Site Preparation and Hazard Assessment
Site Preparation and Hazard Assessment tests your ability to judge ground, setup, and surroundings before the boom goes up.
Ground and setup
OSHA 1926.1402 requires firm, level, drained ground, with blocking under outrigger floats sized to the actual bearing pressure. Lattice boom truck cranes are typically set on fully extended outriggers with floats on mats or cribbing; the chart assumes a level crane within the manufacturer's tolerance (often 1%). Check for underground voids, utility vaults, backfilled trenches, and asphalt over soft subbase. Use the crane's level indicator, not visual judgment.
Power lines
1926.1408 Table A sets minimum clearances from energized lines: 10 ft up to 50 kV, 15 ft for 50–200 kV, 20 ft for 200–350 kV, and higher above that. If you cannot maintain the clearance, the line must be de-energized and grounded, or you must use an approved option such as a dedicated spotter, proximity alarm, or encroachment prevention device. Treat all lines as energized until the utility confirms otherwise.
Hazard assessment
Walk the swing radius and tail swing; barricade accessible areas. Identify slopes, excavations, adjacent structures, other cranes, underground utilities, wind exposure, and escape routes. Wind acts on the boom and load sail area; stop when the manufacturer's limit is reached or the load is uncontrollable.
Worked example
Setting beside a 138 kV line requires 15 ft clearance. The planned boom tip path is 12 ft at maximum radius. The correct response is not to “watch it closely”; it is to de-energize and ground, relocate, or implement a permitted encroachment plan with a spotter and alarm.
Traps
Assuming asphalt is stable; using one mat size regardless of pressure; measuring clearance to the boom only; and ignoring tail swing.