To facilitate a quick shift

Press, Volume CXII, Issue 33094, 8 December 1972, Page 8

To facilitate a quick shift

Some people on cropping farms are taking down fence lines these days to facilitate the movement of long irrigation spraylines over their land. At a field day at the Winchmore irrigation research station last week a means of speeding up shifts without completely eliminating fences was demonstrated under the direction of Mr G. J. Grosbie, of the Ministry of Agriculture and Fisheries in Christchurch.

It involves dropping down a section of the fence line. The technique was explained in a paper handed to fanners attending the field day. It has two versions. The paper said that “Irrifence” and the “Irrigate” had been developed to enable fast and easy shifts of wheeled irrigation spraylines from one field to another. Power-roll and hand-roll spraylines, as they advance up the farm, require to be broken down into individual lengths and shifted on a special trailer when a shift from one field to another is necessary. The “Irrifence,” by virtue of its ability to fall flat on to the ground along its whole length, allows the power-roll sprayline to advance over it with the same facility and ease of movement as in an ordinary shift in a field. The short version of the “Irrifence” —the “Irrigate” —enables the end-tow sprayline to be quickly moved from one field to another without the necessity of travelling a long circuitous path through the two fields—a matter of

some importance when crop damage is taken into account. The “Irrigate” is built in the centre of the fence line and may be two chains or more in length. The endtow sprayline is broken into two parts and each is towed through the gate to its new (and opposite) position before they are rejoined into one. Such a shift was seen being made at the field day and when the central part of a pipe section between two sets of wheels caught in the fence at it passed over it, Mr Crosbie observed that a little skill was needed to pass through the “gate.” However, the marked saving in time that could be achieved was very obvious. The “Irrifence" is basically a North Island “flexifence,” except that the ends have been improved so that only 9ft at each end does not collapse. This, however, is a matter of no importance as the nearest spray nozzle is some 25 to 30ft from the ends. Half a “Soil Con” strainer is built at each end of the fence and the fence is built as a long “Taranaki” gate with wire spacings to suit conditions. The bottom of each gate

opener is “pivotally” mounted to the nearest strainer and the top Of the gate opener is restrained by a chain to the bottom of the furtherest away post. A suitable gate fastener is fitted and the line wires strained by means of a permanent strainer built into each of them. Any type of flexible post may be fitted in the fence to suit the conditions, but it is suggested that the simplest may be a steel Waratah cut off 12in below ground level and inserted into 12in of a 2in pipe, which is set in concrete. Merely to open the gate fastener, lift out a post and displace its lower end 12in is enough to cause the fence to fall over. Mr Crosbie estimates the cost of the various pieces of equipment needed for a gate section at $36. This includes four Bft by 6in pointed cattle posts at $2.20 each, two 9ft by 4in strainer stays at $1 each, 20ft of 5/16in welded galvanised chain at, say, 50c per ft, four 3/Bin shackles at, say, 40c each, Bft of 2|in galvanised water pipe at 74c per ft, 10 permanent wire strainers at 49c each and sundry fittings at, say, $2.60.