RICHARD A. DUNCAN

Transcription

1 THE MECHANCAL HARVESTNG OF LONG CROP SUGAR CANE* RCHARD A. DUNCAN Exfieriment Station, Hawaiian Sugar Planters' Association i The pressing need for greater speed and efficiency in loading hand-cut sugar cane was answered by the use of the first mechanical equipment in the harvesting of sugar cane in Hawaii. Experimental work with several swing-boom and conveyor units ended in 1921, when the purchase of 2 P & H** crawler cranes established a system of sling-loading hand-cut and hand-piled cane. n 1934, a Castagnos cane grab was purchased to experiment with the Louisiana grab-loading system. Larger grabs were designed, and in 1935 the first plantation adopted grab loading. n the beginning, the cane was piled by hand, loaded by grab, and delivered to the mill in satisfactory condition. When this system gave way torakepiled hand-cut cane, the amount of rocks and soil mixed with the cane necessitated additions to the mill, and in 1937, an experimental rock and mud separator was installed. When the increase of leaf trash became objectionable, trash was first elimin- ' ated by burning, then by stripping. Development of cleaning plants progressed rapidly. The complete mechanical harvesting of cane ii Hawaii dates from 1937, when grab harvesting was initiated. By repeated operation of the grab in heavy tonnage cane, a load was quickly accumulated. A ground crew working with the machine continuously broomed the area so that they grab-handled most of the cane. n 1938, uncut cane was raked for the first time by a dragline rake pulled back and forth between 2 tractors equipped with wire rope winches. n 1940, the tractormounted pushrake for uncut cane was introduced and soon became standard for piling and windrowing cane; the grab had already become standard for loading (Fig. a, b, c). Because of its urgent need, the industry had arrived at 2 simple pieces of equipment to deliver heavy tonnage cane into the. transport. This might have been considered a solutio; to the problem except for the field damage, sucrose losses, and cleaning costs, which resulted. Because of the conviction that cane could be properly harvested, experimental work was begun as early as Actually, the first cane harvester had been invented by GNACA in 1906, but for a span of 30 years thereafter, almost nothing further had been done. * Published with the approval of the Director as pap;; No. 69 in the Journal Series of the Experiment Station, Hawaiian Sugar Planters' Association, Honolulu, Hawaii. Corp. (Formerly PAWLNG & HARNSCHFEGER). * * HARNSCHFEGER

2 614 AGRCULTURE A total of 27 different self-propelled experimental cane cutters and harvesters have been tried in Hawaii sipce This figure does not include improved models of Fig. la. Fig. ~b. some of the more promising machines or modifications of original machines. Of these machines, 25 were designed and built in Hawaii, 13 were fully financed by the HSPA, 2 by the HSPA in cooperation with specific plantations, 5 by plantations, 3 by plantations and an employee, and 2 by an individual. The 2 which were designed and built

3 RCHARD A. DUNCAN 1 Fig. a, b, c. The Standard Units for harvesting sugar cane in Hawaii, pushrake and grab. 1 on the mainland by FAL~NER and LETOURNEAU, were financed largely by these companies. These 27 machines are of 3 types: ) cut-only, 2) cut-pile-windrow, and 3) cutload. Each type included machines for both furrow-irrigated and unirrigated, or flat, cultures. All prime movers, except 2, were of the track type. These machines are described briefly, as follows : rrigated Cane CUT-ON?. Two-row, double V-type, ground cutting by means of 2 spear-shaped knives in the furrows. Two vertical cutting knives split the 2 rows and the prime mover, passing over and through the cut cane, was self-clearing. A 2-row pickup-loader was tried for piclring up the cut cane. Both machines were 2-way by turning. 2. One-row, V-type, ground cutting by means of rotary lrnife. A vertical cutting lrnife split the -row and the prime mover, passing through the cut cane, was self-clearing. The machine was 2-way by turning. Unirrzgated Cane. One-row, ground cutting by means of 2 revolving ground lmives and a revolving vertical lrnife on each side. The prime mover, passing over the cut cane, was self-clearing. t was 2-way by turning. 2. Two-row angle dozer, ground cutting by means of revolving discs. The cut cane was shoved to one side and was self-clearing. t was 2-way by turning the prime mover and changing the angle of the assembly. 3. One-row side-cutter-bar, ground cutting by meails of and later 2 rotary hives, with an oscillating, and later a rotary, vertical cutting knife at the end of the bar. The cut cane passed over the bar. The unit was -way and not self-clearing. 4. One-row side-cutter-bar, with cross-conveyor added baclr of bar malring unit self-clearing. 5. One-row side-delivery with rotary ground knife and siclrle bar vertical knife, self-clearing and -way. 6. One-row straddle wheel-type with rotary ground lrnives and rotary side vertical lmives, selfclearing and 2-way by turning. 7. One-row diiect-mounted with reciprocating spear-shaped ground knife and oscillating vertical

