PART 1: MATERIALS SPECIFICATIONS - British Columbia · FOUR STRAND BARBED WIRE FENCE...

G:\!Workgrp\DKARA\Improvements 15740-\Fence Specs\eFS_Barbed_Fence specs 2010.docx 1

Kamloops Forest District FOUR STRAND BARBED WIRE FENCE SPECIFICATIONS

2010/12/6

CONSTRUCTION IS TO BE IN ACCORDANCE WITH THE FOLLOWING AND ATTACHED SPECIFICATIONS AND SKETCHES:

Page PART 1: MATERIALS SPECIFICATIONS_________________________

1.1 Wooden Materials ……………………………………………….2

1.2 Metal Materials ……………………………………………….3

1.3 Visibility Strips ……………………………………………….3

PART 2: FENCE CONSTRUCTION SPECIFICATIONS________________

2.1 Braces ………………………………………………………..……4 ..

2.2 End Braces …………………………………………… ………4/5

2.3 Corner & Change of Direction Braces ……………………….6/7/8

2.4 Line Posts & In-line brace assembly diagram …….………………8

2.5 Line Posts When Crossing Depressions (Using Dip Anchors)……9

2.6 Barbed Wire …………………………………………….………..11

Diagram 9 Staples………………………………………...……………12

2.7 Droppers ……………………………………………………..13

2.8 Slip Wire Gates ………………………………………………14

2.9 Cattle Guards ……………………………………………………..15 PART 3: GENERAL SPECIFICATIONS___________________________

3.1 Stream Crossings …………………………………………… 15

3.2 Fence Right of Way Clearing ………………………………. 15

3.3 Ground Disturbance ……………………………………… 16

3.4 Seeding …………………………………………………… 16

3.5 Use of Trees …………………………………………………… 16

3.6 Removal of Garbage ……………………………………… 16

3.7 Fires ………………………………………………………… 16

3.8 Procedure to Modify or damage a fence 16 3.9 Wire Tension measuring device………………………………….. 17

Recommended Contract Clauses………………………..…………….17


PART 1: MATERIALS SPECIFICATIONS_________________________ • Materials and or fence components may be sampled and items failing to meet specifications

will be required to be removed and replaced 1.1 Wooden Materials • All wooden materials are to be pressure treated to CSA standard # 080.5 for posts (An average net retention of 6.4 kg/m3 [0.40 pcf] by assay of chromated copper arsenate) Presently three suppliers meet our requirements for treatment of wood fence materials. They are Paxton Forest Products Inc., Kamwood Products Ltd. and Princeton Wood Preservers Ltd. Materials from other plants that treat wood fence products with preservatives must meet the above requirements for treatment and be pre-approved by the Contract Officer.

• This includes gate stakes, posts, all rails, 'A' frame members, droppers and twist sticks

• Any cut ends or edges will be brush treated with preservative on site

• Heartwood posts and rails are not acceptable Line & Brace Posts • Type -Pine posts

-treated -pointed & domed

• Size -line posts 4-5 inch x 7 feet long – 6 foot long where required by contract officer -‘A’ frame members and gate stakes 3-4 inch x 7 feet long -brace posts 5-6 inch x 8 feet long Brace Rails • Type -Pine rails

-treated -square ended

• Size -4-5 inch x 10 feet long Twitch Sticks • Type -wooden, treated, paint cut ends with preservative

• Size -minimum 3 inch diameter -length to suit brace Droppers – Wooden • Type -wooden; fir, pine, spruce, hemlock -square droppers only -without weakening knots or other flaws -cedar may be used, but see note on attachment about stapling

• Size -minimum 1 ½ inch x 1 ½ inch, (maximum of 2 x 3 inch) x 36 inch long • Treatment -all droppers square and round to be pressure treated as above (except cedar).


