Aloha!
I am taking a break from major muscle movement on the Triple O to let the credit card cool and address some smaller issues that impact smooth operations and appearance. One of these that touches on both are my bridge abbutments. All four are two paving bricks set vertically side-by-side. For reasons lost to me now, I cemented them in about a inch or so below the gravel that is the top couple inches of my fill. At one point, they were more or less level, but one will require a shim. For all practical purposes, they all look like the one in the pictures.
My thought was to cover the bricks with a thin coat of "Quickcrete" and scribe in some bricks, but I have been singularly unsuccessful in getting Quickrete to stick to vertical surfaces for fine work like this. I'd rather not order a commercial product to glue to the brick face, as I'll get creamed in shipping, so a hardware store substitute to quickcrete would be preferred. Anything would look better than paving bricks, and, if it comes to it, I'll bite the bullet on shipping.
The next challenge I think will be easier to surmount, but I wanted to run it through more experienced folks. I planned to use construction cement to glue 1/2"x3/8" "timbers" to the top of the bricks to serve as shims, where required, cofferdams for the fill beyond the canyon lip, and lateral bracing in the case of my truss (not shown).
For the moment, we are bracing the approach with scrap concrete, but this area has become a source of derailments and electrical faults we've isolated to the buckles and rolls that result from this temporary expedient.
Here are the photos:
As ever, thanks for your thoughts! Eric
As ever, thanks for your thoughts!
Eric
You are experiencing "compaction by gravity", a natural event we all face in the GRR. The top few inches of the soil (ground level before you began construction) contains vegetable matter, grass, grass roots and the like. This vegetable matter will continue to decompose for the next few years. As it decomposes it will continue to compact, thus lowering the ground level ever so slightly. Your "sub-bed" of gravel will continue to shift and settle tighter. Every time one of your valcanos is active, small tremmor waves move through your gravel. Have you ever puored a powder into a jar and then tapped the side of the jar with a spoon and watched the powder settle making room for you to add more? Every time there is an earthquake in Japan or California your empire receives another very small jolt, thus it settles a bit more. Your top layer of soil contains vegitable matter which will decompose and settle, plus this top fill, being made of smaller particles than the gravel below, will continue to migrate down into the small voids between the gravel stones. This is entirely a natural event, for the next few years you can expect the ground level below you rails to compact down as much as 1/16th inch a year.
Having said all of that DO NOT glue your shims in place. As the ground below your abutments begins total compaction, the upper layers will continue to settle at a faster rate. In about 5~8 years the shims will be taller than the surrounding soil. I began construction on my empire in 1996 an there are currently several sections of track where the ties are no longer in contact with the ground. Simple addition of new balast will fix the problem. If you had built the foundation of your abutments had been built several inches below original ground level you would be experiencing the opposite problem, rains sitting firmly on the abutments but an air gap between the rails and groud level.
Now for adding texture to the face of your abutments. Move away from cement to stucco. Stucco is a lot more adhesive than cement for vertcale surfaces. Apply about a quarter inch, or more, of stucco and then scribe the block lines. Alternatly, build a jig or form in which to pour the cement or stucco, as it sets up you can scribe in the brick lines, after it has cured you can then glue them in place.
Tom Trigg
You sound as if you are concerned about movement. If the rail ties rest firmly on the shims they are not going to move. Tiny fingers would be the most likely cause of movement, followed by massive tropical storms. If your thought is to have a single piece of shims, have a thought of a prototypical lashing found in the desert. 8x8 or 8x12 timbers lashed together in cribbing style. On the 8 inch top (the 8x12's stand tall) cut a slot for 2x4's pined to the timbers. As the ground level subsides you could pull the shim and sand the bottom side to make it thin enough, thus keeping the weathered edge on top. If you glue the shims to a sbustraight then your sanding will expose a new topside while the edges are aged. It is your empire, do as you like. I had one of the timber bents of my bridge become "airborne" (due to ground setteling and SWMBO did not want the "grass" to be covered.) I made a cribbing stack for new footings for the timber bent which she approved and placed with little disturbance to the "grass".
Tom,
Thanks again. Small hands and track-seeking feet are constantly shifting things about, as you guessed! I think I can make some sort of cribbing as you suggest. I lack a "Dremel" type cutting tool, so notching won't be possible, but I can find a workable solution with tools and "timbers" at hand or readily available that should at least be evocative of the real world. In the meantime, I am going to find a better interim solution for my shims until I turn to on this project.