4 616 AGRCULTURE lrnives on the sides. Cane was piclred up and conveyed over the prime mover. Machine was 2-, way by turning and self-clearing. 8. Two-row V-type, ground cutting by angle blades, oscillating or rotary vertical knife at the center. Prime mover passes through cane. Machine is self-clearing and 2-way by turning. g. Two-row V-type, with rotary ground-cutting knives. 10. One-row sickle bar, ground cutting by means of a specially designed siclrle bar with an oscillating vertical knife at the end of the bar. Machine was not self-clearing and was -way. 11. One-row, ground cutting by angle blade on side of prime mover, and large diameter free-cutting vertical lrnife at end of blade but not attached to it. Cut cane passed over blade and under drive and support of vertical knife. Machine was not self-clearing and was -way. rrigated Cane i CUT-PLE-WNDROW 4. One-row (Ginaca), reciprocating ground knife, saw-type vertical side knife. Cane was conveyed over prime mover by means of a deck and overhead conveyor with a bundle side-discharge. Machine was self-clearing and -way. 2. TWO-row, turntable-type machine with reciproc~tin ground lrnives and oscillating verticle side lrnives. Cane was conveyed over the prime moyer by means of a declr and an overhead conveyor. Machine was self-clearing and 2-way by reversing. ;. Two-row cutter pushrake mounted on a crawler crane, wity reciprocating ground knives and rolling coulters for vertical side cutting. Machine was self-clearing and 2-way by reversing. 4. One-row with rotary ground lmife, rotary or oscillating vertical side lcnlfe, and deck-type conveyors. Side-mounted on prime mover and side-discharge. Machine was self-clearing and -way. 5. Two-row pushrake with rotary ground lrnives and no vertical side lmives. Machine was selfclearing and 2-way by turning. 6. Rake-type tines on a crawler-crane slrimmer boom. Machine was self-clearing and 2-way by reversing. Unirrigaled Cane. One-row with rotary ground knife, rotary or oscillating vertical side knife and deck-type conveyors. Side-mounted on prime mover and side discharge. Machine was self-clearing and -way. 2. One-row with rotary ground lrnives, rotary vertical side knives. Cane was carried over prime mover with a deck conveyor. Machine was self-clearing and 2-way by turning. 3. One-row side-cutter bar with a pushralre on the front of the prime mover to accumulate the previously cut row. Machine was self-clearing and -way. 4. One-row with special design prime mover, rotary ground knives, rotary vertical knife, and declrtype coilveyors. Partial side mount and side discharge. Self-clearing and -way. *. CUT-LOAD rrigated Cane. Two-row, wheel-type (LETOURNEAU), ground-cutting and vertical side-cutting by angle blades, helical lrnife for re-cutting, air blast for detrashing. Self-propelled transport loaded alongside. Self-clearing, and 2-way by turning. 2. One-row with rotary ground knife, oscillating and rotary vertical side mives. Cane conveyed over prime mover with deck conveyor. Self-propelled transport loaded at rear. Self-clearing, and 2-way by turning. 3. One-row with special-design prime mover, rotary ground knives, rotary free-cutting vertical side knives, deck type conveyors, recutting by revolving sickle bars. Self-propelled transport loaded alongside. Self-clearing, and 2-way by being double ended. 4. Six-ft.-diameter rotary cutter head attached at end of 25-ft. crawler crane boom. Cane finely cut, and thrown and blown through 10 in.-diameter pipe. Machine was self-clearing and reversible. Unirrigated Cane. One-row (FALCNER), rotary ground knives, rolling coulters for vertical side cutting, recutting by a revolving blade, suction for detrashing, special design prime mover, self-clearing and 2-way by turning. t is interesting to note that the necessity for cutting the division between the row and the adjacent cane was almost universally accepted, as was alsothe desirability of the track-type prime mover. The basic principles used are fewer than the number of

