.4S241 Conveying to pile* forest products laboratory t forest service A 12) 11 //Y ' ^°\ °| - I L U ' S ' DI£PAR ™ ENT 0F AQR1CULTURE _M4- 'Z>J* ^^- * m 'SC SMALL SAWMILL IMPROVEMENT PRACTICAL POINTERS TO FIELD AGENCIES METHODS OF LOADING LUMBER AT THS REAR ; = L Several methods which permit more orderly handling of lumber the small sawmill warrant more general adoption. Depending upon production vol- ume, one or another of these methods appears well suited to various types of small mills. These methods are in addition to the one described in a previous report of this scries (See .4S2221*) which has proved effective '-mere neighboring and yards do not require extensive track way. Lumber Proo. — Mills built directly on the ground can use the lumber prop method, which permits grouping of items by species, thickness, width, length, or grade at the mill instead of at the pile. A series of rolls carries the lumber out the rear of the mill, and one man piles it, by required items, on special props (fig. l). Spacing between props should be adcauate to permit backing the "agon truck or bumuer under the load; the prop is just high enough so that the vehicle's bunk conta.cts the load about an inch ahead of the prop, th< prop itself being placed about one- third the length of the load from the front end. About 500 board feet make a load. The bummer or other two-wheeled vehicle is backed under the load so as to en- gage it just ahead of prop. The load is chained to the bunk and, with the driver standing on the front end to minimize drag, the bummer is started, causing the prop to fall forward* The back of the load drags on the ground. One man drivin i single horse can usually move production from mill to pile where the yard is with- in a quarter-mile of the mill. Rolls. — For mills built off the ground, a simple yet effective method to handle loads up to 1M board feet utilizes an inclined platform and rollers (fig. 2). The platform's incline from mill to truck is 1-1/2 inches in 10 fe . .th the rear about 2 inches above the truck bed. Three wnnrt ml ir-.r^ r.anh— £»i in In "11 n dia- meter and 7 feet long, are blocked on the skids 5 feCV'ajpart,- i^lQ'pfif^f orj f are required, the platform is extended to carry several loflUtVi** liur. ^o transfer the load to the truck, the vehicle is placed oppositl the load so that the llngest boards will clear the platform when the lumber has blen shifted ioi U^«truckl A 4" x 8" x 7' timber is placed on the truck bed about la lootQfWdm^rts'n'e^r, v.'itk the 8-inch face on the truckbed. a 5-inch roll* r is Iplaced just ahead on thi truck bed, the blocks are taken from under the rollers supporting the load, and usJally gravity moves the load on the truck. As it engages tneyffificj{Jy^\fll'Qf HQ ElP, 3 ) nd before the rear of the load drops off the platform, ti^'aJLJ .H" Ihi"I'li ill "a. Tried with the 4-inch fa.ee against the truck bed to minimize the shock of the dro . Loadii v -, Sca ffolds . — Variations of devices to support loads clear of ground, so that a vehicle can be backed under and the load icked up as a unit (figs. 3 and 4) are suited to mills built off the ground. (One very like that of figure 3 but for lighter loads has been previously described in . 4S2I '*.) The type shown in figure 3 is used for loads of about 1M board feet moved by a truck or wagon relatively short distances to the yard. No grouping is usually made at the mill, other than some sorting of like items within the load. Usually R899-16 1 Maintained at Madison, Wisconsin in cooperation with the University of Wisconsin. See outline in Small Sawmill Improvement Working Plan, March 1930, for explanation cf indexing system proposed. * two m n transport and pile the production directly from the vehicle. Sup >orts (a) are hinged. The ground line of the road "bed is so inclined that, in backing be- tween supports (a), the rear end of the truck bed, or, if bunks are used, thv rear bunk, engages the load of lumber just ahead of support (b). As the truck continues to bac". , the load is