Ballast shrinkage, track distortion

[CSX_road_slug]

I've risen to my level of incompetence in mrr.

Two years ago I finished laying all the track for my main line.  Made absolutely sure it was as 'perfectly' level as possible, so my 89ft auto racks could handle it.  When I test-ran my trains they seemed to run OK, i.e., no derailments.  About 6 months later, I put down ballast.  Over the next year or so, my trains seemed to perform OK.  

Anyhow, I was away from actively running trains for the past 6 months.  Since I started operating again recently, I've been getting derailments out the wazoo!  Closer examination shows that the track has 'rippled' in several places, as if the ballast has been gradually shrinking and pulling the track down with it.  And I can't simply correct these impefections the way I did before, because now the track & ties are essentially cemented in place.

Have any of you ever faced this issue?  I don't know if I need to tear up the entire main line and install all new track, or if there's still hope that most of this track can be saved.

 

[KingConrail76]

Though I've never heard of this happening, I guess anything is possible. Have you tried using a "straight edge" to see if the track is actually "pulling down" and not buckling, or raising upwards, from expansion (from compression at tight rail joints).

Also, not knowing how you affixed your ballast, could you re-wet your ballast to loosen the glue? Or maybe carefully slice into the sides between the tie level and roadbed level with a sharp, stiff blade? (what type ballast? real stone or "plastic" ballast?)

Hope you find an answer that works for you, good luck.

[aav]

              What did you lay your track on?  roadbed,subroadbed,etc.   How did you do your ballasting?  materials,techniques,etc.    

             Sometimes a "climate change" in your basement can cause things to happen,  like changes in humidity, etc.    Will cause expansion  and contraction issues. 

[loathar]

Are you sure it's not your bench work or table top doing it? Is your layout in a climate controlled area?

[aav]

          I'm kind of thinking in line with Loathar,  that your benchwork might be moving.  This could cause that effect, especially if you didn't leave a little bit of room at some of the rail joints to account for that.

[hobo9941]

Temperature alone, will cause expansion and contraction, and cause the track to buckle, as I found out, with my layout in an unheated garage in northern Michigan.

[selector]

100' of contiguous Code 100 NS rail will expand 1/4" with a rise in temperature of 30 deg.   That is essentially nothing to worry about, especially when in the real world of layouts we have expansion joints every 3-6'.  All you need is four 1/16" expansion joints over that 100' distance and you have provided the gaps that need to be filled to accommodate the expansion.

My guess is that it will be humidity changes that affect the dimensions of lumber that cause buckling or lifting.  If wood shrinks much, it is conceivable that fasteners will also lose their functionality to an extent, and sections can slip or sag.

If your ballast were well and truly solidly glued, I can't see this happening to your tracks.  The ballast should also show signs of fracturing and my bet if this is the case would be the power of hydraulics.

[modelmaker51]

What kind of support do you have under the roadbed and sub roadbed?

[CSX_road_slug]

What did you lay your track on?  roadbed,subroadbed,etc.   How did you do your ballasting?  materials,techniques,etc.

In one area, my track is on cork roadbed, which is glued to 3/4" plywood; the other spot, the cork sits directly on the plywood.

I used Woodland Scenics medium (HO scale) ballast with diluted Elmers glue to hold it together.

Are you sure it's not your bench work or table top doing it? Is your layout in a climate controlled area?

I have a wall-mounted heat pump to keep my garage warm in winter and cool in summer.  Finished ceiling, with plenty of insulation.

100' of contiguous Code 100 NS rail will expand 1/4" with a rise in temperature of 30 deg.   That is essentially nothing to worry about, especially when in the real world of layouts we have expansion joints every 3-6'.  All you need is four 1/16" expansion joints over that 100' distance and you have provided the gaps that need to be filled to accommodate the expansion.

My guess is that it will be humidity changes that affect the dimensions of lumber that cause buckling or lifting.  If wood shrinks much, it is conceivable that fasteners will also lose their functionality to an extent, and sections can slip or sag. ...

Crandel, I have plenty of expansion joints, every ~8-10ft or so.

I'm starting to suspect that maybe, like some people said, it might be a humidity problem causing my wooden benchwork to warp.  If that's the case, I'm not sure what I can do; I can't affford to put in all metal benchwork.  OTOH, I'm afraid if I tear up and re-lay the track in these 2 defective areas, that still more problems like this will keep happening...

[Pruitt]

If the problem is humidity, Ken, the solution is simple - humidifiers in winter and dehumidifiers in summer.

A few years ago, I had more or less the same problems you're having now. Track I laid in summer was bending all out of shape in winter. Never saw that before I moved to my current house. But our basement is humid in summer and dry in winter. I added a couple of humidifiers that winter, and within afew weeks the trackwork all straightened out! The following summer i added a dehumidifier, and now I try to keep the humidity between 40-60 per cent all year round. No more problems!

Try adding a humidifier - they're not that expensive, and it may save your layout.

The only bad part is that my portable humidifiers have to be filled every day. So (oh, darn!) I'm forced to at least go into the train room every evening.

[CSX_road_slug]

...  A few years ago, I had more or less the same problems you're having now. ...  I added a couple of humidifiers that winter, and within afew weeks the trackwork all straightened out! The following summer i added a dehumidifier, and now I try to keep the humidity between 40-60 per cent all year round. No more problems!  ...

That's reassuring to hear, Mark!  Guess I'll be investing in a set of those myself. 

[cacole]

This problem has nothing to do with ballast -- it's your benchwork shrinking or expanding due to changes in humidity, especially if you used pine framing and plywood and didn't seal or paint it to avoid moisture absorption.