Signals
1.5 hours
Learning Objectives
- •Identify who is authorized to direct a crane operator under 230 CMR 6.00
- •State the hand signal standard required by 230 CMR 6.00
- •Recognize the standard hand signals and the emergency stop signal
- •Explain operator duties when signals are unclear, lost, or conflicting
Topics Covered
- •Only an approved signaler may direct the operator's movements
- •SAE J1307 hand signals required by 230 CMR 6.00
- •Standard signals: hoist, lower, boom up, boom down, swing, stop, and emergency stop
- •Emergency stop (crossed arms) may be given by anyone and always takes precedence
- •If the operator loses sight of the signaler, all crane movement must stop
- •Conflicting signals: stop until the conflict is resolved
- •When radio communication is used, agree on procedures and a "lost-signal" rule beforehand
- •Pre-lift communication: operator and signaler agree on the plan before the lift
- •The operator may always refuse an unsafe signal or lift
Resources
Self-Check Questions
Question 1: Under 230 CMR 6.00, who is the only person authorized to direct the crane operator's movements?
- A. Any worker on the job site
- B. The general contractor's superintendent
- C. The approved signaler assigned to the lift(correct)
- D. Whoever is closest to the load
Show Explanation
Explanation:
Only an approved signaler may direct the operator. Taking direction from anyone else, even a supervisor, violates the regulation and creates confusion that leads to accidents.
Question 2: Which hand signal standard does 230 CMR 6.00 require for hoisting machinery in Massachusetts?
- A. SAE J1307(correct)
- B. SAE J386
- C. OSHA J1
- D. There is no required standard
Show Explanation
Explanation:
SAE J1307 is the hand signal standard required by 230 CMR 6.00. Both the operator and the signaler must know and use these standard signals.
Question 3: A laborer who is not the designated signaler suddenly gives the emergency stop signal. What does the operator do?
- A. Ignore it because it is not from the designated signaler
- B. Stop all crane movement immediately(correct)
- C. Ask the signaler whether to stop
- D. Finish the current motion first
Show Explanation
Explanation:
The emergency stop signal may be given by anyone and always takes precedence. The operator must stop immediately — that person may see a hazard the operator and signaler cannot.
Question 4: Mid-lift, the operator loses sight of the signaler behind a stack of materials. The correct action is to:
- A. Keep moving slowly until the signaler reappears
- B. Stop all crane movement until visual contact (or agreed communication) is restored(correct)
- C. Have a nearby worker relay signals
- D. Guess where the load should go
Show Explanation
Explanation:
If visual contact with the signaler is lost, the operator must stop. A signaler who cannot see the operator and load cannot safely direct the lift, and informal relays introduce errors.
Question 5: The operator receives conflicting signals from two people at once. What should the operator do?
- A. Follow whichever signal seems easier
- B. Follow the louder or more senior person
- C. Stop until the conflict is resolved; an emergency stop from anyone takes immediate priority(correct)
- D. Average the two signals
Show Explanation
Explanation:
Conflicting signals mean the situation is not clear, so the operator stops until it is resolved. The one exception is that an emergency stop from anyone overrides everything and is obeyed immediately.
Question 6: A signaler directs a lift that the operator can see would overload the crane. What may the operator do?
- A. Nothing — the operator must always follow the signaler
- B. Refuse the lift; the operator may always decline an unsafe signal or lift(correct)
- C. Perform the lift but blame the signaler afterward
- D. Perform half the lift
Show Explanation
Explanation:
The operator is the last line of defense. Even when directed by an approved signaler, the operator may and should refuse any signal or lift that would be unsafe — the operator is responsible for the machine.