Wire Fence for Livestock

7/28/2019 Wire Fence for Livestock

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Agriculture1+1 CanadaPublication1848lE

Wire fences for livestockmanagement


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Wire fences for livestockmanagementD.A. QuintonResearch StationKamloops, B . C .

Cover illustrationFive-wire range fence

Agriculture Canada Publication 1848lEavailable fromComm unications Branch, Agriculture CanadaOttawa KIA OC7OMinister ofsu pp ly and Services Canada 19 90Cat. No. A53-184811990E ISBN 0-662-17718-5Printed 1990 3.5-09:90f iga lement di sponible en fr an ~a i sous le titreClBtures de fils pour la conduite d u betail


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CONTENTS

Introduction 6Fence components 6Braces 7Posts 7Wire 8Fasteners 8Droppers 8Basic principles 8Post spacing 8Wire properties 9Elasticity 9Stapling 9Temperature 10Brace assemblies 11Fence materials 12Wooden posts 12Types of droppers 15Types of wire 16Types of fasteners 17Staples 17Dowel pins and spikes 17End-post fasteners 17Wire splicers 19In-line strainers and tension springs 20Tools 21Special tools 21Common tools 23Planning the fence 23Boundaries 23Laws 25Hazards 25Terrain 25Soils 25Performance 25Location 25Preplan 26Specifications 26Four-wire barbed-wire range fence 26Five-wire range fence 27


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Six-wire high-tensile livestock fence 28Eight-wire high-tensile livestock fence 28Ten-wire high-tensile livestock fence 29Ten-wire high-tensile cattle feedlot fence 29Twelve-wire high-tensile horse fence 30Layingout 31Across level ter rain 31Over uneven terrain 31Around curves 31Construction 33Clearing the line 33Placing end, corner, and gate posts 33Stringing the guide wire 34Constructing brace assemblies 37Driving line posts 42Stringing line wires 43Tensioning line wires 45Stapling 45Install ing droppers 48Gates 49Safety 50Acknowledgments 52


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INTRODUCTION

Fences are a vital part of livestock and forage managementsystems. Although they are mainly used to confine or exclude variouskinds and sizes of livestock, fences also influence animal movementsand behavior. Without good fences there would be no protection forcrops, no control over breeding, feeding, or safety of livestock, and noestablished boundaries for rangeland.Originally, fences consisted of stone walls or barriers of logs orstumps placed around highly productive fields and buildings forprotection. Fencing then evolved into a management tool used toobtain more benefit from less-productive lands. It s fir st practical useon an extensive scale came with th e introduction of barbed wire in t helat e 19th century and the introduction of woven wire a few years lat er.After the introduction of cheap wire, the re was minimal developmentin fencing technology or in understanding of the role of fencecomponents. Posts were spaced one log ap ar t and wires were tightlyattached to them to simulate the rig idit y of logs. Pos ts wereeventually treated to curtail rot and were sharpened and set bypounding rather than by backfilling and tamping, but little elsechanged until recent years.Today's high costs for land, machinery, fertilizer, fuel, feed andfarm materials, and labor have dictated more-efficient use of land.These economic conditions, plus the need to replace many fenceserected with inexpensive labor and materials in the 1940s, haveintensified the need for good, low-cost fences. This need has, in tur n,led to research to identify what constitutes good fences and fencingmethods. This research has led to the use of high-tension (136-kgstress) fences constructed of either barbed wire or smooth, high-tensi lewire and to electrification of the lat ter . The best fence is the lowest-cost fence th at will do the required job over the longest time.

F E N C E C O M P O N E N T SThe basis of a modern fence is a pair of anchors termed braceassemblies, between which wires ar e strung . Posts are set in l inebetween the brace assemblies to maintai n wire spacing and to supportthe wires. The wires are loosely attached to the posts with staples.Wire spacing is further stabilized by the attachment of droppers or

stays. All these components act together a s a unit in which resilientmaterials, correct anchoring, and a good right-of-way a re exploited toproduce an economical and effective fence.


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BRACESTo unders ta nd fence function and performance, i t is necessary toknow th e forces placed on a fence. Most 12-112 gage wire used todayhas a b reak ing s t reng th of 450 kg fo r barbed wire an d 590 kg fo rs mo o th (h ig h - t en s i l e ) w i r e . A b r a c e a s s e m b l y w i t h f i v e w i r e satta che d, each t ightened to 136 kg tens ion will th us have to hold a

susta ine d force load of 680 kg. As the an chors for the fence and thecomponent g iving i t s trength , the brace assemblies must withs tandthe tensioned force of the wires plus any additional forces up to thepoint a t which the wires break.POSTS

Pos ts and the i r se t t ing a re the mos t expens ive i tems in fenceconstru ction. There fore, the fewer posts required, the less expensive afence will be. The pr imary functions of l ine posts ar e to m aint ainproper wire spacing, to absorb some of the weight of the wire, toprevent overturning, and to add vis ib il i ty to the fence; they are notrequired to add appreciable s trengt h or r ig id ity to the fence. Th us l ineposts can be spaced a t in tervals f rom 1 0 to 30 m ap art . The actual postspacing is dependent upon th e terr ain and th e purpose of the fence.Research has shown that fencing cos ts are not appreciably reducedwith post spac ings g rea te r tha n 18 m (Fig . 1).

Post spacing (m)Fig. 1 Post spacing versus fence costs.


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WIREFence wire is a restraining tool that plugs the holes between postsand brace assemblies. High-tension wire should be sufficiently elasticto withstand applied stress forces and should be galvanized to re tardrus t. Barbed wire must be prestressed to 270 kg to straighten t hetwists before it will behave elastically to applied forces. High-tensile

wire, being a single strand, does not need prestressing. Wire should beattached firmly to brace assemblies a t a standard tension of 136 kg at0C or equivalent.The barbs on wire ar e essentially a holdover from the days of low-tensile strength wire when i t was believed th at t hey were a nimportant deterrent to animals. Research has shown that the elastic,unified performance of modern fence designs is a more effectivedeterrent. A panel of wire fence, cross braced with droppers, moveswith the animal challenging it, yet does not allow the wires to bespread and the fence breached.

F A S T E N E R SStaples or fasteners are the means by which wire is attached tobrace assemblies and the means by which wire spacing is maintainedon line posts. A flat surface on either leg of the s taple ac ts as a wedgeand guides the path of each leg through the wood. Being spacing toolsrather than attaching tools, staples should not be driven tightlyagainst the wire on line posts. Leaving a space between the staplecrown and the wire on line posts allows the wire to slide between thestaple and the post. This allows for expression of elastic action of thewire and distributes stress loads over the entire length of the wire.Conversely, driving staples tightly against the wire on line postsresults in short, independent, more rigid lengths of fence that will

stretch or break under stress loads.D R O P P E R S

Droppers, or stays , ar e used both to maint ain wire spac ingbetween posts and to give visibility to the fence. They also function indist ributing stress forces over all the fence wires. Droppers should beinexpensive, easily attached, and strong enough to resist bending orbreaking un+r stress loads.

B A S I C P R I N C I P L E SP O S T S P A C I N G

Common practice and belief is that fence posts must be closetogether with wire tightly attached to them to make a strong fence.


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However, with tensioned wire, the reverse is true. When an impactforce is applied to a fence wire, the lateral forces acting on the postslessen as distance between them increase (Fig. 2).

Fig. 2 Effect of post spacing on lateral loads applied to a fence.Thus, closely spaced posts absorb more of the force of an impact onthe wires and the chance of post failure, by breaking or overturning,increases. If the staples holding the wires have been driven tightlyagainst the wire, the problem is compounded. These short spansbehave as individual fences and a re required to absorb the total stressload applied to them, greatly increasing the chance of failure of bothposts and wires.

W I R E P R O P E R T I E SElasticity

Pretensioned (straightened) barbed wire and high-tens ile steelwire elongate a t a ra te proportional to an applied tension, up to theelastic limit or yield point of the wire. The stress-strain relationshipis approximately linear to the yield point, which is about 80% of thebreaking strength of the wire. A wire subjected to a tension less thanthe yield point will return to its original length when tension isremoved. However, if the tension exceeds the yield point, the wire willstretch permanently.

