Aluminium Track, Have we being mislead ???

Garden Railroading
1

Around 10 years ago I started making inquiries about a train in the garden. Lots of info available, but down under brass or stainless steel track was far too expensive so had to find an alternative. Aluminium seemed to be the only suitable alternative so started asking questions. All the advice I got was it would’nt work, expansion too great, too much maintenance etc, etc .

But, on a beer income couldnt afford the champaign rails so I tried it. It worked and most of the advice I got why I should not use it was completely wrong. Its cheap, no problem with conductivity, and it does not need all the extra cleaning. ( once every 3 months a very light sand).Now, with part of a wire brush under a cleener wagon I dont even have to sand it anymore.

Anyway, I then found out that a fellow modeller in Sydney, Australia had done it more or less simular to my efforts.

Why am I saying all this you ask, well, with all the negatives I heard its amazing that because of the high cost of copper etc one large model rail supplier is now, or going to, produce new rail in guess what? , yep, aluminium… Sure it may be better shaped than mine but lets face it, its still aluminium. The stuff so many said would not work…Theres a comment that says it will have a special coating, why, it works perfectly without it. Its only if you live next door to the salt water will you have problems.

I just hope that some starting up were not put off by the high costs of brass or stailess rail and didnt try aluminium because of the negative comments.

So, if your just starting with your g scale, or even O gauge train in the garden and cant afford the top ready made track and are prepared for a little hard graft, dont be put off by all the negative comments, I suppose mainly by people that have not actually tried it.

Dont get me wrong, I dont intend to put the doubters down but I feel that many have accepted the bad hype from the past, which in the main seems to be unfounded, without

2

We just recently finished laying a mix of brass and aluminum track on our large outdoor club layout using PVC crossties from Train-Li and rail from several sources. We’re running only battery power because we also have a lot of the Train-Li PVC rail in the layout.

Everyone warned us about expansion of aluminum rail compared to brass or stainless and advised against using it, but so far that has proven to be like Chicken Little crying about the sky falling.

Even in the very intense Arizona sun, there seems to be no more expansion or contraction from differences in temperature than with brass rail.

3

The environment makes a big difference. The arid climate of Arizona is different. For example, many people leave steel unpainted out there. It gets a light patina of rust and then usually stops. Here in San Diego, the same stuff would rust away completely in just a few years.

Aluminum is also sensitive to the environment. The salt air here would dissolve it in no time at all.

So, when someone asks, people have to reply in general, and say “try it out”

Your aluminum expands more than other rail, but proper tracklaying can handle expansion and contraction.

No one has mislead you, it’s that problems with aluminum track IN GENERAL are greater than other types.

Different environments can make something possible where the same installation is impossible somewhere else.

Regards, Greg

4

To expand on Greg’s comment, I live about 17~18 miles inland from Greg, and about 300 feet farther above sea level. Most morning I can look downhill to the top of the coastal fog. The air temperature here is normally 5~9 degrees warmer than where Greg lives. These slight differences in our “micro-climates” make for serious differences in how our materials react. You will never know what works best in your area unless you try it. Everyone has a bias as to materials to use. In my case I use only the “old LGB brass” (I’ll soon have to bring in something else) simply because of the patina it quickly devlopes.

If expansion is a problem, simply put in a slight curve. In my case, there is a 110 foot absoultly straight run. I had a bit of movement in the return curve at the end of the run. The curve was moving less than a quarter inch. The boss want the problem solved even though it caused no problem with operations. I pulled and tugged on a section of the rails so that over about a 10 foot run the rails were offset from the straight centerline by about three inches over a ten foot run. About twenty feet later I put the “opposite” curve in the rails to return to the original centerline. An extreamly shallow “S” curve. After that there was no apparent movement in the return curve.

5

Kiwi,

To the best of my knowledge there have been many manufacturers of aluminum rail over the years. I investigated large scale back in the mid 1970’s and it was available then. Pure aluminum is a great conductor of electricity, however one of the major draw backs of aluminum as a material is that it oxidizes almost immediately on contact with the air, and the oxides are non-conductive. The second for our garden railroad purpose is the expansion factor. Aluminum expands at a rate of .0000123 inches per inch of length per degree of temperature rise. This is 18% higher than brass at .0000104 inches.

As for the ‘salt air’ issue, I am really confused. I live in the panhandle of Florida right on the Gulf Coast. Almost all of the boats around here use aluminum for railings, towers and a lot of other ship fittings. I don’t see these items vanishing in a couple of years. I am sure boat owners would not be too happy replacing these items every couple of years.

My tuppence worth.

Bob C.

6

You sure it isn’t chrome.

7

To all so far, thanks for the comments, suggestions and brickbats,

to answer some of the questions :

-Rain where I am , yes , plenty of it, mainly on the weekends.

  • Snow, once a couple of years ago ( about an inch) - but not normally, only on the hilltops in the middle of winter.

  • Where do the trains sleep - Refer the photo gallery on the track page, www.gscaletrains.net.nz ( place the curser at the top of the photos for description.

8

Thanks for the info. You’ve done a lot, and innovated.

As an aside, all the aluminum used on boats is anodized… if the anodization is intact, the aluminum is protected.

25 KM sure beats my 5,000 feet to the ocean!

Yes, expansion is greater but can be managed. Nice big chunks of aluminum for rails, nowhere near as fragile or thin as scale rail of aluminum.

Your railway works and has proved itself.

Regards, Greg

9

So, how do the real full size railroads handle expansion and contraction since most rail is continuous welded and temps run from 20 below to 120 above? I know the answer, I’m wondering if anybody else has given this some thought. The answer does have practical application to our garden railways.

