# Another trestle question...



## Biblegrove RR (Jan 4, 2008)

What can be used as "FOOTINGS" to keep your bents from direct contact with soil which will produce rot? I was thinking of setting them directly on the ground 1st, then placing a "box" around them a couple inches high and filling with concrete. This way they are not just setting atop a footing but actually part of it....? I can always cover these with Lime/ballast etc. too? any help with or w/o pics will be appreciated!


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## Steve Stockham (Jan 2, 2008)

Dig holes an inch or so deeper than what your trestle legs will be. Set the trestle in them and pour concrete. Whether you have the top of the concrete footing flush with the ground or an inch or so above is really a judgement call. The concrete will do what is most necessary and that is protect your wood from rotting in the ground as well as anchoring the trestle very solidly.


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## armorsmith (Jun 1, 2008)

John, 

That is not entirely true. Embedding the trestle bents in concrete is a double edged sword. In a light rain situation it helps. However, when the bents get saturated from a prolonged rain or a real heavy downpour where the water seeps down into the cavity of the concrete, the concrete then prevents the wood from being able to dry out, thus accelerating the rotting process. I live in Florida where my water table is sometimes as high as 12" below grade. Fence posts embedded in concrete here will rot considerably faster than those set in gravel that allows the wood to dry with the change in water table. 

My recommendation for your trestle bents would be to pour a pad under the bent but an inch or so above grade. When securing your bent to the pad, place a piece roofing paper (tar paper) between the bent and the concrete. An additional bit of anti-rot would be to make the bottom timber our of pressure treated. I have started to make any wood members that will be 'grounded' out of pressure treated, material I have recycled from other places. This material is already dried out and usually doesn't twist when I cut it. I cut all my pressure treated material outside with the breeze/fan at my back. 

My tuppence worth. 

Bob C.


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## Steve Stockham (Jan 2, 2008)

Good catch Bob! I forgot to mention the bit about the pressure treated wood. Personally, I don't use concrete footings. I still dig the holes but I fill them with small gravel pieces and poultry grit. This works for my railroad. As to concrete footings, they are still better than sticking the wood into bare soil but you _do_ need to use pressure treated wood if at all possible. If you can't find any then use redwood.


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## Biblegrove RR (Jan 4, 2008)

Cedar fence boards will be used for the bents I guess. Thanks guys, I still need more ideas...


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## mpaterso (May 11, 2009)

Please take care when selecting/cutting pressure treated wood. Some treatment processes result in toxic "dust" when cutting. We discovered this just recently when preparing for a major show and had to deal with an environmental inspection.


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## armorsmith (Jun 1, 2008)

Mpat, 

Note that I specified that I cut pressure treated material outside in the open air. I keep the breeze at my back, taking any dust away from me. Lacking a breeze, I have an old furnace blower I locate behind me to generate a whirlwind taking the dust away. The thing I forgot to mention is that I also have a real good shop vac that attaches to the dust chute on my table saw. A suggestion for the panic stricken would be to also wear a dust mask, I don't, but then that's me. 

Steve, 

The gravel base also works well. The roofing paper seems to add a layer of 'insulation' between the concrete and wood which makes the wood last longer. I have seen this technique used on the prototype, several different railroads. The only difference is they use creosote material that we can't get. Also, using recycled pressure treated material that has already 'dried' real well allows you to glue your assembly. I have gotten a good supply of used pressure treated 2x4 and 4x4 from taking down old stockade fencing. Sometimes a pass or to over the joiner helps take the warp out, but otherwise it is quite stable. 

Bob c.


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## docwatsonva (Jan 2, 2008)

I built this trestle out of treated fence boards for my old RR in Virginia. I laid a 1" base of crusher fines and set the trestle bents directly on top of the fines. The trestle was in place for 8 years. As you can see in the photo, ground cover even surrounded the bents.

When I removed the trestle for my move to NC, the bent bases showed no signs of rot. I guess the stone dust allowed excess moisture to drain away from the bases'.











Doc


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## Biblegrove RR (Jan 4, 2008)

ok.... treated pine or cedar planks? I have heard that cedar lasts a very very long time.


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## Totalwrecker (Feb 26, 2009)

Treated pine is nasty stuff to work with while cedar is relatively benign, except in Texas where Cedar Flu is real...but I think that was alergies to the pollen. 

Cedar has natural ingredients that repell most bugs...termites included. Redwood is no longer safe from termites in this region. 

Here in Arid Az I attached the bents to the track stringers in place and then brought gravel up to the bottom of the bents and then covered that wth dirty sand. For a natural look. It took a couple af washings with a hose to settle the foundation, but hasn't moved since and we get monsoons here most every year. 

I don't worry about rot, I do have to be concerned with wood eating insects such as subterrainian termites, they will build a mud tunnel over treated wood to get to natural wood. I've seen those tunnels on my cedar planks and saw where they tried to eat the wood, but stopped quickly and left. 

listed above were some tips for pressure treated wood; good ventilation, but I would add gloves, goggles, a mask and wash afterwards.... you don't want to touch or breath that dust. 