StaplingDriving staples tightly against the wire on line posts interfereswith the wire's elasticity and reduces the wire's tolerance to impacts.Little force is required to deflect such rigid wires and even small forcesresult in the generation of large wire tensions in short spans of fence.


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However , i f the s tap les a re no t d r iven t igh t ly aga ins t the wi re thedef lec tion caused by a n impac t i s d i s tr ibu ted over a g rea te r l eng th o fwi re and the e longat ion per met re of wi re i s t iny . As a r e s u l t , am i n i m a l in c rea se i n w i r e t ens io n i s g en e ra t ed . To i l l u s t r a t e t h i sprinciple c onsider th e following:post sp acin gs of 6 me l on g a ti o n r a t e p e r m e t r e of w i re of 0 .9 3 m d 1 0 0 k gorig inal w ire tens ion of 136 kgbrace a ssembl ies (w i re a t t ache d t igh t ly ) spaced 200 m a p a r t .Condition 1 Stap les a r e d r iven to ho ld w i re t igh t ly to l ine pos ts a nd aforce sufficient to deflect a wire 30 cm is appl ied .So lv ing the t r i ang le , the resu l ta n t e longa t ion in the w i re i s then30 mm over the 6 -m wi re o r 5 mm per each m et re o f wi re . Becausewi re e longa tes a t 0 .93 mrn tm for each 100 kg app l ied , an e longa t ion of5 m d m es u l t s i n an i n crea s e i n ten si o n of ab o u t 5 3 8 k g. B ecaus e t h ewi re w as o r ig ina l ly t igh tened to 136 kg t ens ion , th i s increase wou ldexceed the tens i l e s t ren gth of the wire . If the s tap les and posts hold ,the wi re wou ld b reak . Otherwise , pos t s wou ld pu l l loose , s t a p le swould pull out , and the wire would s t re tch perma nent ly .Condition 2 Stap les a r e d r iven to al low w i re movement be tween postan d crown of s tap le and a force suff ic ient to deflect a wire 30 cm isappl ied .So lv ing th i s t r i ang le , the resu l tan t e longa t ion in the w i re i s then30 m m spread over 200 m o f wi re o r 0 .15 m m per each m et re of w i re .Because wire elongates at 0.93 mm lm for e ach 100 kg of load ap pl ied ,a n e l o ng a ti o n of 0 . 1 5 m m / m re s u l t s i n ab o u t a 1 6 - k g i n c r e a s e i ntens ion.Th is increase , added to the orig inal tens ion (136 kg + 16 kg) , i swel l wi th in th e elas t ic l im it of the w ire . Th e wire would withhold theforce ( t u r n t h e an i m a l ) an d r e t u rn t o i t s o r ig i n a l len g t h an d t en s io nwhen th e force was removed. The re would be no damag e to the fence.Remember-when the s taples ar e driv en to hold the wire t igh t ly tol ine posts , re lat ive ly sm al l deflect ions (sma l l loads) resu l t in r elat ivelylarge wire tens ions and the y ield point of wire is more l ikely to beexceeded. Th e wi re and fence a r e then more suscep tib le to perma nen td a m a g e , s a gg in g , a n d f a i lu r e .Temperature

Another factor to consider is expansion and contract ion of wirewi t h ch an g i n g t em p e ra t u re s . A 5C change in t empe ra tu re resu l t s i na 5-kg chang e in wire tens ion , independent of length . Th us ei t he rm ak e a l l o wan ces fo r t em p e ra t u re wh en t i g h t en i n g f en ce w i re s , o rincorporate in the fence a me ans by which wire tens ion can be readi lychanged. Recommended wire tens ion is 136 kg a t OC, 12 6 kg a t 10C,116 kg a t 20C, and so on .


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BRACE ASSEMBLIESBraces a re the anchors fo r the fence wi re so mu s t be a s squa re anda s s t r on g a s p oss ib le . P l ac e b r ac e a s s e m b l ie s a s f a r a p a r t a s t h ete r ra i n wi ll a l low, up to a ma x imu m sepa ra t ion of 400 m .B r a c e po s t s g e n e r a l l y r o t a t e on t h e i r a x i s i n s h i f t i n g t oequ i l ib r ium when tens ion is a p p l i e d a n d b r a c e c o m p o n e n t s c o m e

under compress ion . On ly 25 mm of such movement ca n reduce t ens ionby ha l f in a 100-m span . Th us a tension of 45 kg i n a 100-m fence i sreduced to 23 kg . However, the sam e movement (25 mm ) in a 200-mfence only reduces the tens ion by one- qua rter from 45 kg to 34 kg.Te s t r e s u l t s of t h e fo rce a t f a i l u r e of s ev e ra l t y p es of b rac eassembl ies (F ig . 3 ) a re g iven in Tab le 1. Because a l l doub le b raceassem blies tes ted were s t r ong enough to withs tan d forces suff ic ient tob re ak the fence wi res , type 3 was se lec ted as the s tan dar d fo r end an dco rn e r b race s. Th i s b race i s e a s y t o b u il d , co m p e n s a t e s fo r l e s s -exac t ing workmansh ip , an d is aes the t i ca l ly p leasing . Wh ere a s ingleb race is desired , a type 4 brace wou ld g ive su f fi c ien t s t ren g th bu t mu s tbe b ui l t to exac t ing specif ications .Table 1 Strength of brace assemblies at failure using posts215 cm x 127 mm driven 76 cm-- ingle braces Double brace sBrace Deflection Load a t Deflection Load a ttype a t 680 k g f a i l u r e a t 6 8 0 k g f a i l u r e(m m ) (k g ) (m m ) (k g )


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Fig. 3 Types of brace assemblies tested.

F E N C E M A T E R IA L SWOODEN POSTS

The most suitable material for high-tension and high-tensile fenceconstruction is wood-specifically, sharpened round wooden posts thatcan be driven into the ground and that have been chemically treatedto resis t rot. Softwood posts, such a s pine, absorb chem icals well, are


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l igh t in we ight , a r e fa i r ly s t rong and inexpensive , and have a long li feexpectancy.P r e s s u r e - tr e a t e d pos t s a r e r e l a t i ve l y s t r a i gh t a nd a r e s ha r pe ne dto fac i l it a t e dr iv ing . Pos t s va ry i n d iam ete r f rom end to end a nd f rompos t to pos t. A l l d iame te rs speci fi ed in th i s publi ca tion a re m in imu mrecomm enda t ions and re fe r to th e sm al les t end of the post .P o s ts , t r e a t e d t o r e s i s t w e a t h e r , ro t , fi r e, a n d t e r m i t e s , a r ea v a il ab l e. P r o p e r l y t r e a t e d u n d e r p r e s s u r e , t h e y w i ll l a s t u p to4 0 y e a r s . A v oi d p o s ts t h a t h a v e b e e n d ip p e d , s o a k e d , o r h a dprese rv a t ive brushed on them. Such pos t s may be inexpens ive , bu tthey a re poor va lue . They wi l l l a s t on ly a re l a t ive ly sh or t t im e beforethey wi ll need rep lacement . Pos t s used in brace as sembl ies mus t bes t ron g enough to wi ths tand the w i re t ens ion of the en t i re fence a s we lla s to absorb impac t s t re s ses wi thout fa i ling . By themse lves , w i res canexe r t forces on en d pos t s th a t exceed 110 0 kg for a 10-wire fence. Linepos t s m us t ca r ry pa r t of the we ight of the wi re and m us t abso rb pa r t ofan y impac t forces ac t in g on the w i re . Tes t re su l t s for pres sure - t rea tedpine pos t s a re g iven in F ig . 4 a n d T a b l e 2.

Fig. 4 Average breaking strengths for qressure-treatedpine posts with loadssteadily applied.

