Crane Operation and Load Handling
Operation and load handling begin with a lift plan: verify load weight, center of gravity, rigging, and the configuration represented on the chart. Know the radius-measured from the center of rotation to the center of gravity of the load-before the lift, and recheck it as the boom moves. Capacity falls quickly as radius increases, so a common operational error is planning at one radius and lifting at another.
Use smooth control inputs. Shock loading, side loading, and rapid swings can damage the boom or cause loss of control, and none of these conditions is covered by the load chart. Keep the load low and controlled when traveling, and only travel with a load if the manufacturer's travel chart and site conditions permit. Tag lines control rotation but must not be used to pull a load outside the radius. Communication is part of the lift: a qualified signal person, agreed hand signals or radio protocol, and a stop signal that anyone may give.
Avoid two-blocking by watching the anti-two-block device and the hook block; never rely on the device as a normal operating stop. Account for wind, especially with large sail-area loads. Multi-crane lifts require a plan, one person in charge, and reduced capacity per crane because load distribution is uncertain. Personnel lifting is prohibited except with an approved platform and compliance with the applicable standard.
Worked check: load 18,000 lb at 35 ft radius; chart capacity 24,000 lb. Add hook block 900 lb and rigging 600 lb: gross 19,500 lb, leaving 4,500 lb margin. If the load drifts to 40 ft where capacity is 20,000 lb, margin shrinks to 500 lb-so control radius, not just load weight.
Traps: reading radius at the boom hinge; subtracting rigging after comparing to capacity; using unqualified signalers; traveling with the load too high; and assuming the LMI prevents all contact.