By E.F. Lindsley JACKS, HOISTS & PULLEYS Use brains, not brawn to move heavy loads safely. On my first construction job I learned that every crew had one or two macho types who loved to boost their egos by bear-hugging some heavy piece of material or equipment and Sumo wrestling it into place. As the years went by I observed that most of these human derricks ended up unable to work because of badly damaged backs, arthritic joints, or severe injuries from so-called "construction accidents." How many expensive items they damaged with their roughhouse tactics is another question. Building construction, from the pyramid builders to the three-person crew erecting a modern home, frequently calls for moving or lifting heavy materials and objects.