How Chinese Crews Drilled Through 1,659 Feet of Sierra Granite at 8 Inches a Day

How Chinese Crews Drilled Through 1,659 Feet of Sierra Granite at 8 Inches a Day Discover the incredible engineering feat as we reveal how Chinese crews meticulously drilled through 1,659 feet of challenging Sierra granite, progressing at an astonishing rate of just 8 inches a day. Learn about the unique methods and sheer determination that allowed them to conquer this monumental tunnel boring project against all odds.