Specifications.pdf

AG-04N7-S-13-0020

Barry Point Suppression Fence

Fremont-Winema National Forest

FENCE SPECIFICATIONS

LET-DOWN UNDER TENSION

1. Clearing

The fence shall be located in the center of the cleared right-of-way. A six foot right-of-way on each side of the fence is to be cleared of logs and trees. All brush on let-down side of fence shall be cleared. Brush on the opposite side shall be cleared adequately to provide a trail way. Limbs shall be removed to a height of 8 feet on trees used as posts in the fence. Limbs and brush removed from the right-of-way shall be scattered off the right-of-way. All stumps on the let-down side shall be cut at ground level straight across and on the right-of-way shall not be higher than 12 inches from the ground. All rocks over 4" diameter shall be cleared from the let-down side of the fence if possible.

2. Hazard Trees

All dead trees within 6 feet of the fenceline will be felled. Any large snags that are likely to fall towards the fenceline must be felled prior to construction of the fence; any tree in question will have to be approved by the Forest Service before leaving it. The felled hazard trees will be bucked up to a distance of 6 ft. on either side of the fence and the material removed from the 6 ft.

right-of-way on each side of the fence. The remainder of the felled hazard trees need not be limbed or bucked.

3. Let-Down Fence Details

3.1 Fastening Wood Stay to Post

The wood stay shall have a wire loop of No. 9 wire or barbless fence wire stapled at the top and loose enough to hold or release from the post. This top loop shall be stapled to the outside of the stay. The bottom loop shall be looped around the post and stapled on the outside of the wood stay.

3.2 Wire Loops

Where steel posts with stays are used, wire loops shall be 7-8 inches in diameter, twisted twice and made from No. 9 wire or barbless fence wire. Where trees or rock jacks are used, the loops shall be secured to the upright of the rock-jack or the wood nailer attached to the tree with enough slack to enable flipping the loop over the wood stay on the fence.

4. Fence Line Location

All fence line locations are flagged ribbon or marked by existing posts. Gate locations are flagged in red polka dot ribbon. Deviations from the flagged line of more than 10 feet will need approval of the COR.

5. Construction

5.1 Line Wires

Three line wires shall be spaced as follows: The bottom wire will be 18 inches from ground level; the next two wires shall be spaced at 11 inch intervals above the bottom wire for a total height not to exceed 40 inches.

5.2 Posts

Construction shall be with 5 1/2 foot steel T-type posts set not more than 16 feet apart (+/- 2 feet), but the spacing may be closer to keep the bottom wire at an acceptable height above the ground line. Live trees or line jacks may be used in lieu of steel posts. If live trees are used, they must be a minimum dbh of 8" and must have a nailer (“scab”) attached as shown in Exhibit No. 6. The outer bark of the tree will be shaved to create a flat nailing surface for the stay, but will not be shaved so much that it cuts into the inner layer of bark. The bottom of the nailer may be touching the ground but will not buried in the soil or shaved bark from the tree. Steel posts shall be driven into the ground, past the top of the flange plate. Posts will be driven with the wire spacers to the outside, so the wire loops will catch between the wire spacers when the fence is standing. Steel posts shall be relieved of upward pull of wires by use of rock anchors and tiedowns. There can be no more than ten steel posts in a line without having a scabbed live tree (8" dbh or larger), line jack, or similar structure.

5.3 Stays

Wire stays shall extend only a few inches below the bottom wire (30" wire stays used). They shall not hit the ground or buckle under pressure. One stay shall be placed evenly between posts along the entire fence. The stays shall be screwed down until the eye is set on the top wire.

5.4 Gates

The locations of the gates will be flagged by the Forest Service. Gates 16 feet in width shall be placed at road crossings. All other gates shall be 14 feet wide. Ends of the gate shall be attached to trees, rock jacks, rock cribs or “H-braces”. Rock cribs will be constructed as shown in Exhibit 2. “H-braces” will be constructed as shown in Exhibit 1, 1a, or 1b. Gates shall be constructed with four wires spaced in accordance with specifications in Exhibit 7.

5.5 Water Gaps

Water gaps shall be constructed at stream crossings in accordance with specs..

