# Trestles and the ladder system



## d_sinsley (Mar 29, 2011)

Ok So I am no where near ready to start laying track but I am dreaming about a layout. The wife has deeded me a 50 X 12 foot area in the side yard. I wont bore you with all the details but it will have two separate loops one over the other with one crossing and one area to switch between loops to make one long double loop. I am hoping to make the ladder using 2 1/2 X 3/4 wide vinyl trim. I wanted to stay at or below 1.5% grade. I accomplished that in my design and came up with the crossing point being 12 1/2" separation from top of rail to top of rail. Figuring if I had to leave the 2 1/2 inch ladder material in place it would give me a 10" clearance. I model in F scale with and the loco I am building now will be less than 8" tall. My corner radius are all 4'plus (8' dia.). 

I probably should mention that I am not planning on having this elevated to far off the ground as I have plans to have paths cross it by making small steps/bridges to walk over the track (tunnels for the train). Where the crossing occurs, the lower track will be at ground level with the bottom of the vinyl on the ground and crushed rock brought up to the top of the Vinyl. Then the ladder will rise to the max height of 12 1/2".

Here are a few questions. Is 10" of clearance going to be enough to allow others to play? No giants will be able to run but any smaller equipment should make it with the corners and clearance, right? Oh I doubt it matters but there will be no track power, sorry none battery guys. 

Now for the main questions. How does one construct trestles in the ladder system? I have plans for one that I would like to be about 3' long for the crossing. It will cross a canyon. Do you break the ladder and then use the trestle to support the track? If so what do you use for a base for the trestle to keep it from heaving? My thoughts would be to dig two holes with a post hole digger down 30" (that's supposedly frost line though I have never seen it that deep and I do excavating work for a living) and pour two concrete pillars to ground level with some bent over rebar sticking up about an inch or so. Then pour on top of that (it would be one monolithic pour but for explanation purposes) a 2 1/2" thick (thickness of the vinyl) slab wide enough to catch the bottom of the bents and 3' long. This would be the base I could work off of for the trestle. I would also pour in two bolts on each side that the ladder would anchor too. This would be the starting point for the whole system. Does this sound reasonable? Am I trying to reinvent the wheel? Overkill? Not enough? would be easy to do and seems like a rock solid starting point.

Suggestions and links appreciated.

Devon


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## jimtyp (Jan 2, 2008)

Devon, my 2 cents ;-) I think 10" clearance from top of rail is good, I usually shoot for 11". 

For trestles mixed in with the ladder, I break them up as you stated, and have the trestle support the train. The trestle just sits on top of the ground. Heave is usually only a concern for items in the ground. Alternately, you could just continue the ladder and use that as your stringer for your trestle, supporting your track. 

You mentioned a double loop, but I don't see where you decided how far apart the loops should be. I would recommend at least 8" center-to-center. And keep in mind that you may want the inner loop to be no less than 8' diameter turns, so the outside will be a bit bigger. And it seems like you would have room for that if you have a 12x50 space.

Another item to consider is how far apart are you going to put your ladder supports? Even on the ground I have supports. 

-Jim


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## d_sinsley (Mar 29, 2011)

jimtyp said:


> Devon, my 2 cents ;-) I think 10" clearance from top of rail is good, I usually shoot for 11".
> 
> For trestles mixed in with the ladder, I break them up as you stated, and have the trestle support the train. The trestle just sits on top of the ground. Heave is usually only a concern for items in the ground. Alternately, you could just continue the ladder and use that as your stringer for your trestle, supporting your track.
> 
> ...


Jim,
The minimum curve is the inside track on centerline (8' dia.). I had them spaced at 6" on center but that could easily be 8". The area where the two loops join each other is like 9" to account for the turnouts and cross over. I am doing this all roughly on the AnyRail program. When it is built I can deviate to make it all perfect. The loops are not parallel loops except for about 1/3 of their length. 

Support posts are a bridge (pun intended) I haven't crossed yet. Recommendations? 

I would rather not use the ladder in my trestle as it just wouldn't look right, so I would like to do it as you mention, by stopping the ladder and supporting it with a proper trestle. That will increase the clearance some also as the part that supports the track that the train passes under won't be 2 1/2 inches tall I wouldn't imagine. I haven't gotten that far either. 

Thanks for the advice.


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## Totalwrecker (Feb 26, 2009)

Many use pvc pipe for support, use the size that corresponds to your gap, use clamps under your stringers to set grade.
I made a spline for my trestle (a glue-lam) with not so tall stringers, then flipped it and glued/pin nailed it and the bents together. Braces came last. I used a block of wood for a spacer on the straight part. A fast way to keep them true to each other.
Attach to your ladder and bring the supports up to it. It was strong and even tho' my trestle stringers were 1" tall, it was hard to see unless you got down to look at it.
John


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## d_sinsley (Mar 29, 2011)

Totalwrecker said:


> Many use pvc pipe for support, use the size that corresponds to your gap, use clamps under your stringers to set grade.
> I made a spline for my trestle (a glue-lam) with not so tall stringers, then flipped it and glued/pin nailed it and the bents together. Braces came last. I used a block of wood for a spacer on the straight part. A fast way to keep them true to each other.
> Attach to your ladder and bring the supports up to it. It was strong and even tho' my trestle stringers were 1" tall, it was hard to see unless you got down to look at it.
> John


John,

Do you have pictures of the construction of your trestle design. I found Black Bear Constructions site and was going to build it in the same fashion that they build their 5 pile open frame straight trestle. It is built almost exactly like I see mine in my head. I also found this 

http://3.bp.blogspot.com/-JeJpHked-x0/UYkR6bbfBZI/AAAAAAAADms/eDYnlnUO5nY/s1600/3.jpg

And that is what I want. I would love to see yours and maybe I can incorporate the best of all worlds.


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## Totalwrecker (Feb 26, 2009)

Sorry those pics are lost in the old software here and lost/dead computers at home....
I built a crude frame on a 2x12" and glued layers together to hold a curve. 3 layers and a spacer x 3. I was a little sloppy and ran a belt sander over it.
John


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## wigginsn (Jan 9, 2008)

Hi Devon,

This link (if it works) kinda shows the laminated stringers method on the one I did a few years ago.

http://forums.mylargescale.com/16-track-trestles-bridges-roadbed/7974-new-trestle.html

Construction method was different to most as I had a compound curve on a grade to follow so it was all done in situ.

Cheers
Neil


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## fyrekop (Sep 20, 2011)

Neil,
Thanks for the post and I'm rethinking my trestle building project, now that you have done the brain-burning part. Will break out the metric-to-inches calculator.
Again well done and it looks great
Alan W.


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## wigginsn (Jan 9, 2008)

LOL, good luck with the conversions Alan.

Jimtyp asked about cedar being concreted into the ground in the link - the trestle was dismantled after 5 yrs and there was no sign of decay or rot where they went into the ground. Not sure if I'd do it again but it worked that time. 

Your mileage may vary.. 

Cheers
Neil


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## d_sinsley (Mar 29, 2011)

wigginsn said:


> LOL, good luck with the conversions Alan.
> 
> Jimtyp asked about cedar being concreted into the ground in the link - the trestle was dismantled after 5 yrs and there was no sign of decay or rot where they went into the ground. Not sure if I'd do it again but it worked that time.
> 
> ...


I think on this issue drainage would be the key. Drain the water away and cedar should last along time. It lasts along time even in contact with water but dry it should last years.

I have a combination of cedar and redwood all cut up ready for a pin nailer. Wife said I have to wait 'til after Christmas. torture.


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