Insimbi isindayo kunezinto zokwakha ezifana nokhonkolo, kodwa amandla ayo aphezulu kakhulu. Isibonelo, ngaphansi kwezimo ezifanayo zomthwalo, isisindo sophahla lwensimbi luyi-1/4-1/3 kuphela ye-span efanayo ye-truss yophahla lukakhonkolo oluqinisiwe, futhi uma i-truss yensimbi enezindonga ezincane ilula, kuphela i-1 / 10. Ngakho-ke, izakhiwo zensimbi zingakwazi ukumelana nemithwalo emikhulu futhi zinwebe izikhala ezinkulu kunezakhiwo zikakhonkolo eziqinisiwe.Umphumela wokonga amandla muhle. Izindonga zenziwe ngensimbi engasindi, ewonga amandla futhi emile emise okuka-C, insimbi eyisikwele, namaphaneli esangweji. Banokusebenza okuhle kokufakwa kwe-thermal kanye nokumelana nokuzamazama komhlaba okuhle.