Rigging Equipment Over The Floor (1980)

[Music] [Applause] Heat. Heat. [Music] The use of jacks. rollers, dollies, and other rigging equipment is subject to certain hazards that cannot be prevented by mechanical means, but only by the exercise of intelligence, care, and common sense. It is therefore important to have competent and careful personnel trained in the safe operation of the equipment and the handling of heavy loads. For protection of the rigger, protective clothing should include a hard hat, safety glasses, gloves, and safety shoes. To prepare to move a load, it is usually necessary to raise the load high enough to place skids, rollers, or dollies in place. On heavy loads, this is usually done by the use of jacks. There are normally several types of jacks available to the rigger. The ratchet, screw, or hydraulic type are the most often used. There are several good points to remember when lifting a load. Always make sure when raising a load that the jack is in a true vertical position and that it is resting on good footing. Always place a thin piece of wood between the lifting portion of the jack and the load to prevent the jack from slipping on metal-tometal contact. Do not place the jack directly on the ground. Even if the soil appears firm, the size of the jack base is not sufficient to support the lifting capacity of the jack on the ground. It is important that all jacks be alike with regard to type and capacity. Avoid the use of only one jack. The use of two will make the lift more stable. In jacking heavy equipment, it is a good practice to follow up each lift with temporary blocking. Scraps of 4x4, 2x10, and 1x6 blocks of wood can be used in various combinations to follow the load as it goes up. The blocking should be uniform on each side and each end. Should anything fail, the load would be limited in the amount it can drop down. This same procedure should be followed when lowering a heavy load. Always remember that regardless of the type of jack being used, it is important not to overload it. The lever or handle on a jack is designed by the manufacturer to ensure against overloading. A longer lever or cheater should never be used. Although the load can be lifted easier, it is possible to overload the jack due to the fact that the same force exerted on a longer lever will lift a greater load. Remove the operating levers when not in use to avoid accidental dislocation of the jack and reduce the tripping hazard. If step or ratchet type jacks are used, the lead man of the crew can signal verbally to keep the men operating in unison. In this manner, each jack takes a portion of the lift, avoiding a three-legged condition. If the load is to be left at the desired height for an extended period of time, shoring or cribbing should be placed under the load to take the weight off the jacks. Place the blocking in a crisscross arrangement to form a crib or pen. Placing all blocks on top of each other in the same direction invites tipping like stacked dominoes. When moving equipment, there are several methods which may be employed. Dry skidding, wooden or pipe rollers, heavy steel dollies, endless roller chain skids, and compressed air casters. When placing the rolls under a load, jack one end just high enough to place a roll about 1/3 of the distance under the load. Never raise the load higher than necessary to do the job. Place chocks in front and behind the first roll to prevent movement and locate the jacks at the other end. Jack the load high enough to place a roll at the halfway point and another about onethird of the distance from the end. Place another roll at the head of the load so it will enter once the load has started to move and clean the area in the path of the move to prevent the rolls from hanging up on small obstructions. As the rear roll becomes free, it should be moved to the front of the load to maintain equal spacing between the rolls. Caution should be taken in all roller operations that hands and feet are not caught under the rolls. Rolls should always be used when moving a load up a ramp. Chalk the rolls to prevent the load from moving backwards. Changes in direction can be made by striking the rolls near the end with a sledge in the direction the turn is to be made. Always chalk the rolls when leaving the job for an extended period of time or at the end of the working day. The use of 2x10 planks will provide a smooth track for the rolls when moving a load over rough floors, macadam or hard dirt. Ramps which must be built up from a surface to a truck bed should be supported at intervals with cribbing to carry the load. The rear wheels of the truck should be chocked to prevent movement. and jacks should be placed at the rear of the truck body to prevent the rear springs from altering the height of the bed when the load is transferred from the ramp to the truck. Endless roller chain skids operate around a loadbearing frame plate which supports the load. They may be the swivel type, the straight rigid type, or the swivel and lock type. Roller skids are placed as directed by the shape of the base of the load. The hardened teeth furnished on all type skids furnish the necessary friction by firmly embedding themselves into the wooden planks which are placed between the skids and the load. Always avoid metaltometal contact. In most cases, short pieces of planking just long enough to cover the skids will be enough. Care should be taken to prevent the load from sliding on these planks. An easy way to accomplish this is to nail chocks to the planking in convenient places. The use of two skids placed at one end of the load will double the capacity of a fork truck. Swivel skids can be used when turning is desired, but they should be closely supervised. Rigid skids can be used to move in a straight path. On loads requiring threepoint support, place two straight skids under