Getting a fence straight

[jcummins]

Below is a layout of a portion of pasture. The black line is a fence along a road. The red line is a fence I want to build. The longer portion is about 2000 feet, the shorter maybe 450 feet. How do I get that point in the middle of the pasture that will give me a straight fence. Where the red meets the black, I have corner post there.

 

[HOSS]

You might try triangulating (sp?) the bottom point by measuring off of the side and bottom fence lines. Then set a post in concrete. I have stretched high tensile as far as 1200 ft but never 2000 but you may try stretching heavy duty high tensile between the two points. As long as it don't touch the ground or anything else it will give you a straight line to set tension posts about every 100 feet. GPS may put you within a few feet but that might as well be miles.

If you can see each fence post from end to end you can use a rifle with a scope. Take an empty rifle and put it on top of one post and align the crosshairs with the post at the far end. Have someone set T-Posts with orange survey tape on top in line with the crosshairs every 100 feet or so. Good luck.

 

[Angus Cowman]

How I do barb wire is to take set my corners and stretch it tight if it touchs the ground I put 3" pvc pipe under it and keep snapping the wire till it lays
I have done this going over hills and uneven terrain and it works the best most of the time the fence will be with in 1 or 2 feet
The only other way I have tried is using a transit and shooting from corner to corner the person carrying the story pole has to carry a level and keep the pole level and I shoot it and they place a flag nail when they get in the right spot

if the ground is level the wire works great

 

[novatech]

A transit is best. You may be able to rent one.They may even a laser which really makes it easy.

 

[Brute 23]

Pathagreom Theorem

Given a right-triangle with side 3, and side 4, the hypotenuse 5.

 

[iowafarmer]

Pathagreom Theorem

Given a right-triangle with side 3, and side 4, the hypotenuse 5.

reworded a^2+b^2=c^2 so 3^2+4^2=5^2

hope that helps if you are doing barb wire the whole length of 2000 ft you should put 3 wood poles in the middle and brace them. Then you split the wire and tie it to the middle post that way you can keep the fence tighter and can tighten one side and not the other.

 

[jcummins]

Pathagreom Theorem

Given a right-triangle with side 3, and side 4, the hypotenuse 5.

reworded a^2+b^2=c^2 so 3^2+4^2=5^2

hope that helps if you are doing barb wire the whole length of 2000 ft you should put 3 wood poles in the middle and brace them. Then you split the wire and tie it to the middle post that way you can keep the fence tighter and can tighten one side and not the other.

I was thinking of three H braces along the 2000 ft...and pull each section separately. I probably will have a gate at the 90 degree turn to the road.

 

[Angus Cowman]

actually if going 2000 ft I would put the braces in the center (I use pipe and pipe corners) and then I would put one single post in between each corner and the center braces if you are on level ground if going up and down hills I would put braces at the low spots and single post at the top of each hill

If using pipe for corner post and braces I wouldn't use less than 3" for post and 2" for cross bracing if using wood I wouldn't use less than 6"

 

[Brute 23]

I mis-understood the question I think.

Do you have only 1 corner set where the black line meets the red?
IF so, go in the field and set one post where you want the two sections of fence (red lines) to meet. Set it good, and tie off a strand of wire (either to the inside or outside of the post) and run it to the other posts already set (where black and red meet). That will give you a straight line to set your other corner posts off of for the H-braces, line posts, t-posts.

OR, If you have H-braces set where the black and red line meet alread....
Then you need to tie off a strand of wire off to each outer corner post, then line the wire up with the edge of thesecond corner post in the H, and take off from each end. Where ever the two wire cross is where your other H-s will be set (where the two red lines meet).

Hopefully that helps, its all about tieing off one wire and getting a stright line to set the corners and line posts.

 

[Jogeephus]

If I understand the question right you are wanting a corner post set in the field any you have corner posts set at the two areas where the red meets the black. If this is the case, I'd use a good compass. If your drawing is true all you are looking for is the point due west of the southern post and due south of the northern post. The compass will get you extremely close. The scope and pythagorean theorem can be used to tweek the inside brace posts.