5.6 Fastening Barbed Wire to Wood Stays

The barbed wire shall be stapled to the inside of the wood stay and next to the post so when the wood stay is laid down; the wires shall be on the upward side. The wires shall be fastened to the wood stay with 1 3/4 inch staples. See Exhibit 8

5.7 Wire Stretching

Wire will not be tightened excessively. Excessive tension will weaken the barbed wire by removing the capacity for it to stretch. Excessive tension may also pull scabs from tie-trees and make putting the fence in the upright position difficult because the fence is to be built in a slight curve. Location of stretch points will be determined by topography and the availability of tie-trees. Selection of stretch points will provide for a slight curve between them to enable the fence to slacken when let down. The curve can be to the left or to the right, or any combination, while facing the direction of fence construction in order to take advantage of available tree-ties or adjust direction of fence construction.

5.8 Tension Devices

These will be constructed at all stretch points. Sections shall be dead-ended on a 4"x4" or two 2"x4" stays nailed together to tie-trees, rock crib or rock jack as shown in Exhibit 2. The rigging must be assembled so that the fence can be “let down” flat on the ground and not hang up on the upright steel post. Where the pivot point attaches to the anchor, a short span of chain (3-4 links) inserted between the anchor and the tension wires, will help the fence let down smoothly. Care must be taken when stretching the line wires to ensure that the wire loops that attach the dead ended stay to the upright steel post can be flipped over to allow the fence to be let down.

5.9 Splicing

Splices in the wire shall be made by wrapping the ends of the wire back around the wire six times, thereby forming an eye at the end of the wire; the other wire end is then placed through the eye and wrapped back around itself at least three times. All wraps shall lie directly adjacent to each other, thus forming neat, tight wraps. See Exhibit 10

5.10 Rock Jacks

The material should be distributed along the fence line at approximate locations for the jacks. Rock jacks should not be spaced farther than 200 feet apart unless there is a tree-tie, rock crib, or H-brace within this interval. Tree-ties, rock cribs, or H-braces may be substituted for rock jacks. Rock jacks or line jacks will be placed at the top and bottom of all abrupt breaks in the slope. See Exhibit 2

5.11 Trees

Solid live trees over 8 inches dbh may be used in place of posts, provided they are located not over 3 feet out of line. Tree branches shall be removed completely around the fence, to a height of 8 feet. A scab shall be securely nailed, (see Exhibit 6) with 50d or 6" or 8” helix nails to the tree at three points: top, center, and bottom. Nailer shall be pre-drilled to reduce the incidence of splitting.

5.12 H-Braces

“H-Braces” may be used as end points if no tree-ties or rock is available for rock jacks. Posts will be buried a minimum of 3 feet and spaced 8 feet apart. A pressure treated 4"x4" will be used as the cross-piece brace between the posts, 4”x6” in heavy snow zones. This brace will be placed approximately 40" from the ground. Two diagonally placed tension wires of double wrapped 12 1/2 ga smooth two strand wire will be secured at ground level and 48" with pig-tailed ends. This is then tightened with a twitch stick made from a stay until the wire is very tight. The loose end of the twitch stick can be rested against the 4"x4" cross-piece. See Exhibits 1, 1a and 1b

5.13 Stapling

Staples shall be driven at a slant to the grain of the wood to prevent the wood from splitting and will not be driven so deep as to nick the barbed wire. Staples should be driven to contact the barbed wire, but allow slippage of the barbed wire between the barbs. See Exhibit 4

6. Materials

6.1 List of Materials

5 1/2 ft. 133 heavy duty "T" type steel fence posts

12 1/2 gauge galvanized barbed wire, 4” barb spacing, Class 1

12 1/2 gauge galvanized barbless wire, Class 1

1 1/2 hot dipped galvanized staples

6” Nails, ring shank or 60D common bright smooth

8” Nails, ring shank or common bright smooth

Peeler Core or Split Larch wood material for stays

Stays—9 square inch cross section, 4 feet long

Rock Jacks—No climb fence wire and T posts

Figure Four legs—5 1/2 ft. 133 heavy duty "T" type steel fence posts

6"-7" round CCA treated posts for H-braces.

FENCE SPECIFICATIONS FOR 4-WIRE AND 3-WIRE CONSTRUCTION

Fence Line and Gate Location

The layout of the fence will be marked on the ground by the existing fences and/or with flagging. The fences run through mostly dry wooded uplands. Small diameter trees may need to be cleared to construct the fence line. Local Juniper can be used for gate sticks, toggle sticks and rock jacks.

The fence shall be located to the center of the cleared Right-of-Way. Gate locations will be designated by the C.O. or inspector. Wire gates will be installed at all cattleguard locations. The fence shall be kept as straight as possible, following the designated Right-of-Way.

