CALIFORNIA AGRICULTURAL EXTENSION SERVICE CIRCULAR 47 October, 1930 EQUIPMENT FOR THE BULK HANDLING OF GRAIN ROY BAINER and J. D. LONG Cooperative Extension work in Agriculture and Home Economics, College of Agriculture, University of California, and United States Department of Agriculture cooperating. Dis- tributed in furtherance of the Acts of Congress of May 8 and June 30, 1914. B. H. Crocheron, Director, California Agricultural Extension Service. COLLEGE OF AGRICULTURE UNIVERSITY OF CALIFORNIA BERKELEY, CALIFORNIA 1930 Digitized by the Internet Archive in 2011 with funding from University of California, Davis Libraries http://www.archive.org/details/equipmentforbulk47bain EQUIPMENT FOR THE BULK HANDLING OF GRAIN ROY BAINERi and J. D. LONG2 Handling" grain in sacks, rather than in bulk is a peculiar feature of California agriculture, a feature which investigators are unanimous in declaring uneconomical under present day conditions. It has evolved from a day of limited rail transportation facilities and from the necessity of sailing vessels having a cargo which would not shift in making the hazardous journey ''around the Horn." Putting grain in sacks now as it is threshed results in sack costs, higher harvest-labor charges, field waste from rodents, theft and burned or broken sacks, higher warehouse handling and storage charges, insurance and waste and less incentive to improve the quality of the grain by cleaning out the dockage at country points. The practicability of bulk handling has been seriously questioned only in the case of export barley for malting. Experience has shown however that with careful handling and proper equipment the bulk method does not damage this high quality grain for brcAving purposes. For those lots of g-rain which may necessarily be marketed in sacks, it is preferable to harvest in bulk and sack from the elevator as the grain is being shipped. STORAGE OF BULK GRAIN Storage of bulk grain appears to be a ''bug-a-boo" to farmers who are considering changing from sack to bulk handling methods. It does constitute a problem, but not one sufficient to delay greatly the change. Of primary importance is the fact that bulk storage does not neces- sarily mean a loss in the identity of the grain. Individual lots of high quality grain can be separated as readily in the various sized bins of an elevator as in a sack warehouse. For economy of elevator opera- tion, however, lots of grain from various sources but of the same numerical grade may be placed together. The storage problem is greatly simplified in this state, particu- larly for farmers just making the change in their handling method, by reason of the fact that it is practical for grain to be stored on the ground for as long as three months following harvest. Where hard. 1 Assistant Professor of Agricultural Engineering and Assistant Agricultural Engineer in the Experiment Station. 2 Junior Agricultural Engineer in the Experiment Station. 4 California Agricultural Extension Service [CiR. 47 level ground is selected and cleaned of vegetation there is no grain waste of consequence. The chances of loss from fire and moisture are practically eliminated in grain so stored. Even in the middle-western states where light summer showers are common, grain is stored tem- porarily on the ground without great loss. Some California farmers have practiced ground storage for the past few years and under their marketing plan of selling the grain during or immediately after har- vest it has been shown that temporary or emergency storage on the ground is practical. Portable elevators facilitate the handling of the bulk grain (fig. 1). Fig. 1, — Ground stuiago on the T. A. Kilkenny ranch, Dixun, California, The canvas spread on the ground was used only the one year as it was found unneces- sary. A portable elevator and typical farm storage bins show in the background. Farm Storage. — Where grain is to be sold during or soon after harvest special farm storage structures, except for farm seed and feed, are of doubtful economy. Where the ranch is within 10 miles of a railroad siding and where the grain is handled by trucks, carrying direct from the harvester or a small-capacity transfer bin to a siding storage would seem more economical. As more farmers turn to bulk handling and the siding and terminal storage facilities become more congested, more farm storages vdll prove necessary. If properly located and operated, the farm storage will permit greater flexibility in marketing the grain, this advantage in some cases being sufficient to pay off in one season practically the entire erection cost. The selection of the type of farm storage structure will vary accord- ing to the individual requirements. Portable bins will be satisfac- 1930] Equipment for the Bulk Handling of Grain tory in some instances, permanent bins preferable in others. In some instances farm barns or sheds may be remodeled economically to provide sufficient storage. On steep hillsides provision can some- times be made to erect storag-es midway up the slope which can be filled from above and emptied from below, the grain being moved in and out entirely by gravity. Where considerable quantities of grain are being handled a number of bins grouped together with built-in elevators and conveyors will be required for economical handling. Provision should be made in such farm elevators for installing grain cleaners and grinders. Storage bins cost approximately 10 to 