I-dual lead worm kanye nesondo lezikelemu wuhlobo lwesistimu yegiya esetshenziselwa ukudluliswa kwamandla. Iqukethe isikelemu, okuyingxenye ye-screw-cylindrical enamazinyo angama-helical, kanye nesondo lesikelemu, okuyigiya elinamazinyo ahlangana nesibungu.
Igama elithi "umthofu okabili" libhekisela eqinisweni lokuthi isibungu sinamazinyo amabili, noma izintambo, ezisonga isilinda ngama-engeli ahlukene. Lo mklamo unikeza isilinganiso segiya esiphezulu uma kuqhathaniswa nesikelemu esisodwa esiholayo, okusho ukuthi isondo lezikelemu lizozungeza izikhathi eziningi ngokuphenduka ngakunye kwesibungu.
Inzuzo yokusebenzisa i-dual lead worm kanye nesondo le-worm ukuthi ingakwazi ukuzuza isilinganiso esikhulu segiya ekwakhiweni okuhlangene, okuyenza ibe wusizo ezinhlelweni lapho isikhala silinganiselwe. Kuphinde kuzikhiyele, okusho ukuthi isikelemu singabamba isondo lesikelemu endaweni ngaphandle kwesidingo sebhuleki noma enye indlela yokukhiya.
Amasistimu amasondo okuhola ama-lead worm kanye nezikelemu avame ukusetshenziswa emishinini nasezinsizeni ezifana nezinhlelo zokuthutha, okokuphakamisa impahla, namathuluzi omshini.