lifted clear of support (b), and supports (a) fal ba.ck, pivoting on the hinges. If 3 truck bed is used, cross members must be placed so fs to support the load more than 6 inches off the bed, to allow (c) to bo taken from under the load. The distance between supports (a) and (b) will depend upon the truck bed length or distance between bunks; the extension of lumber beyond the support (c) is regulated to clear the cab. The width of the pile is that readily taken on the trv The type shown in figure 4 is used for truck-trailer loads of 4M board feet and relatively long hauls. The load is supported to just clear the bolsters as the iler end truck pre backed under. The driveway is planked under the load, end enough incline given to eng;.ge the trailer bunk with the lor i at the moment the bunk of the truck is behind the support (a). The jack is placed en support (b) and one end of support (a) is lifted, the blocks removed, end the end of the sup- port lowered until it rests on the post. The jack is taken to the other end of support (a), ?.nr the process repeated until the support can be r . load is chained to the vehicle : s then ready to move. The s] scifications in figure re for bunks 8 feet wide, dual drive, and dual wheel trailers. Sliding Skids. — The specifications shown in figure 5A ere for truck-trailer loads of 4M board feet and relatively long hauls. The lumber is piled across skids (a) to a load width suited to the bunks of the carrier as indicated ^oy angle iron guides (b), To ; .ovc the load, a cable from a hand v ; anchored bund hi h across the truck road is connected to the chains (c) and, ' ._:. oper; I , pulls the loaded ski. In ovor the rolls. Loading and unloading are facilitated if truck raid trailer bunks are provided with 4-inch channel iron bolsters with rollers inset to clear the bolster by about l/2 inch (see fig. 53). The truck is placed so that the skids will be ahead of the bolsters rather than opposite, the skids bein moved when the load is placed on the bolsters. If r : truck with a solid bed is used, the skid.s arc pulled directly on the truck bed and remain under the load. 3y lengthening the skidway, several loads can be stored i ainsl irregul. rities of truck schedules. The truck driver or helper operates the Lch. At the de- livery point, unloading consists in piecing a heavy chain around the load and pull- ing it laterally on the skids by a power device, or by lifting the lord with an overhead, crane. Trucks and Rails . — Another method suited to heavy loads requires two firmly fixed sections of railroad rails, each of a length equf the over-all load width (7 feet) across the true ie (fig. 6A", . On. rail is about 30 inches back of the rear axle of the truck and the other about 7 feet ahead 0: rail. Kiln trucks with a welded extension (fig. 63) cen be placed on rails ck of the mill, spaced exretly es the rails on the truck. The motor tni'"k is spotted so that its rails are rn extension of those from the mill, with not over a 3-inch gap. A jack is used under each end of the rail nearest the crib to bring to and hold the true rails at the same level as those of the mill. A winch and cable ■ re used to pull the load on the truck. At the unloading point, rails ro- vided with the proper spacing to permit running the kiln trucks with the lumber off the ha,uling truck, using jacks and winch as outlined. Contributed I . J. fc , Forest Products Laboratory, £899-15 -2- November, 1941 Digitized by the Internet Archive in 2013 http://archive.org/details/oadingOOfore < PROP IN PLACE 1x6 I BOARDS •< 4-0 *■ 1 1 1 1 1 J_ r - '- -, E i i i i i i mJk.-. i i SIDE VIEW OF PROP END VIEW OF PROP FIG. 1 LUMBER PROP METHOD FIG. Z INCLINED PLATFORM AND ROLLERS Z U 40072 r IV) k <5> k 5 k k k k -J k FIG. 5 A SLIDING SKIDS IN£L IRON BOLSTERS FIG. 55 TRUCK TRAILER FIG h A RAIL TRUCK fc?. SKIDS IN PLACE WELDED CONSTRUCTION 7' : - h " M H . .— — "-« 4' CHANNEL lftON\ ^^P 4' CHANNEL IHON\ ^ DETAILS OF SKID Z 11 40074 F FIG. 6B RAIL SKIDS UNIVERSITY OF FLOKIUA M«| 3 1262 08926 8857 (