Building a retaining wall

One of the projects I'm working on is building a retaining wall along the fence where the track is slightly above the ground but not high enough for a trestle. If I had more room I'd build up the land using rocks and soil, but because this stretch is squeezed in between another track and the fence, a wall is the logical solution. It's actually a double wall that will be filled on the inside with gravel. Only one side is visible to the viewer which I am decorating with cut stone; the other side I'll leave exposed. The slope of the rail along this section is approximately 2.5%.

This is the first of two three-foot sections. The second one will be one inch lower because of the slope. I'm hoping this will look good. A more realistic approach would probably be to build this as six one-foot sections, each one stepping down by 1/3 inch from left to right. But I thought doing this is just two sections would provide greater strength and integrity for the wall, which is my primary concern. And I figure if I don't like it I can always rebuild it.

I started with two three-foot long cedar 1x4s and tied them together using cut sections of treated deck rail posts. Why these materials? Because that's what I found in the garage. I'm hoping between the cedar, treated wood, sealers, and some very good drainage I plan to have in place, that this will stand up to the elements.

Next I checked for placement where this section will be going. Currently the track is being held up here by two five-foot long stringers—which you can see in the background—with wood blocks underneath for support. I should have noticed at this point that it is way too narrow. There's enough room from the trucks to pass but the car bodies could get clipped by the wall edges. 

For the decorative side I'm using a cut stone "tile" from Home Depot which can easily be cut down into strips to fit my wall. The "tile" I settled on has cut stones that are uniform in width and height (1 x 1/3 inch), but varied in their depth. And there's no spacing in between for grout, so it looks like stacked cut stone. Unfortunately some of the pieces are polished which doesn't look realistic, but it's subtle enough that it passes the 10-foot rule (it looks fine to a viewer 10 feet away).

I'm using a regular tile adhesive to adhere the stone to the wood. This is not intended for outdoor use, so I plan on putting an enormous amount of sealer on it and then we'll see how long it lasts.

Once the side pieces had set sufficiently, I added strips of stone along the top edge. I tried cleaning the adhesive off as much as I could but there was still some left. It was around this time that it occurred to me that my structure was too narrow.

I wanted to see how it would look and verify that yes, indeed, it was too narrow. After I widen it, I'll place stone along the top edge of the outer wall, and also along the inside edge of that wall near the top. I don't want any wood visible to the viewer, but don't need to cover most of it as it will be buried in gravel.

A close-up showing the top of the visible side. The excess adhesive was way too visible so I pulled out my Dremel 3000 and cleaned it up in no time.

Here's another view looking down. On the left at ground level is part of an eight-foot diameter curve. I need to be very careful with final placement of the wall to ensure that my longest train cars can still navigate the curve without scraping the wall.

The PE&A isn't the only railroad doing maintenance today. Here's a view from my desk at work of BNSF's Stacy Yard. A lot of noise today as a crew was replacing ties along one of the tracks.