Archive




TimberKing Sawmills



Please visit this sponsor

The Largest Inventory of Used Chainsaw Parts in the World

Toll Free 1-800-582-0470

LogRite Tools


Forest Products Industry Insurance

Norwood Industries Inc.

Sawmill & Woodlot Magazine



Wood Processing equpment. Splitters, Processors, Conveyors

Your source for Portable Sawmills, Edgers, Resaws, Sharpeners, Setters, Bandsaw Blades and Sawmill Parts

EZ Boardwalk Sawmills. More Saw For Less Money!

STIHLDealers.com sponsored by Northeast STIHL

Woodland Sawmills

Margeson Insurance

Peterson Swingmills

Pacforest Supply Company

Forestry Forum Tool Box

Author Topic: Need to make a log bridge.  (Read 15403 times)

0 Members and 1 Guest are viewing this topic.

Offline Viking

  • Full Member
  • **
  • Posts: 98
  • Gender: Male
Need to make a log bridge.
« on: November 25, 2003, 09:37:18 am »
it only has to be about 10-15ft long and about 3ft high. About 3-4tons max load. I have pine"every type" birch, poplar and cedar. which would be most suitable for the job ? all tress are 16"+

Offline Scott

  • Senior Member
  • ****
  • Posts: 394
  • Age: 27
  • Location: Saint John NB
  • Gender: Male
  • Logger in Training
Re: Need to make a log bridge.
« Reply #1 on: November 25, 2003, 01:04:11 pm »
Don't use poplar or birch. They rot way too fast.

Offline Jim_Rogers

  • Board Moderator
  • *****
  • Posts: 5105
  • Age: 61
  • Location: Georgetown, MA
  • Gender: Male
  • Keep your chisels sharp.
    • jrsawmill.com
Re: Need to make a log bridge.
« Reply #2 on: November 25, 2003, 02:01:20 pm »
What type of bridge is it?
A logging trail bridge for a skidder?
A trail bridge for snowmobiles?
A bridge for cars and pickups to use in a driveway?
Are you going to use the logs in the round or are you going to have them milled into timbers?
We'd need some more information in order to give you some help.
Jim Rogers
Whatever you do, have fun doing it!
Woodmizer 1994 LT30HDG24 with 6' Bed Extension

Offline Viking

  • Full Member
  • **
  • Posts: 98
  • Gender: Male
Re: Need to make a log bridge.
« Reply #3 on: November 25, 2003, 02:12:07 pm »
it will be used for a 4x4 3/4 ton or 1 ton pickup truck to drive over, and the logs will be round, but i can shape them with a chainsaw.

the bottom of the creek "in the area im putting the bridge" is cap rock, so i can put supports directly in the middle. i just dont want to not use a bridge and dammage the two edges of the creek.

Offline Jim_Rogers

  • Board Moderator
  • *****
  • Posts: 5105
  • Age: 61
  • Location: Georgetown, MA
  • Gender: Male
  • Keep your chisels sharp.
    • jrsawmill.com
Re: Need to make a log bridge.
« Reply #4 on: November 25, 2003, 02:20:00 pm »
Are you going to lay the logs across the water and then put a deck on it for the 4x4's and pickup?
How wide will this bridge be?
Whatever you do, have fun doing it!
Woodmizer 1994 LT30HDG24 with 6' Bed Extension

Offline Viking

  • Full Member
  • **
  • Posts: 98
  • Gender: Male
Re: Need to make a log bridge.
« Reply #5 on: November 25, 2003, 02:25:24 pm »
8ft wide should be more than enough since it wont be for a dully. im to sure about the other part yet.

Offline woodmills1

  • Senior Member x2
  • *****
  • Posts: 4726
  • Age: 62
  • Location: Hudson, NH
  • Gender: Male
  • the truth shall set you free
Re: Need to make a log bridge.
« Reply #6 on: November 25, 2003, 09:07:55 pm »
I have a NH or federal publication on making bridges using 2x stock laid on end.  I can try to find it if you want.  Always intested me to build bridges but never did one yet.
James Mills    Lovely wife   collect old tools  vaccuming fool  36 bd ft per hour
 oak paper cutter,   apple jacks   ebonic yooper rapper nauga seller, Blue Ox? its not fast, 2 cat family,  LT70 and edger, 375 bd ft/hr, we like Bob, did I say free heat machine no oil 9 years, big splitter

Offline Viking

  • Full Member
  • **
  • Posts: 98
  • Gender: Male
Re: Need to make a log bridge.
« Reply #7 on: November 25, 2003, 09:54:12 pm »
sure :) if its not to much trouble.

