Ladder Bridge Designs

[dogwonder]

So my brother has about 2 acres of land that he'd like to use to construct some ladder bridges to play around on. Does anyone know a good place to get some bridge designs? There's nothing worse than building something that will fall apart and we'd like to maybe duplicate some stuff that has already worked.

DW

[adurham]

go to www.Gutsploder.com there is tons of pictures of the North Shore trails, woodlot, and most of the good things in lower BC.
-Ashlon

[ioscope]

DW lol

[Changleen]

Isn't the risk of the whole thing collapsing under you part of the fun?

[dvasis]

A ladder!?!?! one of the easiest things to build: two 2x4's with cross sections.

[dogwonder]

I agree that half the fun is the trial and error part of building bridges, but with his wife and 2 year old daughter in viewing distance, too many mishaps will scrub the whole project. Since neither of us are engineers or licensed carpenters, but do understand how a saw cuts wood, so we're willing to give this thing a shot.

Where we need assistance is how to reinforce the riding surface (think supports), and what steps should be taken for where it touches the ground (do I put metal reinforcements around the part that is sunk in the ground to prevent rot?).

Thanks for the help...

DW (as in DogWonder)

[lovebunny]

DW (as in DogWonder)
haha yes but dw also stands for david weagle who just happens to frequent this board as dw

[dogwonder]

So I hear...yee of the DW Link suspension design. I don't have anything nearly as cool on my resume. Will being a slave to the man earn me any points?

DW

[BuddhaRoadkill]

Since no one else did, I'll post the obvious: IMBA (http://www.imba.com/resources/trail_building/index.html)
You should find plenty of knowledge and ideas there.
In particular, this PDF file (http://www.imba.com/resources/trail_building/trailbridgedetails.pdf) looks to be what your looking for.

Enjoy

[zod]

DW, here's a couple rules I've learned to follow after several years of building.......not saying these are the only way but they have certainly helped me and my friends to build solid structures!

1: Bury all supports at least 18" to 24" into the ground. If your elevated section goes higher than 6 feet make sure to go even deeper to compensate for top weight. Alway use treated wood if it is going into or touching the ground....I always use landscape timbers for my supports. And get some good posthole diggers, these are expensive but they'll cut your hole digging time in half! http://www.acehardwareoutlet.com/ProductDetails.aspx?SKU=72583

2: Get a good tamp, an axe handle works good, something fabbed out of metal so it's heavy works better. The tamps like they sell at Lowe's are no good because the base is too big to tamp back down a post hole good.......you want the base of your fabbed tamp to be no bigger(in lengthXwidth)than say a pack of smokes.

3: User screws, not nails. Screws cost more yes, but you will use a lot less of them and more importantly they won't back out like nails. Get a cordless drill with an extra battery, leave one battery on the charger up at your bro's house and then you can swap them when you run out of juice. We actually use square drives which are even more costly but you never round a head out and they are easy to remove should you have to disassemble a section, which I do from time to time to drop a tree or make a change. Square drive hookup -- http://www.mcfeelys.com

4: Always do cross supports between your two posts.

5: Always do down-angle supports from you bridge to the posts.

(4 and 5 are huge, cross-bracing can take something that feels wobbly and instantly make it rock solid)

6: Learn to build WITHOUT tying into trees for support. It's the easy way out, can damage the tree, and learning to build without tree support will make you a better builder.

7: Do all of your cutting with a chainsaw......at first doing precision cuts with a chainsaw are a pain in the butt but over time you get good at it and it's a lot easier than walking up to the house to use power saws!

8: get out and build, the more you do it the better get and you will develop your own theories :thumb:

[wannabeabonedoc]

I have to agree with zod on what he said. I've built several bridges on my local trails, and it's a matter of building it and seeing what works and what doesnt. IMBA.com says not to use pallets, but usually if you go to hardware stores or lowes even they'll have free pallets you can use. Just root through them and find the ones that arent messed up. Best of luck to ya!

[santacruzed]

print what zod posted and you are set

[dogwonder]

Wow, that is some impressive info, between the website and Zod's tips, I think I got a good feel on what to do. A couple of questions.

for #'s 4 & 5 above, how far apart should the posts be? I was thinking 6 feetish, but would like some opinions. Second, what kind of lumber should I use for the posts? I understand it should be treated, but should I use 4 X 4's? 6 inch diameter poles? Finally, is just putting treated wood into the ground bare ok? Or should I put something like a metal reinforcement around it?

One last thing, and this is a bit advanced, but I personally really like bridges with berms. So if I were to build a wooden berm or bridge with any kind of banked turn, any thoughts on how to design and build? I would assume that the planks should be closer together so I will probably need to taper some of the planks, but before I start getting crazy here, would like to know some thoughts. Should you start with the stringers on posts first then add the planks last? Maybe some pictures of these as well?

Again, thanks for all the help.

DW

[santacruzed]

http://www.ridemonkey.com/forums/showthread.php?t=101849&page=32&pp=15

[zod]

for #'s 4 & 5 above, how far apart should the posts be? I was thinking 6 feetish, but would like some opinions.


Are you refering to side by side posts? Or are you asking how far apart to set of supports should be (down the ladder bridge) from the next set of supports?
If you were asking about the first, I don't have one supports where the two legs are further than 4 or so feet apart and many are as close as say 2 feet and some even closer. If you put your supports deep enough into the ground and cross brace it ain't gonna fall over. Now that being said, the higher you go the farther apart you want you supports typically. As far as how far one set of supports should be from the next well that is really dependant on how long/strong the wood you are using for your runners is. I have sections where there are supports stacked up on each other every 5 feet or so, but then in some of the newer section I am using narly oak 4x4's for runners and in that section I am going 12+ feet between supports! I like it like that b/c it save me a lot of money on posts :thumb:


Second, what kind of lumber should I use for the posts? I understand it should be treated, but should I use 4 X 4's? 6 inch diameter poles?