15 cents per busheP capac- ity ; farm elevators with built-in equipment 20 to 40 cents per bushel (figs. 2, 3, 4, 5). Fig. 2. — A portable grain bin built of wood. In an 8 X 8 x 12 foot size it will hold approximately 500 bushel. Construction features include solid bridging between floor joists, diagonal bracing let into the outside of the studs, and inside sheathing lapped alternately on the corners. A roof, a door, and outside sheathing may be added. Loading Elevator. — For an individual farmer handling a medium- sized grain acreage a portable or stationary elevator leg, loading direct from the truck into a railway car may be satisfactory loading equip- ment, and the only special equipment necessary. Where several such farmers cooperate but wish to make individual shipments, a loading elevator having storage units may be used. In its simplest form this consists of a stationary elevator leg surrounded by several bins of about 50 tons capacity, one for each farmer. Grain hauled to the ele- vator by an individual is put in his storage bin until a carload is accumulated, when it is loaded through the elevator leg into the car. 3 In figuring capacities of small grain storage structures l^/i cubic feet are allowed per bushel of grain. A sack may be considered as holding 2 bushels, 100 pounds of barley or 120 pounds of wheat at the normal weights of 48 pounds to the bushel for barley and 60 for wheat. Approximately 40 bushels of barley and 33 of wheat weigh a ton. California Agricultural Extension Service [C^R. 47 Such a structure may be expanded by the addition of storage units and cleaning machinery into the small country elevator, capable of handling a considerable quantity of grain (figs. 6 and 8). Fig, 3. — A transfer bin and portable elevator used on the Ealph Zacharias ranch, Patterson, California. Fig. 4. — A farm granary with built-in elevator, Remodeled Warehouse. — Structurally sound sack warehouses may be converted into storages for bulk grain but the few instances in which this has been done in California have not proven entirely suc- cessful. A great deal of attention must be directed toward securing the proper design and construction ; remodeling should be undertaken only after mature deliberation and consideration of the salvage value of the warehouse for other purposes. 1930] Equipment for the Bulk Handling of Grain In the instances where warehouses have been remodeled the costs have been practically as great as for new construction and the facili- ties provided inferior. It must be borne in mind that the success of bulk handling- depends upon having adequate facilities properly designed for their purpose. LLEIVATION PLAN Fig. 5. — A type of design for a large farm elevator. With four 16 x 30 foot bins and two overhead bins as shown (all self-cleaning) the capacity is 23,000 bushels. Country Elevators. — The dearth of elevators at country railway stations constitutes the weakest link in the efficient handling of bulk grain in California at the present time. Country elevators may be divided into two general classes — those in which the storage bins and workhouse are together in a single unit and those where workhouse and multiple storage bins are connected 8 California Agricultural Extension Service [C^R- 47 units. The latter type is apparently the more popular and offers greater possibilities for expansion. Properly built it is also more nearly fireproof ; the bins in such a design are usually of steel or con- crete and the isolation of the storage units from the working floors results in a lessened fire hazard. In the circular bin, monolithic con- Fig. 6. — Statiuuaiy clcvatur leg loading direct into railroad car. The truck dump pit is at the left of the elevator. Crete designs, the tanks may be arranged closely together in two or more rows and the spaces between tanks arranged for a bin, thus increasing the storage capacity of the plant. The convenience of operating the elevator is a most important item to consider in the design. If possible, it should be planned to be operated by one man, except for a relief man during rush seasons, in 1930] Equipment for the Bulk Handling of Grain 9 order to cut down the operating: cost. To make it possible for one man to handle a large capacity plant, labor-saving: conveniences nnist be built in. These may include control of all equipment from the ground floor of the work house ; a man-lift to facilitate inspection of the ele- vator head and other overhead machinery; a distributor head with which the discharge of the elevator may be directed into one of several bins from the work house floor ; car pullers for ' spotting ' railway cars for loading ; a large grain pit where a considerable quantity of grain may accumulate before starting the elevator leg ; various sized bins to accommodate various sized lots of grain; and hoppered bins to elimi- nate cleaning out flat-bottomed bins — an item of increasing importance where the bins will be filled several times during the season. With but few exceptions the location of the elevator should always be adjacent to a railroad siding or boat landing to secure gravity flow from the elevator head to the car or boat. The height of the head is important in securing sufficient momentum in the discharged grain to carry it to the rear of the shipping compartment without shoveling. In most elevators provision should be made for sacking some grain when this may be requested. Hoppered bin