Clearing

It will be the contractors responsibility to cut a 12-foot right-of-way (6’ both sides of the fence) cut as well as an 8-foot height right-of-way (R-O-W). Clear zone is to be reasonably cleared of all brush, saplings, sections of logs, and trees less than 6 inches diameter at breast height (DBH). Live trees to be used for line or corners will be left. Live trees that the fence will be attached to will have the limbs removed to a height of 10 feet. Limbs and brush removed from the Right-of-Way shall be scattered off of the Right-of-Way. Stumps shall not be higher than 4 inches. Slash and brush must be scattered and not pushed out of the Right-of-Way by mechanical means, which results in windrowing against live tree boles. The Contractor shall obtain approval from the Government to cut any additional trees above 7-inch diameter. No live trees or snags larger than 20.9 inch DBH will be approved to be cut unless these trees will fall across the fence in the future. Snags or live trees that are hazards will be marked by the COR and felled by the contractor or Forest Service.

Wires

Line Wire Spacing Four wires spacing shall be spaced as follows: The bottom wire will be 16 inches from ground level, the next wire shall be spaced 24 inches above ground level, the third wire shall be spaced 32 inches above ground level and the top wire shall be spaced 42 inches above ground level, for a total height not exceeding 42 inches. (16, 8, 8, 10) Three wire fence spacing is 18, 11 and 11. Where possible, wires should be placed on the side receiving the heaviest livestock use (outside).

Steel Posts T post will have a spacing of 16 feet (+/- 2 feet) and no more than 18 feet centers. T posts will be driven into the earth to the top of the spade, if in rocky or compacted soil no more than the top 1/4 of the spade can be showing above ground when set.

Securing Wire

Wires shall be secured at all rock cribs, rock jacks, stays, end ties, gate ties, wire wraps, etc. with staples. When tying the barbed wire off at trees, rock jack or gate end piece, the barbed wire shall go twice around the post or stay and be secured back by six tight wraps.

Splicing wire Wire splicing shall be made by wrapping ends of the wire back around the line wire six times, forming an eye at the end of the wire; the other end is then placed through the eye and wrapped back around itself at least six times. See Exhibit 10. All wraps shall lie directly adjacent to each other and excess ends trimmed. No more than 4 splices will be allowed in a quarter mile stretch per wire. If more that 4 splices are necessary the contractor is to contact the C.O.R., or inspector or replace the wire at the contractors expense.

Wire Stretching Barbed wire should be stretched tight and have no visible sag.

Smooth Wire One wrap of No.9 or smooth fence wire shall be twisted tightly around each nail joint in line and gate jacks or other structures. The wire shall then be twisted with pliers at least four times. All No. 9 wire or smooth fence wire ties shall have the ends bent down and into the wooden structure. Excessive ends shall be cut off.

Live Trees Live trees may be substituted for rock jacks. Sound live trees must be at least 8 inches DBH if they are to be used as corner or gate jacks and at least 8 inches DBH if they are used for line jacks.

The trees must not be likely to die within a few years. Trees selected must be located so that the wire will either pull against or brush against the tree [nailer (scab) included]. When a new span is started nailers shall be placed around the tree to prevent wire contact. See exhibit 6a. In all cases, wire will be separated from tree bark by nailers. Remove some bark to provide a good nailing surface. At no time shall the inner bark be removed to cause the tree to bleed.

Rock Jacks The material should be distributed along the fence line at approximate locations for the jacks.

Rock jacks should not be spaced farther than 200 feet apart unless there is a tree-tie, rock crib, or H-brace within this interval. Tree-ties, rock cribs, or H-braces may be substituted for rock jacks.

Rock jacks or line jacks will be placed at the top and bottom of all abrupt breaks in the slope. See Exhibit 2

Corner and Gate Jacks Corner jacks shall be used at all corners, at all fence ends, and both sides of all gates, unless gate is between two trees or a tree is one side of gate. See exhibits 1, 1a, 1b. The jack shall be placed on the side that causes the wire to pull against the jack rather than away from it. Corner jacks are to be used only when trees of desired diameter are not available.

Line Jacks A line jack shall be built or placed at the apex of the vertical angle in the fence, whenever the fence crests topography with breaks of 10 percent or greater (vertical angle). See exhibits 1, 1a, 1b. At no time shall the distance between line jacks exceed 200 feet. At the bottom of the vertical angle, a rock weight (see detailed drawing) may be used, provided the rock weights are tied to the wires to maintain proper spacing between wires and ground. Rock weights (dead man) will not be substituted for line jacks.