 

[SRBeef]

Buy or borrow a simple, hand held GPS unit, some batteries and a package of colored marker flags on wire.

Assuming the red line is running straight north south, start at your upper point and walk straight south, keeping the same longitude coordinate all the way, put in a flag every so often and you will have a straight enough N-S line to put posts in.

Go to the bend in the road on the right side of your sketch. Let the GPS stabilize and note the coordinates of that point. Then walk west holding the latitude coordinate constant, putting in a flag every so often.

Where your two flag lines cross is that intersection point and corner of your red lines. It will have the longitude of your first point on top of the red line and the latitude coordinate of the bend on the road.

If you find this point and let the GPS stabilize, you should be within about 10 feet or so of the exact point, depending on how good a gps unit you are using. You can buy a simple Garmin unit at many outdoors stores for not very much money. You don't need one with street maps of France, just a hikers unit with latitude and longitude readouts.

If the red lines are not north/south and east/west it gets a bit more complex - you just need to determine from a map what the latitude and longitude of the intersection point is.

Or just find the red/red corner with this method, put in a good corner and use the wire snap method to get a straight line as suggested above.

I laid out a fenceline through some heavy woods for the dozer and fencing crews with the gps and flag method and it worked well. Good luck.

 

[hillrancher]

A GPS is easy or a transit or laser lever is real cheap that will range for 2500 feet with a compus row on it.

 

[jcummins]

A GPS is easy or a transit or laser lever is real cheap that will range for 2500 feet with a compus row on it.

SRBeef...that sounds like a good idea. My long fence should be real close to true north/south. Some other ideas sound reasonable too. And to clarify.....the point in the middle of the pasture is what I'm trying to determine, and keeping both new fence lines straight. I have good braced corner post to tie to in the black lines.

Hillrancher, by cheap...can you give some links to a laser lever as an example going to 2500 feet.

 

[1982vett]

How important is the accuracy of the fence line. Is it a property boundary or just a partition fence?

 

[grubbie]

Here's how I do it; First of all, H braces every 500 feet. Stretch a wire from corner to corner, then put up a few steel posts in between to hold it up and in place. You can get real close by just "eyeballing" down the fence line and having someone else moving the post back and forth till its in line. (The further back that you stand from your closest corner post while aligning it with the far post, the more accurate you will be.) Just set them in deep enough to stand up incase you double check later and need to move them. Keep in mind you can bend them into line as well if its only a little out of line. These are only temporary. Then use this line to put up H braces and stretch wire between braces for your line. You will be suprised how straight you can get your fence. OR......and I haven't done this because nothing here is flat......go to home depot and spend 30 bucks on a laser level or transit if the land is flat enough.

 

[SRBeef]

Sounds to me that the key is to find that intersection point in the middle of the field. I like GPS because once you have one you will find all sorts of different uses for it.

One thing to keep in mind is that some GPS models will give you areas. This way you can walk or take a 4-wheeler or pu or a horse around the edges of a field, even an irregularly shaped field, and it will give you the field area in sq ft or acres.

Something about the idea of using a GPS receiver on horseback that sounds sort of interesting!

Good luck with your fence project.

 

[dun]

Just move to the Ozarks and you won;t worry about straight fencelines. Anything 3-4 feet on either side of a centerline is considered straight.

 

[V_Key]

Math Way
Site:
http://www.1728.com/trig.htm

Steps:
Rotate Triangle so "A" is on Top and "B" is on the Bottom Right
Set a Transit centered on "A" looking down known Fence Line (Note Angle #1 on Transit)
Swing Transit to view "B" (Note: Angle #2 on Transit)
Subtract #1 and #2 to get Angle "A"
You could also measure the Distance from "A" to "B"
You now know:
2 Angles (1 Angle is 90°) and (1 Angle = "A"), the length of AB

Plug in the numbers Here:
http://www.1728.com/trig.htm

East Way
Pull a long String Down Known Fence Line
Set a Transit at "B"
View "A"
Swing Transit - 360°- (90°+ Angle "A") = Angle "B" Swing Transit and drive a stake at 90° Angle "C" (Transit View and String)