S e v e r a l ty p e s of t r e a t e d p o s t s a r e a v a i l ab l e f r o m r e p u t a b l em a n u f a c t u r e r s . B e f o r e p u r c h a s i n g p o s t s , b u y e r s s h o u l d s a t i s f ythemse lves wi th the qua l i ty of prese rva t ive and m ethods of prese rv ingused. I t is too l a t e t o r e t u r n a n i n f er i o r p r oduc t a ft e r i t ha s be e n i n t heground for 1or 2 ye a r s .P res e rv ing chemica l s can cause reac t ions in people suscept ib le toa l l e rg ies . Us e pro tec t ive fu l l - l ength c lo th ing , g loves, and eye or facesh ie lds when w orking wi th chemica l ly t rea ted pos ts .


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Table 2 Lateral load-bearing capaci t ies of dr iven pos ts

Size Soil(mm)

Depthdriven Force Failure(cm) (kg)

102 Soft clayMedium clayStiff clayVery stiff clay102 Soft clay

Medium clayStiff clayVery stiff clay102 Soft clayMedium clay

Stiff clayVery stiff clay127 Soft clayMedium clayStiff clayVery stiff clay152 Soft clayMedium clayStiff clayVery stiff clay

overturn1overturnleanleanoverturnoverturnleanleanoverturnovert urnleanleanoverturnoverturnleanleanoverturnoverturnoverturnlean

1 Greater than 130-mm lean.

Recommendat ionsPen ta- t rea tedpos t s Pentachlorophenol is a wood preservative used totr ea t softwood posts. The dry chemical is mixed with oil and forcedinto the wood in a pressure chamber. Pentachlorophenol cry sta lsremain in the wood when the pressure is removed. Pen ta- tre ate dposts should either contain a minimum of 4.0 kg of pentachlorophenolper cubic met re of wood or meet CSA Standard 080.5.C C A treated posts Chromated copper arsenate (CCA) dissolved inwater is an excellent preservative for wood posts. After pressuretrea ting , evaporation of the water leaves the sa lt, which is poisonous.to decay fungi and insects , deposited in the wood. These posts ar e dry,do not have an oil residue, and can be painted. They ar e a light greencolor after treatm ent. CCA-treated posts should ei th er contain a


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Fig. 5 ( a )Angle-grooved wood and ( b ) nap-onmetal droppers.

TYPES OFWIREAll wire for high-tension and high-tensile fences should be 12-

1/2 gage, triple-galvanized (Type 111) steel wire. To be safe andfunction properly, barbed wire should have a tensile strength of atleast 4900 kglcmz. High-tensile wire should have a tensile strength ofa t leas t 9800 kg/cm2. Table 3 shows a comparison betweencharacteristics of barbed and high-tensile wire.

Aduantages of high-tensile over barbed wireIt is cheaper than barbed wire (less than half price for equallength).It is easier to string out and handle. All the wires can be strungout and tightened in the same operation because there are nobarbs to tangle with other wires or vegetation. This feature alonecan save walking 9 km for each 1.6 km of five-wire fenceconstructed.It is safer for livestock and wildlife, no barbs to damage hide.It behaves elastically along the ent ire length of wire because thereare no barbs to hang up on staples. Thus i t tolerates greater shockloads.It requires no prestretching to obtain elastic properties.It has a greater tensile strength than barbed wire of the samegage.


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Table 3 Wire specifi cationsBreakingDia- streng th Elastic limit

meterWire type Gage (mm) (kg) (kglcm2) (kg) (kglcm2)Barbed 12-112 2.54 431 4 92 1 399 4 007High-tensiletying 12 2.69 590 10 545 499 8 928High-tensilefence 12-112 2.46 644 1 2 4 4 1 485 10 179Max-ten200'" fence 12-112 2.51 823 16 57 6 735 14 76 0

TYPES OF FASTENERSStaples

It is recommended th at staples (Fig. 6) not be fully driven into lineposts. Thus longer staples ar e needed. These should be 45 mm long,corrosion resistant with opposing slash cut points. Galvanized stapleshave a gre ater holding power than smooth staples . Staples shouldnumber about 60 per 45 0 g.Dowel pins a nd spikes

Dowel pins of varying length or spikes, will be needed forconstructing brace assemblies. Both should be corrosion resi stan t.Spiral spikes will hold better than smooth or coated spikes, but aredifficult to remove.

End-post fas tenersWire may be tied off at end, corner, and gate posts by usingvarious knots. Tests have shown th at these reduce wire strength by40% and are the weakest part of the fence. They are presented here a san alternative to mechanical fasteners.


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Fig. 6 Staple. Fig. 7 Knot For tying off high-tensilewire.

Fig. 8 Oval compression sleeves.

Fig. 10 Figure-eight knot forsplicing high-tensile wire.

Fig. 9 Wirevise for high-tensilewire.

Fig. 11 Reliable Wirelink for high-tensile wire.


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KnotsBarbed wire It is traditional to staple barbed wire tightly to braceand end posts, and to anchor the wire by double wrapping around theend post and fastening along the line wire by tightly twisting aroundthe line wire. This works well if staples are driven snugly against thewire, but not so tightly tha t the wire is weakened or damaged. Inhigh-tension fence, drive the staples on brace and end posts adjacent tothe barbs, where possible, to prevent wire slippage in the direction ofwire pull when the wire puller is released after tightening.High-tensi le wire This wire may a190 be tied off at end or brace postswith a special knot (Fig. 7) after s tapling to brace and end posts. To tiethis knot, allow about 76 cm of wire beyond the end post and wrap thisaround the post from the livestock pressure side. Passing the free endunder the line wire, loop it back over the top of the line wire allowingseveral centimetres of clearance from the post. Pass the free endbetween the loop wire and the post, and pull, snugging the loop tightlyagainst the post. Secure the free end to the line wire with pigtailwraps star ting over the line wire.

Mechan ical fastenersCom pression s leeves These sleeves may be used to tie wire off a t endposts and braces (Fig. 8). Tests show that these fasteners retain 100%of the str en gt h of th e wire when properly ins tall ed. To usecompression sleeves, leave about 60 cm of wire beyond the postBefore stapling, thread two or three oval sleeves onto the wire. Slidethese back beyond the post. Wrap the wire around the post from thelivestock pressure side and thread the free end through thecompression sleeves. Position the sleeves a few centimetres from thepost and double crimp each sleeve with a swager (described under"Tools").Wirevise Another method of secur ing high-tensile wire to end posts iswith a Wirevise (Fig. 9). Drill a 9.5-mm hole through the end posts, atthe desired wire height, a t a slight angle away from the livestock sideof the fence. Thread the wire through both the hole and the Wirevise.Slide the Wirevise forward and embed it into the hole. The Wirevisewill clinch the wire when reverse tension is applied and will be flushwith the post. Cut surplu s wire off flush with the fitti ng. Thisfastener is effective to 100% of the strength of the wire.

W I R E S P L I C E R SWire may be spliced with knots, which are generally effective to60% of the strength of the wire, or with mechanical fasteners.Mechanical fasteners a re effective to 100% of the wire streng th wheninstalled properly.


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12 (a)In-line wire strainer, ( 6 )handle, and ( c ) tension-indicator spring.

All forms of construction require an assortment of tools designeddo specific jobs. Few things are more frust rat ing than not having aa poorly designed tool that does not workIn erec ting high-tension fences the job requires the use ofin special and common tools.

toolsThe following special tools a re shown in Fig. 13:a Wire benders-hand fabricated of metal to work with high-tensile wire. A small pair of vise-grip pliers works well too.b Post-hole auger .c Wire sheaves--constructed of 13-mm plywood, these consist ofaluminum rollers, either adjustable or fixed, and a means oftemporary att achment to line posts. They function in spacingline wires parallel to the ground when placing tension on afence. For high-tensile fences, spikes can replace the rollers, orthe wire can be prestapled because there are no barbs to hangup. A number of these will be needed depending on the t err ain .d Hand swag ers -cr imp ing pliers for compression sleeves. Theseare available commercially or can be fabricated from a pair of450-mm bolt cutters with an 8-mm capacity. Drill a 9.5-mm


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Fig. 13 Special fencing tools.


