The engineers 'perseverance and courage in overcoming all the difficulties had been fully demonstrated. Since tunneling was started simultaneously from both ends, special techniques and equipment had to be employed to make sure all the sections were aligned.
但是光憑「血氣之勇」是打不開「山門」的，開隧道要有專門的技術、精確的測量，才不至在兩頭對挖時，發生中間銜接不上的窘況。