Milagra Ridge WWII Radar Site

 (1944-1946) - A World War II U.S. Army Radar Site established in 1944. Used to provide fire control information to large caliber (6" and above) coastal gun batteries in the Harbor Defense of San Francisco against enemy warships. Located on Milagra Ridge Military Reservation near Pacifica, San Mateo County, California. Closed in 1946.

History




Constructed under project No. RAD-9-184 and transferred for use at Milagra Ridge Military Reservation on 22 Aug 1944. This was the 9th of 11 SCR-296-A radar sets within the Harbor Defenses of San Francisco. Construction costs to date of transfer were $ 14,477.62. The physical plant consisted of a transmitter building, a single powerhouse building with a 1000 gallon fuel tank, and a 25' steel tower and an antenna housing disguised as a water tank atop the tower. The transmitter building was built of concrete and backfilled with earth to conceal it. The powerhouse building was constructed with galvanized iron and not concealed. The 25' tower was placed on footings attached to the top of the transmitter building. Access to the antenna on top of the tower was by a small hoist operated by an electric motor.

The radar equipment was installed by the Signal Corps. It required 16.3kW of 120/240 AC, 1 phase, 60 cycle power furnished by commercial power backed up by the on-site generator. The 25 kW generator was furnished and installed by the Signal Corps.

Site Operation


The Radar track data was provided by telephone to support Battery Wallace as the primary battery and to secondary batteries including Battery 243 and Battery 244. Battery Wallace was a 12" gun battery located on Fort Barry in Marin County.

Closure
Closed in 1946. The SCR-296-A Radar equipment was declared obsolete by AG letter on 17 Jan 1946. The Tower and radar equipment were to be disposed of while the buildings were to be retained.

Current Status
Foundational surface remains including the escape hatch cover and some pipe stacks. The entrance to the underground transmitter building is mostly buried and the interior of the building cannot be accessed.

See Also:
 * Milagra Ridge Military Reservation
 * Battery Wallace (2)
 * Battery 243
 * Battery 244
 * US Radar Sets
 * SCR-296-A Radar Set
 * Western WWII Radar Sites

Sources:
 * . page 155-156

Links:
 * RCW-Corrected to Aug 1944, CDSG.
 * California Military Museum - Milagra Military Reservation