Largest underwater explosion [Non-nuclear]

Last updated: May 12, 2018 at 19:31 pm

The destruction of Ripple Rock, which was the tip of an underwater mountain and a navigation hazard in Discovery Passage (Seymour Narrows), British Columbia, was the world’s largest planned non-nuclear underwater explosion. The twin-peaked summit was only 3 m (9 ft) underwater at low tide, which resulted in at least 120 vessels damaged or sunk, and 114 people drowned. 1,270 metric tons of Nitramex 2H explosives were used to blast 635,000 metric tons of rock and water up to 300 m (1,000 ft) into the air on April 5, 1958. The depth at low tide after the explosion was lowered to 14 m (45 ft). The destruction of Ripple Rock was broadcast live by the CBC (Canadian Broadcasting Corporation) and the three-year engineering project was the subject of a documentary film by the NFB (National Film Board). Ripple Rock lies approximately 1.6 km (1 mile) from the wreck of HMCS Columbia, a popular artificial reef sunk near Campbell River in 1996.

“Ripple Rock is one of the vilest stretches of water in the world.” — Capt. George Vancouver, 1798

Blast to end Peril at Ripple Rock. Popular Mechanics. June 1956, pp. 120-121.
Vancouver, G. (1798). A Voyage of Discovery to the North Pacific Ocean and Round the World 1791–1795.

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