Practice 2
2 hours
Learning Objectives
- •Apply OSHA Subpart P excavation rules to backhoe loader trench work
- •Recall Massachusetts Jackie's Law trench permit and notification requirements
- •Integrate inspection, hazard recognition, and safe operation into job-site decisions
- •Confirm exam readiness across all four modules
Topics Covered
- •Review: OSHA Subpart P — 5-foot cave-in protection threshold, soil types A/B/C, sloping ratios
- •Review: access/egress within 25 feet, spoil and equipment 2 feet from the edge, water accumulation rule
- •Review: 20-foot depth threshold for a registered professional engineer's protective system design
- •Review: Massachusetts Jackie's Law (520 CMR 14.00) — trench permit on public or private property, unattended-trench protection, one-hour State Police reporting
- •Review: Dig Safe (811) utility location and hand-dug test pits before machine excavation near utilities
- •Review: pre-shift walkaround and removal-from-service conditions; competent-person daily excavation inspection
- •Review: tip-over, struck-by, cave-in, and overhead power line hazards; slope operation; never lift personnel in a bucket
- •Final scenario practice integrating regulations, equipment, and operation with full reasoning
Resources
Self-Check Questions
Question 1: You are about to dig a 6-foot-deep trench in Type C soil with a backhoe loader and workers will enter it. Which is required?
- A. Nothing — 6 feet is shallow enough to skip protection
- B. A protective system: slope the walls back to 1 1/2:1, or use shoring or a trench box(correct)
- C. Only a warning sign at the edge
- D. A registered engineer's design, because all trench work requires one
Show Explanation
Explanation:
At 5 feet or deeper, cave-in protection is required. In Type C soil, simple sloping must be 1 1/2:1, or you must use shoring or a shield (trench box). An engineer's design is only required beyond 20 feet.
Question 2: A homeowner hires a crew to dig a trench across a backyard on private property. Does Jackie's Law require a permit?
- A. No — Jackie's Law only applies to public ways
- B. No — private residential work is exempt
- C. Yes — Jackie's Law requires a trench permit on public or private property(correct)
- D. Only if the trench is deeper than 10 feet
Show Explanation
Explanation:
Jackie's Law was enacted after a child died in an unprotected backyard trench, so it deliberately covers private property. A trench permit is required before creating a trench on public or private property.
Question 3: A trench will be left open overnight, unattended, on a job site. Under Jackie's Law, what is required?
- A. Nothing, as long as work resumes the next morning
- B. It must be made safe against unauthorized access — for example with covers, barriers, or backfill(correct)
- C. A single strand of caution tape
- D. It only needs protection if it is near a school
Show Explanation
Explanation:
Jackie's Law requires unattended trenches to be made safe against unauthorized access using covers, barriers, or backfill. An open, unguarded trench overnight is exactly the hazard the law targets.
Question 4: You are digging near a marked gas line with the backhoe. What is the correct practice?
- A. Dig at normal speed since the line is marked
- B. Hand-dig a test pit to expose the line, then excavate near it carefully by machine(correct)
- C. Skip the call to Dig Safe since the line is already visible on a map
- D. Use the loader bucket to scrape the line clean
Show Explanation
Explanation:
Locate marks are approximate. Hand-dig test pits to physically expose the line so you can see exactly where it is, then work carefully with the machine. Striking a gas line can be catastrophic.
Question 5: During your pre-shift walkaround you find the reverse alarm is not working and the operator's rear view is obstructed. What must you do?
- A. Operate normally and back up slowly
- B. Remove the machine from service, or do not back up unless a designated employee signals it is safe — the alarm is required under 1926.602(correct)
- C. Have a coworker shout when backing
- D. It is only an issue when working at night
Show Explanation
Explanation:
1926.602 requires a working reverse alarm when the rear view is obstructed, or a designated signaler to direct the backing. An inoperative alarm with an obstructed view means the machine cannot legally or safely be backed until corrected.
Question 6: Spoil from a trench is piled right at the edge of the excavation. Why is this a problem?
- A. It looks unprofessional
- B. The spoil weight is a surcharge load on the trench wall and a common trigger for cave-ins; OSHA requires it kept at least 2 feet back(correct)
- C. It blocks the backhoe bucket
- D. It is only a problem in wet weather
Show Explanation
Explanation:
Spoil at the edge adds downward surcharge load on the trench wall, a leading cause of cave-ins. OSHA requires spoil, materials, and equipment to be kept at least 2 feet from the edge.
Question 7: A competent person inspected the trench this morning, but a heavy rainstorm just passed through. Can work resume immediately?
- A. Yes — the morning inspection covers the whole day
- B. No — under 1926.651, the competent person must re-inspect after rain or any event that increases hazards before work resumes(correct)
- C. Yes, as long as the trench box is still in place
- D. Only the operator needs to glance at it
Show Explanation
Explanation:
1926.651 requires the competent person to re-inspect after rainstorms or any other hazard-increasing event. Rain dramatically changes soil stability, so a fresh inspection is mandatory before workers re-enter.