Umda wokusetyenziswa kwebhokisi yesiphambuka enobungqina bokudubula:
I-Zone 1 kunye ne-Zone 2 i-atmosphere yerhasi eqhumayo, i-Zone 20, i-Zone 21, kunye ne-Zone 22 yokusingqongileyo yothuli oluvuthayo, i-IIA, i-IIB, i-IIC yezinga le-IIC yendawo eqhumayo kunye neqela lobushushu leqela le-T1-T6.