of this metal are a bit more conductive than the oxides of brass and, therefore, nickel-silver just seems to stay cleaner longer. You all have probably seen advertisements for locos with nickel-silver wheels and the ads from Northwest Short Lines for replacement/substitute nickel-silver wheels. This is, generally, a very good trend because it puts both rails and wheels of the same metal at the point of current pick-up and minimizes the oxide production. (Nickel-silver wheels on non-power rolling stock don’t really prevent anything, but they’re nice to look at).
   
2. In our Non-Perfect World, over-lubrication, humidity, cooking vapors, smoking, forced hot air heating, wood stoves and fireplaces all contribute to an environment in which the oxides tend to bind together and also to wheels and rails. Conditions vary, from layout to layout, and the mess can be seen as decreased engine performance, headlight flickering, scratchy sound systems, spotty DCC operation, film that’s almost invisible, a thick "tire" on rolling stock wheels and, in some cases, crossings and switches that stall out the engine because the points seem to concentrate a build-up of crud in those places.
   
3. "Normal" house dust, dander, baby dust bunnies, cat hair, smoke particles and sawdust all get mixed into the formula and bind with the oxide crud to, in some cases, create a truly impressive challenge.
   
4. Scratches on the rail heads or wheels, from abrasive cleaning, gives the crud a place to "root" to and build up from there and will be seen as patches of crud in various places along the way.
   
5. Non-powered rolling stock wheels (metal or plastic) are a vast storehouse of accumulated crud. I agree that plastic seems to accumulate faster than metal, but it’s all a matter of degree. A thorough cleaning of the rails is a positive thing, but with dirty wheels, the effect is negated very quickly because of re-deposit back onto the rails.

I clean my layout 2x  a year after 100's hours of usage, Not all that bad, just an old habit, I have...🙂