Cedar fence boards are relatively cheap, pt isn't. 

John


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## docwatsonva (Jan 2, 2008)

John's right. If I were to do it again, I'd use cedar.

I am using cedar fence boards to make retaining walls (cribbing) for my new layout.











Check back with me in 8 years to see if cedar has held up as well.

Doc


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## Biblegrove RR (Jan 4, 2008)

that looks great Doc! are they 1/2" and what is the length please? I need some of these too! It would be a great way to run on a hillside eh?


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## docwatsonva (Jan 2, 2008)

John,

The cedar fence boards at Lowes are nominally 5/8". The length of my crib pieces are 10". Don't ask me why, they just looked about right. I ripped all the pieces on my band saw. It's more comfortable than my table saw.

I made about 35 ft. of cribbing. They were done in sections. Here's a photo of a completed section ready for sealing.










Here's another phto in my workshop:











I used 3/32" copper-coated steel welding rod (about 10 cents a foot) to connect the sections. The rods were cut about 1 ft. longer than needed. When the cribbing was installed, I drove the rods into the ground. This locked in the lower part of the cribbing. Since the sections are not glued where they come together, this method of assembly also permits the wall to be bent in any direction to accomodate curves, etc.

I added bump-out sections to the back side of the cribbing with additional pieces of rod slipped through holes at the back. These keep the top/rear of the cribbing in place.










Here's another view of the cribbing.










Hope this is of some help.

Doc


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## Chrisp (Jan 3, 2008)

I can also vouch for the crusher fines approach. When I built the trestle in front below, I dug a trench and filled it with about 1-2 inches of tamped fines, then set the trestle on top. After making sure everything was level, I added another inch of fines to cover the lower bents, then covered that with the larger gravel you see in the foreground. Once wet, crusher fines hold almost like cement. The supports for the truss bridge in the back are redwood 2 x 2's hammered into the ground around 12-18 inches into holes filled with crusher fines. Despite the spindly appearance, they can support my heavy live steam engines just fine.










The trestle uses redwood from an old trellis, and I've build other structures from parts of an old redwood gate. This old redwood seems to last forever, I recommend recycling any really old gate or fence as the quality of the older wood can still be quite good, oftern better than new wood.


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## Biblegrove RR (Jan 4, 2008)

Very nice work guys... No Redwood around here and I use ground up limestone as crusher fines etc. I think this will have to be the approach to proceed with. A trench dug out and packed with the lime.


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## xo18thfa (Jan 2, 2008)

Doc: That cribbing look great. A professional touch all around. I can see how cribbing could solve a lot of problems on rough terrain.


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## denray (Jan 5, 2008)

John
I have a 32 foot trestle with the tallest at 42 inches, I too have experienced with fence post in concrete will rot the post very fast in Missouri, if you put the bottom 2or3 inches in the dirt and then cement it will not rot. Completly in concrete, the concrete creates a bowl to hold the moisture. On my trestle I did not want vegetation growing under or in my trestle, so I poured cement just under the bents, right up even with the bottom of the bents. On every other bent I placed a 4-6 inch piece of 3/4'' angle iron beside one of the bent legs, with the angle protruding out of the concrete 1-2 inches. Then I took a hose clamp and clamped the wood to the inside of the angle, creating a very very strong trestle, no movement and won't rot. Dennis


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## Totalwrecker (Feb 26, 2009)

Cribbing can also make terrain, I had built a fill to elevate track across a lower level, first I tried big rocks to hold the shape, but rain and critters had me reshaping it all the time. The big rocks also crowded my trestle so I used cribbing on both sides and it has held up great. Other than seasonal reballasting, no worries and looks better too. How often do you see 2 horseshoe curves of large rock occurring naturally? The cribbing declares it man-made and justified...










Where the tops are double wide is a bridge for drainage, the culvert under the fill work was always getting plugged, now the gap is wider. The timbers are of 2 lengths as they follow the curve. 









First I used big rocks inside and then medium rocks followed by near ballast sized rocks to fill the cribbing. I like the look of some washing out as seen above.
Track needs it's fall ballasting....










John


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## Biblegrove RR (Jan 4, 2008)

very nice! and gives me some ideas for sure.... This leads me to a question I have concerning a hilside run I have to do. Since I feel you guys are qualified to help me, I won't start another thread. or should I? Here is a pic of what I need to do... 









I was going to continue with the concrete roadbed and place drainage culverts under every so often but I need to change it up a bit. As you may be able to tell, on the steep grade in the middle, there are lower wash outs already in place in the yard and I would like to leave them as natural as possible for proper drainage etc. Trestle, concrete roadbed, cribbing or all of the above?


