How many feeders?

[BRAKIE]

First let me explain I never been one for feeder wire overkill.Now in that truth I drop feeder wires every 6-8 feet which I find works quite well.Now on small industrial switching layouts 10 feet or less in length I do not use feeders.
Now on the few loop layouts I have built over the years I usually use Atlas sectors for block wiring and fore go any feeders as they are not needed.You see I simply run a single wire from the track to the selector per Atlas' instructions.Simple yet efficient.

[Anonymous]

Brunton,

From what I've seen and talked to other people about this, the layout expansion problems "appear" to be heat related because that's when the humidity goes up iin an area. When moisture gets into wood it swells, hence the layout gets bigger and the rails buckle. By adding expansion joints you're accomodating this process in your design. You can also control the humidity or move to a drier climate to solve the problem as well. Design or material changes can eliminate the problem up front. Foam doesn't swell with humidity. Those people that build their layouts on foam probably will never see a problem.

The corrosion that we're all worried about is a slow acting effect, and it's mostly galvanic corrosion. Whenever two dissimilar metals come in contact, a battery action is formed. If water is allowed into that point then you can get an "electroplating" effect, where metal is transported from one side to the other. Obviously not good.

The other corrosion is a chemical acidic action which is caused by the residual flux and again, moisture. In this case, a stranded wire is WORSE simply because you have a much higher surface area per unit volume of copper. If you're truly worried about corroding wires you should go to solid wire whenever possible. Stranding makes sense though in those cases when you have to repeatedly move the wire. Solid wire is less durable in that situation.

Obviously corrosive fumes are bad news. High humidity with salt (coastal areas) are famous for this problem. Ever seen a swing set in those areas?

In this whole discussion I think the main thing to remember is that you have to build according to the environment you have to deal with. The addition of tons of feeders may be overkill, but once you've been bitten by a problem, you tend to keep hitting it with a hammer until it's been dead for a very long time.

Mark in Utah

[Pruitt]

QUOTE: Originally posted by mark_in_utah

High humidity with salt (coastal areas) are famous for this problem. Ever seen a swing set in those areas?
Mark in Utah

When I worked at Cape Canaveral in Florida (on the space program - manned and unmanned), one of the guys had a pickup truck that the salt air corroded so badly you could see though it! It looked like rusty swiss cheese. We all used to joke that he would be killed when he fell through the floor on the highway, and his own truck ran him down.

My first year in NJ I had some expansion/contraction problems, and my rails kinked really badly in several places. Humidity in the summer was so bad that we had trails of water drops on the floor from where the water pipes were sweating! In the winter the humidity was only about 30%, so there was a lot of variation, season-to-season. I solved the problem with humidifiers in winter and a good dehumidifier in summer. Now the basement runs 45-60% RH all year around, and there are no more kinked rails. It's not the level of humidity that's a problem; it's the variation.

[grayfox1119]

Mark, you make good sense. I looked up the coefficient of linear expansion with heat/cold for nickel-silver a while ago, and it is so small, that I can't believe that this causes a problem. I do believe, and have had experiences with plywood, that proves this WILL definetly expand and shrink at a far greater rate than any track will. For those that use pine for their sub track, that wood is no different, it too expands and contracts greater than the rails ever will. Our tracks are not like real rails out in the hot sun or freezing cold, we are not THAT prototypical.
So what I do, is paint all surfaces of the wood, top, bottom, and sides with a sealer. This prevents high summer humidity from swelling the wood, nor extra dryness of the winter when the temps are -10F outside and the humidity in the train room m ay be only 20%, from shrinking the wood. THIS is where all the trouble comes from, the wood, not the rails. If someone needs more proof, take some flex track, solder a loop together, and place it on a piece of poly on the cement floor. This will not kink over an entire year of temperature extremes. Now place the same loop on a piece of plywood, unsealed ( bare plywood). Check that out in the middle of summer after days of high humidity. Than again on a cold winter day, or after days of very low humidity.

[selector]

I'm confused. I'm no engineer, but if humidity causes expansion, then there should be NO buckling in the rails. Since the layout will swell radially, in all directions, including up and down, one should only observe that the gaps between the rails are widening. Conversely, when the humidity drops much below that at which the tracks were laid (gapped), then, and only then, should they close the gaps to the extent to which they might impact at the ends and deflect along the axis.

I believe that 20 feet of monolithic rail in HO might lenghten a whole 2-3 mm in a rise of 15 deg, hardly a cause for concern....for gapped rails. However, wood on which track was laid and gapped when it was 40% humidity will swell by nearly a cm, longitudinally, when it rises to 80% water content. There-in lies the problem...a five-fold (or thereabouts) increase in gap due to water content in absorbent material over the expansion of metal rails due to temperature.

Again, I'm no engineer, so my figures might not withstand close scrutiny, but I believe my reasoning to be basically sound.

As for soldering joiners, I have done none of it, and can attest to having no problems running three sound-equipped locos on my 40 feet of track , fed by only three sets of feeders, each soldered directly to the rail web.

Copper piping soldered at the joints will leach lead into the water over time, and the solders themselves will begin to exhibit copper sulfate residue when the water has any amount of dissolved sulfer in it...as we do with our well.