1.2 Metal Materials Wire • Type - barbed wire, 4 point barbs

• Size - double strand 12 ½ gauge

• Breaking strength - minimum 950 lbs

• Rust protection - class 3 galvanization

• Dropper wire - soft galvanized 17 gauge (rebar wire not acceptable) Staples for posts • Type -slash point -galvanized -barbed shank

• Size -2 inches long Dip Anchors • Type and size -firm ground 2 inch x 2 inch x 4 feet steel angle iron with sharp point. -soft ground 3 inch x 3 inch x 5 feet steel angle iron with sharp point. Contract officer may accept suitable substitutes. Metal T Posts For use on severe steep ground only as per contract officer instruction – must be

new heavy duty metal T posts > light duty is not acceptable.

1.3 Visibility Strips • 6 inch strips of high visibility plastic e.g.” Vexar” fence.

• To be attached with aluminum hog rings to the top wire every 2 feet. • Rails may be required as directed by contract officer - Rails to be 3 inch – 4 inch x 12 foot

treated.

• Locations of rails as required by the Contract Officer. PART 2: FENCE CONSTRUCTION SPECIFICATIONS________________ 2.1 Braces • Strong corners and braces are the essential foundation of a barbed wire fence. Corners shall

be constructed wherever there is a change in direction.

• Between corners the fence shall be built in a straight line.

• All corner and brace posts shall be driven to a minimum 3 ½ foot depth.

• As long as the ground continues to accept the post relatively easily, the post will be driven until 46 inches remains aboveground.

• A tie point is needed a maximum of every 400 m of the line wires. • This then dictates the spacing of braces, whether end braces (see below) or corner braces (see

section 2.3, page 6).


2.2 End Braces

Diagram # 1 TWO-POST END BRACE • A two-post brace will be constructed at end of fence sections, such as at gates, etc and at

tensioning points. Post 8 foot 5-6 inches dia. Rail 10 foot 4-5 inches dia.

• Maximum 10’ between vertical posts. Minimum length for rails 9’ 8” for adjustment

between posts – cut end to be painted with preservative. • Compression (horizontal) brace rail shall be 10 feet in length on each side of the corner with

a minimum diameter of 4", shall be pressure treated, and shall be secured with 10" Ardox nails (or 3/8” rebar) through drilled holes in both the two posts and the rail. Split rails are not acceptable and must be replaced if splitting occurs.

• Rails shall be installed at a height that is between the top two wires (approx 37” from ground).

• Diagonal brace wire shall be 2 strands of 12 gauge high tensile galvanized wire, and shall be held in place by the head of the Ardox brace nail (top end) and staples (bottom end).

• The wires will be located 8 inches from the ground at the bottom end.

• All wire tie off must include a double wrap. • The wire shall be tensioned by twisting with a 'Twitch stick' which shall be wired to the

horizontal brace. • All brace assemblies shall be constructed with posts perpendicular to the ground (i.e.

following slope). • Do not leave nails/rebar or wire ends projecting in a dangerous manner. BRACE WIRE

NAIL


Diagram #2 END BRACES AT EDGE OF GULLIES OR CREEKS • At edges of large gullies or creeks the fences from both sides will be tied off at end braces,

and a separate section built through the gully or across the creek.

• At very sharp, short, stable gully, the fence may go straight across without end bracing, provided the span does not exceed 40 feet.

• An ‘under fence’ then may be built through the gully.

• See section 2.5 page 9 and Diagram 7, page 10, for anchor installation.


2.3 Corner & Change of Direction Braces

• Corners will be placed so there is at least 6 feet clear on both sides of the fence to allow sufficient room to drive cattle down one side and operate a quad for maintenance on the other side of the fence.

• If corner post is in a moisture receiving area, two dip anchors will be used. The 3 or 4 post corner must be used on all corners with a change of direction of 20 degrees to 90 degrees. See next page for braces on change of directions less than 20 degrees. Diagram #3a 4-POST CORNER BRACE • Use a 4 post corner on change of direction of 20 to 90 degrees. • These changes of directions are often called “dog legs”. • Each fence section of a 4-post corner brace acts independently of the other. • Tie slack wire between the two end posts to close this space.