bottoms, besides saving labor, lessen the chance of some grain remaining in the bottom of the bins to harbor weevils and to cause a mixture of grains or grades. To provide a profitable activity for the elevator attendant during otherwise slack periods it may be advisable in some locations to con- sider carrying side lines — mill feeds, flour, coal, ice, hay, etc. — as is done in mid-west elevators. Selection of Materials and Design of Elevato7\ — The selection of the kind of elevator best suited for erection in any locality will depend on the construction material preferred, the type and capacity required, and the cost involved. Three materials — lumber, steel and concrete — are being used in California elevators. Lumber is utilized by nailing dimension mate- rials (2 X 4 or 2 X 6) flatwise, called cribbing, or by using a well braced wood frame and bins lined with matched lumber. Either construc- tion may be sufficiently sturdy, but the crib construction settles a great deal during the first filling and requires careful handling during this period. Lumber construction has the advantage of low first cost but offers trouble with grain weevils and has a high insurance rate. Steel has been used to a considerable extent in this state. There appears to be no truth in the rumor that grain sun-burns on the exposed side of such bins. Some trouble has been experienced, however, in the tanks of light weight metal sheets from wind damage and with the side- 10 California Agricultural Extension Service [Cir- 47 wall crinlding' near the bin outlet, where this was located near the side, due to a release of pressure near the bottom as the grain started t® flow out. These difficulties have apparently been satisfactorily met by reinforcing- the top edge with an angle iron collar and the sidewall with vertical braces. It is possible to secure metal tanks of heavy gauge sheets or i)lates which do not require special reinforcing. Port- land cement concrete is used in both the monolithic and stave forms. The stave type can be moved if necessary with relatively little loss ; the monolithic may be made somewhat stronger and so is generally used for the larger elevators. Monolithic concrete bins are preferably ^ Pig. 7. — Two monolithic concrete storage bins and metal covered workhouse used by Fred Harvey, Gait, California. A design which may be expanded into a large elevator. poured continuously, day and night, to avoid horizontal construction joints. Square, rectangular and hexagonal shaped bins may be poured of concrete but the circular tanks are usually cheaper in the sizes 14 feet in diameter, and larger, due to a more efficient use of m^J:erials per unit volume. Division walls and floors may be included in the design of monolithic concrete tanks to divide the tank vertically or horizontally into several bins. In both the monolithic and stave con- crete types attention must be given to waterproofing (figs. 7, 8 and 9). The type of elevator selected should be governed by the individual conditions. In general this will depend on the number, size and arrangement of the storage bins needed ; the characteristics of the site and use ; the construction material preferred ; and the preference of the owner. The height of the bins affects the economy of the structure ; 1930J Equipment for the Bulk Handling of Grain 11 Fig. 8. — Loading plant of Balsdon and Scarlett, Graino, California. Fig. 9. — A concrete stave elevator. 12 California Agricultural Extension Service [C^R- 47 the higher the structure — up to about a 60-foot maximum for country elevators — the cheaper the unit-capacity usually becomes. The head- house of the elevating shaft should be kept as low above this as possible. Putting in short elevators between machines on the same floor level may be cheaper than building a higher workhouse for all-gravity flow. To escape broken and cracked grain, particularly objectionable in the case of export barley, belt conveyors should be used for horizontal movements of grain rather than augers or screw conveyors. Elevators designed to handle rice as well as wheat and barley should be equipped with a separate elevator, cleaner and scale for the rice, to avoid the possibility of mixing grains. Lacking this, special attention should be given to the selection of equipment which can be thoroughly cleaned. The capacity of the elevator legs is an all-important characteristic, for the satisfactory operation of the plant. The elevating capacity should be at least equal to the maximum speed with which grain is likely to be delivered to the elevator; facilities in the design for increasing the capacity of the elevator by changes or by adding a sec- ond elevating leg should be considered. The cleaning capacity will vary from that sufficient to clean 100 per cent of the receipts as they enter the elevator to only 5 or 10 per cent for seed purposes. A cleaner may be operated 24 hours a day during the rush season and this over- load capacity may be considered in the design. Even where a cleaner is not desired or intended in the original layout it will usually be an economy to plan space to accommodate one at a later date without extensive alterations. Storage capacities will likewise vary from 100 to 10 per cent of the average season's receipts, the lower range consti- tuting what is usually termed a loading station. Because of the natural movement of grain during harvest to the terminal mills and elevators, and the likelihood that