Large Scale Central

Brian D or any other "former scientist"

Track and Trestles
#1

Brian, I was at a friends layout a week or so ago where we were talking about brass vs stainless steel. On the layout theres a 25’ ish section of brass on the mainline, the rest of the mainline is stainless (150’ ish). We noticed drops in speed on the brass, he used a cleaning pad, and all was fine, well for about 15 minutes… then the same thing happened.

I then began to question as to why it would happen so quickly?? It’s not like brass oxidizes that quickly!! So I was thinking it must not just be the track, I looked at the wheels of the Aristocraft RS-3 and noticed that the Stainless/Alloy crap silver wheels had rings of brass coating on it. When I got home I checked my U25B and the same ring appeared. My USA trains SW-2, which appears to be a harder metal than aristo did not have this.

Is it possible that the track cleaner is leaving a film on the track and the wheels of the loco are picking it up and either sticking from compaction, or is it possible that the film is “welded” from the track power to the wheels??

I see everyone talking about the track being the problem but could it be the metal wheels and a reaction between the two?

The USA trains and LGB stuff has the sliders which continually scrape the rails so they don’t have the same problems as the Aristo and Bachman stuff.

Ok time to sit back and see if anyone can answer without the “battery power anyone” Bs and have a discussion about the original topic in question. Heaven forbid a solution to the brass cleaning issue actually be answered scientifically!

#2

I think rather than rings of brass they are rings of worn off plating. Many wheels are made from brass with a bright metal plating.

#3

I was a biologist (immunology and genetics) so this is a bit out of my field. I, too, have been curious about the stainless vs. brass phenomenon. Brass is supposedly the better conductor yet the trains run better and faster on stainless. I have heard this repeatedly from people who have a bit of both types of track. We need a metallurgist or EE (hey, one on my bros-in-law is a EE!) to report on this.

-Brian

#4

I’m no scientist, but the plating rubbing off the wheels sounds like the culprit. The wheels on my Buddy L loco have copper showing through the plating - or at least, some kind of copper colored brass.

As for why your loco runs better on the SS than on brass, that’s beyond me.

#5

I’m not a metallurgist. Heck, I don’t even play one on TV. But here is what I have learned by keeping my mouth shut and my ears open.

Yes, brass is a better conductor of 'trons than is stainless, until it oxidizes, which can happen in as little time as 10 minutes, especially where there is any appreciable humidity. The brass will still look shiny, but there will be a one or two molecule thick layer of verdigris (brass rust) on the track, severely reducing the flow of 'trons.

Stainless, on the other hand, is a poorer conductor of 'trons than is brass, that is, until the brass rusts, then stainless is far superior.

I have a friend who has all LGB track, wonderfully weathered that rust color that we all love so well. I noticed that he was having to set his track power throttle at a much higher setting than I thought was required. I sneaked behind some bushes and cleaned a 10 foot section of track, just to see what would happen. On the next round, the locomotive took off like a rocket for those 10 feet, and then put on the brakes when it got back on the weathered track. This only lasted for about 15 or so minutes, and by the end of an hour, there was no noticeable change in speed over that section at all.

#6

So what you’re telling us Steve, is that folks who use brass track with track power are using an excessive amount of electricity to run their trains compared to us stainless users, therefore, contributing to global warming. I’m calling Al Gore! :lol:

-Brian

#7

Hmmmmmmmmmmm. I didn’t think of that.

#8

Mark,

It’s the plating coming off the wheels. That why I got rid of my Aristo engines. I spent more time cleaning the wheels then running. It seem like once the plating come off the dirt biulds up more. Never had any problems with USA or LGB.

#9

No scientist or metallurgist here, either.
But I do have a little experience with electroplating.
So, it might have something to do with the electrons moving from the track, thru the wheels and up thru the motor and thence back thru the other wheels and back to the track. (That’s how DC works–travels in a straight line from the power supply-rail-wheel(pick-up)-motor-wheel(pickup)-rail-power supply). The opposite direction when polarity is reversed.

It’s the movement of electron from the track to the wheel surface that is the culprit. The rest, wiring, etc, has a solid conduit.
However, due to simply being not constant, the electrons have to “jump” up or down from the wheels, skates, or whatever to the track. This causes arcing, which may due to magnetic flux, may cause the corrosion.
But what they hell, what do I know? :slight_smile: :).
Sounds good tho, doesn’t it, Mark. :slight_smile: :slight_smile:

jb

#10

I guess I don’t run my Aristo stuff enough to wear through the plating. Never had a problem.

Because stainless track is harder than brass track it probably accelerates the wheel wear. The stainless is probably also quite a bit harder than the plating (likely nickel) on the Aristo wheels.

So what we’ve discovered is that if you run your engines a lot, you either need to stay away from Aristo or convert to battery.

/ME Ducks to avoid the beer bottle Mark hurls across the room in my direction

Or do what I do, leave 'em on the shelf most of the time and run the Bachman stuff and your live steamers :o

#11

Mark gives a salutary explanation for all on why not just one but at least 3 other manufacturers can survive producing on board control equipment powered by an on board power source.

#12

Early Aristos had a problem with bad wheels-that’s what got me over to battery power years ago. Newer Aristos are okay on the wheel wear thing, but too late for me! My Z is track powered, but the wheels are fine so far. Jerry

#13

The actual metal composition of the rails is really a mute point. The issue is the conductivity at the point of power transference between the railhead and the wheel tread and its subsequent return to the opposite railhead. Track is a solid material, composed of electrons readily transferring energy between them - result, conductivity. The wheel tread/railhead interface is not a solid material. It is microscopic irregularities that impede the electron flow, both in travelling to the motor terminal and in its return electrical path. We also know that the oxides of brass are not conductive and this impedes electron flow.

My solution is to ensure as many electrical pickup/transfer points on a loco and/or tender, or to use trailing power pickup cars to spread the electrical footprint. By having the maximum number of pickups, I find the railhead stays cleaner and dirty wheels are a thing of the past. Dirty wheels are the result of microscopic arcing as carbon is formed at the wheel tread/railhead interface when electron flow is interrupted. No nuclear theory or brain surgery here.

#14

In my experience LGB is the best as far at surviving dirty track. Never tried a USA Train engine–I bought one but it arrived defective and is on its way back to USA trains for repair. I have a Bachmann annie that runs very well on dirty track as well. My two aristo engines (pacific and mikado) show the effects of dirty track first. I’d have to assume it’s the wheels, although they are also pulling a lot more weight which I suppose might matter

#15

Mike,
USA’s are somewhere in the middle.
You are right about LGB. For the 26 years or so I’ve run 'em on track power; A little cleaning and the wheels look as good as new.
Aristo is at the bottom of the list due to (maybe) no power shoes, or a poorer electrical pickup system.
They seem to be the first to start jerking after you’ve cleaned track for a days run.

#16

Thanks guys for the insight you have presented, nice to see a topic stay on target!!

#17

I’ve always wondered about the power shoes, if they help or hinder track cleaning. They give you a very solid contact point, and they scrape along which should help clean the track.

It’s got to be the wheels with Aristo. I’ve never owned an aristo diesel, but I have two aristo steamers and they are the first to show the effects of dirty track. I haven’t cleaned the wheels in quite a while though. The plating is worn through–it wore through very quickly

#18

At the risk of getting the same beer bottle hurled in this direction, this all sounds like a good endorsement of battery power…:wink:

Me quickly exits…stage right…

#19

Not …taking…bait…

#20

I find it amazing how quickly the brass develops resistance.