ELECTRICITY USED IN FENCING

Press, Volume XCVIII, Issue 28920, 13 June 1959, Page 8

ELECTRICITY USED IN FENCING

I Experience At Massey College In the view of Mr \V. R. R. Hewitt, of Massey ; Agricultural College, it is only a matter of time before the electric fence will displace fencing as it I is known on many farms today. “Absolutely satisfactory” was his description of the electric fence. Since a paper had been given on electric fencing I at the sheepfarmers’ meeting at Palmerston North 1 I last year, Mr Hewitt told the recent farmers’ ! j conference that he did not think he would be I exaggerating to say that more than 100 miles of | i electric fencing had been erected in New Zealand.

Mr Hewitt, basing his . remarks >t on experience with electric fenc- a ing on the college s Rata property | in Hawke's. Bay. said that it t could not be emphasised too much a that to be satisfactory an electric p fence had to be erected with the 5 same care and attention to detail { as a good post and wire fence. a The college, he said, had got t the cost down to £167 a mile. 11 though some improvements con-,! templated since might increase it; j slightly. This compared with | r £966 a mile for the ordinary s type of fence erected in the North,* Island with eight wires, five posts j r to the chain and 25 battens and-c £655 for the Hunter fence. s ! It was recommended that the | line of the fence should be bull-I * dozed to smooth i| out. Sharp’ dips should be avoided at all c costs. This work should cost no f more than 5s a chain. All gate-p ways and angles should then be- ( cited and erected. The gateway! should be strongly built with at ‘least a chain of netting on either side of it if the gateway was in , the centre of a line. This might, not be necessary where stock were ( always being handled and were |j reasonably quiet, but on extensive j areas under run conditions it was p definitely essential. Stock had to j be kept off live wires. It could*’ well be imagined what would ‘ happen at a gateway if this was, I not done. Big Enough An ordinary post was quite big ‘enough to use as a strainer but! •it had to be properly footed and 'breasted as the strain exerted on this post was terrific. An ordin•ary post was quite sufficient for jangles, but it should be strongly : erected and tied back against the strain. The method now used for attaching insulators to the angles .comprised a chain assembly costing Is. lOd tor each wire. The. ; chain assembly had only to be islipped oxer the angle post and a staple would hold it in place Initially a tong angle insulator. . through which the wire had to be [ ; threaded, had been used and 'while it was cheaper by about 3s 3d an angle on a five-wire fence -the cost would be about the same where paid labour was taken into account A guide wire could now be run out and a waratah standard driven into the ground on all the 1 • brows. A bolt through the standard at ground level and two pieces of wood on either side of the standard would prevent it from sinking in soft ground. There were several insulator' systems for carrying the wires on the standards- Two insulated ■. chain asemblies cost 7s lOd and = 4s 9d respectively. The smalll bobbin insulator used by the college was attached to the standard by a 2i-inch galvanised gutter bolt with a plastic washer be-1 tween the base of the insulator and the standard. The cost of the insulator was 4d the bolt, washer and wire to hold the fence I wire in place 2d more. This j 'meant that with a fence with; four wires electrified the cost was. 2s against either 7s lOd or 4s 9d The cheapest insulator of the; lot—24d or lOd a standard for j insulators on a four-’.ire fence — was made bv splitting tour inches ■of half-inch alkathene lengthwise down the centre and encasing the wire in it and tying it to the standard with a piece of soft Once the standards were erected on all brows it was only necessary to puli the wires down on • all dips. While it was recom-. mended that al! sharp dips should be avoided as much as possible ! where it was necessary to span them it was desirable to put some ' pipes at the bottom and bulldoze : a nil over them or alternatively wires could be pulled down so' • far on either side of the dip and the space underneath blocked with several short lengths of barb wire coming of! the foots on either side down tc a foot at the bottom of the gully. Dropper Assembly The footed dropper assembly favoured had an arrowhead which could be driven into the ground by placing a round iron bar of suitable length in the hole in the head. Pressure was then exerted on the footwire when the arrow-! head would pull into a horizontal; position and it would then require: more pressure than the fence. would exert to move it any further. The whole assembly con-; sisting of arrowhead, foot-wire, insulator and clips and chain cost IDs, If it was intended to deaden the bottom wire at any time 4in: of iin alkathene tubing a: rhe bottom of the chain would be necessary at a cost of 2|d for each foot assembly All that now remained was to run out the remaining wires and connect them to the standards and the foots. Originally an eightwire waratah standard and four wires were used The bottom wire was an earth wire running' the whole length of the fence and ; either overhead or under the ground at gateways. The earth pvas 4in above the ground, and

: c the others were spaced at 8. 164; i iand 274 in above the ground. This c fence was efficient and high enough—a point which might not' i be believed—but it was felt that i ( 'a better fence .might be erectedj > by using another wire and a j seven-wire waratah standard. t It was advisable to strain the j fence from the middle as tightly i . as possible. Now the Hunter s method of tying the wires was I used. A piece of chain was tied ’to one end of the wire and a ■ • loop made at the other end. The c > fence was then strained from the t ’middle and the looped end i slipped through one of the links', i 5 in the chain and a wire pin j ’slipped through the loop. This « i reduced the cost to 6d a wire • i ! compared with 3s 9d using a■, strainer. | j ’ At the college erection costs|! based on labour at 7s 6d an hour!’ were 6s lOd a chain. !1 • For wire 12J gauge super j’ dreadnought steel wire was pre-; ferred to 12-gauge galvanised J ; wire because it was stronger and ’' idid not stretch. Wind Changer | A wind charger consisting of al windmill costing £56. controller’ £lO 10s and battery £3 15s was’claimed to electrify at least five s miles of fence and to do much * more where insulated chain as- i semblies were used on all stand- j ards. Experience of the college» I was that only once in two years! ; had the battery gone flat and this! i might not have happened had the i windmill been in a more exposed | !position. Another unit now on; the market at £5B charged at halff the rate of the other, but seemed l’to require less wind to operate ] 1! Where the wind velocity was| H often at gale force there could! i be substantia! wear and tear. If the ordinary electric fence; controller worked off a six-volt; battery was used the battery i ■ should be recharged every two or! ’ three weeks. It was necessary to; ? have two batteries, one of which! ' could be at home being recharged | ■!by a small trickle charger. I! The other method was the elec-1 !tric mains controller which! plugged into an ordinary electric! point, but the disadvantage of; j i this was that the maximum pulse; J rate was 70. which was con-! > \ sidered to be far too slow. j Under Fence Growth | 1 ; Of growth under the fence con-' 3 tacting the wires and shorting ; ? !the fence. Mr Hewitt said that plunder intensive stocking the j sheep ate right up to the fence! f!on both sides, especially if the! i. bottom wire was an earth, and ■ • the grass ne'er got long enough l I to do any damage. Under less' stocking there was some i growth and a good- sharp shove!' , i was the best method of remov- ;! ing it. If it was possible to deaden the bottom wire only the j odd thistle would touch the other 3 wires. Even if grass did overigrow the wire in places in their experience it would not short the f . fence even when wet. Sometimes the electric fence e had been condemned because s jpeople had not taken the trouble Y; to train sheep to it. At Massey si an electric fence using seven wires had been erected in a big a i holding yard at shearing time. shorn sheep used this yard. At the college there had been c '• no trouble. It was now possible to turn off the fence and neither " cattle nor sheep would go near it.