M'madera akuluakulu a migodi ndi ma quarries, zida zobowolera nyundo zapamwamba ndizomwe zimagwiritsidwa ntchito kwambiri pobowola miyala. Ndi kuya kwa 5-15 metres, zida zapamwamba zobowola nyundo zimatha kukulitsa luso lobowola. Ngati mumasamala za migodi, ndiye kuti kubowola nyundo pamwamba mosakayikira ndiko kusankha kwanu bwino. Titha kupereka zida zapamwamba zobowola nyundo komanso zowongolera zokhazikika kwambiri ku China. Nthawi yomweyo, adaputala yathu ya shank, ndodo yobowola ulusi, ndi zobowola za ulusi zilinso zapamwamba kwambiri.