Diagram #3b 3-POST CORNER BRACE ( Only for 90 Deg. Corners)

• A 3 post corner must have wires tied off on the corner post Tie –off for each strand must be a double wrap. \


Diagram #3c INSIDE BRACES (for changes up to 20 degrees) • A bisecting post corner (Inside brace) may be used where the change of direction is less

than 20 degrees. The location of the brace will split the angle evenly. • This assembly uses 2 - 7 foot posts 4-5 inches diameter and one, 6’minimum, 4-5 inch top

rail

• The bisecting post corners must be protected from cattle rubbing damage to brace by: • a) normal spec fencing behind brace, or, • b) by 4 inch pressure treated rails drilled, nailed, and wired under the brace rail Note: a supply of longer rails will be required for this.

• Wire will not be tied off on a bisecting brace.

• Use adequate slider staples when wrapping around corners (Diagram # 8, page 11).

• Barbed wire may be substituted for lower non-supporting rails (top rail remains as part of structure).

2- 7’ posts 4-5” and 6’ top rails 4-5” ”

∗ One centrally placed rail between top rail and ground is acceptable.

Option #1 BISECTING CORNER LESS THAN 20°


2.4 Line Posts • Posts will be spaced at all significant dips and rises so as to ensure that the bottom wire

between the posts shall remain 16 inches above the ground, plus or minus 2 inches.

• The maximum distance between line posts is 18 feet.

• Top of posts will be approximately 46 inches above ground.

• Use adequate guide pins to start post holes; add water if required.

• Tops of posts shall not be cut off.

• Mushroomed, shattered, split and broken posts are not acceptable.

• Wire shall be tensioned every 400 metres at an inline brace. Wire must be tied off at this point with a double wrap on each post.

Diagram #4 IN-LINE BRACE

Diagram #5 POSTS TO BE PERPENDICULAR TO GROUND


• Posts will be aligned perpendicular to surface of the ground

Diagram #6 “A” FRAME CONSTRUCTION • "A" Frames shall be constructed of posts where it is impossible to set a post. • “A” Frames must be stable weight (ie. Rocks) may need to be added to the “A” Frames

• If a succession of “A” Frames must be used, they may need to be anchored with steel posts.

• All crossing points of posts must be nailed and wired off.

2.5 Line Posts When Crossing Depressions (Using Dip Anchors) Due to the amount of tension on fence wire, when a post is set on ground lower than its 2 neighbouring posts, an upward force is exerted. When the soil is moist in the spring the post may pull out. • On firm soil with a dip elevation of 1 foot (i.e., 1 foot below a line between the tops of the

adjoining 2 posts) use a 5-6 inch x 8 foot post set 3 ½ feet deep.


• If there is any chance that the soil may saturate in the spring, add an anchor.

• On firm soil with a dip elevation of 1 to 3 feet, use a 5-6 inch x 8 foot post and one anchor.

• If the soil may saturate, use 2 dip anchors.

• On dips greater than 3 feet, use a 5-6 inch x 8 foot post and 2 dip anchors.

• Double staple or “bench” staple line wires (see Diagram # 8 on page 11), as necessary to prevent staple failure or wire breakage.

The above requirements may be varied by the contract officer, as warranted. Diagram #7 DIP ANCHOR • Driven at 45o in line with fence, and nailed to post with 6 inch galvanized Ardox nail.

• Use the 2 x 2 x inch x 4 foot anchor in normal upland soil.

• On organic or other soft soil use the 3 inch x 3 inch x 5 foot anchor. Do not leave sharp ends of anchors exposed as a dangerous projection. Wood line posts are acceptable as anchors with any cut end to be treated with preservative.

2.6 Barbed Wire


• Spacing on posts from ground level are 16-18 inches, 23 inches, 32 inches and 42 inches, as shown in Diagram #1, page 4.

