NCCCO Site Hazards & Risk Assessment 2 — Questions and Answers
Question 1: What is the first step in a job site risk assessment for crane operations?
- Set up the crane immediately
- Conduct a site survey identifying all hazards including power lines, underground utilities, ground conditions, overhead obstructions, and proximity to structures (Correct answer)
- Just ask the foreman about hazards
- Read the load chart
Correct answer: Conduct a site survey identifying all hazards including power lines, underground utilities, ground conditions, overhead obstructions, and proximity to structures
A comprehensive site survey identifies all potential hazards before the crane arrives. This includes overhead (power lines, structures), underground (utilities, voids), and surface (soft ground, slopes) hazards.
Question 2: What underground hazard must be identified before setting up a crane?
- Gold deposits
- Buried utilities (gas, electric, water, sewer) and underground voids or structures that could collapse under crane weight (Correct answer)
- Underground rivers only
- Nothing — crane outriggers can handle any ground
Correct answer: Buried utilities (gas, electric, water, sewer) and underground voids or structures that could collapse under crane weight
Underground utilities can be ruptured by outrigger loads, and underground voids, basements, or tunnels can collapse. Utility locating (dial 811) and ground surveys are essential before crane setup.
Question 3: How should ground bearing capacity be evaluated for crane setup?
- If the crane doesn't sink, the ground is fine
- Through engineering analysis of soil type, recent weather (saturation), fill vs. native soil, and proximity to excavations (Correct answer)
- Just use larger outrigger pads
- Ground bearing capacity is only relevant for very heavy cranes
Correct answer: Through engineering analysis of soil type, recent weather (saturation), fill vs. native soil, and proximity to excavations
Ground bearing capacity evaluation considers soil type, moisture content, fill material, proximity to excavations, underground structures, and freeze-thaw conditions. Engineering analysis may be required for heavy cranes.
Question 4: What is the hazard of setting up a crane near an open excavation?
- Dust from the excavation
- The excavation may have weakened the surrounding soil, which could collapse under the crane's weight causing the crane to tip (Correct answer)
- No hazard if the excavation has shoring
- Only matters for excavations over 20 feet deep
Correct answer: The excavation may have weakened the surrounding soil, which could collapse under the crane's weight causing the crane to tip
Excavations create zones of reduced soil strength. Crane loads near excavation edges can cause the wall to collapse, pulling the crane into the excavation. The angle of repose determines the safe setback distance.
Question 5: Before a lift, what weather conditions should be assessed?
- Only temperature
- Wind speed and gusts, precipitation, lightning, visibility, and temperature extremes (Correct answer)
- Only if rain is forecast
- Weather doesn't affect crane operations
Correct answer: Wind speed and gusts, precipitation, lightning, visibility, and temperature extremes
All weather factors affect crane safety: wind (stability, load control), rain (visibility, ground conditions), lightning (electrical hazard), cold (brittle steel, ice), and heat (operator fatigue, hydraulic efficiency).
Question 6: What is a 'critical lift' and what additional planning does it require?
- Any lift over 10 tons
- A lift that exceeds 75% of rated capacity, involves hazardous materials, or passes over occupied areas — requiring a detailed, engineered lift plan (Correct answer)
- A lift that takes more than an hour
- Any lift in bad weather
Correct answer: A lift that exceeds 75% of rated capacity, involves hazardous materials, or passes over occupied areas — requiring a detailed, engineered lift plan
Critical lifts have higher consequences of failure. They require an engineered lift plan, review by a qualified person, pre-lift safety meeting, increased monitoring, and contingency procedures.
NCCCO Site Hazards & Risk Assessment 2
What is the first step in a job site risk assessment for crane operations?