Large Scale Central

Frost Heave!

Track and Trestles
#1

My railroad was built using multiple construction methods…

Track laid directly on PT lumber plank.

Track laid directly on ground. While I trenched and gravel filled, that was 20 years ago and there is little trace of the gravel trench left.

Track laid on concrete roadbed.

Track laid on back filled PVC ladder roadbed with ties at ground level.

By far, the most susceptible to frost heave is the ladder. Every spring, as soon as the ground dries out enough to walk on, I go around and push the ladder back into the ballast with my foot. I end up with a little bit wavy track, but there is no high speed service of any kind here, so a little undulation is OK.

This spring, Mother Nature threw me a curve. In several spots, the ladder roadbed joins with concrete roadbed. Shelves for the ladder were designed into the concrete when it was poured. When I went to push the roadbed down today I found that it had lifted above track level on the concrete and was now resting there :frowning_face:

I think you can see from the shadows of the ties how far above the concrete roadbed the track has been lifted…

I expected this to be a big track lifting and roadbed excavation project. I started with a small exploratory excavation to see it it might be possible to muscle the ladder with track still attached back where it belonged…

By the way, If you need a great kneeling mat get one of those. They are pricey, but work better than anything else I’ve tried. I have two!

There were two spots where the ladder had lifted above the concrete; both sidings off the main at Indian Hill Junction…

Not only was it a beautiful Spring day today with lots of sun and temps in the 70’s, but the roadbed went back where it belonged without too much effort and I had an inspection train out on the line before dinner…

As of this evening, all track, except Deep Cut Tunnel is in service. I need to open the hatch and use the gas leaf blower to clean it out. Rain tomorrow. Maybe Sunday.

#2

Initially, I thought you had consumed too many Frosties and had vomited them out. Which was a very disturbing image. But it appears your heaving was much milder. Glad to hear it was a relatively simple fix!

#3

So with all of your different methods, which has worked out the best? Rank them?

#4

Reinforced concrete about 4" thick has been the most stable. I’m sure it moves, but so slowly I don’t notice.

The Pressure Treated decking is elevated on posts and not touching the ground. It is the oldest on the railroad. It has been rebuilt once, in 2019. It has held up very well.

Track on the ground has been pretty good as well, but it rises noticeably over the years.

It’s a toss up on maintenance needs of the ladder and direct on ground. Both need annual work.

Concrete needs a good wash under the track once in a while to get rid of wayward ballast. The PT wood roadbed is the least maintenance of all.

So - If I were starting over today most would be on raised benches. Track at ground level would be on concrete.

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#5

For me, in a climate similar to Jon, the decking I have has been the most stable, followed by “On the ground in a gravel roadbed”, and the ladder third. I had more problems with frost heave and twisting with the ladder roadbed.

#6

So just a trench however many inches down filled with gravel?

#7

My track has been down for years on the ground with little annual maintenance. (less than a days work).
3/8 minus crushed rock ballast, a little leveling, aligning, etc and she’s good. It survives snow up to 2-3 feet deep and downpours occasionally.
Anyone that I know that has a railroad around here that started with a ladder system has long since tore it out because of Jon’s problems.

#8

Yes. Mine are 6 to 8 inches deep and 8 or 10 inches wide, filled with gravel.

#9

This is an interesting discussion. One i certainly am no expert on. But here in the inland NW frost is a reality. When I built mine I used local knowledge from the most experienced guy in our club Chuck Inlow.

He in my opinion perfected the ladder system. It used laminated straps of cedar spaced with cedar blocks to make the ladder. This is put on pvc posts which are driven in the ground. Now he did tell me he had to push it back down. So I went a step further and dug post holes 2 feet deep. Thats generally below our normal frost line. I then poured concrete in the holes and put in the pvc so they filled with concrete as I pushed them in making the one with the concrete footing.

I did this before I brought in my fill dirt. That added another 18+ inches over the footing. I can say my track does not wiggle vertically. I have never had to fix a hump or dip. Sure it moves side to side with expansion and contraction. But frost hasn’t been an issue yet.

A lot of hard work in the beginning but well worth the effort.

#10

While I didn’t intend this thread to be a roadbed method discussion, I like the way it’s going :slightly_smiling_face:

I think Devon has developed a good method if you want to build with ladder near or on the ground. Unfortunately, here in New England our topsoil is shallow. In many areas of my yard I reach glacial till within 6" of the surface. Driving stakes (or fence posts as I found out during COVID lock down) more than a 6 or 8 inches in the ground is next to impossible. Our frost depth here is regularly down to 36". Local code says foundations should be set at 42" minimum. Usually that involves blasting or a huge hole to remove boulders.

I have one section of ladder that has been stable. It was built atop an existing stone wall that was raised with concrete blocks and the ladder placed on top before back filling…

That was 10 years ago this coming summer. I have no frost issue in the short section supported by the wall.

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#11

Joh,

up here in NH the section coming out of the basement up to the first bridge is all ladder, and i do have to push it back down on its 2" PVC posts, and has been a hard section to keep ballasted as well. but i live with it. will be a few weeks yet before i can work on anyway as i had further hand surgery the other day.

I did manage to get some work done in the basement in between. added more static grass and building front to represent an old plan from MRC of a small ice house. i mirrored the design and added a roof hatch, and an icing platform. the original plan supposed the ice was lifted by fork truck

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#12

well that sounds like real fun a day of blasting !!! One of my son in laws does the blasting in Chicago for the tunnel company he works for. Night crew drills the holes, his crew sets the charges and he gets to push the big red button, then second shift gets to do all the cleanup.

#13

When I was excavating for Deep Cut Tunnel back in 2010 I ran into a rather large rock that had to be moved. Fortunately it was granite and was decomposing. I was able to chip away at it and break off enough to finish my excavation…

#14

That looks like the Rathdrum prairie.

#15

Slightly different problems out here. No issues with frost heave but I am still having issues with bamboo shoots popping up, one even dislodged one of my black roadway bricks. Trouble is I have to use chemical weaponry and wait a few days until I am sure they have taken effect in the roots before I can remove the surface shoots. Overall I am missing the simplicity of my indoor layout. Yes I know, I’m lazy :stuck_out_tongue_winking_eye: