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Interaction of tractor tracks with a peat bog soil
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ABSTRACTS pendently. The test data have indicated that the unit swelling in the horizontal direction almost invariably exceeds that in the vertical direction, regardless of how compaction is accomplished. A n attempt has been made to relate this unexpected result to soil structure and double layer phenomena. (Applied Mechanics Review)
65. A. F. Poletaev. Rolling of the driven wheel. Trakt. Selkhozmash., 1963, 33 (2) 5-7: bibl. 2, illus. (R.) Theoretical Paper. (N.I.A.E.) 66. V. N. Prokofev. The selection of the optimum arrangement of a hydrostatic transmission for a general purpose agricultural tractor. Mekhaniz. Elektrif. sots sel. Khoz., 1965, 23 (l) 11-14; bibl. 6, illus. (R.) In a theoretical study it is suggested that a 6-fold power range could be achieved not by increasing the transmission ratio but by using a variable delivery pump with 3 equally powered motors on each of the 4 driving wheels. This would enable a reduction of the installed power by 4"45 times, the weight of the pump 1 '2-1 "3 times, of the motors 1 "4-1 "5 times and of the transmission as a whole 6-6"5 times. The motors would be successively switched off during acceleration by a distributor valve. (N.I.A.E.) 67. L. D. Revutzkii. The effect of operating conditions on the wear of tractor tyres. Mekhaniz. Elektrif. sots. sel. Khoz., 1964, 22 (6) 55-56; bibl. 3, illus. (R.) Study of tractor tyre wear as a function of tyre pressure and D.B. pull in farm operations including ploughing, cutting of cereal crops, hay raking and transport on asphalt surfaces and farm tracks. (N.I.A.E.) 68. G. Rinno and A. Heissner. Indirect determination of soil moisture content by reflectance measurements. Arch. Gartenb., 1964, 12 (5) 371-383; bibl. 11, illus. (G.r.e.) The equipment for determining spectral reflectance of soil in laboratory and field experiments consisted essentially of an incandescent light bulb, an annular photoelectric cell through which the light beam passed and a galvanometer for recording the fraction of light reflected by the soil The relationship between reflectance and soil m.c. was investigated for different wavelengths and over a range of soils. (N.I.A.E.) 69. M. M. S h l u f m n . Measuring torque with strain gauges. Mekhaniz. Elektrif. sots. seL Khoz., 1964, 22 (5) 43; illus. (R.) The damping coefficient of a shaft with dynamic loading is determined by twisting the shaft, fixed at one end, and measuring the 'untwisting' time when the load is instantaneously removed. (N.I.A.E.) 70. V. A. Skotnikov. Interaction of tractor tracks with a peat bog soil. Mekhaniz. Elektrif. sots. sel. Khoz., 1964, 22 (3) 10-13; bibl. 6, illus. (R.) A 55 hp marshland tractor was tested with trailed and mounted machines on a soil of 7 2 - 8 4 ~ m.c. and 1-42-4"3 kg/cmr strength, the peaty layer being 1 "5-1.7m deep. Factors studied included soil reactions, forces acting through the hydraulic linkage from a mole plough, sinkage, tension and slip of the tracks, etc. (N.I.A.E.) 71. V. A. Skotnikov. Trafficability of track-laying tractors. Trakt. Selkhozmash., 1963, 33 (1) 4-7; bibl. 8, illus. (R.) A review of work done on drained and undrained peaty marsh soils with and without a turf cover to determine ground pressure of tractors and soil reaction, etc. Equations are derived. (N.I.A.E.) 72. W. Soiree. Four-wheel or rear-wheel drive for high power farm tractors. Grundl. Landtech, 20, 1964, 44-52; bibl. 14, illus. (G.) D.B. pull data on 85 hp tractors are given to illustrate the superior performance of a 4-wheel drive model over a conventional rear-wheel drive one at different wheel slip values and on dry loam, sandy loam, damp sandy loam and damp clay loam. Other advantages, e.g. favourable relationship between tractor weight and tyre width for row crop work, and disadvantages, e.g. costs, of the 4-wheel drive tractor are indicated. (N.I.A.E.)