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hole to crimp a 3.97-mm oval sleeve that accepts barbed wire.Drill a 6.35-mm hole to crimp a 2.38-mm oval sleeve thataccepts high-tensile smooth wire.e Wire pullers-these should have smooth jaws to protect th egalvanized surface if working with high-tensile wire.f Fencing pliers.g Two-person post pounder.h Tensionmetersh l consists of a compression spring installed inside a pipe. Agraduated 8- or 9.5-mm plunger i s attached to pass throughthe spring so a pull on both ends compresses the spring.One spring that works well compresses 15 mm for every45.4 kg of load applied up to 272 kg. Other spr ings willwork as well if calibrated.

h2 consists of a straight piece of 20 X 50 mm board 107 cmlong. Drive two nails on a s tra ight line 102cm apart a t theends of the board. At the middle of the board drive a thirdnail 13 mm below the line joining the end nails. Tension ismeasured by pulling the fence line wire to just touch thecentre nail and multiplying the scale reading by 20.i Wire reel.

Common toolsThe following common tools are shown in Fig. 14:a Notched marking stick.b 25-cm crescent wrench.c 12.7-mm electric drill.d Claw hammer.e Hand brace and 9.5 X 200 mm bit.f Saw.g Plumb bob.h 18-m chain or tape.

PLANNING T H E F E N C EB OUNDARIE S

Whether your fence will divide properties, follow terrain contours,or facilitate cattle movement on your range, you must establishboundaries. It is often advantageous to have a surveyor determineproperty bounds before building perimeter fences. Then, if it isdesirable to fence on contours to facilitate catt le movement, s trike a nagreement between neighbors. Remember, however, that the fencem ay outla st the neighbor.


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Fig. 14 Common fencing tools.


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Check local laws to be certain that the fence you plan will legallyspecifications and requirements. Your district agriculturistable to provide this information.

Locate hazards or constraints such a s bogs, emb ankm ents ,as. Provide special fencing for these are as if necessary.k with electrical, telephone, water, gas, and sewer authorit ies tosible buried lines and easements tha t may exist.

Check your topography. Fencing in hilly areas and on curves canRemember tha t all wires on any fence should be

Check your soil. Soils can greatly affect the materials andof fencing. Generally, however, whether your soil is soft,clay, or is sandy, the best method of sett ing posts isTests have shown tha t the force required to pull a driven10 times greater than that of a post set by digging,ing, and tamping. Driving posts in hard soils may requireto drive the post, but it may be worth thera effort. Similar ly, some situat ions may require a deadman bered in the bottom of a hole to hold a post in place (Table 2).

Consider what you expect of the fence. For example, a fence tha t isning calves or yearlings in a confined pasture . Usu ally ,ter or boundary fences mus t be more secure and versatile thanfences. Perimeter fences must often contain more than onef livestock, protect crops, or tu rn away wildlife. Your plans andof animal behavior will be helpful in designing the fence.

Design fences so they ar e more than dividing barriers. Fences can


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livestock, easy access to water, increased use of forage, and ease ofmovement of livestock and of farm machinery.

P R E P L A NSketch your layout to include everything that can influence

mater ials or construction, such as fence dimensions, corners, angles a tchange of direction, gate locations and widths, and rises and dips.From this sketch, itemize the materials that will be required, such asthe number of posts, amount of wire, staples, fasteners, and otherhardware. Furth er, the costs involved can be estima ted moreaccurately before the job is started.

SPECIFICATIONSHigh-tension fences are versatile and it is possible to select a

design for practically any requirement or set of requirements. Thesefences can be easily modified by adding or removing wires. Smoothhigh-tensile wire fences can also be electrified. Many fences areoverdesigned for their intended purpose. Although these fences mayproduce additional safety, the extra materials and labor involved maynullify any benefit gained. Gates in range and pasture fences areusually of wire and are attached to the end posts. Following arespecifications for several fence designs.

FOUR-WIRE BARBED-WIRE RANGE FENCEThis design is adequate for cattle on range where there is notunusual crowding to force calves aga inst the fence. It allows wildlifeto move freely by crawling under, or jumping the fence. The 101-cmfence is used in areas of high deer traffic. Cattle, particularly bulls,may atte mpt to jump low fences.Height of top wire:Wire spacing from ground up116-cm fence:101-cm fence:End postslength and diameter:driven depth:Brace postslength and diameter:driven depth:Top braceslength and diameter:

38,25,25, and 28 cm38,20,20, and 23 cm


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Line postslength and diameter:driven depth:Post spacings:Droppers:Dropper spacing:Tension per wire:

200 cm X 76 mm76 cm18.5 mmetal snap-on or wood3 mTension barbed wire to 270 kgto remove kinks; then relaxtension and fasten a t 136 kg a t0C or equivalent , to gainelasticity.

WI R E R A N GE F E N C EThe five-wire high-tensile fence is a range fence replacing thebarbed-wire fence. I t is a fence for light livestock pressure.tock pressure.

Height of top wire:Wire spacing from ground upbarbed wire:high-tensile wire:End postslength and diameter:driven depth:Brace posts' length and diameter:driven depth:Top brace

length and diameter:Line postlength and diameter:driven depth:Post spacings:Droppers:

31,20,20,20,and 23 cm40,18,18 ,18, and 20 cm

240 cm X 76 mm76 cmup to 18.5 m.galvanized metal snap-on orwoodDropper spacinglight grazing pressure: 4.6 mmoderate-to-heavy grazingpressure: 3 mTension per wire

barbed wire: Set to 270 kg to remove kinks;then relax tension and fasten at136 kg a t 0C or equivalent togain elasticity.136 kg a t 0C or equivalent.igh-tensile wire:


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SI X - W I R E H I G H - TEN SI LE LI VESTO C K F E N C EThis fence replaces the four- or five-wire barbed-wire fence. It isdesigned primarily for light-to-moderate livestock pressure by largeanimals.Height of top wire:Wire spacing from ground up:End postslength and diameter:driven depth:Brace postslength and diameter:

driven depth:Top braceslength and diameter:Line postslength and diameter(minimum):driven depth:Post spacings:Droppers:

Dropper spacinglight grazing pressure:moderate grazing pressure:Tension per wire:

116 cm33,15 ,15,15,18 , and 20 cm

200 cm X 76 mm76 cmup to 18.5 mgalvanized metal snap-on orwood4.6 m3 m136 kg a t 0Cor equivalent.

EI G H T-W I R E H I G H - TEN SI LE LI V ESTO C K F EN C EThis fence will contain both smal l and large an imals on range andwill discourage some wildlife and dogs.Height of top\Vire spacing wire:: from ground up:End postslength and diameter:driven depth:Brace postslength and diameter:driven depth:Top braceslength and diameter:Line postslength and diameter:driven depth:Post spacings:


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Droppers: galvanized st ee l sn ap -o n orwoodDropper spacinglight grazing: 4.6 mmoderate grazing: 3 mheavy grazing pressure: 1.5 mTension per wire: 136 kg a t 0C or equivalent.

TEN-WIR E HIGH-TENSILE LIVESTOCK FEN CEThis fence can contain most kinds of livestock, can turn awaymany small domestic or wild animals, and may be used to replacewoven wire. It is a deterrent to carnivores, especially if the second,fourth, and top wires are electrified.Height of top wire:Wire spacing from ground up:End postslength and diameter:driven depth:Brace postslength and diameter:driven depth:Top braceslength and diameter:Line postslength and diameter:driven depth:Post spacings:Droppers:Dropper spacinglight pressure:moderate livestock pressure:heavy livestock pressure:Minimum tension per wire:

118cm10, 10, 10, 10, 13, 13, 13, 13, 13 ,and 13 cm

200 cm X 76 mm76 cmup to 18.5mgalvanized steel snap-on orwood4.5 m3 m1.5 m136 kg a t 0C or equivalent.

