GERMAN FENCING WIRE.

Hokitika Guardian, 4 May 1918, Page 1

GERMAN FENCING WIRE.

HOW’IT HAS DETERIORATED

AN EXPERT’S DEDUCTIONS

Writing on the subject of fencing wire, now a very high-priced article in New Zealand, Mr J. Orchiston, Chief Telegraph Engineer of the Dominion, says: —“Much loss to the farming interests throughout the 'Dominion has resulted during recent' years from the use of cheap German and other low-grade fencing wires, which- only had a lifi\ of half a dozen years or so. The loss can he safely placed at hundreds of thousands of pounds. Some time ago there was a considerable amount of investigation in the United States as to the cause of the rapid deterioration of modern wire as compared to that produced formerly. The conclusion arrived at -was that the chief reason for the deterioration was due to the admixture of manganese in the process of manufacturing tho steel. “Each molecule of manganese loft in the metal will set up local galvanic' action, .with the . result that the wire ®will become pockmarked, or flayed off m junks as if some sharp instrument had boon used to bito pieces out of the motel Other impurities in the metal will of course all tend to its disintegration. The'purer the metal the less oxidisation ; in other words,' the longer it will last-.

“Prior to some forty years ago all wire was made of ordinary iron, but on the, advent of what might- lie termed tho steel era the manufacture of iron .wire practically ceased. The cheaper steel wire also gained favour from the fact that- it would stand a greater strain before stretching. After some years it was discovered that it was not- so lasting as the previous iron wire. Tt then became the practice to largely galvanise fencing wire, but even this did not make up for the impurities resulting from tho cheaper methods of manufacture. The Germans seem to have led the way in regard to cheapness and poor quality, and British firms had' to follow suit or. simply lose the trade, as t-h,. average farmer had and has no moans of telling one wire from another. The cheap German wire looks just as well, or in fact- sometimes better from outward appearance:, a's that, of the superior British article. I leave, it to the farmers themselves to judge how many have knowingly bought- German wire because it was ten shillings a t-on cheaper and have been sorry for themselves afterwards.

“Th<T Post and Telegraph Dopartment is, of course', tlio'largest user of wire in the Dominion, and I’think a little outline of its experience might ibe of interest. Tn 18(54 the General Govern inent commenced the erection of tcleirraph line from .Marlborough to Southland. A considerable quantity of the wire then erected is still in use, J and what has been dismantled was principally on account of alterations to the route etc., A great deal oP the wire erected in both islands during the ’sixth's is still doing good work, and likely to last many years longer if left alone. A fter 1882 I observed a marked difference in the class of wire coming to hand, and subsequently learnt that it was steel, and that.as the British Post Office had agreed to take steel wire at a cheaper rate .than the previous iron wire the manufactures had practically coascd to make iron telegraph wire by the old process. The result is that the wire erected during the later ’eighties and ’nineties is not so good as that- of the.’sixties and ’seventies and most of it will have to he replaced before, that erected during the earlier period. “At'odd times between the years of 1895 and 1910. when the supply of standard wire bad run out some fencing wire was purchased to complete pressing needs. Tn one ens'e such wire erected ill 1905 began to fall down' in 1911, and bad to he wholly renewed in 1912, a total life of only seven; years, whereas much of the fifty-three-year-old wire, as already indicated, is still serviceable in. the South Island. Naturally, one is apt to ask, the use of siif'li inferior material? There is a very simple means of arriving at the approximate purity of the iron. The purer any metal is the greater its electrical conductivity; consequently the more impurities the poorer the conductor. Beckoning the conductivity of absolutely pure iron at 100 per cent., the best class of telegraph wire is expected to represent 97 per cent, from an electrical conductivity point of view. It is doubtful, however, if any steel wire can be obtained as high as this, and the British Post Office Telegraphs has set the minimum standard as low ns‘B7 per cent., which has been the minimum adopted in Now Zealand. T am, however of opinion that this is too low. and it, is proposed to raise the standard. • The old telegraph wire erect ed in the ’sixties approximated 95 per cent. 1 “Some recent importations of . a new class of iron wire manufactured in America have reached the 97 per cent, mark, and it is anticipated that this wire will he good for at least fifty years, although the galvanising does not comply witlf our specifications. SoniJ fencing wire tested by me lias been as low as 50 per cent., which’is a clear indication that such wire will have a short life. During the lastseven years hundreds of tons of telegraph wire have been rejected in Wellington, much to the disgust of the manufacturers and their local representatives. Although the purity of the metal is of primary importance from silasting point of view, it is also desirable that the wire should he galvanised, and I may here state 1 have never found any fencing wire which would comply with our specifications in this respect. Tn so far as the tensile strength of the low grade wire is concerned little fault can bo found with it when new.. In, fact it will invariably hear a greater strain before stretching than the firstclass wire, “With a view to assisting those in need of good wire, the Hon. the Bqsl. master-General has been pleased to approve of the Department, undertaking the testing of fencing wire for the percentage of conductivity, and also loi ii-alvanising, at the small chaige of.two shillings and sixpence per sample. Each sample should consist of cleftn feet, to be made up in a coil of not loss than, say, nine inches in diameter, nee from kinks.”