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## Totalwrecker (Feb 26, 2009)

All of the above... sort of. I don't use concrete... I'm not saying don't, just that I don't.
I assume you'll cut the grass sections out and make a cut along the side of the hill for level track. You'll need an upper retaining wall, wood or stone were common. Trestles can span dropouts and drainages, or small bridges. 
If you are planning to elevate above the grass, then you won't really need walls.
Railroads would rather move dirt than build long trestles as they required more expensive workers and supplies... So a cut seems to me the best solution. The upper side of the cut would be angled back to save on cribbing, where possible. A large rock could be placed close enough to trackside, to require cribbing around it from near verticle (near rock) and then tapered up into the less steep angled wall. You can also excavate an openeing and stack rocks as an outcropping and partially recover with dirt, A nice touch is finding both halves of a broken rock and put one on either side of the track for a rock cut... Visual breaks help the illusion.

Have fun and we want to see how you solve the riddle!

John


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## toddalin (Jan 4, 2008)

It's best to keep the wood off of/out of the moist soil and especially the water. We use double bull-nosed pavers as supports. As a bonus, they are typically glazed and fired so the water does not "wick" up to the wood. These are typically used around jacuzzis and spas and as cap stones on walls.


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## Totalwrecker (Feb 26, 2009)

Nice shots, Toddalin, looks like the bears have cleaned out the fish! 
Very nice pavers, I cast a couple of 'footings' and they don't look as nice as yours.... 

John


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## Biblegrove RR (Jan 4, 2008)

Todd, I actually thought of using some kind of pavers but the only ones I have seen around here like these are "Bullet" type that connect end to end. One end is rounded like yours, but the other is concaved to match the next one. I could build a form and make my own I guess???


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## toddalin (Jan 4, 2008)

Posted By Biblegrove RR on 25 Nov 2009 10:41 AM 
Todd, I actually thought of using some kind of pavers but the only ones I have seen around here like these are "Bullet" type that connect end to end. One end is rounded like yours, but the other is concaved to match the next one. I could build a form and make my own I guess??? 

You should be able to find "double-bull nosed" bricks if you search around.


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## John J (Dec 29, 2007)

Make the track portion of the Trestle strong enought to carry the train between the abutments with out the bents. Then attach the bents to the bottom of the tracksection. 
The footing of the bents should be of the ground. Then spread some gravel and sand around the base of the bents so they look like they are in the ground. That should keep them dry and they should last longer. Of course I could be wrong on thie thery.


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## Ray Dunakin (Jan 6, 2008)

I like to suspend the bents from the deck, with the bottom of the bents hanging just above the surface or the rock or ground. Then I build forms around the bottom of each bent, using foam core board and hot glue. I pour a mix of vinyl concrete patcher and high strength mortar into the form, let it set, the peel off the form. Here are a few pics... 

http://www.raydunakin.com/Site/IRR_Trestles.html 

Most of the time, mine are built onto rock, but a few are set in hard, sandy soil. For those, I dig a shallow pit under the bent and build the form in the pit, so that the cast foundation will be set into the ground. 


I use Western red cedar, and the bents are painted prior to being installed.


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## Biblegrove RR (Jan 4, 2008)

Thanks guys! Ray, what is your mix ratio on the patcher and mortar?


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## Ray Dunakin (Jan 6, 2008)

John, I usually mix the mortar and vinyl patcher about 50/50. This was chosen mainly because it produces a good color and texture for a realistic appearance. So far it seems to hold up well.


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## RimfireJim (Mar 25, 2009)

I scanned through this thread and didn't see anyone mention this (though it's not directly an answer to your question): 

For a protypically-correct look for your trestle, consider whether you are using pilings (round) or timbers (milled square or rectangular). Pilings are driven into the ground to bedrock, with no footing. A timber bent rests on a horizontal sill that sits on a footing which is usually cast concrete. This detail is rarely executed in garden railroads, but somebody on this forum posted some pictures of their work awhile back showing it done correctly and it just looked "right", if you know what I mean. I searched for the thread, but couldn't find it. 

That said, I don't think you can go wrong emulating what the real railroads do: pour a footing with a material that won't rot (concrete), and use a mud sill of a rot resistant wood. If you use pressure treated lumber and mill it down to the size of a scale sill, I'd use one of the factory treated surfaces in contact with the footing to get the maximum benefit from the pressure treating, which doesn't penetrate completely through 2X stock.


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## Splicer (Nov 29, 2008)

First, I suggest you use Cedar if at all possible. Ask anyone still here that remembers me, I built a trestle over 50' long and curved and used Cedar to make my bents. I then placed the bent on the ground. Then I took concrete and spead it around the base of the of the bent, and did that at each bent. Then I put gravel the entire length. I & others thought it looked very prototypical and it worked really well. 

http://rides.webshots.com/photo/115...9863CAfIlb


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## Biblegrove RR (Jan 4, 2008)

I am thinking that as long as they do not sit in water or wet soil... Cedar should hold up.


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