Explosive Military Advances

Explosive Military Advances. Coastal Defense System 1885-1905. With the Industrial Revolution of the late 19th century came rapid advances in military technology. Guns capable of firing up to 12 miles were installed on foreign battleships, rendering the nation's coastal defense system obsolete. In response to this new threat, the United States made plans to modernize its coastal defenses., San Francisco ranked highest on the West Coast for this modernization effort. Beginning in the 1890s, the U.S. Army acquired land and constructed over 35 gun batteries in the Bay Area. It also installed a system of underwater mines outside the Golden Gate. All of the concrete batteries that you see on the Presidio today date from this era., Captions , Left: Utilizing new communications technology, telephones linked observation posts to command posts and, in turn, relayed firing commands to the batteries. Another innovation, electric searchlights, illuminated targets off the coastline. (Photo: San Francisco History Center, San Francisco Public Library) , Right: Battery Godfrey, c. 1908 , This battery used newly developed breech-loading, long-range rifles that shot 12-inch diameter projectiles up to 12 miles. The reinforced concrete gun emplacement had an adjacent underground ammunition magazine. (Photo: Original postcard in California Historical Society)