Caution: Do not use metal droppers on electrified fence.TEN-WIRE HIGH-TENSILE CATTLE FEEDLOT FENCE

This design differs from other high-tensile designs because of theincreased livestock pressure. In this design, posts are either drilled forthe passage of wires or are staggered on alternate sides of the wire iflivestock pressure is likely on both sides of the fence. Gates are ofheavy metal or wood and may or may not be part of a brace assembly.


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Height of top of wire:Wire spacing from ground up:Gate postslength and diameter:driven depth:End postslength and diameter:driven depth:Brace postslength and diameter:driven depth:Top braceslength and diameter:Line postslength and diameter:driven depth:Post spacings:Staples:Tension devices:Wire splices:Tension per wire:

133 cm25, 10, 10,10 ,13 ,13 ,13 , 13, and13 cm

244 cm X 101 mm107 cm3-m centres45 mm galvanized, slash points(not needed if posts are drilled)One in-line wire strainer perwireThree c r imped s l ee ves o rWirelinks136 kg a t 0C or equivalent.

T W E L V E -W I R E H IG H - T E N S I L E H O R S E F E N C EThis fence will secure full-grown horses and foals, while de ter ringsmall animal s. The top and bottom wires can be electrified to

discourage horses from pawing and reaching over the fence.On high fences it may be necessary to drive posts tha t are too longto be driven by a hydraulic ram. In these instances, hand-plant thepost by augering and backfill to a depth that will allow driving withthe ram. Then drive the post to the specified depth.Height of top wire: 146 cmWire spacing from ground up: 10, 10, 10, 10, 13, 13, 13, 13, 13,13,13, and 15cmGate postslength and diameter: 274 cm X 152 mmdriven depth: 122 cmEnd posts

length and diameter: 174 cm X 152 mmdriven depth: 122 cmBrace postslength and diameter: 274 cm X 127 mmdriven depth: 122 cm


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Top braceslength and diameter:Line postslength and diameter:driven depth:Post spacings:Staples:Wire splices:Tension per wire:

244 cm x 101 mm91 cm4.3m centres45 mm galvanized, slash pointsT h r e e c r i m p e d s l e e v e s ,Wirelinks136 kg a t 0C or equivalent.

LAYING O U TA C R O S S L E V E L T E R R A I N

Locate survey pins or stakes at ends of line and stand sightingpoles a few centimetres beyond where the beginning and end of thefence will be. Place one or more intermediate poles and align all polesby sighting over the sta rt ing pole to the end pole (Fig. 15).O V E R U N E V E N T E R R A I N

Rises or dips in the sighting line require the use of specialtechniques. For a rise, set two sight ing poles about 3 m apart at thetop of the rise, so that both can be seen from either end of the fence(Fig. 16). When crossing a dip, place two poles and align these bysighting from the highest point on both sides of the dip (Fig. 17).A R O U N D C U R V E S

Running high-tension wires around curves and corners withoutconstructing brace assemblies is possible, bu t ex tra care is necessary.Measure the exact location of posts and use larger-sized posts asneeded. Drive posts deeper and at a 10-cm lean off vertical toward theoutside of the curve to allow for movement when tension is placed onthe wires. On sharp curves, reduce post spacings and staple all wireson the outside of all posts in curves. The section on "Construction"gives directions on rounding corners.


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Fig. 15 Sighting a fenceline on level terrain.

Fig. 16 Sighting a fenceline over rises.

Fig. 17 Sighting a fenceline through dips.


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CONSTRUCTION

Remove all obstacles that will interfere with fence construction,brush and tall grass. If possible, level the fencerow.ll result in a straighter fence that is easier to maintain.

N G E N D , C O R N ER , A N D G A T E P O S T SEach section of high-tension fence begins and ends at either ant, brace post, or gate post. Thus the location and placement ofe posts are the most important factors in how your fence turns out.

semblies, which must withstand the tension of the wire. Theing these posts is as follows:Select a straight, 244-cm long post of proper diameter. Mark theexact location where it is to be placed and auger a pilot hole 90 cmdeep and smaller in diameter than the post. Auger this hole sothat the top of the post will lean 50 mm off vertical opposite thedirection of pull of the l ine wires (Fig. 18). Posts can be driven insome soils without augering pilot holes.Drive the post to a depth of 122 cm. Some soils may beparticularly loose (such a s bogs) in which case strengthen posts ifpossible by placing deadman anchors (Fig. 19). Each anchor i sconstructed from a short (30-cm) piece of 10 X 10 cm trea ted post.Cut one end of this on a 45" angle and fasten a cable (made from

Direction of pull

18 Proper placement of end posts. Fig. 19 Deadman anchor to preventexcessive twisting of end post.


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twisting wire together) securely to it , about 10 cm back from thediagonal end. Enlarge one side of the bottom of the augered hole,jam the anchor in and pull i t taut, forcing the anchor to a positionparallel to the soil surface. Drive the post past the anchor andattach the cable to the post in the same direction as any twist t ha twill be placed on the post by the line wires.3 . Proceed using steps 1 and 2 until all end posts are driven.

It may be necessary to drive posts that are too long to fit under theram of a post pounder. In these situations, auger a hole and set thepost by backfilling and tamping to depth such that the post can bedriven to the full specified depth using the post pounder.STRINGING THE GUIDE WIRE

Proper st ring ing of the guide wire is the key not only to a s traightfence but also to one tha t ha s all wires parallel to the soil surface. Theprocedure for stringing the wire differs depending on whether thefenceline crosses level or uneven ter ra in or rounds curves.Level terrain1. Either anchor the wire reel or t ie off the free end of the wire on theend post a t the desired height for the bottom wire. If wire is tiedoff, use a portable reel for paying out wire.2. Pay out the wire, using the wire reel to avoid kinking the wire, ina stra igh t line to the fa r end post. Maintain enough tension toprevent loops or recoils of slack wire.3. Proceed about 90 cm past the end post, att ach a wire puller to thefree end of the wire and pull i t up until taut (about 45-kg tension).

Note: It i s desirable tha t wire pullers have smooth jaws to preventdamaging galvanization of the wire.4. Make sure the wire is str aight between the posts. Whip the wireup and down or add more tension to accomplish this .5 . Wrap the wire from the livestock pressure side and secure the wireback onto itself at the premarked height of the bottom wire.Temporarily t ie off with either an end post tie-off knot, a crimpedsleeve, or with a Wirevise (see section on "End-post fasteners").Uneven terrain1. Locate the guide wire by either using the sighting poles or bydriving permanent posts a t the top of rises. If permanent posts areused, take care in post location (use sight ing poles) and in the sizeof post used in relation to its ultimate function as part of thefinished fence.2. Pay out the wire on the livestock pressure side of the fenceline.Attach a wire puller to the wire and tighten the wire to 45 kg. Ifpermanent posts have been driven, use wire sheaves (Fig. 13c) to


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guide the wire. If the sighting poles are used, take care in relationto the terrain. In the case of high points, the wire will rest on theground; it will bridge the dips.3. If wire is on the ground, raise and whip it up and down at thehighest point on each rise to get it straight and touching thesighting poles. Mark locations for driving rise posts.Note: When driving posts, ensure tha t they are 13 mm off t heguide wire to maintain a straight fence.4. Drive rise posts, attach wire sheaves or staple smooth wire atdesired height for bottom wire (see section on "Stapling").5. Near the sighting poles in each dip, mark the locations for dipposts either by using a plumb bob (Fig. 20) if you can reach theguide wire, or by sighting using the sighting poles (Fig. 17).6. Drive a 244-cm post to a depth of 122 cm a t the location of each dippost.7. Reduce the tension on the guide wire sufficient to pull it down tothe bottom wire height on the dip posts. Use wire sheaves orstaple smooth wire to guide the wire. Retighten the wire to 45 kg.Note: An alternate method of handling large dips is to allow thefenceline to bridge the dip permanently (Fig. 21). This practicedoes not necessitate lowering the guide wire into the dip asdiscussed above, nor does it require longer dip posts. Fasten ashort span of fence in the dip to the fenceline posts proper but donot tighten it to 136 kg tension.