the heavy end of the load and a swivel skid placed centrally at the other end. The single swivel skid is steered by the operator with the aid of the turning handle connector. Always use three skids unless the shape of the load requires the use of four. If four skids must be used, secure the skids to the load to prevent the loss of any one skid because of an uneven floor. For maximum turning, place four turn and lock skids under the load. When the desired point is reached, stop the load, unlock the swivel plate, and turn the skids to the angle required for the turn. All turns of the skids must be made while the load is stationary. In case of rough floors and extra-large weights, the turning of the skids will be made easier by arranging the move so that the skids will be stopped on a piece of thin gauge metal. The problem of roller skids digging into soft concrete and failing to track properly can be solved by laying steel channel on the floor to serve as a track. Large steel dollies with well pockets to receive 6x6 or 8x8 cross ties are the most desirable when moving heavy unstable loads. The load is rested on the cross ties eliminating metal-to-tal contact. The cross ties are wedged tight in the well pockets tying the dollies together. Four dollies are usually used, one located at each corner of the load. The dollies are equipped with swivel casters which allow the load to be moved in any direction. Wooden dollies with swivel casters can be used on light loads in any combination of two, three, or four dollies depending on the size and shape of the load being moved. When moving loads over a finished floor which must not be damaged, air casters are the answer. They are supported on a thin film of compressed air so no contact with the floor is made. If air casters are used on an uneven or rough porous floor, the air will escape and the casters cannot perform. To solve this problem, lay thin sheets of metal or masonite end to end to serve as a track. Tape the cracks where the sheets are joined to avoid loss of air from under the casters. Do not force movement of the load or damage to the casters will result. If increase in air pressure does not achieve complete flotation, some or all the casters are not getting enough air volume. A small amount of water poured around the casters will bubble when free float is established. When using air casters, friction between the floor and the casters is so low that a floating load will float downhill on a slight grade. Restrain loads for positive control with common rigging methods. To move loads over cracks that cannot be permanently filled, such as sliding door tracks, floor joints, or elevator gaps, materials such as thin gauge metal or unimbossed lenolium can be used to prevent loss of air under the casters. On a level floor, the amount of push needed to move a floating load will be roughly 1/ 1,000th of its weight. For example, a 3,000lb load on an air film will move with a force of 3 lb or less. When moving topheavy loads, the use of outriggers will prevent the load from tipping over. If in doubt whether the load is topheavy or not, it probably is. So, use outriggers to be safe. If the load has a water or oil reservoir on top, drain it to reduce the weight and lower the center of gravity. The outrigger should be secured to each end of the load and long enough so that the load will not tip should a roller skid or dolly be lost. When moving loads long distances or when the construction of the load requires it, timber skids are commonly used. The skids are for all practical purposes simple wooden beams fastened to the load. Chamfer the ends to permit easy entry of the rolls and prevent the skids from hanging up on small obstructions when dry skidding a load. Fasteners used to secure the skids to the load should be recessed into the underside of the beams to prevent contact with the floor rolls or dollies. When moving a load down a steep ramp and no restraint can be provided, dry skidding will provide enough friction between the skids and the ramp to prevent the load from moving freely. Control of the load during movement is important and can be accomplished in several ways. On light loads using wooden dollies, manpower will probably be enough. On larger loads using roller skids or steel dollies, a motorized tug bar may furnish enough power to accomplish the job. When using the tug bar, a block of wood between the tug bar and the load is recommended. On heavy loads, a lift truck may be required to furnish the necessary power to obtain movement. When moving any load, close observation of the roller skids, dollies, wooden rollers, or air casters is necessary for a safe move. Look out for obstructions or nearby materials which might get damaged. Another frequently used method to move a load is the snatch block and winch. A snatch block is a single block with one end of the frame arranged with a hinge to allow a loop of wire rope to be placed on the shiv instead of feeding the end into the shiv. The snatch block can be attached to the load or a building column and will double the pulling power of the winch. It also slows the movement of the load, giving the rigger better control. It may be used in combination with roller skids, dollies, or wooden rollers. Use softeners on the building column to prevent damage to the wire slings and the building column. The snatch block and winch is especially useful when dry skidding a load from a truck to a loading dock or when dry skidding a load down a ramp. When a snatch block is used, the hook should have a safety latch or be moused with wire, especially on a side pull as when attached to the load or building column. Safety in moving loads across the floor can be accomplished by selecting the proper equipment, care in its use, good training, common sense, and critical observation while the move is being made. [Music]