4.14.1 Jacking mechanisms should be:
                        
                        
                        
                        
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                                 .1 arranged so that a single failure of any component
                                 does not cause an uncontrolled descent of the unit;
                               
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                                 .2 designed and constructed for the maximum lowering
                                 and lifting loads of the unit as specified in the unit’s operation
                                 manual in accordance with paragraph 14.1.2.8;
                               
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                                 .3 able to withstand the forces imposed on the
                                 unit from the maximum environmental criteria for the unit; and
                               
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                                 .4 constructed such that the elevation of the
                                 leg relative to the unit can be safely maintained in case of loss
                                 of power (e.g., electric, hydraulic, or pneumatic power).