CurvesSet line posts in curves before stringing the guide wire using oneof the following techniques.

R o u n d i n g s h a l l o w c u r v e s For change of direction less than20 degrees (Fig. 22), proceed as follows:1. Set two short stakes (A and B) on the fenceline at the beginningand end of the curve.2. Stretch string between stakes A and B.3. Mark the mid point (C') and measure the perpendicular distance towhat would be the fenceline (C) had it continued in a straigh t linefrom stake A.4. a) If the distance in step 3 i s less th an 61 cm, dr ive a244cm X 100 mm post 122 cm deep a t th e point (C) ofintersection with the original fenceline.b) If the distance in step 3 is from 61 cm to 122 cm, drive a

244 cm X 127 mm post a t point C.C) If the distance in step 3 is from 122cm to 178 cm, drive a244 cm X 152 mm post a t point C.Note: Drive the post a t a slant of 10cm off perpendiculartoward the outside of the curve. On fences with less thanseven wires, the diameter of posts can be reduced by 25 mm.


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Fig. 20 Use of plumb bob for locating post position in dips: (a) plumb bob,( b ) ighting pole, and (c) guide wire.

Fig. 21 Bridging a narrow gully with high-tension fence.

BA string C - - - O- -- - - - - - - - - , - O , - - - - - - - - - - - - - - - - - - - -

C

Fig. 22 Rounding a shallow one-post curve.

Rounding a long, gradual curve This technique is a continuation ofthat using one-post to round a shallow curve (Fig. 23). Determine theposition of each post from the previously set curve post and drive each10 cm off the perpendicular to allow for movement when the wires ar etensioned. Posts will be a t A, C, B, D, and so on a s already described.


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a sha rp corner or curve Rounding a sharp corner is similarto rounding a shal low corner or curve , bu t al l posts a r e44 cm X 152 mm and lean 101 mm toward the outside (Fig. 24).educe the post spacing to fit the curve radius. However, do not setss than 122 cm apar t to maintain soil stability.ote: Use caution when tensioning wire around curves to ensure wireespecially barbed wire) does not hang up on the post.

23 Rounding a long, gradual corner or curve.

24 Rounding a sharp corner or curve.

NG BRACE AS S EM BLIESConstruct braces at corners and ends of fences, at gates, and in theine at appreciable changes in slope of the terrain. Space bracesy not more than 400 m apart . Use posts in brace assemblies of


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at least 244 cm X 123 mm and drive them a t least 122 cm deep. Forall diagonals on braces use a t least 12-112 gage wire, double or triplewrapped to prevent breakage. Construct all joints carefully usingeithe r dowel pins or spikes as fasteners. Use dowel pins th at a r ecorrosion res istant and spikes that ar e a t least 8 9 mm longer than thepost diameter. Tighten line wires and fasten them securely to the endpost of the brace so that the pull is through the brace. Then fastenthem snugly to the firs t and second braceposts.Construction details

Shown here are construction details for type 3 braces (Fig. 3).hese braces a re easiest to build (less exacting) and ar e sufficientlystrong for all fences, of 12 or fewer wires, described in this bul letin.owever, where high stress is anticipated and with fences of 7 or morewires, use double brace assemblies for corner assemblies and endUse double braces also either in cases where smalle r posts ar esed, when posts a re not driven a full 122 cm, or in loose or boggy soils.-33 show various brace assemblies.Inside brace assemblies, as shown in Figs. 30, 31, and 32, aresubject to cattle rubbing on them in areas of moderate-to-high ca ttl eressure. Rubbing is undesirable and mu st be considered inon if these braces ar e selected.

ons truction procedureHaving driven the end posts, rise posts, corner posts, and gateosts and strung and tensioned the guide wire, use t he followingct a type 3 brace.

1. Lay a 244cm x 101 mm top brace on the ground parallel to t heguide wire and butt i t against the end post to measure the locationfor driving the first brace post. Holding the guide wire aside, drivethe post 122 cm deep to estab lish a 2.5-cm le an opposite t hedirection of pull of the line wires.Note 1: All post holes may require augering a 7-cm hole 90 cmdeep.Note 2: Allow 25 mm overlap for squar ing of brace posts if spikesar e used.. Again, holding the guide wire aside, measure with the secondhorizontal brace and drive the second brace post without any lean .When the guide wire is released it should just touch the posts.3. If spiking, square the tops by removing not more than 13mm ofwood from the inside top of the brace and end posts and spikethrough th e post into the ends of the horizontal brace.. If using pins, use the following procedure:Measure up 118 cm from the ground on the brace side of the endpost and drill a 9.5-mm hole 51 mm deep para llel to the linewires.


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Fig. 25 Corner brace assembly showing joint detail using pins.

\ 25 rnrn lean no lean

26 Single-span brace assembly.

50rnrnlean

r---- Direction of pull

0 C-L 1 DEnd post Brace posts

3

0

I I Posts driven 122crn I 1I I I II I I I-

ig. 27 DoubIe-span brace assembly.


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Fig. 28 Double brace assembly for rise posts.- ullFig. 29 Double-span dip assembly.

Assembly bisects

Fig. 30 Medium corner brace assembly for change of direction greater than 20'but less than 60'.


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2@0 rn x 100 mm post25-mm lean toward line wires

Posts driven 122 cm

Fig. 31 Medium corner brace assembly (Fig. 30) showing construction.

Fig. 32 Double brace assembly for shallow corner in soft or boggy soils.

Fig. 33 Double brace assembly for angles greater than 60".


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Drive a 9.5 X 100 mm galvanized-steel dowel pin 50 mm deepinto the drilled hole in the end post.Measure up the fi rst brace post 118 cm and drill a 9.5-mm holethrough the post paralle l to the line wires.Drive a 9.5 X 230 mm steel dowel pin thro ugh the post,stopping when the pin emerges flush with the post surface.Mark, drill, and drive the pin in the second brace post similar tothe first.Drill a 9.5-mm diameter hole 51 mm deep in the centres of bothends of the horizontal top braces.Lift the first horizontal brace and position it on the pinprotruding from the end post, align i t with the pin on the firstbrace post and drive the pin 51 mm into the fir st top braceleaving 51 mm of the pin protuding to receive the second topbrace.5. Cut a 12.1-m length of a t least 12-112 gage fencing wire and bend a15-cm loop in one end. Staple thi s loop or hook it over theprotruding pin on the brace post. Maintaining hand tension on the

wire, stretch a diagonal and wrap the wire around the end postunder a horizontal staple and back over the pin or staple on thebrace post. Complete two complete tig ht wraps in the samemanner.6. Pull as much slack up a s possible and staple the wire to the bracepost.7. Facing the diagonal wires, opposite the livestock pressure side ofthe fence, insert a 38 mm X 50 mm X 60 cm, treated, twitch stickabout 50 cm between the four diagonal wires, perpendicular to thewires so the end of the stick rests against the horizontal brace.8. Maintaining this length, tilt the stick toward the post so that thestick clears the top brace and pull the stick toward you to twist the

wires together. Make six or eight complete revolutions twistingthe wires and stopping with the stick in the upright position. Tiltthe stick back so it rest s against the top brace and cannot unwind.9. Cut a length of wire and staple i t over the end of the twitch stickonto the top brace to secure the twitch stick.10. Bend the horizontal guide staples over the wire at the bottom ofthe end post and brace post to hold the wire.11. Install the second top brace similarly to the first one.12. Install diagonal wires similarly to the first one.

DRIVING LINE POSTSHaving set the end posts and strung the guide wire, use thefollowing procedure to drive the l ine posts.1. Measure the location of posts by pacing or by stretch ing a tape andmarking the location of each post. Set posts 18m apart on levelterrain or a s far apart a s the terrain will allow (up to 18m) omaintain the wires parallel to the ground on uneven te rrain.


