Garden RR metalurgy

[Anonymous]

[font=Courier New]OK, just for clarification, which of the alloys commonly used for outdoor track has the least amount of expansion/contraction? Keeping in mind that 120 degree (F) summers are the norm here [8D].
(Please don't let this become a discussion of brands.)

[Anonymous]

Sorry.I'm not a scientist.But I do know that,if it is vaguely shiny on the top,I can run my trains[(-D]
Sorry to be so flippant but I don't think that there is much difference between brands.
(I did'nt mention any [}:)])

[Anonymous]

I consulted my old engineering reference books and found, without getting too technical, that there is negligible difference among the brands of brass track commonly used. Stainless steel and nickel-silver would be about 20 percent better (less expansion), while aluminum would be about 20 percent worse (more expansion.) I hope this helps.

[Anonymous]

Thank you. Now to find out whether or not nickel silver is better than stainless steel, and by how much.

[tangerine-jack]

A slight edge goes to stainless, simply because of the other benefits that metal would have in your environment. You never mentioned if you were going electric or what, but nickel is better for track voltage, stainless for all else.

I believe if you leave small gaps at each rail joiners (about 1/8") as expansion blocks and let your track float on ballast (chicken grit is a good choice) as opposed to rigidly fixed, then you shouldn't have any problems with the track buckling or distorting. Keep in mind that the longer the length of metal, the greater the length of total expansion, so you must calculate rate of expansion by length of rail, then figure out about how large and how many gaps you need. I have seen some railroaders with more imagination than me use a type of sliding joint where each rail was relieved of 50% of its width for about an inch or so thereby interlocking the two rails, allowing them to expand considerably and still leave a solid surface for the train to roll on, obviously a slip joiner and not a screw type is used for this application.

Brand does matter, the better brands have better alloys in thier metals and are subject to less expansion than pure metals themselves, and unless the manufacturer has done lab testing, it's all ball-park calculations anyway. Perhaps you should buy a few feet of each type and experiment. Real railroads have problems with expansion also, just another one of the joys of garden railroading along with rain/animals/meteors etc.

Hope this is some use to you[oX)]