Umnyango womlilo wensimbi wakhiwe uhlaka lwensimbi kanye neqabunga lomnyango wensimbi. Isakhiwo sensimbi singaqinisekisa ukuthi asinakuthinteka ekuthintekeni kokuguqulwa kanye nokulimala kwamandla angaphandle, futhi singasetshenziswa ngokujwayelekile isikhathi eside ngaphandle kokushintshwa. Izingxenye ezigqokeka kalula emnyango womlilo wensimbi, njengama-pulley, zonke ziyi-hardware yekhwalithi ephezulu, ikhwalithi ephezulu futhi ihlala isikhathi eside.