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2. Lay out a 198 cm X 100 mm line post a t each location for driving.3. Drive each post perpendicular to the soil surface to a 76-cm depthto maintain a stra ight fence. Take care tha t posts do not push theguide wire out of alignment. It is a good practice to allow 13-20 mm clearance between th e driven post and the guide wire.4. On uneven terrain, take care to drive all posts perpendicular tothe soil surface (Fig. 34). This act ion maintains maximumstability in the soil and maintains the fence height.5 . Generally set posts on the downhill side of the wire on fencesrunn ing across a slope and on the side of wire opposite the greaterlivestock pressure for more level situat ions .

L

Guide wire

Fig. 34 Vertical p lacem ent of l ine posts .

ST RING ING L INE W IRE SThe re are special considerations to make when working with wire.Barbed wire has barbs th at catch an d tea r clothes and flesh, and i t willrecoil when cut. High-tensile wire is stiffer, is harder to bend, and has

a greater tendency to recoil than barbed wire. To cut wire, hold theneeded end in one hand and step on the other end. If you must releasea cut end secure it with something or push it several centimetres intothe soil. Wear clothing th at completely covers your ar ms and legs,heavy soled shoes, leather gloves, an d safety glasses.The natu re of barbed wire practically dictates th at wires be st rungone at a time to avoid tangling. Because smooth, high-tensile wiredoes not tangle, it is possible to str ing all wires a t the same time.ToString Wire

Use the following procedure to s tr ing wires:


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1 . Load wire onto payout reels and, beginning a t end post position, onthe livestock pressure side of the posts either tie off the wiresbeginning with the second from the bottom, or anchor the wirereel.2 . Slowly pay out the wires down the fenceline staying as close aspossible to the posts. Maintain enough tension on the wires toprevent loops and kinks from forming.3 . Smooth, high-tensile wire may be periodically stapled on mid-point posts to guide the wire. Leave staples loose enough for wireto slide through them (see section on "Stapling").

4. Continue to pay out wire to about 152 cm beyond the far end post,maintaining the payout tension on the wires.5. Position wires on posts with the use of tension sheaves for barbedwire and periodic loose stapling for smooth, high-tensile wire toensure that wires will be parallel to the ground surface whentightened. Then there is no need to pull up or push down thewires, which would change the tension during final stapling.6 . If an in-line wire strainer is not being used, cut the wire from thereel and attach a tensionmeter to it. If barbed wire is being used,tighten it to 272 kg, then relax i t to 136 kg, and tie i t off a t the endpost. Tighten high-tensile wire to 136 kg and tie i t off at the endpost. If an in-line wire stra iner i s being used, tie the wire off a t a nend post without tightening it first . Staple all wires to the braceassembly.7 . If in-line wire strainers (Fig. 12) are used, cut off each wire fromthe reel, position all wires on the end post and tie them off usingan end-post knot or crimped sleeves. Do not tension.a) Return to the mid point of the span; working from the top wire,attach a wire puller about 122 cm from the post and pull thewire tight.b) Cut the wire a t the mid point of the slack between the jaws ofthe wire puller. Install an in-line stra iner by threading twocompression sleeves onto the wire nearest the post and slidethem back about 30 cm. Thread about 15 cm of the wirethrough the holes in the shank of the in-line strainer and bendthe wire back on itself. Slide the sleeves forward to catch thewire and crimp them.C) Thread the line wire through the drum of the in-line strainerand cut off surplus wire close to the drum. Turn the drum tosecure the wire and insert the ratchet pin. Continue turningto take up all slack. Remove the wire puller.d) Continue as above for all wires using in-line strainers.e) If an in-line tension-indicator spring is to be used, attach itbetween the in-line strainer and the line wire in the secondwire from the top.


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TEN SI ON I N G L I N E WI REFences constructed with a tensionmeter are tensioned at end postsbefore tying off. If proper construction techniques ar e followed, wiresare spaced and fences are tensioned to 136 kg at 0C or equivalentallowing for temperatures . These fences will remain well tensionedafter the fence shifts to equilibrium and will need no further tension

adjustments at the time of construction.The method for tightening fences using in-line strainers is asfollows:1 . Starting with the wire with the in-line tension spring, attach ahandle or wrench and turn the drum of the strainer until the wireis taut and free from other wires.If in-line tension springs are used, measure the coiled portion ofthe spring. Continue turning the drum until the coil is shortened38-45 mm, which will give a t least 1 1 3 kg tension on the wire.2. Crank the remaining in-line strainers to about the same tensionthat was placed on the wire with the in-line tension spring. Checkeach wire against the spring tensioned wire by pulling toward you

until the resistance of each feels the same. With practice, thismethod is surprisingly accurate.3 . To tension wires without in-line springs, draw the fence taut bycranking up the in-line strainers. Continue cranking the strainerand check the tension by measuring wire deflection using theapparatus and spring scale shown in Fig. 13. After tensioning thefirst wire, additional wires can be tightened by feel, making finaladjustments by measuring deflection pressures with the board andscale.4 . After all wires are tightened, staple all wires at their correctheight on all posts following proper stapling techniques. Removeall wire sheaves before stapling.STA P LI N G

Staple each wire to the line posts after it has been tensioned.Contrary to popular opinion, never drive staples on line posts tightlyagainst the wire. Driving staples tightly increases friction on the wireand prevents even tension in long spans of wire. It also kinks the wireand results in short rigid spans with li ttle or no elasticity to reduce thestress of livestock pressure against the fence. Tight s taples alsoprevent movement of wires in response to temperature changes and,with imposed loads, stretching of the wires occurs, resulting insagging or breakage.Drive staples just tight enough so the wire could be removed andrethreaded through the arch of the protruding staple (Fig. 3 5 ) . Amajor failure of wire fences is caused by staples pulling out, whichcould be the result of several factors, including:improper staple used for the jobwires stapled on the wrong side of the posts for livestock pressure


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wires sta pled on inside of posts on curvesexcessive tension in the wiress taples dr iven im properly so there is l i t t le res is tance to pulling.

I I

Fig. 35 Proper stapling.

Proper TechniqueFollow steps 1 o 6 for the proper s tapling technique.

1. Select the correct s taples . The longer the s taple the gre ater t hehold. Tes ts show that 45 mm X 9 gage s taples dr iven in woodp o s t s h a v e 5 0% m o r e r e s i s t a n c e t o b e i n g p u l le d o u t t h a n38 mm X 9 gage s taples dr iven in to the sam e posts . For long l ife ,select s taples ei ther manufactured from galvanized wire, or hot-dip tumbler galvanized af ter forming. Staple s should have s lash-cut points so the legs will bend with driving, giving the staplema ximu m holding power.2. Nev er drive stap les vertically into wood posts. Doing so can causespli t t ing along the grain of the wood, result ing in l i t t le holdingpower of the s tap le . R o t a t in g . th e s tap le s l igh t ly o ff ver t ica lstrad dle s the gra in, increasin g the holding power of th e staple.3 . Drive s taples with s lash points so their legs curve outwards a sth ey p en e t r a t e th e w ood (F ig . 3 6) . T h e s l a s h cu t a c t s a s a nasymm etr ical wedge forcing the leg to curve away from th e f la tsurface. Tes ts show th at s taples dr iven so th at each leg curvesaw ay f ro m th e v e r t i c a l c en t r e l in e h av e 4 0 % mo re p u l l -o u tres is tance than s taples dr iven incorrectly . W hen placing a s tap leover the wire aga ins t th e post , ro tate the s taple s l ightly (200ffvert ical) a wa y from the flat surface of the point on the upper leg(Fig. 37).4. In d ips, d r ive s tap les a t a n upward ang le and on r i ses d r ive s tap lesa t a downward angle (Fig . 38). The wire is then pull ing th e s taplein on th e post instead of out.

