Mobile Crane Nccer Study Guide 2

In a two crane lift the center of gravity should be - Answer - Closer to the crane with the greatest capacity For rubber-tired cranes working on rubber, the part of the load chart governed by stability is based on what % of the crane's capacity? - Answer - 75% As a general rue on tandem crane lifts neither crane should be loaded greater than what % of net capacity - Answer - 75% On long boom cranes, what is the major effect of abruptly stopping a rapid swing? - Answer - Action may overturn the crane or collapse the boom The most important thing to remember when performing dual crane lifts is: - Answer - The cranes should not be loaded beyond 75% of their rated capacity The total weight of a loaded personnel platform and related rigging shall not exceed what % of the rated capacity for the radius and configuration of a crane or derrick - Answer - 50% Pre-operational inspections are necessary and required: - Answer - Enhance cranes safety by discovering discrepancies prior to operating. If a crane has to be level to within 1% of grade, the maximum allowable variation in grade in a horizontal distance of 20' would be: - Answer - 2.4'' On a standard running rope, how many broken wires are cause for considering replacement? - Answer - 3 broken wires in one strand in one lay On a standing rope, how many wires need to be broken at an end connections before replacing? - Answer - 2 According to ASME B30.5, mobile crane standard, how many randomly distributed broken wires in rotation- resistant- rope is cause for considering replacement of the rope? - Answer - 2 broken wire in 6 rope diameters The lay length of a wire rope is defined as - Answer - Distance of one strand as it makes one revolutions which of the following signifies the grade of steel used in wire rope? - Answer - XIP (Extra Improved Plow Steel) Which end fitting has the highest efficiency rating? - Answer - Swaged Sockets