The best bang for the buck for posts is landscape timbers from Lowes or Home Depot, Wal-Mart, etc. Call around and find the best price. I got a lot of really nice free lumber hookups going on now but I still purchase landscape timbers for my supports b/c they are SO strong and won't rot for a long long time.


Finally, is just putting treated wood into the ground bare ok? Or should I put something like a metal reinforcement around it?

Bare is fine, dig your post hole, put the support in the hole, throw the dirt back in around it, tamp it down tight, and your done. I have to go back from time to time and tamp the ground back around posts that come loose, especially if it is on a section where there it lateral movement like in turns. No big deal though, it's a once and a while maintinance thing. I haven't tried this, but you could pour some sacrete in the hole instead of putting the dirt back in it. I think it would slow the process up though and is overkill. I do have one type of stucture I might start doing this with though. Skinnies that only have on support instead of a side-by-side set of supports come loose a lot and require tamping quite often. If I build another section like this I might sacrete the holes.

http://gallery.unicyclist.com/albums/albux54/DRD_rebirth_2.jpg


One last thing, and this is a bit advanced, but I personally really like bridges with berms. So if I were to build a wooden berm or bridge with any kind of banked turn, any thoughts on how to design and build? I would assume that the planks should be closer together so I will probably need to taper some of the planks, but before I start getting crazy here, would like to know some thoughts. Should you start with the stringers on posts first then add the planks last? Maybe some pictures of these as well?


SantaCruized posted a link to some shots but here they are in sequence. Making elevated berms is a slow process and is not a great project to try to tackle as you start geting into building north shore though. If I didn't have a friend who builds deck and is a rainman with lumber this turn would have NEVER turned out as good as it did........and remember YOU ARE GOING TO USA A LOT OF LUMBER making a banked turn. Start looking for free hookups and get used to dumpster diving on construction sites. When you see a house is in framing process the dumpster will be full of sweet FREE woody goodness :D

http://gallery.unicyclist.com/albums/albux54/pz_nascar1.jpg
http://gallery.unicyclist.com/albums/albux54/pz_nascar2.jpg
http://gallery.unicyclist.com/albums/albux54/pz_nascar3.jpg
http://gallery.unicyclist.com/albums/albux54/pz_nascar4.jpg
http://gallery.unicyclist.com/albums/albux54/pz_nascar5.jpg
http://gallery.unicyclist.com/albums/albux54/pz_nascar6.jpg
http://gallery.unicyclist.com/albums/albux54/pz_nascar7.jpg
http://gallery.unicyclist.com/albums/albux54/pz_nascar8.jpg
http://gallery.unicyclist.com/albums/albux54/pz_nascar9.jpg
http://gallery.unicyclist.com/albums/albux54/pz_nascar10.jpg
http://gallery.unicyclist.com/albums/albux54/pz_nascar11.jpg
http://gallery.unicyclist.com/albums/albux54/pz_nascar12.jpg
http://www.orgautomation.com/images/Josh_Wood_berm.jpg
http://gallery.unicyclist.com/albums/albus81/tiles_nascar.jpg

[urbaindk]

If I didn't have a friend who builds deck and is a rainman with lumber this turn would have NEVER turned out as good as it did........


That is a thing of beauty. Having built my share of decks, barns, skate ramps, and a few ladders here and there, I agree "rainman of lumber" is right. I would never have enough patience to cut all those angles to peice that thing together. That's fine work!

And kids notice that he built the frame in the driveway. Trying that out in the woods with out a mitre saw handy would be a chore and a half.

[zod]

Thanks!

Most of the cuts were done with a chainsaw :dancing: but we did use a miter for a few angle cuts we didn't feel we'd get right with the Stihl :thumb:

yes though, no way in hell we could have built that thing down in the woods

[teaguers]

If you want to be true to the north shore tradition build as much as you can with scrap wood that is in the area, downed trees, branches and such. Definitely try not to nail into trees, bad karma. And as opposed to what was mentioned earlier treated wood is bad. The chemicals get into the ground. Cedar is best if you've got it. A good naturally built stunt is a thing of beauty, and often more fun to ride :)

[RaID]

that berm looks sweet

[zod]

Treated wood doesn't have enough chemicals in it to hurt anything. Put non-treated wood in the ground for supports and you will have rotted bug infested supports in less than 2 years.....no thanks! In Washington and in BC cedar is abundant but down here in the dirty South it is not.........I think I have 3 cedar trees in all my woods. Most of what I'd have (if I wanted to go all natural) to work with is white pines and that rots REAL fast once it's touching the ground. Landscape timbers on the other hand will still be like new 10 years from now! :thumb:



Thanks RaID

[elRey]

Start looking for free hookups and get used to dumpster diving on construction sites. When you see a house is in framing process the dumpster will be full of sweet FREE woody goodness
whenever i do that some contractor shows up and gets pissed. there are lots of construction sites around my house and they are good if you need a couple extra screws or nails too!

[urbaindk]

whenever i do that some contractor shows up and gets pissed. there are lots of construction sites around my house and they are good if you need a couple extra screws or nails too!


You have to ask and make nice with them. Once they understand what you are doing, most will be really helpful. If you show up and start taking stuff with out asking you will get yourself in big trouble. Be smart.

[fatson]

ill berm dude