Historic California Posts, Camps,
Stations and Airfields
Anti-Motor Torpedo Boat Batteries
Cabrillio, Cortez and Fetterman
Harbor Defenses of San Diego
Cabrillo, Cortez and Fetterman
by Rustin M. Ruhge
In the fall of 1942, the Army decided to install 90-mm anti-motor
torpedo boat (AMTB) batteries in the harbor defenses. Each battery
consisted of two fixed and two mobile guns. The mobile guns were
kept in storage until an emergency occurred.
The mission of these batteries was to attack enemy motor torpedo
boats, to defend against enemy landings, to assist against enemy
air attacks and to attack enemy submarines within range.
After considerable discussion, the Office of the Chief of Engineers
decided that San Diego would receive three four-gun 90-mm batteries.
Battery Cabrillo was located at Point Loma down the hill from
the earlier Battery Point Loma with its 4 155-mm guns; Battery
Fetterman at Ballast Point; and Battery Cortez on the Silver
Strand at Fort Emory. At each battery two guns would be emplaced
and two would be mobile.
All three batteries were completed in August 1943 and the six
guns were mounted in September. The District Engineer supervised
construction of concrete emplacements. The post engineer installed
the electricity and the troops performed the necessary labor.
The cost of each battery was $20,000.
The guns of Battery Fetterman were first placed on North Island,
but were moved to Ballast Point at the request of the U.S. Navy.
Fetterman had been rebuilt in 1940 to accommodate an anti-aircraft
battery. Nothing remains of the three AMTB batteries today. Battery
Fetterman survived until 1986 when it was demolished for a parking
In the following table are the pedigrees of the guns in the three
90-mm AMTB batteries.
Completed Works - Seacoast Fortification
Coast Defense Study Group
The Form 7 for 90-mm
AMTB Batteries, Cortez, Fetterman and Cabrillo. National Archives,
RG 77, OCE, Box 129, File 600.914, Harbor.