Signalman should coordinate to ensure Safe Lifting Operation with proper signals.
Signalman should coordinate to ensure Safe Lifting Operation with proper signals.
l信号员必须确保使用正确的信号，保证起重机动作安全。
Signalman should coordinate to ensure Safe Lifting Operation with proper signals.
l信号员必须确保使用正确的信号，保证起重机动作安全。