some grain will be stored on the farms, from 25 to 50 per cent storage is usually sufficient for a country elevator. Provision should be itiade, however, for increasing this capacity without extensive remodeling (figs. 10, 11, 12). The decision as to which material, type and capacity best suits the individual condition wdll rest with the owner. Usually, and right- fully so, it will depend largely on costs — an elevator is a commercial investment which should pay dividends. In considering costs two items are of interest — the initial and the annual costs, the latter being much the more important to a properly financed builder. In computing the annual costs both overhead and operating charges should be considered. The former consist of inter- est on the investment, up-keep, and depreciation; and the latter of 1930] Equipment for the Bulk Handling of Grain 13 5ECTIOM AA 1 2 3 4 5 6 7 8 9 10 It 12 t3 14 15 16 17 18 19 20 5U 22 23 24 z PLAN rig. 10. — A type of elevator design particularly suitable to lumber construction. 14 California Agricultural Extension Service [CiR. 47 labor, power and incidentals, including fumigation and insurance. Up-keep can be kept at a minimum by proper use of materials and by ' ' good housekeeping. ' ' Depreciation should not be figured over a term longer than 20 to 30 years, as at the end of that period changes in LLLVATION PLAN Fig. 11. — A type of design with high workhouse and low storage bins for metal construction. The storage can be increased by adding units to the left and putting in horizontal conveyors. local conditions, methods or equipment may render the structure obso- lete. The operating costs will depend largely on the plan of the elevator and the quality of the equipment. Forethought in planning the details of the elevator design and management will be amply repaid in lower operating costs and more satisfactory operation. SECTlon AA PLAN Fig. 12. — A type of design especially suitable for a medium to large concrete elevator. Not« the two divided transfer bins (X) and the interstice bins (Y). A horizontal belt conveyor is used above and below the storage bins. 16 California Agricultural Extension Service [Cir- 47 The initial costs of elevators which have been erected diiring^ the past few years have averaged from 20 to 45 cents per bushel, based on the storage capacity, this figure including all equipment and struc- tural costs. FIELD EQUIPMENT FOR THE BULK HANDLING OF GRAIN The field equipment necessary for the bulk handling of grain con- sists of some type of bin, usually mounted on the harvester, and a grain-tight box, mounted either on a truck or wagon, for hauling the grain from the machine. Fig. 13. — The weight of bin and contents are carried on the main frame of this remodeled harvester. The size of the bin on the harvester depends to some extent upon the size of the hauling equipment. It should have capacity to hold a little more than one truckload of grain so that the harvester will not be forced to stop because of short delays of the trucking equipment. There are two general methods for mounting the bin on the har- vester ; one in which the weight of the bin and contents are carried oti the main frame of the harvester as shown in figure 13 ; the other in which an auxiliary wheel or truck is furnished to carry the extra weight as shown in figure 14. In general the latter method is to be 1930] Equipment for the Bulk Handling of Grain 17 recommended, where a chang'e is being made from sack to bulk hand- ling equipment, since in most cases the frames and wheels of these machines were not originally designed to carry the added weight of a bin of grain. This added weight, when carried on the frame, often- times puts such a strain on the machine that the different parts are thrown out of alignment. This is especially true on rough ground. However, there are several machines throughout the state with bins mounted directly on the frame, that are operating entirely satisfac- torily. Fig. 14. — An auxiliary wheel or truck is a satisfactory means for carrying the bulk bin. Both types of bin mounting are employed on harvesters now on the market (fig. 15), but in these cases, the added weight was taken into consideration in their design. Another method of handling the bulk grain at the combine is shown in figure 16. A wagon equipped with a grain-tight box is simply trailed alongside of the machine. This offers a quick easy way for making the change, but there -are only a few instances where it can be used since the motor truck is almost universally used for hauling grain at the present time. Several wagons would be needed, especially if the haul was very long. Then, too, considerable time is lost in chang- 18 California Agricultural Extension Service [Cm. 4^ ing' the wagons. The corners can not be turned quite as short, because of the longer turning radius required for the wagon. All companies manufacturing harvesters, make bins which may be mounted directly on the machine, or carried on an auxiliary wheel, to Fig. 15. — -Both types of bin mounting are employed on harvesters now on the market. take the place of sack handling equipment. The cost of these installa- tions varies considerably with the different models, because of the remodeling necessary on some of the harvesters to accommodate the bins. Quotations may be had on these machines by writing to the manufacturers. 1930] Equipment for the Bulk Handling of Grain 19 Fig. 16. — lliL' \va