Track Roadbed/Ballast

[slotracer]

I have tried the search feature, didn't find the answers I was looking fo thus I am creating this post.

 

We are building our first garden Ry ......location about 8500 ft up in the Rockies west of Denver. Temps mid nineties in summer with low humidity but we get heavy rains June-July. Winter snow of course, max low maybe 15 or 20 below once a winter. I know the track is going to expand, contract adn move.

 

RY is being built on elevated garden areas, soild (Mostly decomosed granite) has been sittin 7 ywears so deently compacted. Cover is with 45 mil TPO single ply roof membrane.

 

I have had conflicting recomendations for track sub-base and ballast. One Source told me to use unwashed crusher fines as they compact and hold up very well. Another source told me this stuff is suceptable to expansion when it absorbs water and will throw the track all out of alignment, he recomended 1/4 crusher rock. Anothe source said pea gravel.

 

I am fortunate as there is a quarry aggregate business located within 5 miles of my place that even sells in 5 gallon bucket quantities which makes application easier.

 

Question is, what is your opinion of what to use, what to avoid and why.

 

We are not fastening the track (Brass Aristo and LGB) just pouring in the material and labeling, layng on the track and aplying finished ballast between ties.

[Greg Elmassian]

Never heard of crusher fines expanding, first find out what the available rock is made from, granite good, limestone bad.

Greg

[ttrigg]

Like Greg, I've never seen crusher fines expand from water content. It is rock dust after all, the operative word here is ROCK dust. On the other hand I have had to repair rock dust wash outs from moderate to heavy rains. (I live in San Diego, so my idea of moderate to heavy rain probably does not match yours.) Crusher fines to 1/4 inch minus have sharp edges and will interlock quite well. Pea gravel on the other hand is round stones and will not interlock and will move, recommend leaving it in the fish tank, not in the garden RR. For your sub-roadbed I would suggest digging a trench 3~4 inches deep, line with garden fabric (weed cloth), the fill and hand tamp 1/2 inch minus crushed rock. The fabric is not for weed control but to prevent migration of the crushed rock into the local fill material. A layer of 1/4 inch minus crushed rock to form the roadbed will work nicely. Crusher fines for the balast will work just fine. Have a look and see if your quary operations offer a bonding agent called "Stabalizer", it is a long strand polymer bonding agent. It will be mixed into the crusher fines before added as balast, then slightly watered into place. Once dry, it will hold the crusher fines in place from any amount of water falling on your empire. If for any reason you need to lift out a section or two of track it will mostly stay attached to the rails and ties. Simply break it off buy hand, and crush the clumps in the palms of your hands (work gloves prefered) then reaply the dust as balast and re-wet in place. About two years ago I pulled about 20 feet of track that had been in place for at least 6 years and the Stabilizer worked just fine. Stabilizer was originally made for holding rock dust driveways in place. If you have the time, search back several years in this section for a topic line about balast glues, there is quite a discussion of Stabilizer complete with an address to contact the manufacturer. 

[Rex in Pinetop]

Hi, We're in AZ at about 7,000 ft.  We also experience the "monsoon" type down pours in the summer.  One particular section of our mainline gets extra water being right under the metal roof runoff.  We tried spraying that section of track with Titebond III.  We had mixed results since the water flow/splash was so great.  We since then have added cribbing and the combination of the glue AND the cribbing seems to be holding up. 

Rex