Chapter 146 of the Massachusetts General Laws requires hoisting licenses. But a statute alone does not tell an operator how to run a machine safely on a live job site — that is the job of the implementing regulation. For 2A excavating machinery, 230 CMR 6.00 is that regulation. It translates the broad legislative requirement of safe operation into specific, enforceable rules: who gives signals, where workers may stand, who may be on the machine, and what published standards apply. Every exam question that touches job-site conduct traces back to 230 CMR 6.00, so understanding what it requires is the foundation everything else builds on.
How 230 CMR 6.00 fits into the regulatory picture
Massachusetts General Laws Chapter 146 gives the Division of Occupational Licensure (DOL), Office of Public Safety and Inspections (OPSI) authority to license hoisting operators and set safety standards. The rules that flow from that authority appear in the Code of Massachusetts Regulations under 230 CMR. Hoisting machinery is broadly governed by 230 CMR 6.00, and excavating machinery operated under a 2A license falls squarely within that regulation.
One source of confusion on the exam: older study materials may reference 520 CMR 6.00, which was the former citation before the regulation was recodified. 520 CMR 6.00 is superseded — the current, enforceable citation is 230 CMR 6.00. Think of 230 CMR 6.00 as the floor: manufacturer specifications and applicable OSHA requirements layer on top, but 230 CMR 6.00 sets the baseline every licensed 2A operator is legally held to.
Hand signals and the authority of the designated signaler
The most heavily tested rule in 230 CMR 6.00 is this: only the designated signaler may direct an operator's movements on a job site. It does not matter whether the site superintendent is more senior or a coworker is gesturing urgently — if that person is not the designated signaler, the operator does not follow their signals.
The regulation requires those signals to conform to SAE J1307-2023, the published hand-signal standard for excavating machinery. A defined standard means that a signal learned on one job site means exactly the same thing on a different crew in a different city, removing the kind of ambiguity that causes serious incidents. One rule follows directly: if the operator loses sight of the designated signaler at any point, the machine stops and stays stopped until the signaler is visible again.
Who may be on the machine and where workers must stand
230 CMR 6.00 is explicit about personnel. The licensed operator is in the cab. One apprentice working under the direct, in-person supervision of that operator may also be present. No other unauthorized persons may be on the machine during operation.
Ground workers must stay outside the full working radius of the boom and bucket during any swing movement. The working radius extends to the machine's full reach in every direction it can swing — a worker who looks clear from one angle can be inside the danger zone the moment the operator slews. The operator confirms the zone is clear before any swing begins.
One prohibition that surprises apprentices on the exam: an excavating machine may not straddle an open trench. Positioning a machine over an open excavation creates a collapse hazard for the operator and anyone working below. The rule is absolute, regardless of trench width or time pressure on the job.
Manufacturer specifications as a regulatory requirement
230 CMR 6.00 requires operators to follow all manufacturer specifications for the equipment they run. This is not a suggestion to consult the manual when something looks wrong — it is a mandate that ties the operator's conduct to the machine's engineered limits: rated capacities, approved attachments, operating angles, and any other performance boundaries the manufacturer has established. Running outside those limits is not just poor judgment; it is a regulatory violation. The operator's manual is a legal document as much as a technical one.
Key Takeaways
- •230 CMR 6.00 is the current, enforceable regulation governing all hoisting machinery including 2A excavating equipment — 520 CMR 6.00 is the old superseded citation and should not be used.
- •Only the designated signaler may direct operator movements; all hand signals must conform to SAE J1307-2023.
- •If the operator loses sight of the designated signaler, the machine stops until the signaler is visible again.
- •No unauthorized personnel on the machine; no workers within the full working radius during boom or bucket swing.
- •Straddling an open trench is prohibited; following manufacturer specifications is a regulatory requirement, not optional guidance.
