How much expansion?

[Ray Dunakin]

I'm going to have about 250 to 300 feet of mainline. It'll be "floated" on ballast, and will have a lot of bridges/trestles. The rails will be connected with Split-Jaw rail clamps. How much expansion can I expect, and should I use some of those expansion segments that Split-Jaw makes?

Is there any kind of formula or rule of thumb to determine how much expansion you'll get from a specific length of track?

I'm in sunny San Diego, so it gets up into the 90's in the summer, and occasionally higher.

[ttrigg]

Ray;

I too live in "Sandy Eggo" (Oceanside), my track "floats" on ballast over our "white clay" ~160 ft mainline loop. I also have a ~200 ft "siding loop" which sits directly on top of the shredded bark mulch the wife has under her roses. My main line has been operational for just about two years and have not noticed any problems due to rail expansion. I use a combination of soldered joints and split rail clamps. I was most concerned about expansion inside my curving tunnel, but no problems in two years. I do not think we have enough rapid temp change to cause expansion problems. (or could it be that I have enough curves and twists to allow the track to "flex" from heat?)

[kimbrit]

Over in sunny/wet/cold/snowy/sunny wet UK I haven't noticed any problems with my bolted together Aristo track. My track floats in gravel and any movement will come out as slight misalignment because it floats. If it's really hot where you are Ray leave the track out in the sun for an hour or three before you clamp it.
Kim

[tangerine-jack]

That is the benefit of the floating track method, it allows the track to expand and contracts as a unit and is free to do so. You shouldn't notice any change in track alignment unless you have an area that is under stress due to poor track laying. If you want to do an experiment, mark the edge of the track with a stick or something thrust into the ground next to the ties in a few places when it's cool, then notice the change in track location relative to the marker sticks when it's hot. Trust me, the track moved!

Leaving a few 1/8" gaps here and there is not a bad idea, but don't make the gaps so large that a piece of ballast will become lodged in the gap redering it useless.

[kstrong]

QUOTE: ... but don't make the gaps so large that a piece of ballast will become lodged in the gap rendering it useless.

Good point in theory, but almost impossible to achieve in practicality. Rain, sprinklers, and wind will invariably get ballast and dirt between your rail joiners. Occasionally, you'll have to slide the joiners back on one rail to clear them, then slide them back to hold both rails together again. Not often, but not never, either. This is far less of a concern with floating track than it is with track that's secured to a sub-roadbed where the gaps are far more necessary to compensate for expansion.

There are those who suggest laying your track on the hottest day, or sitting your track out in the sun so it expands before you put it down. Again, great theory, but not all that practical. The rail gets--quite literally--too hot to handle. Gloves help, but sliding rail joiners on with a pair of gloves will challenge anyone's dexterity.

Later,

K

[Marty Cozad]

"dexterity." Kevin, you need to watch your language[;)]
Beisdes, I bet you did try it.[:p]

[kstrong]

It wasn't the gloves, it was the bandages on my fingers after I grabbed a section of track that was sitting in the hot Colorado sun. *ouch!!!* From that point on, I kept the track in the shade, and just left around 1/8" gap between each rail section. I've only got one section where I have expansion troubles, which will be dealt with later this spring.

Later,

K

[Marty Cozad]

I've been out working trackside and layed my for-arm across the rails. WOOW that will leave a mark!!!

[bobgrosh]

I have about 300 feet of brass (LGB) rail in the Florida sun, also free floating and using split jaw rail joiners on every rail. Longest straights are about 50 feet. Don't leave gaps, With split jaws, it won't do any good anyway. The rails won't slide in the regular split jar joiner.
I'd say, maybe buy one or two pairs of the fancy split jaw expansion joiners and keep them on hand, just in case you have a problem between two bridges. I wold not install them tho, unless you discover a need later. Seven years and no problems with split jaws on floating track. Plenty of problems with LGB and Aristo joiners prior to going with split jaws.

B0B

[hueycrewman]

G'Day Ray, I live in Queensland , Australia, and I am about to lay track. Our temperature runs from about 23F  to 115F and I'm sure that I'm in for problems. I am going to freefloat as well, but I'd like to know if any readers have used the expanding rail units and if so how did they perform? Are they entirely reliable? How have readers wired them in for track power? Does dirt get into the expansion slides and cause problems? Any experience of these would be appreciated by myself and I am sure Ray. Parts of my empire will be in tree shade at least some of the time, and I was thinking of using some shade covers on the hottest days, which could double as frost covers for plants in winter. For this I was thinking of concrete reo with either hessian or tin on top for the shade/dew cover. At least I have only two bridges to worry about. Regards to all Hueycrewman 

[Greg Elmassian]

I live in San Diego, like Tom, but only a mile from the ocean, so my temperature swings are even less. I have Aristo stainless, and lay the track with a credit card in between sections that use the Aristo joiners. No gaps where the split jaws are.

On the Aristo forum, there are several people using the expanding sections, now made by Split Jaw, and Hillman. On long straights, the people in Arizona and Nevada get about 3./8" to 1/2" of expansion.

I would definitely recommend using these sections on long straights. Curves in free floating ballast are almost always fine, all the problems reported have been on straights.

Regards, Greg

[hueycrewman]

Thanks Greg, I've ordered two for use in the hottest straight areas so I'm hoping this will be sufficient. All info is muchly appreciated, regards hueycrewman

[Anonymous]

Hi - I am a relative newcomer to garden railways, and live in a climate with strong summer sun and mild winters (Auckland, New Zealand).

I recall working out that, given that the rail can get very hot in sunlight, it would be reasonable to estimate a temperature differential of 50 deg Celsius or 90F, and this worked out at about 1mm for every metre of rail, or 0.1% expansion.

I laid my first track in summer and during the winter, it tended to get straighter due I assume to contraction, and there is no doubt that the gaps I left became wider. As we move again into summer I will be interested to see if the opposite tends to occur, and the track starts to kink.

Regards

Bruce

[Greg Elmassian]

Ray, I'm in Carlsbad, about a mile from the water. I butt the rails together, and float the track in ballast. I have one 60 foot long straight on a concrete wall and the tracks are pinned to a piece of wood embedded in the concrete. On this track, I used a credit card to set the gap. No problems this last summer at all.

Where do you live? Do you belong to the SDGRS? You and Mike and I should hook up sometime. Maybe meet at Reeds one day? I need some Kadees and will go there tomorrow.

Regards, Greg

[Ray Dunakin]

<BLOCKQUOTE><table class="quoteOuterTable"><tr><td class="quoteTable"><table width="100%"><tr><td width="100%" valign="top" class="txt4">Where do you live?</td></tr></table></td></tr></table></BLOCKQUOTE>

I'm in University City, just west of Miramar.

<BLOCKQUOTE><table class="quoteOuterTable"><tr><td class="quoteTable"><table width="100%"><tr><td width="100%" valign="top" class="txt4">Do you belong to the SDGRS?</td></tr></table></td></tr></table></BLOCKQUOTE>

Not at this time.

<BLOCKQUOTE><table class="quoteOuterTable"><tr><td class="quoteTable"><table width="100%"><tr><td width="100%" valign="top" class="txt4">You and Mike and I should hook up sometime. Maybe meet at Reeds one day? I need some Kadees and will go there tomorrow.</td></tr></table></td></tr></table></BLOCKQUOTE>

I'd like to, but I don't think I can make it there today.