provision made for slinging. When the horizontal center of gravity of container is off the 'center of measurements, we provide slots in the skids and mark the cases at those points "Sling here." In addition we provide a center line on each side of the case indicating the center of gravity and so stencil it on the case. In photograph No. 1, page 11, it will be noticed that the skids are slotted at each end. This is for the slinging. The same feature will be observed in numerous others of the accompanying illustrations. Another way of providing for the use of slings is illustrated in photograph No. 25, page 93. However, since this photograph was taken an improvement has been made over this method. The horns or extensions which are shown in the photograph as engaging the slings are cut off and the underside of the skid is slotted for slinging. This reduces the cost of shipping to the extent of the measurement of the horns previously used since, of course, steamship companies figure cubic measurements over all extreme dimensions. In photograph No. 27, page 94, especially careful attention should be directed to the location of the slots in the skids which are cut out for slinging the apparatus, the center of gravity being midway between the two slots. The strings which are shown in one of the photographs, No. 23, page 88, are placed under the bearings in the process of packing rotating elements for electrical apparatus and are for testing application of weight applied to the several bearings in order that we may determine whether the strain as imparted by the load going into the container is being equally distributed to the three bearing points. The cribbing made to take the shaft bearings is a solid wood mass built so as to engage this shaft. Now before placing the load into the carrier or container, these strings are placed under each of the three bearings and as the load is lowered into the container, by the tension applied to these strings we are able to detect the equalization of pressure between the three points of bearings. CHAPTER V OFFICIAL SPECIFICATIONS-EXPERT INSTRUCTIONS REMENDOUS progress in the science of export packing was made during the course of the World War, and the lessons to be derived from the exact and specific instructions issued by the War Department of the United States Government are certain to ensure a marked improvement in the packing practices of manufacturers and shippers in general. Probably in no other country has the export packing problem been attacked so scientifically and in so thoroughgoing a fashion as in the United States, where national needs from the outset of the war brought officials face to face with problems of overseas shipping which were not encountered by other nations. The results of official study, painstaking investigations and comparison, the researches of the Forest Products Laboratory, plus the ingenious inventions of men called into the service of the army in devising the best possible packing methods-these all resulted in the publication of official specifications by the War Department and in a great deal of consequent and subsequent literature, based on these experiences and researches, which it is believed ought to be preserved in permanent fashion. Important excerpts are here included, with the conviction that the matter reprinted in this chapter will be found vital by every manufacturer or shipper disposed to give serious attention to this most important problem. Certain duplications have been omitted from the of ficial specifications reprinted in this chapter because identical advices or instructions appear in other chapters. It is none the less quite natural that there should be some repetitions of observations and instructions both among the documents themselves, which are now reprinted, and in the several other chapters of this book. It has been thought desirable to include many such repetitions, not only because sometimes involving slight variations in phraseology, but also because many of the problems dealt with merit repeated emphasis. The documents which follow include extracts from the War Department specifications on making boxes and packing in boxes; a pamphlet on the same subject by Capt. Knowlton, issued by the Safepack Mills; the War Department specifications on the making of crates, on baling and on marking; an article from "The Barrel and Box" on the nailing of boxes; technical notes from the Forest Products Laboratory, etc. STANDARD BOXING SPECIFICATIONS OF THE Nailed and locked corner boxes must be well manufactured from lumber which is sound (free from decay and dote) and well seasoned. Lumber must be free from knot holes and from loose or rotten knots greater than one inch in diameter. Knots whose diameter exceed onethird the width of the board will not be permitted, and no knots will be permitted which interfere with the proper nailing of the box. For these specifications, well-seasoned lumber has an average moisture content of 12 to 18 per cent based on the weight of the wood after oven drying. To determine this moisture content weigh a piece of material before and after oven drying to a constant weight, dry at 100° C. (212° F.), and divide the difference in weights by the lesser X 100. Width of Lumber.-(a) Any end, side, top, or bottom 6 inches or less in width should be one-piece stock. (b) No piece less than 211⁄2 inches face width shall be used in any part, except for cleats. (c) The maximum number of pieces allowed in any end, side, top, or bottom more than 6 inches wide should be as follows (narrow pieces should always be placed in the center of the ends, sides, top, or bottom): Width of face Six inches and under.. Over 25 inches... Maximum number of pieces 12345D CO Surfacing.—All material must be surfaced one or two sides. When surfaced one side the surfaced side shall be the outside. Joining.-Ends 1 inch or less in thickness should be either cleated or butt joined and fastened with not less than three corrugated fasteners, two driven from one side and one from the opposite side. Cleats should be not less than 2 inches wide and should have a minimum thickness of five-eighths inch. Triangular cleats of not less than three-fourths inch face measurement are permitted. Nails. All nails should be standard cement coated box nails. Plain nails driven through and clinched may be used for cleating. The size of the nail shall depend upon the species and the thickness of the lumber in which the points of the nails are held. When the nail specified for use under these specifications is not obtainable, use the next penny lower, and increase the number of nails in each nailing edge by one. 1 Metal Bindings.-All packing boxes for over-seas service must be strap ironed. Strapping shall be cold rolled unannealed steel not less than five-eighths inch wide by 0.015 thick, treated to prevent rust, and shall have a tensile strength of not less than 850 pounds. The treatment must be of a character to prevent injury to strapping when bent or nailed. Strapping placed at least 1 inch from each end is preferred, with double corner nails and such additional nails or staples holding straps to sides, top, and bottom 'See Capt. Knowlton's observation and recommendations under this head, Chapter III. as well minimizing festooning nails or staples spaced about 6 inches apart. Strapping must be drawn tight by mechanical means in order to have the maximum of tension. STANDARD SPECIFICATIONS FOR WIRE-BOUND BOXES Boxes must be well manufactured from lumber which is sound (free from decay and dote) and well seasoned. Lumber kiln dried at excessively high temperature or low humidities or below 6 per cent moisture, must be avoided. Material must be free from knot holes and from loose or rotten knots greater than 1 inch in diameter. No knots will be permitted which interfere with the proper nailing or stapling. Cleats. Cleat material must be free from knots and cross grain. Cleats must not be less than three-fourths inch wide, seven-eighths inch thick. Wires.-Wires shall not be less than No. 14 gauge nor spaced more than 6 inches apart. Staples. Staples shall be spaced not more than 2 inches apart over each wire. Staples which are not driven into cleats must be clinched. Ends. On boxes not to exceed 20 x 15 x 10 inches inside measurement and carrying not to exceed 90 pounds the ends may be the same thickness as the sheet material, and should be nailed or stapled on the inside of the cleats. Nails and staples shall be spaced approximately 2 inches apart. On larger boxes of heavier weights the ends shall be nailed to battens or to solid ends set between the cleats. A seven-penny nail must be driven through cleat into each end of each batten. Number of Pieces.-Sides and tops shall be one-piece stock, and bottom one, or two-piece stock if made of rotary-cut lumber not less than one-fourth inch thick. If two-piece sides and tops and three-piece bottoms are used, material must be at least one thirty-second inch heavier than one-piece stock, or wires spaced not more than 5 inches apart. |