230 CMR 6.00 — Rules Specific to Excavating Machinery
1.5 hours
Learning Objectives
- •Explain the role of 230 CMR 6.00 relative to MGL Chapter 146
- •List the four 230 CMR 6.00 operating rules that apply to all 2A equipment
- •State the SAE hand signal standard required by 230 CMR 6.00
- •Identify who may ride on or operate the machine during a job
Topics Covered
- •230 CMR 6.00: minimum safety standards for hoisting machinery in MA
- •SAE J1307-2023: the required hand signal standard for excavating machinery
- •Only approved signaler may direct operator movements
- •No unauthorized personnel on machine during operation
- •Crew may include operator plus one apprentice under direct supervision
- •No persons within full working radius during bucket/boom swing
- •Prohibition on straddling open trenches with excavating machinery
- •Operators must follow all manufacturer specifications
- •Differences between 230 CMR and 520 CMR references
Resources
Self-Check Questions
Question 1: Under 230 CMR 6.00, who is the ONLY person authorized to direct an excavator operator's movements on a job site?
- A. The general contractor's site superintendent
- B. Any crew member present at the job site
- C. The approved signaler assigned to the machine(correct)
- D. Either the operator or the site safety officer
Show Explanation
Explanation:
230 CMR 6.00 requires that only an approved signaler direct the operator. Taking direction from anyone else — even a supervisor — violates the regulation and creates unsafe conditions.
Question 2: You are operating an excavator and need to swing the boom. A coworker is standing within the full working radius. What must you do?
- A. Sound the horn and proceed carefully
- B. Ask the signaler to wave them off, then proceed
- C. Stop the swing until the worker clears the radius(correct)
- D. Slow your swing speed and maintain visual contact
Show Explanation
Explanation:
230 CMR 6.00 prohibits any persons within the full working radius during boom/bucket operation. The only correct action is to stop and wait until the area is clear — no exceptions.
Question 3: Under 230 CMR 6.00, is an excavator allowed to straddle an open trench?
- A. Yes, if the trench is less than 5 feet deep
- B. Yes, if a competent person approves the position
- C. No, straddling open trenches is prohibited(correct)
- D. Yes, if outriggers are deployed for stabilization
Show Explanation
Explanation:
230 CMR 6.00 explicitly prohibits excavating machinery from straddling open trenches. The weight and vibration of a machine positioned over a trench dramatically increases cave-in risk.
Question 4: Beyond the licensed operator, how many additional people may be on an excavator during operation under 230 CMR 6.00?
- A. No additional personnel — operator only
- B. One apprentice under the direct supervision of the operator(correct)
- C. Two helpers if the site superintendent approves
- D. As many as can safely fit in the cab
Show Explanation
Explanation:
230 CMR 6.00 allows one apprentice in addition to the licensed operator, but only under direct supervision. Unauthorized passengers on the machine at any time violate the regulation.
Question 5: Which SAE standard specifies the hand signals required by 230 CMR 6.00 for excavating machinery?
- A. SAE J386-1969
- B. SAE J1307-2023(correct)
- C. SAE J320a
- D. SAE J237
Show Explanation
Explanation:
SAE J1307 (most recently revised 2023) is the standard hand signal set for excavators and backhoes required by 230 CMR 6.00. SAE J386 covers seat belts, J320a covers ROPS, and J237 covers braking.
Question 6: If the operator cannot see the designated signaler during an operation, what must the operator do?
- A. Slow down and proceed with extra caution
- B. Stop all machine movement immediately(correct)
- C. Switch to radio communication
- D. Ask a nearby worker to relay signals
Show Explanation
Explanation:
If visual contact with the signaler is lost, 230 CMR 6.00 requires the operator to stop immediately. A signaler out of sight cannot safely direct the machine — no relay system or substitute is permitted.
Question 7: An excavator operator receives conflicting hand signals from the site superintendent and the designated signaler simultaneously. Which signal takes priority?
- A. The site superintendent's signal, as they have overall authority
- B. Whichever signal the operator judges to be safer
- C. The designated signaler's signal
- D. The Emergency Stop signal if either person gives it; otherwise stop until resolved(correct)
Show Explanation
Explanation:
If conflicting signals are received, the operator must stop until the conflict is resolved. However, if either person gives an Emergency Stop (crossed arms), that always takes immediate precedence over everything else.
A deeper, regulation-by-regulation companion page for this lesson.