5 RCHARD A. DUNCAN new machines built. Almost all of the conceivable combinations have been tried. Four of these machines have survived the initial stage of development and are in use to a limited extent, namely, the 2-row V-cutter for unirrigated cane, the 2 sidemounted cut-windrow machines, for irrigated and the other for unirrigated cane, 3 and the special prime mover cut-windrow machine for unirrigated cane (Pig. za, b and 3a, b). A great deal of the cutter development has been aimed at improving the quality of cane delivered to the mill and reducing field damage, with the minimum change in the present harvest system. A self-clearing cutter-only, such as the V-cutter, is the ultimate in this respect. Pushrakes and grabs are used for windrowing and loading. For grab loading, there must be adequate concentration of the cane. A self-loading transport for V-cut unirrigated cane has been developed which reduces the use of the pushralce for windrowing. The cut-windrow type of machine accumulates the cut cane on the machine and concentrates it in heavy windrows. This accords with the present system of harvesting and reduces the use of the pushralte up to 95 %. Sometimes the windrows are placed along a roadside to ease the transport problem, but there is a definite limit to the amount of cutting time which can be sacrificed in the interests of transport. n 1954, it became apparent that the values of mechanical cutting alone are nominal. The ratoons are better and start to grow sooner when it is used, but little if any increase in sugar yield could be detected. Certain costs, such as replanting, could be drastically reduced, but the savings were surprisingly insignificant in relation to the total production cost. Since it was logical that a change of harvest equipment and system should at least pay its way, studies of sugar losses in harvest fields and cleaning plants, as well as costs of owning and operating cleaning plants, were given consideration. The criterion for the ultimate value of a machine or system was its ability to eliminate the use of pushrakes and grabs. This possibility always pointed to cutting and picking up sugar cane as a continuous operation, and sending it to the mill without returning it to the ground. As the first phase of a system, the current cut-load machine was designed and fabricated in t is a 2-way machine intended to reduce non-productive time and to eliminate the need for opening up at the ends of the rows. The double-ended arrangement was selected in lieu of the turntable type. The 2-way by means of direct mounting requires turning space at the ends of the rows. t is estimated that under some conditions the transport will be loaded directly; but in most Hawaiian fields, infield transport with transload to the mill-transport will be preferable, if not always essential (Fig. 4). A survey by the ndustrial Engineer has shown that the economic attractivenes of a cut-load system will depend on the amount of sugar which the system can save ' between the standing cane and the mill carrier. Contributions to better agriculture and reduction of certain costs, such as ratooning, are expected; however, it is difficult to show much economic advantage on these phases. Quite as important as development of machines and a new system are the field and irrigation layouts and the organization of harvest operations. Where rocks and other hazards exist, they must be reduced to a negligible level. Fields must be laid out to fit the characteristics of the machines since it is very unlikely thas machines without

6 618 AGRCULTURE Fig.?-a

7 RCHARD A. DUNCAN 619 limitations of any kind can be developed. f the machine can start operating without needing to have the field opened up, rakes and grabs could be completely eliminated. Fig. 3a. Fig. -ja, b. Side-mo~ulted and special prlme inover cut-wmdro~v machllles for irr~gated and un~rr~gated cane. Othcr important phases are the selection and training of operators, preventive maintenance programs as well as seasonal overhauls, and competent supervision of all operations. So far, no easy way of attaining a quality harvest job has been found. The profits

8 620 AGRCULTURE Fig. 4. Experimental cut-load machine, irrigated or unirrigated cane. are there, but must be earned by everyone from the plantation manager to the en-, gineer. The number of different cane cutters and harvesters are being increased from 27 to 28 in the attempt to attain a simpler, lower-cost harvester. A flail type, direct cut-throw unit, based on the design of forage harvesters of this type, is an entirely experimental unit to obtain such data as the minimum cane left on the ground, horsepower vs. capacity, etc. The possibility of developing such a machine into a successful production unit will be wholly dependent on the performance of this experimental unit. DSCUSSONS N. H. DONALDSON (Jamaica): What is the pressure of the air blast used on the detrashing machine? R. A. DUNCAN (Hawaii): t's low pressure, very low pressure, and high volume, in the neighborhood of $ lb, per sq. in. H. RODRGUEZ (Cuba): Was the cane shown in the film green or burned? MR. DUNCAN: The seed cutter was cutting green, unburned cane. The cut-load machine was cutting burned cane. The cutter-transport, believe, was cutting unburned cane also. t was too wet to get a burn. n harvesting here if they can get a bnrn, they do, even a partial burn.