Rock Cribs The woven wire (crib wire) will be cut at 10 foot 4 inches long. The crib wire will be spliced together so that the crib wire will become a circle. The crib wire will not be more than 4 feet in height when standing on end. There will be 2 T posts driven together in the center of the crib. 4 T posts driven in each corner of the crib and 4 T posts used for the flooring of the crib. On the outside of the crib there will be 2 T posts (stretch T posts) driven not more than 10 feet from the crib and not less than 6 feet from the crib in the direction of the fence. There will be at least 3 guide wires stretched between the 2 T posts in the direction of the fence. There will be no less than 4 wires of barbed wire stretched between the crib and 2 stretch T posts. The fence will be attached to the 2 stretch T posts. The rock crib will then be filled with rock the size of a baseball and no larger than soccer ball size. See Exhibit 2.

Wood or Metal Stays Wood stays may touch the ground but will not be buried or embedded and will allow fence some limited movement along the ground. Wood stays shall be placed at intervals as shown in the drawings or specifications. All stays shall be placed in the fence so that the wires are at right angles to the stays. Wood stays will be placed and attached between each steel T post, rockjacks, or trees. See Exhibit 3, 3a.

Nailers Only Live Trees will be used for attaching the fence to. Nailer/Scabs shall be required on all trees that the fence is attached. Wire or cable shall not encircle a tree without nailer protection and adequate wood stays to prevent the wire or cable from touching the bark. See exhibit 6.

Water Gaps Water gaps shall be built at stream crossings and draws subject to periodic flooding.

Rock Tie Downs (Dead Man) (See exhibit 11)

Rock tie downs are permissible to maintain proper wire spacing and height. They shall be built of No. 9 or smooth fence wire and placed around the rock weights in two directions to form a cradle. Ties downs shall not be substituted for other structures. Rocks used in weighting shall be in contract with the ground surface when in place. A T post maybe substituted instead of a rock.

The T post will be driven to the earth 2/3rds the length of the T post at a 35 to 45 degree angle to the earth and fence. Then the No. 9 or smooth fence wire will be rapped twice around the T post, the remaining wire will be twisted around the No. 9 or smooth fence wire at least 6 times.

Stapling (See Exhibit 8) Staples shall be driven at a slant to the grain of the wood to prevent the wood from splitting and will not be driven in so deep as to nick the barbed wire. Staples should be driven to contact the barbed wire, but allow for slippage between the barbs.

Gates Gates will be attached to trees or gate jacks or rock cribs at locations designated by the C.O.R.

or inspector. Gates locations will be designated by an orange, red or white painted band on trees.

Gates shall have one wood stay in the center and one wire stay centered between it and the end piece of each side. Wire all stapled stays with No. 9 wire or smooth fence wire. Gates shall not exceed 16 feet in width.

Gate end pieces shall be constructed of 3-inch diameter material. Barbed wire shall be wrapped with two wraps and tied back by four complete wraps onto its self. The wire shall then be secured to the post with one staple.

Wire loops shall be placed on the stand-up end gate. Double wrap twisted No. 9 or smooth fence wire around stays and post. Staple loop on each side of the holding structure. Place one wire loop above bottom wire and one loop below top wire. At the let down end of the gate, which will be opened, make double wrap loops at bottom and top. Staple the loops to the gate jack or other structures.

The gate toggle stick shall be constructed using a ¼ inch chain (to be furnished by contractor) with a 3-foot long flattened peeled pole 2-1/2 to 3 inch diameter or a 3 foot pipe, 1 inch in diameter with 1/8 inch wall thickness. Fasten with one loop of No. 9 or smooth fence wire and staple around anchoring structure and level. This lever should fit snuggly tight, allowing the top double loop to be dropped over the gate end piece. Wire loop shall be separate from the chain binder.

Fence and Gate Materials (See attached exhibits)

Wood Western larch is the preferred material. No limb wood, white fir, or ponderosa pine will be used.

Wood material shall be free from rot. Where applicable wood material shall be placed in the fence with the large end down.

Figure 4’s Where steel T posts can not be driven figure 4’s will be made of steel T posts. The upright T post will be driven as deep as possible and 2 other T posts will be wired to the upright T post to create a figure 4. Any steel T posts that maybe in any of the fences will be reused as figure 4’s.

Fence Removal:

Barbed wire will be removed from all trees whether dead or alive. All fence material will be removed from the barbed wire and placed out side the fence right of way. The barbed wire will be rolled up and it will be the responsibility of the contractor to remove the barbed wire from the forest.