Nothing lasts forever.

[wccobb]

My personal preference is to solder a feeder to every other joiner and let the solder flow to a good bond on each rail in the joiner. 1) One end of EVERY "hunk" of rail is firmly soldered to a feeder. 2) The other end of EVERY "hunk" of rail is an expansion joint. You need both, and one expansion joint per layout might just ask for a whole lot from one expansion joint. Absolutely no quarrel with those who solder to each "hunk" of rail & leave all ends for expansion joints. Unless you've got totally controlled temperature & humidity, having lottsa expnsion joints with smaller gaps is usually better.
Yes, I'm still with DC. Can run 6 Athearn (@3.5 amp) some 40 ft. from the powerpack with no observable voltage drop. (16 ga. buss & 20 ga feeders - and agreed, that's a little light for DCC. It's wire I had and I'm being "thrifty").

[Don Gibson]

MYTH'S - or MISSES?

Expansion: Wood and Homasote expand's with moisture. Metal Rail expand's with temperature. Running increases temperature.

Ever run in the dark ?. See those electrical spark's from arc-ing?
Read David Harrison's latest post re: CMS&I's (temp. controlled) rail expansion problem's.

Nickel Silver rail: doesn't oxidize; or - it's oxide conduct's electricity.

There is no silver in nickel silver. It's an alloy of Brass.

Contaminant's cause restriction of electrical flow:

Oxidation, tarnish, corrosion, Yes. How about foreign substances (including smoke and oil). Cook bacon in the kitchen? Oil in the track cleaner? - read label.

Electrical losses per ft. of various metal's - compared to copper .

Anyone remember your LIONEL train's slowing down when it got the furthest away from the transformer?
1.Lionel track was 'tin' plated
2. brass conduct's better than nickel silver
3. differences are small on small railroad's such as 4 X 8's.
Someone else can give the loss comparison's, but it only become's significant on longer run's.

Since I have had to replace whole section's of 'bowed-out' rail (in a temperature and humidity controlled basement) I'm not being one of those 'theoretical' types, or "it never happened to me" crowd. I don't plan on having my house burn down, either, but I have fire insurance.

It seem's that for everybody there is 'Good Practice', - or practice that is ''Good enough''. Think about it.

Best part is everybody get's to choose for themselves.

[pennsyj1fan]

OK, you run a lot of feeder wires for HO, how about approximately 350' of G Guage Aristo Brass track outside, anyone do G also. I usually ran one wire but haven't gotten power to everywhere I need it. I use 12 guage braided copper wire. Any tips or help I can get for this problem. Is there something I can run the feeder wire to and then hook up my new powerpack to so I get power to all the feeder wires.
Thank you.

[selector]

If I understand your question, you must have a main bus under the length of your track, and that should be in the 10-12 guage range for your outdoor railway. Every 6-10 feet, you should have a 16-18 guage feeder wire of about 1-2' drop from the rails down to the bus, below. We're not talking 15 amp service here, right, so those guages should provide minimal voltage drop. Once your bus runs about 100 feet, though, there will be significant reduction in that initial voltage. So, at some point, the most distant from your controller, you should provide a booster in power, another power supply. (This depends on your track layout, whether a long out-and-back, or a loop.) This booster will keep the far side of your setup properly energized, and if your feeders are well installed, you should have no problems with power.

Now, I have no garden scale experience, but I'm sure the reasoning and ball-parking are fairly close. You need gapped sections, each fed, and several of them powered by their own power supply that is slaved to your controller. At least, that is the way it works in HO for the reduced voltages, wire guages used, etc. I hope someone speaks up and reinforces what I am saying. I can't think of another reason for your power gaps other than bad contacts to the tracks.

[Marty Cozad]

QUOTE: Originally posted by pennsyj1fan

OK, you run a lot of feeder wires for HO, how about approximately 350' of G Guage Aristo Brass track outside, anyone do G also. I usually ran one wire but haven't gotten power to everywhere I need it. I use 12 guage braided copper wire. Any tips or help I can get for this problem. Is there something I can run the feeder wire to and then hook up my new powerpack to so I get power to all the feeder wires.
Thank you.

I ran track power for about 8 years on my outdoor model railroad untill I hit the 500 ft mark and realized it was easier and cheaper to run RC on board battery power. Saves a ton of time .
In the old days I ran two main feeders and installed jumper wires on all joiners with brass to each block on the line.
Now the freedom of multi MUing and train control is great. Aristo Craft has out of the box battery ready engines to just plug into a battery car ( to start out with) and I can run any time. the only,, question I ever face is, how long with the battery last.
i have not cleaned rail, wheels, etc in 5 years. There is no wire at all on my 1,600 ft of track. BTY we also run live steam at the same time.



This lash-up of 3 powered SD 45s are pulling 35 cars and will run about two hours. I make a station stop and switch out my 18 volt DC tool batt and I'm on my way.
Takes 30 mins to recharge, thus two batt will run all day.
Theres 60 pounds of prime movers pulling appr 140 pounds of train.
I don't know if i helped but may have caused some thoughts.[;)][:p]