Izinduku zensimbi engenasici, ngezinye izikhathi ezibizwa ngokuthi izikhonkwane zensimbi engagqwali, ziyizinduku eziqondile ezinezintambo ngobude bazo bonke, ezivumela amantongomane ukuthi acushwe kunoma yimuphi umkhawulo. Lezi zinduku zivame ukusetshenziselwa ukuhlanganisa izingxenye ezihlukahlukene noma ukunikeza ukusekelwa kwesakhiwo.