Self-propelled irrigator

Press, Volume CXII, Issue 32885, 7 April 1972, Page 14

Self-propelled irrigator

Another Australianmade self - propelled I sprinkler irrigation I system has recently I been demonstrated in North Canterbury and South Canterbury. It is the water winch manufactured by Simpson Pope, Ltd, of Adelaide, manufacturers of irrigation equipment. Up until recently there were five of the machines in Canterbury — four in Mid-Canterbuiy and one in the Leeston district. The sturdy unit, shown in the photograph, has a drum with 1400 ft of cable on it. When the machine is set up it is placed at one end of the field and the cable is towed 20 chains or 1320 ft to the other end where it is attached to an earth anchor. When the water is turned on the unit proceeds to pull itself up on the cable from one end of the field to the other. Attached to the back of the machine is a 10 chain or 660 ft length of 4in hose. This hose is connected to a hydrant located mid-way up the field on the main supply line. As this hose can reach either end of the field, it is able to supply the unit for the entire run. When it is time to move the machine, the hose is purged of water by low pressure, high volume purging equipment, which means that the hose lasts longer, and picked up on a reel and transported to the next row where it is laid out. The purging of the hose and reeling it in takes a bare four minutes. The sprinkler is then towed around to the next row and connected for its run. Changing of the machine takes about 30 minutes. This machine takes 22 hours to make a run applying two inches of water to 10 acres. Over a period of

two weeks it will cover the equivalent of about 140 acres with this application of water. A part circle gun makes it possible to irrigate on one side of the tow path only if that is required. The unit in the photograph is the largest of two models and may be equipped with 660 ft of 4in or 3|in hose. It can apply from 14,000 to 25,000 gallons of water per hour and with all ancillary equipment, including the reel, costs $9930. A smaller model has 2|in or 3in hose and has a capacity of 5000 to 13,000 gallons of water an hour. With 330 ft of 2Jin hose the cost is $6095. Features of the units include a boom which can be tilted to give more uniformity of spread in windy conditions. Lowering the trajectory of the water stream into the wind minimises distortion. The steering system is very sensitive so that the unit follows the cable very closely and it comes to a stop automatically at the end of its run. The speed of travel and consequently the rate of water application can be adjusted in the time that it takes to get a spanner and alter the jet sizes. A fibre glass cowling protects working parts from becoming fouled by vegetation and hot dipped galvanising affords protection against corrosion. A horizontal type reel is easy for handling and storage and means that after the hose has been laid out it is not necessary to walk along and manually shift it out of the unit’s tow path. One of the units being used in Mid-Canterbury had, up until about two weeks ago, covered more than 900 acres since the end of November. It has been found that working expenses only for the unit work out at 72c per acre

inch of water applied compared with $l.lB for two sin spraylines shifted manually. Where it was used in wheat in ear but still green the wheat was standing up again in 24 hours. Likewise lucerne was also standing up within 24 hours of treatment and only the two wheel marks were discernible. In a crop of peas in flower no damage was done by the unit—no plants were pulled out nor was there any sign of flowers being knocked off by the jet stream. In fact the impression is that less damage is done to crops by this unit than with manual shifting of spraylines. One of the units being used in Canterbury has been extensively modified to water potatoes — its clearance off the ground has been raised considerably and its track widened anti the steering modified. Representatives of Andrews and Beaven, Ltd, who are sole New Zealand distributors for all Pope irrigation equipment, say that there should be no problem in feeding fertiliser also through the water winch.