What is risk assessment at the time of tower crane lifting ?

risk assessment is when you identify the possible threat or hazard in a certain situation and come up  with preventive measures to avoid accident.

 Incorrect lifting however, can lead to disastrous accidents. Every year, incorrect lifting procedures cause injuries, loss of work time and property. People, machinery, loads, methods and the work environment, are all important factors for correct lifting.

The "crane operator" is responsible for operating the crane correctly and safely.

He shall hold a valid crane operation certificate;

He shall be familiar with hand signals for communication.

For more information please read this: http://www.oshc.org.hk/others/bookshelf/CB952E.pdf 

TRAVEL RESTAINT SYSTEMS FALL ARREST HARNESS SYSTEMS EDGE PROTECTION SYSTEMS

thanks guys for answer my question

Risk assessment while using a tower crane is where you identify what risks are involved and by doing that you can take preventive measures to minimize the risks

travel restraint systems • fall-arrest harness systems • edge protection systems