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Aviation History
1953
1953 - 0469.PDF
FLIGHT, 10 April 1953 465 AIRCRAFT HELP NEW ZEALAND FARMERS Top-dressing a Million Acres of Soil FROM small beginnings three years ago, aerial top-dressing has grown into New Zealand's biggest privately owned aviation industry, employing about 70 pilots and 100 aircraft. During 1952 well over a million acres of hill country were top-dressed from the air, over 100,000 tons of fertilizer being distributed. This is a phenomenal increase on the modest start made in 1949, when only 5,000 tons were dropped and less than 50,000 acres covered. For some years New Zealand farmers have been concerned at the deterioration of their hill-land, normally used for grazing sheep. Their machines cannot negotiate the steep slopes and man power has not been available for spreading fertilizer by hand, as was done before the war. In 1949 an agricultural committee reported that there were 10 million acres of land below the 3,000ft level, which, if top- dressed with phosphatic fertilizer, could be doubled in carrying capacity—from one sheep to the acre to two—while a big area of hill-land could be saved from erosion. After the war the practicability of using aircraft for distributing fertiliser became apparent, and trials, using two converted Avenger torpedo-bombers, were instituted by the Royal New Zealand Air Force. Although equipment was experimental, and consequently makeshift, the trials proved that fertiliser could be successfully spread on both flat and hilly country. In 1949 private firms began operations. Tiger Moths were the only aircraft available, and they are still the mainstay of the 32 companies now operating. Fitted with a hopper which holds 400 lb of fertilizer, and with other modifica tions, these machines today cost about £1,400 to put into opera tion in New Zealand. A few Canadian Beavers, converted to carry 1,600 lb of fertilizer, are now going into operation. Working under optimum conditions, a Tiger Moth can make AN AIRFIELD SOME measure of the immense scale of work involved in modern airfield construction, and of methods currently employed, is obtainable from an account of progress on a large site "somewhere in the Midlands." The contract is being under taken for the Air Ministry by John Laing and Son, Ltd., from whose monthly news-sheet Team Spirit, comes the following review of progress made. Twelve months ago (says the article) "moving in" operations were taking place in an isolated area in the heart of Warwickshire. The contract was for runway construction, and now as the latter stages of this work are approaching, work is commencing on another important contract at the same site, this time for technical and domestic accommodation. The two contracts form an impres sive project of civil engineering and building construction on a vast site stretching into the horizon on all sides. A year ago the preliminaries for establishing a site camp to house 500 men involved the construction of 23 Nissen huts, extensive renovations to an existing building which is now used as a recreation centre and cinema, and extension of another building which provides canteen facilities for serving some 4,500 meals a week. These were an urgent requirement, for without adequate accommodation the smooth progress of the contract could not have been planned. Since the commencement of the contract a year ago, the con siderably smaller disused airfield, abandoned after the war, has been superseded by the construction of a runway nearly 1 £ miles in length and 200ft wide, a taxi-track of approximately the same length, and two access tracks connecting the taxi-track with the runway. The shape of the construction resembles a bushman's saw, the runway forming the blade, the taxi-track the frame, and the access tracks run across at one-third intervals. Excavation included the removal of half a million cubic yards of earth, and 80,000 yd super of concrete from the existing run way, and taxi-track has been broken up and used to form part of the base course filling material. The removal of access tracks and 13 existing hard-standings was also necessary. This contract extends beyond the boundaries of the former air field, across hunting country which included two fox coverts and two coppices. A bridle path crosses the west end of the site. Seven hundred trees forming part of one coppice which extended on to the path of the runway have been taken out, and three ponds have been filled in. The runway and taxi-track, constructed on 8in of graded hard core, are of a working course of concrete four inches thick fol- 12 trips an hour, and, flown by two or more pilots in rotation, can drop 21 tons of fertilizer in a day of 10 hours. This figure is extremely high, however, and 10 to 15 tons dropped is the average for a good working day. Usually operating from the nearest suitable field to their "target area," the machines spend little time on the ground. Specially developed loading trucks, from which the aircraft hopper can be filled in under two minutes, do away with the necessity of even stopping the engine, except for re-fuelling. Operational height is usually between 80 and 100 ft, when individual fields and areas can be treated as the farmer requires. Granulated phosphate is the ideal fertilizer. Such is the extent of the industry, and so great is the experience gained in the past three years, that the Aviation Industry Associa tion of New Zealand, whose membership is largely made up from the owners of aircraft engaged in top-dressing, has supplied to the Society of British Aircraft Constructors, for the information of that body's members, general characteristics of a suitable air craft for the job. They ask for a rugged machine, able to operate from small fields, but carrying a good payload and easily manoeuvrable at slow speeds. Fertilizing is not the only aerial agricultural activity in New Zealand. There are about 20 classes of work, including sowing, spraying, laying poison for rabbits, supply-dropping, and the locating of stray stock on large, hilly properties, where it might take days to do so by horse or on foot. More than 50 tons of rabbit poison were scattered from the air last year; 100 tons of supplies dropped; and 100 tons of seed sown on 30,000 acres. At least two companies are interested in pur chasing helicopters, which would be chiefly used for spraying gorse with hormone solutions in an effort to reclaim land which has become overgrown. G. F. B. TAKES SHAPE lowed by a I2in layer of high-grade concrete, 2 Jin of tarmacadam and i|in of bituminous macadam. The most satisfactory method of laying the four-inch working course was to use a Barber Greene paver, laying the concrete by the method used for spreading macadam. Two Koehring pavers are in use for the i2in slab, with Blaw Knox spreading and finishing machines. The weighbatching plant consists of two 100-ton aggregate bins each with three compartments loaded by N.C.K. grabs, and one bulk cement plant with storage for 200 tons of cement. Drainage involved laying 7,000 yd of pipes varying in size from 33m to 9in, with four outfalls along the track. All lighting ducts are being constructed with Ductube and the total length of ducting will be more than four miles. At this contract there was no supply of water until the recent construction of a reservoir for storing water for concreting. Prior to this all water for concreting and for domestic use in the camp and offices had to be carried by bowser from a source six miles away. Three tanks, each with a capacity of 12,000 gallons, sup plied water needed for the mobile pavers; there was another for mixing the concrete used for the working course; another two were reserve tanks each of 12,000 gallons capacity, and a 10,000- gallon tank for domestic purposes is still in use. During the summer an unexpectedly high rainfall was far from encouraging—4|in of rain was recorded from Tuesday to Friday of August Bank Holiday week—and, since the autumn, frost has been unusually persistent. This, however, is a factor which has had to be contended with at most contracts. The new contract for buildings is in itself a major one, involving the construction of more than 100 buildings (mostly in "Easiform"), with additional standard Air Ministry buildings such as air traffic control tower, stand-by generating-set house and others, including five boiler houses, in brick construction. The interesting feature about such a contract is the carefully worked out shuttering programme required for such a wide variety of spans and shapes of "Easiform" buildings. There are some 30 different shapes of buildings, and heights vary from 12ft to 16ft. The entire "Easiform" construction programme is being carried out with ten sets of steel shutters—standard shutters for the 60ft by 20ft buildings. Airmen's huts, of which 40 are to be constructed, are 84ft in length and 20ft wide; the 25 officers' quarters are each 72ft long and 24ft wide; and there are many varying shapes and sizes for ablutions, messes, N.A.A.F.I., and a number of other buildings.
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