# Planning for expansion and contraction



## Trainhound (Feb 17, 2009)

I'm getting ready to build my railroad in the Spokane Washington area and i will be using handmade steel groovy track 1/2 in x 1/8 in steel strapping iron in slotted redwood ties soaked in linseed oil and glued on using marine goop glue. My test pieces wwre made with galvanized material and they have lasted over 8 years directly upon dirt even with my 350lbs body walking over them. Here is my question, what would be my max length for each section to aviod contraction and expansion problems. I would like to have floating track on ballast. Originally i was thinking about welding it all together but now i think that is a bad idea because it would probably buckle.


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## chuck n (Jan 2, 2008)

My thought is that if it is floating on/in ballast you should be ok. Anchoring the track to a sub strata wouldn't permit any movement and cause problems. The big boys (1:1) weld theirs. I'd recommend a few more curves, rather than long tangents.

I knew a guy in Denver whose track moved several inches over the year and he floated his track and didn't have any problems.

Chuck


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## Greg Elmassian (Jan 3, 2008)

I read a lot over the years about this, and my best advice is install the track, and then see if you need to address expansion and contraction on long straights.

I have a 60 foot straight section in full sun and have never had a kink, and others have had shorter runs with problems. I leave a credit card thickness gap between the 5' rail sections and use split jaw clamps, just for reference.

Regards, Greg


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## Semper Vaporo (Jan 2, 2008)

I'll tell my two stories here again (hope I can keep the details similar!).

My first track was just 40 ft of straight pieces of cheap plastic track laid on four 10-ft long boards. I was just learning to run my live steam Mike and my son and I would just throw the Reverser lever the other way when it reached our end of the track. The plastic was very old and brittle and I feared the wind blowing it off the boards and break the joints, so I put one nail through a tie at each end. I came home from work one day and noticed that the track had taken on the shape of a bell curve with the middle of the 40-ft about 2-ft in the air! Like a fool I walked over to it and just touched the center of the arch and it fell over, breaking several of the joints. Granted this was plastic which probably expands more than metals but it was all in filtered sunshine under some trees... it was just the heat of the ambient air that caused the expansion. It is a fun exercise to work out the distance a small amount of expansion can move the center of the track up if the ends are not allowed to move!

When I built the elevated layout with Nickle Silver rail (a 50-ft straight-away with a 17-ft diameter loop back at each end) I was careful to insert a dime between the ends of each rail when I pushed them into the small rolled spring metal joiners. (Of course I removed the dimes when done! The rail was expensive enough without adding 20 cents to each section and they would be like a derail if left in the gaps!)

The next time it got hot and the rails began to expand lengthwise, the joints all closed up as one would expect. But when it cooled back down, the joiner with the weakest grip slipped first and continued to slip as ALL the rails contracted in the cooler air.. until there was about an inch gap between the ends of the rails that were slipping first... all the other gaps were still closed up tight.

This dumped my Aster Mikado 4-ft to the ground! Not nice!

Thinking backwards here, one will realize that when the rails were expanding the gaps did not all close uniformly... Rather the one with the weakest grip slipped until the rails touched and then the next weakest joiner slipped until those rails touched, and so on for all the nice dime thickness gaps.

I tied fishing line around the end couple of ties in each section of track to the next couple of ties on the end of the next section of track in an attempt to tie all the sections to each other (not quite welded rail but it made the track all one piece -- sort of!). The track at this time was lying directly on the board surface (pressure treated 1x6's on the flat) of the elevated structure. When the track then began to move as a unit, expanding, some of the sharp edges of the plastic ties caught on imperfections in the wood grain and the track thus got stuck at that point... so the track, instead of uniformly moving on the surface of the structure just expanded in one direction and it nearly shoved the curve of the loop back off the end of the structure furthest from the place where it got stuck.


I then added some garden Trim-Plastic to the edges of the elevated structure, sticking up 1/4 to 3/8 inch above the surface and poured a couple of bags of Rose Granite Chicken Grit on the track and gently shook the track to make it float to the surface of the "ballast". This cured the problem of the track catching on things and pulling apart or shoving the track off the edge of the elevated structure. In the Winter time and sub zero outside, the loop-backs would slightly overhang the inside of the curve of the structure and in the summer time when it was really hot, it would slightly overhang the outer edge of the structure.

Based on my experiences, I suggest that you float your track in small angular rock "ballast" (like medium Chicken Grit ["rock" not "oyster shells"]) And have some curves in places to absorb expansion and contraction. Besides, nice "S" curves make the train look good in motion. I had the 50-ft straight section only because I wanted to run my steamer FAST and needed room to get slowed before it hit the curve and "glide" to the neighbor's driveway.


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## Trainhound (Feb 17, 2009)

Thanks for the great ideas, this really helps wirh my track planning.


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## John J (Dec 29, 2007)

Wander through my thread. I have done what you have proposed inside my buildings. Only I sunk them in concrete I plan on adding road way to my layout this winter. I plan on doing what you suggest only I am going to weld it. I also plan on sinking it it concrete. You might get some inspiration out of my thread then you might not. Take a look 

JJ

http://forums.mylargescale.com/16-track-trestles-bridges-roadbed/27650-working-nr-wgrr.html


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