• Height of the top wire is not to exceed 42 inches.

• Between posts, bottom wire must remain 16 inches +/- 2 inches from the ground; adjust post spacing to achieve this.

• Wire shall be stapled to posts with approved staples.

• Staples shall be placed diagonally to the posts (Diagram # 9, page 12).

• When tying off, the wire shall be wrapped twice around the post and the tail neatly wound back (Diagram #8, below).

• Two strand barbed wire shall be pretensioned to 600 lbs, and then released to 250 lbs. to set the two strands tightly together so the wire will act as a single strand of wire.

• This will ensure that wire tension will remain and not become inadequate after the first year or two.

• Wire shall be tensioned every 400 metres at inline brace. Wire must be tied off at this point.

• See section 3.9, page 17 for a simple device for measuring tension. Diagram #8 JOINING AND TYING OFF FENCE WIRE • Commonly used knots for low tensile barbed wire are shown below.

• Knots are effective to +/- 80% of wire strength.

• The “Gripple” mechanical splice provides 100% wire strength.

Illustration shows single wrap but must be double wrapped.


2.7 Droppers • 2 droppers per 18 foot panel will be attached as follows: • Attachment Options:

1. stapled with 1 1/2 inch barbed galvanized staples on each wire or, 2. kiwi stapler (barbed staples only) may be used if approved in writing by Contract Officer – providing staples are “flush” with the wire but not kinking, and tied with ‘soft’ galvanized 17 gauge wire to the top and bottom wire, as per diagram in Section 2.7. 3. Tied off with galvanized concrete wire ties on each wire.

Air staples are not acceptable.

• Maximum space between droppers is 8 feet.

• Droppers are not to touch the ground.

• Droppers should not move after attached to wire. START WRAP TWIST TIE


2.8 Slip Wire Gates • Gate compression brace shall be same specifications as an end brace (Diagram #1, page 4).

Barbed wire slip wire gate construction shall be as illustrated below.

• TY-TEN gate closures (or similar type) will be used on all gates.

• The standard width will be 16 feet, with 4-5 droppers wired in and stapled, with 2-3 inch treated posts at each end of gate, unless otherwise directed by the contract officer.

• On main cattle drive routes, gates will be 20 feet wide. • Height of gate is to be same as fence wire height.

• Wire at end braces must be double wrapped. (not shown in diagram)

2”-4” post 2”-4” POST


2.9 Cattle Guards • Cattle guards will be installed 5 inches above the level of the road, and the back-fill firmly

tamped with the machine bucket, but left 2 inches above the level of the guard.

• The guard will have a 3 foot pit under it, measured from the top of the grid.

• Each side of the guard will be finished with a 5-6 inch x 8 foot posts at each comer, and with three, 4 inch rails between. Do not narrow the running surface of the guard, but do not leave an apparent pathway along the guard.

• A gate shall be beside each guard, (unless terrain dictates that it be away from the gate), and may be attached to one of the cattle guard posts.

• Winter roads: where regular snowplowing is to occur across cattle-guards, one post mounted on the middle of each side (end) in a welded 5” bracket to allow a post to be set upright into the guard and removed in the fall for snow plowing is allowed.

PART 3: GENERAL SPECIFICATIONS___________________________

3.1 Stream Crossings • Operations will be conducted in such a manner that they protect stream banks and minimize

damage to understory vegetation 3.2 Fence Right of Way Clearing • Removal of live, healthy, merchantable trees will be minimized. The right of way may be

'thinned' to allow machine access and fence alignment. Brush, small trees and deadfall will be removed for 10 feet on either side of wire.

