The fort remained active through World War I, but was partially disarmed as part of a program to send heavy artillery and railway artillery to the Western Front. Battery Rivardi's two 6-inch guns were shipped to France for use as field guns in 1917 and were not returned to the fort. Six mortars from Batteries Kearny and Chase were removed in 1918–19 for use as railway mortars; this was part of a general halving of mortars to alleviate overcrowding of their emplacements during reloading. This left Fort Preble with eight mortars and one 3-inch gun. Two gun platforms in front of Battery Rivardi were for 3-inch antiaircraft guns installed at many coast defense installations in the World War I era.