Offline L. Wakefield

  • Senior Member x2
  • *****
  • Posts: 1285
  • Age: 62
  • Location: Hollis Maine
  • Gender: Female
Re: Need to make a log bridge.
« Reply #8 on: November 26, 2003, 03:47:09 am »
Quote
I have a NH or federal publication on making bridges using 2x stock laid on end.  I can try to find it if you want.  Always intested me to build bridges but never did one yet.

 
  I wouldn't mind seeing that one either. I wonder if they have it on line?  lw
L. Wakefield, owner and operator of the beastly truck Heretik, that refuses to stay between the lines when parking

Offline woodmills1

  • Senior Member x2
  • *****
  • Posts: 4726
  • Age: 62
  • Location: Hudson, NH
  • Gender: Male
  • the truth shall set you free
Re: Need to make a log bridge.
« Reply #9 on: November 26, 2003, 04:52:36 am »
It is called User Friendly Guide to Timber Bridges.  Put out by the university of NH cooperative extension.
http://ceinfo.unh.edu/fgen1043.pdf
James Mills    Lovely wife   collect old tools  vaccuming fool  36 bd ft per hour
 oak paper cutter,   apple jacks   ebonic yooper rapper nauga seller, Blue Ox? its not fast, 2 cat family,  LT70 and edger, 375 bd ft/hr, we like Bob, did I say free heat machine no oil 9 years, big splitter

Offline OneWithWood

  • Senior Member x2
  • *****
  • Posts: 5194
  • Age: 60
  • Location: Unionville, IN
  • Gender: Male
  • I am happy!
    • elmhouseindiana.com
Re: Need to make a log bridge.
« Reply #10 on: November 26, 2003, 07:28:46 am »
Hey, thanks Woodmills!
I too am interested in bridging some of the streams on my property.  I had not seen this pub before.  It will make for some good reading  :P
One With Wood
LT40HDG25, Woodmizer DH4000 Kiln
www.elmhouseindiana.com

Offline Viking

  • Full Member
  • **
  • Posts: 98
  • Gender: Male
Re: Need to make a log bridge.
« Reply #11 on: November 26, 2003, 09:09:19 am »
thanks for the guide :)

Offline L. Wakefield

  • Senior Member x2
  • *****
  • Posts: 1285
  • Age: 62
  • Location: Hollis Maine
  • Gender: Female
Re: Need to make a log bridge.
« Reply #12 on: November 29, 2003, 06:46:05 am »
   Totally excellent! Thank you for the reference. I have saved it and will print it out as time and paper allows. I had not realized that historically they had made arched timber bridges, having only seen the steel ones.  lw
L. Wakefield, owner and operator of the beastly truck Heretik, that refuses to stay between the lines when parking

Offline Jim_Rogers

  • Board Moderator
  • *****
  • Posts: 5105
  • Age: 61
  • Location: Georgetown, MA
  • Gender: Male
  • Keep your chisels sharp.
    • jrsawmill.com
Re: Need to make a log bridge.
« Reply #13 on: November 29, 2003, 03:56:48 pm »
I've been thinking about your idea about making a log bridge.
I drew up an idea I had about how to do it.
First I did some math and figured out how strong or how big the logs needed to be in order to support the weight of 8000 lbs. And came up with 16" logs 16' long cut flat on the top by 2" for the decking. These stringers, as they should be called, are 16' long and are supported mid span with a stack of three logs that are 8' long and flattened on two side, the top and bottom.
Place the three 8' logs in the middle of the span and put the (5)16' logs over them. Then attach the decking which should be 4"x10"x8' or wider than 10" if you can but not any narrower.
Add side rails if you choose.

Here are some drawings of my idea:







You can see that the stack in the middle holding up the long ones might need some 2x4 or something to hold them straight up and down, ( I didn't draw them in).

And you'll have to find some very long and strong nails to nail the decking down to the logs.
If choose to build something like this you could leave the bottom of the long stringer logs round, and flatten only where they meet the supporting 8' logs, but don't make them any thinner than 12" and it should carry the weight of 8000 lbs.

What do you think of this design?

Jim Rogers

Whatever you do, have fun doing it!
Woodmizer 1994 LT30HDG24 with 6' Bed Extension

Offline Kevin

  • Administrator
  • *****
  • Posts: 6663
  • Age: 60
  • Gender: Male
Re: Need to make a log bridge.
« Reply #14 on: November 29, 2003, 04:01:46 pm »
I made one of those --Photos MUST be in the Forestry Forum gallery!!!!!--.com/photo/13012199/14138748NVHXEuTUrM]Bridge Link[/url]

Offline Viking

  • Full Member
  • **
  • Posts: 98
  • Gender: Male
Re: Need to make a log bridge.
« Reply #15 on: November 29, 2003, 09:05:41 pm »
Jim_Rogers, wow, thats pretty nice, can i ask which program you used to make the drawing ? and may I use your idea / its great and it dosent really restrict the water flow.