5 . On very s teep d ips o r r i ses , where there i s cons iderab le wireten s io n p u l l in g o n s t ap le s , d o u b le s t ap l in g i s ad v an tag eo u s(Fig. 39).6. When s tr inging and tens ioning l ine wires around the outs ide ofposts s tapling can be used to reduce fric t ion. Simply ha ng a s tapleover the securing s taple and between the wire an d th e post so theline wire is s l id ing on the s ta ple rathe r th an the post (Fig . 40).


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Fig. 36 Staples driven (a) ncorrectly and ( b )correctly.

Fig. 37 Staples rotated away from a flat surface.

Fig. 38 Stapling rise or d ip wires.

Fig. 39 Double stapling rise or dip Fig. 40 Stapling around curves orwires. corners.


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INSTALLING DR OP PER SDropper installation is the last operation performed in theerection of a line fence. Attach droppers to the fenceline wires after allwires are properly tightened and after final stapling is complete.Droppers, acting as wire spacers and load distributors, must beproperly installed to function properly. To space wires correctly, theymust remain vertical and hold the wire in place. Thus, they must beattached relatively tightly to the wire. At the same time, they must befree to move with the wires while maintaining their position on thewires if they are to distribute a load of impact among the wires.As previously mentioned, the number or spacing of droppers usedis dependent upon livestock pressure on the fences. The greater thelivestock pressure on a fence the greater the requirement that wirespacings be rigidly maintained, thus the more closely spaced droppersshould be.

Suspens ionOn fences where the wires a re relatively close to the ground (eightor more wires), it is recommended that droppers do not touch theground, which allows them to move with the wire on impact.On fences where the bottom wire is 30 cm or more off the groundand where there is small livestock pressure on the bottom wires, it i srecommended tha t a dropper (or a post) be in contact with the groundevery 6-9 m. Thus, in an 18-m span, with droppers every 3 m, everysecond or every third dropper would res t on the ground. Thesedroppers drag with pressure of small livestock (calves) on the bottomof the fence and prevent overturning of the fence.

Methods of attachm entDroppers may be at tached onto line wires in one of several ways.

1. Droppers that snap on or use clips are easy to install without priorinstruction.2. Spiral, twisted wire droppers are placed so the legs of the spiralstraddle the top wire. Siight downward pressure and guidance bythe technician results in the dropper twisting itself onto the fence.Remember, these droppers disfigure with livestock pressure.3. Wooden droppers of sufficient size can be stapled to the wires.4. Some droppers are attached with wire knots, depicted in Figs. 41,42, and 43.


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Fig. 41 Single wrap for dropper attachment.

Fig. 42 Figure eight wrap for dropper attachment.

Fig. 43 Figure eight wrap for dropper attachment to high-tensile wire.

GATESGates ar e required in all fences and should be:located to enhance, not hinder, farm managementa t least a s high a s the fencewide enough to permit passage of the widest machinery


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level enough, and hinged, to permit free swingingas long lived a s the fence.The wider the gate, the greater its tendency to pull over the poston which it is hung. Because of this, install gates on brace or end poststo which line wires have been tied off. Use posts of a t lea st244 cm X 152 mm and drive them 122 cm into the ground. Site gatessome metres from corners or perpendicular fences to facilitatemachinery movement. It may be necessary to offset gates in boundaryfences along busy roadways. In such cases, panels of boards are bette rthan short sections of wire fence.The installation of gate hinge pins para llel to fence line wires doesnot allow the gate to swing back against the fence. Installing the pins45" off parallel, on the side of the post from which you wish the gate toswing, will allow the gate to swing fully back against the fence(Fig. 44).

A hinged, wire gate (Fig. 45) designed by S. Clark Martin at theUniversity of Arizona is constructed a s follows:1. Tightly fasten the end pieces to the diagonal so the frame isrelatively rigid.2. Hang the frame on the hinges or pivot.3. Fas ten the first wire from the centre of the latch end to the centreof the hinge end.4. Tighten the first wire to hold the latch end a t the desired height.5. Attach remaining wires, pull them tight enough to hold the latchend vertical.6. Attach vertical supports as needed.7. Tighten the frame so it is rigid.8. Mater ials required:The diagonal and end pieces can be s teel pipe, wooden rails, or a

combination of the two.The hinge can be two bolted pivots on the gatepost or one on thepost and a buried pipe in the ground.Joints between the diagonal and end pieces can be welded ontabs, flattened pipe, or screwed on angle iron braces for woodencomponents. They must, however, be tight.

SAFETYAnyone building a wire fence is subject to cuts and scratchesinflicted by the wire. These can be magnified through carelessnesswhen working with high-tension fences. Always take the following

safety precautions:a Wear tough clothing that will not tear easily and that will notreadily catch on wire ends or barbs.Wear heavy duty , gauntlet-type, leathe r gloves that f it snugly.

a Wear long pants and work boots with heavy soles to protect feetand legs.


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Fig. 44 Hanging gate at 45" allows it to swing fully back against fence.

Fig. 45 Hinged wire gate.


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Have the right tools for the job, keep them in good working order ,and follow instructions for the ir use.Wear eye protection when cutting or tensioning wire and whendriving nails or staples.Use proper shields on power equipment.Use a nail apron or tool bag to carry nails, staples, and tools.Wear a hard ha t and ea r protection when ope rat ing a postpounder.Use driving caps on posts to prevent splintering.Keep children and livestock away from fencing operations.When working with treated posts or lumber, wear protectiveclothing. Some people are allergic to chemicals.Never use unsafe shortcuts .Keep the work area free from debris; pick up all pieces of wire,nails, staples, and so on to protect equipment, livestock, andpeople.

ACKNOWLEDGMENTSThe au thor grateful ly acknowledges Dr. J . W. Zahradnik,Bio Resource Engineerin g Departme nt, Univer sity of B rit ishColumbia, for assistance with information on basic principles takenfrom a research contract "Study on cost reduction of rangeland fenceconstruction in British Columbia" funded by Research Branch,Agriculture Canada. Mr. John Wall, president of Kiwi Fence SystemsInc. of Waynesburg, Pa.; United States Steel Corporation of Pit tsburg,Pa.; and numerous others graciously gave permission to reproducevarious drawings, tables, and other technical information containedherein.


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CONVERSION FACTORS FOR METRIC SYSTEMApproximateImperial units conversion facto r Results in

Lengthinch x 25 millimet re (mm)foot x 30 centime tre (cm)yard X 0.9 metre (m)mile x 1.6 kil omet re (km)

Areasquare inch X 6.5 square centimetre (cm2)square foot X 0.09 square metre (m2)square yard x 0.836 square metre (m2)square mile x 259 hectare (ha)acre x 0.40 hectare (ha)

Volumecubic inch X 16 cub ic centime tre (cm3 mL, cc )cubic foot x 28 cub ic decimet re (dm3;cubic yard X 0.8 cub ic metre (m3)fluid ounce X 28 millil itre (mL)pint X 0.57 l i t re (L)quart x 1.1 l i tre (L)gallon (Imp.) X 4.5 l i tre (L)gallon (U.S.) x 3.8 l i tre (L)

Weightounce x 28 gram (g)pound X 0.45 kilogram (kg)short ton (2000 Ib) x 0.9 tonne (1)

Temperaturedegrees Fahrenheit (OF - 32) x 0.56 degreesor ( O F - 32) x 519 Cel sius (" C)

Pressurepounds per square inch X 6.9 kilopa scal (kPa)

Powerhorsepower X 746 wat t (W)x 0.75 kil owa tt (kW)

Speedfeet per second x 0.30 metres per second (mh)miles per hour x 1.6 ki lometres pe r hou r (kmlh)

Agriculturegallons per acre x 11.23 litres per hectar e (Llha)quarts per acre x 2.8 l i t res per hectare (Lha)pints per acre x 1.4 l i tres per hectare (Lha)fluid ounces per acre x 70 mil l i l i t res per hectare (mLha)tons per acre x 2.24 tonnes per hectar e (t lha)pounds per acre x 1.12 kilograms pe r hectar e (kglha)ounces per acre X 70 grams p er hectare (gfia)plants per acre x 2.47 plants per hectare (plantslha)

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Wire Fence for Livestock