Lub sij hawm "line twj" yog hais txog qhov tseeb tias pob zeb yog pumped los ntawm cov kav dej los yog hoses, tso cai rau nws mus rau cov chaw tshwj xeeb ntawm qhov chaw tsim kho. Qhov no yog qhov sib piv rau cov twj boom, uas siv lub caj npab robotic (boom) los tso pob zeb ntawm qhov chaw tshwj xeeb.
Kab cov twj tso kua mis feem ntau yog siv rau cov kev tsim kho me me, xws li cov tsev nyob thiab cov tsev lag luam, qhov chaw nkag yuav raug txwv. Lawv tsim nyog rau kev xa cov pob zeb mus rau qhov chaw uas cov txheej txheem ib txwm muaj, xws li cov log tsheb lossis cov siv conveyor, tej zaum yuav siv tsis tau lossis siv sijhawm.
Cov khoom tseem ceeb ntawm cov twj tso kua mis muaj xws li lub hopper kom tau txais cov pob zeb sib tov, lub twj tso kua mis kom txav cov pob zeb los ntawm cov kav dej, thiab ib qho kev faib tawm (cov kav dej lossis cov kav dej) coj cov pob zeb mus rau qhov chaw uas xav tau. Cov twj tso kua mis no ua lub luag haujlwm tseem ceeb hauv kev ua tau zoo thiab ceev ntawm kev tso pob zeb rau ntawm qhov chaw tsim kho.