• Dead, defective or leaning trees likely to fall across the fence shall be felled after consultation with the Forest Officer. All branches shall be lopped from the tops of all felled trees, and the remainder of the tree bucked into lengths so each section of the tree makes contact with the ground. In areas where Spruce or Douglas fir bark beetle infestations are endemic and it is necessary to cut live Douglas fir or spruce trees over 20 cm in diameter that cannot be removed; the trees shall be bucked to 30 cm blocks which must be scattered on the ground in order that habitat for bark beetles is destroyed. All disposal shall be to the satisfaction of the Forest Officer. In areas of epidemic bark beetle infestations the Forest Officer may prescribe additional treatments.

• Trees, mud, or any substances likely to cause pollution shall not be deposited in any stream channel nor shall any damage be done within the high water level of any stream channel. Corduroy will be used in wet areas or where approved for small stream crossings.

• Sale or disposal of merchantable trees from the R.O.W. will be as agreed to with the contract officer.


3.3 Ground Disturbance • Ground disturbance shall be minimized. • No dirt is to be moved without contract officer approval. 3.4 Seeding • Any soil that is disturbed will be seeded with a seed mix approved by the contract officer. 3.5 Use of Trees • In general, wire is not to be fastened to trees. However, the contract officer may authorize

the use of a few trees as posts or corner braces in unusual circumstances, as in crossing rocky knolls, swampy areas, or as tie offs when posts cannot be driven securely.

• Nailers shall be used to fasten wire to trees to prevent wire from becoming ingrown into trees. A nailer shall be a treated post or a treated 2 inch x 4 inch fastened to a tree with 10" common nails through drilled holes. Some heavy bark may be removed prior to setting nailer boards.

• Nailers should be also used if wire is to be wrapped around a tree to prevent ‘choking’ or eventually killing the tree. Use five or more nailers spaced around the tree. Leave 2” to 3" of nail for tree growth.

3.6 Removal of Garbage • Any garbage, including pieces of wire, staples, treated or sawed wood, bundle straps, boxes,

etc. will be removed from site and properly disposed of. 3.7 Fires • It is the contractor’s responsibility to be adequately equipped to extinguish any fires that may

be started by the fence crew or machinery. • The degree of equipment necessary will depend on hazard ratings. 3.8 Procedure for damaging or breaching a fence Pre-planning is critical to minimizing damage to a fence. Where possible align a cut block boundary to incorporate the fence into the block or completely out of the block. Road crossing or skid trails should be planned to use an existing gate or short fence section. Prior to damaging or breeching a fence check with the rancher to eliminate, to the best of your ability, having livestock escape from their current pasture during active harvesting operations. All damage to range developments must be fixed to the same condition or better than it was prior to the damage and follow these fence specifications or to the satisfaction of the forest officer. Prior to breaching a fence, establish a two-post end brace (diagram #1) in the fence line on each edge of the intended breach. Secure the wire to each newly constructed brace, and only then remove from between the two braces. If cattle are in the pasture on either side of the breached fence a cattle guard must be temporarily installed or if a road is planned permanently installed. Once a logging operation is complete the breach must be permanently closed by constructing a fence to the same condition or better as before and follow the Kamloops Forest District fence specifications with respect to material and post spacing. All breaches that involve a gate or cattle guard, must have both items installed to district specifications. It is important to track all damages made to a range development and repair work and be prepared to submit them to a forest officer if requested.


3.9 Wire Tension Measurement • A wire tension measuring device can be used to confirm fence wire tension, as shown below.

Recommended Tender Clauses • A description of the machinery, with pictures, and a profile of the crew experience, that

would be used on this project, must accompany the tender.

• Post driving systems will be able to set 5-6 inch by 8 feet posts to depth of 3 ½ feet in glacial till.

• Preference may be given to contractors with vibrating post drivers mounted on a skidder or heavy 4 wheel drive tractor, or tracked machine where ground damage is not a problem.

• The lowest bidder may not necessarily be granted the contract. Suitability for this particular project will be considered.

• The successful bidder and the contract officer will go over the project in detail before construction commences.

PART 1: MATERIALS SPECIFICATIONS - British Columbia · FOUR STRAND BARBED WIRE FENCE...

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