Offline Jim_Rogers

  • Board Moderator
  • *****
  • Posts: 5105
  • Age: 61
  • Location: Georgetown, MA
  • Gender: Male
  • Keep your chisels sharp.
    • jrsawmill.com
Re: Need to make a log bridge.
« Reply #16 on: December 01, 2003, 06:55:51 am »
I made that drawing with my timber framing cad program.
After reviewing my figures, I think you need to make the center support only two logs high and then the third log, which will make the bottom of the deck 3' off the floor of the stream bed.
Also the stringers need to be 14" from cut face to cut face not 12". But as mentioned the cut face only has to be where the stringers rest on the support logs.
I'm concerned about the support logs shifting as you drive over the bridge so I'd nail some 2x stock vertically to the sides of them to make the stay stacked up and be sure to secure them to the stringers so that when you drive onto the bridge the bridge won't shift and push the stringers sideways away from the vehicle.
You might need to put in some diagonal braces between the stringers and the support logs.
And you can use the design if you choose.
Make sure you use straight and strong logs.
The math I did was for eastern white pine, in all the pieces.
I spaced the logs so that there is one in the middle and the one either side is 2' on center. The outside logs are flush with the ends of the 8' support logs. This way they are directly under where the wheels of the pickup truck will be rolling over the deck, giving it the most support.
If you can use wider support deck boards it would be better, but a full 4" x 10" should support one quarter of the weight of a 8000 lbs load at that span.
Good luck with your project and take some photo of the finished bridge when you've got it done.
Jim
Whatever you do, have fun doing it!
Woodmizer 1994 LT30HDG24 with 6' Bed Extension

Offline etat

  • Member*
  • *
  • Posts: 0
  • Gender: Male
Re: Need to make a log bridge.
« Reply #17 on: December 01, 2003, 04:11:23 pm »
I've helped my grandpa, my dad, and one of my uncles build bridges before.  They never really had a plan I could see, just tried to cut some white oak logs, big as they and the horses could snake across, streched two on each side under the wheels, and then two or three spaced out down the middle.  Then floored em with rough cut 2/  white oak.  They just always seemed to know when they had it good enough.  I remember startin the spikes with a regular hammer, and then havin to drive em on down with a heavy blacksmith type hammer.  Havn't been in them woods where the bridges was in years.  Now I'm a wondering if there's anything left of them.  I know horses shore didn't like walkin across them wood bridges!  Had one jump off one one time into some ICY cold water  with me on him.  Best I remember I was about 16.  There was a corn field across the bottom and somebody cranked up a corn picker.  I like to froze before I got back to the house.  Wasn't the horses fault, scared me too so I never held it against him.Oh, and they tried to nail the nails where the tires on a tractor or truck wouldn't run right over them, because them nails WILL back up occasionally.  
Old Age and Treachery will outperform Youth and Inexperence. The thing is, getting older is starting to be painful.

Offline etat

  • Member*
  • *
  • Posts: 0
  • Gender: Male
Re: Need to make a log bridge.
« Reply #18 on: December 01, 2003, 04:17:06 pm »
Also, don't put supports in the middle, if the creek floods those supports will catch every tree limb that comes by.  Then if it builds up enough pressure, it'll take your bridge down stream.  You do want to anchor good to each side of the bank also.  Even if it doesn't flood those supports will soon catch enough stuff to dam water.
Old Age and Treachery will outperform Youth and Inexperence. The thing is, getting older is starting to be painful.

Offline etat

  • Member*
  • *
  • Posts: 0
  • Gender: Male
Re: Need to make a log bridge.
« Reply #19 on: December 01, 2003, 06:08:53 pm »
I know you're probably gettin tired of me but I thought of one more thing.  After the sideways planks are laid on the bridge lay some planks 'lengthways' where the tires are goin to be runnin on the.  This will help distribute the weight of the vehicle across the whole bridge.  We sunk our pilins on each side of the bank, diggin it out with post hole diggers.  The ends of the lengthwise logs spanning the creek started up on the bank, dug in so as to level off, and then crossed the pilins which had a sideways log mounted on top of them.  Everything was dug and chopped out by hand, other than the top floorboards.  Best I remember it would take appx. 3 people and a couple of horses about a week per bridge, not a small undertaking, but a lot of fun.  Yall done brought back some good memories for me and sorry if I'm speaking out of turn here.
Old Age and Treachery will outperform Youth and Inexperence. The thing is, getting older is starting to be painful.