No Unattended Suspended Load
This means the operator not putting down the remote control and leaving the site while a load is suspended. Because a wireless remote control makes the operator independent of the machine, this risk increases noticeably compared with wired systems; a load left suspended can descend over time through a brake or a hydraulic leak.
With a wired remote control the operator is physically tied to the machine; it is hard to drop the cable and walk away. With a wireless one the transmitter goes in the pocket and the operator may turn to another job. The load, meanwhile, stays hanging in the air.
The reasons this behaviour is dangerous:
- A mechanical brake can slip over time; in hydraulic systems a leak at a valve or cylinder slowly lowers the load.
- Another worker may go under the suspended load, because there is no visible person operating the machine on site.
- Wind or an impact creates swing and the load may strike surrounding equipment.
Correct practice is to complete the job and lower the load, and only then put the remote control into its inactive state. It must be written as an operating rule that loads are not left suspended at the end of a shift and that the transmitter is stored in a locked place. Movement stopping when the remote control goes out of range does not remove this risk; stopping does not mean the load comes down.
The context in which this term is used: Wireless Crane Remote Control Selection Guide