ABSTRACTS pendently. The test data have indicated that the unit swelling in the horizontal direction almost invariably exceeds that in the vertical direction, regardless of how compaction is accomplished. A n attempt has been made to relate this unexpected result to soil structure and double layer phenomena. (Applied Mechanics Review)
65. A. F. Poletaev. Rolling of the driven wheel. Trakt. Selkhozmash., 1963, 33 (2) 5-7: bibl. 2, illus. (R.) Theoretical Paper. (N.I.A.E.) 66. V. N. Prokofev. The selection of the optimum arrangement of a hydrostatic transmission for a general purpose agricultural tractor. Mekhaniz. Elektrif. sots sel. Khoz., 1965, 23 (l) 11-14; bibl. 6, illus. (R.) In a theoretical study it is suggested that a 6-fold power range could be achieved not by increasing the transmission ratio but by using a variable delivery pump with 3 equally powered motors on each of the 4 driving wheels. This would enable a reduction of the installed power by 4"45 times, the weight of the pump 1 '2-1 "3 times, of the motors 1 "4-1 "5 times and of the transmission as a whole 6-6"5 times. The motors would be successively switched off during acceleration by a distributor valve. (N.I.A.E.) 67. L. D. Revutzkii. The effect of operating conditions on the wear of tractor tyres. Mekhaniz. Elektrif. sots. sel. Khoz., 1964, 22 (6) 55-56; bibl. 3, illus. (R.) Study of tractor tyre wear as a function of tyre pressure and D.B. pull in farm operations including ploughing, cutting of cereal crops, hay raking and transport on asphalt surfaces and farm tracks. (N.I.A.E.) 68. G. Rinno and A. Heissner. Indirect determination of soil moisture content by reflectance measurements. Arch. Gartenb., 1964, 12 (5) 371-383; bibl. 11, illus. (G.r.e.) The equipment for determining spectral reflectance of soil in laboratory and field experiments consisted essentially of an incandescent light bulb, an annular photoelectric cell through which the light beam passed and a galvanometer for recording the fraction of light reflected by the soil The relationship between reflectance and soil m.c. was investigated for different wavelengths and over a range of soils. (N.I.A.E.) 69. M. M. S h l u f m n . Measuring torque with strain gauges. Mekhaniz. Elektrif. sots. seL Khoz., 1964, 22 (5) 43; illus. (R.) The damping coefficient of a shaft with dynamic loading is determined by twisting the shaft, fixed at one end, and measuring the 'untwisting' time when the load is instantaneously removed. (N.I.A.E.) 70. V. A. Skotnikov. Interaction of tractor tracks with a peat bog soil. Mekhaniz. Elektrif. sots. sel. Khoz., 1964, 22 (3) 10-13; bibl. 6, illus. (R.) A 55 hp marshland tractor was tested with trailed and mounted machines on a soil of 7 2 - 8 4 ~ m.c. and 1-42-4"3 kg/cmr strength, the peaty layer being 1 "5-1.7m deep. Factors studied included soil reactions, forces acting through the hydraulic linkage from a mole plough, sinkage, tension and slip of the tracks, etc. (N.I.A.E.) 71. V. A. Skotnikov. Trafficability of track-laying tractors. Trakt. Selkhozmash., 1963, 33 (1) 4-7; bibl. 8, illus. (R.) A review of work done on drained and undrained peaty marsh soils with and without a turf cover to determine ground pressure of tractors and soil reaction, etc. Equations are derived. (N.I.A.E.) 72. W. Soiree. Four-wheel or rear-wheel drive for high power farm tractors. Grundl. Landtech, 20, 1964, 44-52; bibl. 14, illus. (G.) D.B. pull data on 85 hp tractors are given to illustrate the superior performance of a 4-wheel drive model over a conventional rear-wheel drive one at different wheel slip values and on dry loam, sandy loam, damp sandy loam and damp clay loam. Other advantages, e.g. favourable relationship between tractor weight and tyre width for row crop work, and disadvantages, e.g. costs, of the 4-wheel drive tractor are indicated. (N.I.A.E.)