Kuunza iyo KJ421 Hydraulic Tunnel Boring Rig - mhinduro yekupedzisira kune ako ese mugero anofinha zvaunoda. Muchina uyu muhombe wekuchera wakanyatsogadzirirwa kusangana nematanho ehukuru hwakasiyana, ane michinjikwa-chikamu kubva pa16-68 square metres. Iyo yekuchera rig ine super drilling kugona, inogona kuboora maburi ekuputika uye mabhaudhi munzvimbo yakatwasuka, yakarerekera uye yakachinjika, uye chishandiso chakakosha pakuvaka tunnel.