New Records in Driving a Single-Heading Tunnel

RECORDS in mining operations naturally fall when improved equipment and methods are developed. And tunneling through the Continental Divide is a mining operation, even though the tunnel was not driven to strike a vein at depth. Although many engineering feats have been successfully accomplished in the development of water supplies in the Western States, the Twin Lakes Tunnel in Colorado presents some unusual features that make it noteworthy. To begin with, it is the first trans-mountain water diversion project in the West. The fact that the Continental Divide intervenes between where the water is and where it is needed was brushed, aside as of minor importance. It was enough to know that on the western side of Independence Pass, the highest in Colorado, with an elevation of 12,095 ft., there was water which was needed on the eastern side, where the Twin Lakes are situated, forming the