The project is on hold for a week or so. I am using it as an inducement for my budding civil engineer to get hot on her math homework. Then, as mentioned, we'll use stucco as you suggested (No practical way for me to make a jig), scribe the "bricks," take our measurements, and make our cribbing.
Again, I am very appreciative of your time, suggestions, and guidance. It has all been a great help in steering me out of shoal waters as this project has taken shape!
Aloha,
I had forgotten about tiny toes.
Here is a quick tip. Line your timbers up, side by side. Tightly wrap each end with a rubber band, and readjust so they are even at the ends and top. Clamp in a bench vise or furniture clamps. Using a standard cross cut hand saw make a 1/8 inch deep slice into the top of the timbers. About 3 or 4 of these "notches" is all that is required. Raid a large bushy plant or twigs from the neighbors tree to use as the cross members. This might be a quick task for "grandad" that built the bridges. The only Dremel tool in the house was the one SWMBO used to trim the dog toe nails. I was never allowed to use it.
Short term temp fix. Popsicle sticks.
A very large part of my "rough timber" construction was done with the seasonal pruning of SWMBO's rose bushes. I would bundle up a bunch and toss onto the 10x10 garden shed roof to dry out for use next year. All of my logging cars were filled with "rosewood" timbers. The stems from her "bottle brush" plants also were a good source for lumber. Made a number of "split rail" fences that way. A good pocket knife and an hand powered "egg beater" hand drill were all the tools needed.
I just wanted to report that the requisite math assignments are done, and I can reward my civil engineer by letting her take lead on the project. I'll be incorporating many of the above suggestions; however, I am going to have her scribe the stucco to look like rocks. It will be consistent with our fill material and easier for her (and me!) than trying to scribe lines for stone blocks.
We should get underway this weekend, and I'll post further progress in my "Progress on the Triple O" thread.
Thanks again!Eric
PVT Kanaka Aloha! I am taking a break from major muscle movement on the Triple O to let the credit card cool and address some smaller issues that impact smooth operations and appearance. One of these that touches on both are my bridge abbutments. All four are two paving bricks set vertically side-by-side. For reasons lost to me now, I cemented them in about a inch or so below the gravel that is the top couple inches of my fill. At one point, they were more or less level, but one will require a shim. For all practical purposes, they all look like the one in the pictures. My thought was to cover the bricks with a thin coat of "Quickcrete" and scribe in some bricks, but I have been singularly unsuccessful in getting Quickrete to stick to vertical surfaces for fine work like this. I'd rather not order a commercial product to glue to the brick face, as I'll get creamed in shipping, so a hardware store substitute to quickcrete would be preferred. Anything would look better than paving bricks, and, if it comes to it, I'll bite the bullet on shipping. The next challenge I think will be easier to surmount, but I wanted to run it through more experienced folks. I planned to use construction cement to glue 1/2"x3/8" "timbers" to the top of the bricks to serve as shims, where required, cofferdams for the fill beyond the canyon lip, and lateral bracing in the case of my truss (not shown). For the moment, we are bracing the approach with scrap concrete, but this area has become a source of derailments and electrical faults we've isolated to the buckles and rolls that result from this temporary expedient. Here are the photos: As ever, thanks for your thoughts! Eric Eric, check out ebay for real bricks for doll houses, they are 1" scale but look great on a area like you are trying to cover, I used liquid nails and they have been on there for 10 + years, used regular grout like you find at the hardware store in small containers. Bill
Eric, check out ebay for real bricks for doll houses, they are 1" scale but look great on a area like you are trying to cover, I used liquid nails and they have been on there for 10 + years, used regular grout like you find at the hardware store in small containers. Bill
CCW:
Drat! I think the local craft store even sells these things... As it was, we proceeded today, covering with stucco and then attempting to scribe in the details. My daugther came upon the idea of just pressing the stones into the stucco which was better than my attempts at scribing lines. We will need to do some touch up painting where we spilled stucco and some washes on the abuttments to finish this up, but it is already a far cry from bare paving bricks.
This is a great tip, though, and there will be other projects.
Thanks,
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