The least sign of binding at the juncture points of links indicates collapse in the sides of the link caused by stretching. Such a condition is dangerous, and the chain should be removed from service.
When hoisting with slings, you may often need to use spreader bars to prevent crushing and damaging the load. Spreader bars are short bars or pipes that have eyes fastened to each end. By setting spreader bars in the sling legs above the top of the load (fig. 1-14), you change the angle of the sling leg and avoid crushing the load, particularly the upper portion.
The use of cargo PALLETS in combination with slings is a big advantage on jobs that involve the hoisting and moving of small-lot items (fig. 1-15). You may need to use spreader bars when hoisting pallets to avoid damaging the pallets and load. The pallet provides a small platform or board on which a number of items can be placed and moved as a unit rather than piece by piece. Palletizing obviously is quicker and easier than moving each individual item separately.
The safe movement of equipment and materials does not just happen. It takes knowledgeable people to communicate, control, and rig movements. Personnel safety, undamaged materials/ equipment, and
Figure 1-14. - Use of spreader bars in a sling.
Figure 1-15. - Cargo pallets in combination with slings.
operational efficiency are the responsibility of all personnel involved.
CEs are frequently required to act as signalmen for crane or hoist operators and for the positioning of equipment. There are a number of precautions and procedures that should be observed in these operations.
Whenever the operator's view is obstructed so that he cannot see the path of travel of any part of the equipment, load, or components, a competent signalman is required to be stationed in such a position that he or she can be easily seen by the operator and where the signalman has a full view of the intended path of travel of the equipment, load, or components, yet where he or she will be clear of the intended path of travel. The signalman should assist the operator by watching the load when it is out of view of the operator and communicating with the operator by the use of prearranged visual signals (app. III) or a suitable communication system.
The signalman must
be fully qualified by experience with the operation.
wear high-visibility gloves.
use hand signals only when conditions are such that the signals are clearly visible to the operator.
be made responsible for keeping the public and all unauthorized personnel outside the operating radius of the crane or the path of the equipment.
direct the load so that it never passes over anyone.Continue Reading