Completing this task required the development of innovative engineering techniques for mechanized diamond drilling underwater without the assistance of divers, and experimentation with a range of explosives. The work attracted international attention. In all 15,000 blasting holes were drilled and 90,000 pounds of explosives consumed. 110,000 tons of rock was removed, some of which was used in building river walls for further improvement of the Clyde. Subsequent smaller excavations further widened and deepened the river at this location, until it was made safe for vessels with a draught of up to 28 feet across 320 feet of width from 1903 to 1907. References History of Glasgow Geography of Scotland