An Integrated System of Guns
San Francisco's harbor defenses relied on a complex system of guns, underwater mines, and antisubmarine nets. Central to the system were guns of many sizes, each with its own purpose. These guns were classified by the diameter of the projectiles they fired.
Did You Know?
During the early 20th century, the army relied on standardized architectural plans to construct different types of buildings. That is why Fort Baker Building 533 and the Fort Mason GGNRA headquarters’ building look so similar: they were both constructed in 1902 as hospitals.