10

Is it by varying the rail joint locations?

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I know the answer(s) too. I’d like to hear them.

Greg

12

No IRB, they don’t use rail joints except very rarely and they are not there for expansion reasons. Besides, how much can one rail joint matter on 10 miles of rail when the morning is 30 and the afternoon 80 degrees with some of the rail in the shade and some in the sun?

The answer may surprise you.

13

Just did a quick look up online. As I understand it, the rails are heated to the point that they will not expand any further then tightly anchored to the ties. The ties are well anchored to the earth and therefore the whole system becomes stable and the rail is therefore not allowed to shrink. But rail wants to shrink about 5’ per mile so it seems to me that this system would cause significant stress in the rail eventually causing stress fractures. It would seem more logical to lay the track cold and allow expansion to occur in the vertical direction. I haven’t done the math but a 5’ length change in one mile would result in a very small vertical change.

14

Track is always laid when it’s warmest, and often stretched too. There’s formulas for what to do based on the temperature the track is at.

Greg

15

Almost. Track is laid at a neutral temperature, meaning for the area it’s in the rail is computed for a certain degree value when it is laid down. The forumula is complex, and the railroads have rail heaters and other equipment for this purpose. The expansion/contraction is not an issue as the rail is designed to remain in a state of compression for most of it’s life. That way when a section is cool, the hotter parts can expand, and when the entire rail is hot the steel is compressed and remains in geometry. To have rail in a state of tension will cause massive rail breaks as the tension snaps and relieves the pressures inside the rail.

It sounds counter intuitive, but it works in the real world. The rule of thumb when working on track is “when in doubt, cut it out; it’s a sin to add rail in”. This is because if TOO much rail is added in then it will upset the delicate balance of compression and the track geometry will always be off- most notably around the switches. I’ve seen as little as 4" of extra rail create endless headaches around interlockings. Cut the rail out, weld the section up, and have a nice day you’re done. Rail breaks in the real world happed due to metal fatigue and not contraction. Even when a rail snaps, the sections remain touching due to the compression of the rail, and are sometimes very hard to find.

Real track does not “float” in the ballast and no rail expansion joints are provided. Ballast exists for the one and only purpose of providing drainage. Track can be laid on bare ground (provided it’s leveled of course!) and it will work just fine. The cross ties and rail are the only things that provide structural strength and geometry to the railroad.

So what does that mean on our garden railroads? For one, expansion worries are for the most part a non-issue. Track that kinks when the temperature changes are a result of tension due to the rails being too short (under tension), not too long (under compression). If track is laid properly, without having to force any

16

I live in a temperate area. We never have snow and the top temperature is about 110F (40C). I have to disagree strenuously with you. Contraction during the cold weather sometimes pulls the rail ends away from each other in a rail joiner, but not enough to pull one end out. However, on a very hot day, the brass rail, mostly LGB, expands and if the sleepers (ties) are nailed down, the nail and the sleeper stay put but the moulded chairs are broken off on the outside of the curve as the rail is pushed sideways under expansion.

I don’t know very much about full size rail, but the only time we have problems on our rail network is due to expansion in extreme heat. AND our track gangs always work at night, when the network is quiet…it has nothing to do with when the rail is a certain temperature.

17

There’s fundamental difference here, the prototype has ties that can move in the ballast on curves, and the post above talks about having the ties screwed down.

The first impulse of people in large scale seems to be to try to control expansion and contraction by bolting everything down, and you just cannot “repeal the laws of physics”.

So neither of you is wrong about the specific situations you have presented.

I free float my track in ballast and of course never tear the “spikes” from the ties.

How to handle expansion and contraction on outdoor layouts is the topic of endless discussions about expansion joints, tightness of joiners/clamps, rail loose in the ties, free floating vs. secured, etc.

Regards, Greg

18

The prototype ties do not move in curves or anywhere else. That would cause massive buckling of the track and major geometry problems resulting in trains not only derailing, but also sideswiping each other. The stress of expansion and contraction is not relieved through movement of the rails or ties out of a fixed geometry. The ballast exists ONLY to provide drainage away from the track structure. Track moves out of geometry through the movement of trains, not by normal natural forces. Imagine the track as a table cloth, slide you hand across the cloth and notice the little ridge you are pushing up in front of your hand. Full size track does the same thing when a train rolls over it, just on a smaller scale. Over time the tonnage of trains moving along the track pushes it out of alignment, it has nothing to do with the track “floating” in a ballast bed.

19

I learned about not fixing my track down. That was not my point, it was just illustrating the action of heat expanding the rail and resulting in a consequence. My point was that heat, not cold, causes most of the damage to both my garden railroad and the full size railroads in our country.

Two of these are from Oz, one from the U.S.

20

Tangerine:

I have a friend that worked as a track inspector and the FRA for 30 years. He is in violent disagreement with what you are saying.

First of all, if you think that nothing moves with the rail expands you are in serious denial, by simple physics, the rail HAS to move since it grows in length.

Second, a fundamental concept is that the ballast serves to lock the motion of the ties, to local, and distributed movement, in conjunction with the rail being anchored at regular intervals (with rail anchors).

Doing this distributes the expansion and contraction over the entire length of the track, as opposed to the mistake many modelers make.

Rails moving 3 or 4 inches would cause prototypes to sideswipe? Think about it, you really believe that there is only 3 or 4 inches of clearance to begin with?

Talk to a person who has really worked on railroad track, and you will learn how it is done. In many cases, the prototype method can be scaled down to our models.

It is NOT the only way to make it work, but here, we are talking prototype.

I’ll gladly get you in touch with my friend who can better explain. I had all kinds of misconceptions until I had it explained to me.

Greg