TRACTORS ON FARMS

Hawke's Bay Herald-Tribune, Issue 104, 19 May 1937, Page 15

TRACTORS ON FARMS

The Dangers of UnderLoading ECONOMY IN WORKING At a conference recently held at Oxford, England, on the employment of meehanical aids to cheapen production, Messrs. S. J. Wright and E. B. BlacK (InsGtute for Eesearch in Agricultural Engineering) showed how farmers c.ould get more and better service from their tractors. . Their evidence, however, based on visits to 20 different tractors in various parts of thO country, suggested that, even when doing heavy work at a busy time, tractors were generally underloaded. and that they might on an avcrage be made to do over 40 per cent. more work. Having regard to the fact that even when workang at full rated load there was an ample margin for emergencies, they thought that most farmers could grade their loading up all round. The vast majority of repairs occurred in tEe engine itself, and were not due to actual lack of oil, but to the use of poor, thin oil. VapoTiser3 on tractors sold in this country were designed and adjustcd to run on standard grades of paraffin, or, as they were coromonly called, vaporising oile. The man who deeided to run his tractor on larnp oil, too, or on a cheap fuel oil with no reputation to lose, was also asking for trouble. The primary •eause of dilution of oil in tractor engines was the paraffin not being warmed sufficiently because the engine was run too cold. Left to itself. with no precautions, practically every tractor engine Tan colder than it should. The engine is probably not hot enough if the driver could bear to touch the bottom of the radiator, let alone the top. • Low Texnperature. In the case of a tractor running with cooling water at about (iOdeg. Centigrade, the oil ought to be completely changed after every 20 hours or so of running time. If the temperature was abqa.t 90deg. C., however, it would probably be safe to run for some 45 hours without changing the oil. Measurements taken in the field indicated that it was not uncommon to find farm tractors working with rad'iator temperatures as low as 45deg. C. They had heard of eome utriking cases of tractors .damaged through dilution due to underloading: a tractor of vvell-knu wu make requiring practically a new engine after only 12 months* service — simply because its owner was so proud of it and careful not to overload dt that it was underloaded all tho time. An average tractor working 300-1000 liours per annum cost about £150 a year to run. They estimatod that, taking the average case as they had seen it in the field, about one-third of this could be saved — directly by full loading and indirectly by avoiding depreciation. There were soraething like 40,000 tractor users in the country and they were probably wasting £2,000,000 a year between them. Mr. Wright urged that in buying a tractor it was essential to consider the gearing as well as the Tated horse power, other wise they might find that while they could not woTk on tho higher working gear wdthout a lot of changing, the lower gcar involved a tremendous amount of running with an underload. He thought that tractors should be fitted with four gears, giving, _say, 1 m.p.h. in bottom and 4 m.p.h. in top. The working gears should be fairly close — say, 2J m.p.h. and 2i m.p.h. — \ so that they could be used to adjust the speed of the tractor to take its full load at around the normal speed s. "■> crankcase Dilution. While speaking, Mr. Blaek emphasised that in order to minimise crankcase dilution, a tractox should be got "as hot as possible as quickly as possible," if neceseary to running on petrol for a quarter of an hour with a shutter Over the radiator. He referred again to the risks associated with "cheap" fuels, and also showed lantern slides which demonstrated the need for using plugs made to withfitand the conditions of heat, etc., in the particular make of tractor used. Discussion brought forth references to gadgets designed to meet the problems of overcooled engines and crankcase dilution. One is a special cylin-der-head gasket designed to trap anv paraffin that condensee in the cylindor head. The otlier is a cheap thermostat designed automatically to matatain the temperature of the cooling to at least 180deg. F.