Communication and Signaling
One Voice, Clear Signals
Effective communication prevents incidents. The core principle is a single designated signal person - usually the dogger - directing the crane operator. Only one person gives signals at a time; anyone may give a stop signal. Agree on the method before the lift: standard hand signals, whistle, radio or two-way. Radio communication requires agreed call signs, clear language and confirmation of understanding. Hand signals must be standard, deliberate and given from a position in clear view of the operator.
Emergency and Stop Signals
Know the emergency stop signal and the rule that any person may call stop. After a stop, the lift does not resume until the reason is resolved and communication is re-established. Signals must be acknowledged; if the operator cannot see or hear the signal person, the lift must not proceed.
Traps in Questions
A frequent trap is multiple people signalling - the correct answer is to establish one signal person. Another is assuming a radio removes the need for line of sight and agreed protocol; radios can fail and channels can be shared. Questions may also test that a dogger should not rely on guessed signals or assume an unclear signal means 'continue'.
Rule of Thumb
If a signal is not clearly understood, it means STOP - never assume.
Worked Example
Two workers on opposite sides of a load both give hand signals; the operator receives conflicting directions. Correct action: stop the lift, nominate one signal person, confirm the agreed method and resume only when communication is unambiguous.