Crane cov hlua txuas yog qhov tseem ceeb ntawm crane system, muab kev sib tw ruaj khov rau kev txav ntawm lub crane. Crane cov hlua khi tau muab faib ua cov qauv crane, hnyav-crane cov hlua khi, cov crane nyias muaj nyias, thiab cov hlua crane kev cai.
Ntawm lawv, cov haujlwm hnyav-crane yog tsim rau kev siv cov khoom siv hnyav uas xav tau cov khoom muaj peev xwm zoo thiab muaj txiaj ntsig. Cov kev sib tw loj no tuaj yeem tiv thaiv cov thauj khoom siab thiab muab lub zog zoo thiab ruaj khov. Lawv feem ntau siv nyob rau hauv cov chaw muaj loj xws li cov mills steel, chaw nres nkoj, thiab nkoj nkoj.
