Lapho umgodi wesisekelo ujulile, izinga lamanzi angaphansi komhlaba liphakeme, futhi akukho mvula yokwakha, izinqwaba zamashidi zisetshenziswa njengesakhiwo esisekelayo, esingakwazi ukugcina umhlabathi nokungenamanzi kuphela, kodwa futhi kuvimbele ukuvela kwesihlabathi esisheshayo. Izisekelo zenqwaba yamashidi zingahlukaniswa zibe izinqwaba zamashidi ezingenazikhonkwane (izinqwaba zeshidi le-cantilever) kanye nezinqwaba zamashidi ahangelwe. Izinqwaba zeshidi lensimbi ezivame ukusetshenziswa ziyizinqwaba zeshidi lensimbi ezimise u-U, ezaziwa nangokuthi izinqwaba zeshidi lensimbi ye-Larsen.