Historic California Posts, Camps, Stations and Airfields
Point Sur Radar Site B-85
(Point Sur Defensive Position, Carmel Radar Site B-85)
by Dan Sebby
Military Historian, California Military Department
 
In 1942, the War Department authorized the acquisition of land near Point Sur for use as a radar site. It was initially known as the Point Sur Tactical Position, Harbor Defenses of San Francisco. However, due to the secrecy surrounding radar sites, it was common to give the sites false descriptions that masked their true mission and actual command relationships. Sites were often called "listening posts" or "tactical positions." Some of these sites were also constructed to resemble farm buildings common to the coastal regions of California to further hide their identity. This technique continued throughout World War II. In the War Department Owned, Leased and Sponsored Facilities, 31 December 1945, the Site was still referred to as part of the Harbor Defenses of San Francisco, and it was not shown on any of the Army of the United States Station Lists published by the Adjutant General of the U.S. Army as late as 7 May 1946. The Site was actually under the control of the Fourth Air Force throughout World War II.
 
The station's primary mission was to detect and identify all aircraft in its area of responsibility and to direct fighter interceptors to targets deemed to be possible threats.
 
The Site was initially garrisoned by a detachment of the 656th Signal Aircraft Warning Company which was subordinate to the San Francisco Provisional Control Group, San Francisco Fighter Wing, IV Fighter Command, and Fourth Air Force. On 1 April 1944, the San Francisco Control Group and its subordinate Signal Aircraft Warning Companies were consolidated under a single unit, the 411th Army Air Forces Base Unit (AAFBU). During World War II the site was equipped with the following radar sets:
 

In a 20 March 1946 document titled, Detailed Plan for the Retrenchment of Fourth Air Force Control Group Installations it was recommended that the Site be retained as an active installation. The report also recommended that the Site assume the Identification Friend or Foe (IFF) mission and that it be equipped it be equipped with AN/CPS-1 or AN/CPS-5 radar sets.

On 28 February 1947, all of the air defense radar functions on the West Coast were consolidated and Point Sur's garrison became a detachment of Squadron "B", 412th AAFBU (Western Aircraft Control and Warning Group). The site was inactivated on 30 June 1947,

This site consisted of two parcels approximately 15 miles south of Carmel, California, on the east side of Highway 1 and on a private ranch called the Dowd Ranch. The site was initially was 20 acres and was reduced to 17.65 total acres. The Dowd Ranch leased these parcels to the Army for one dollar per year.

Buildings on the site were the typical wood framed "Theater of Operations" type with selected operational buildings incorporating concrete fortification. Research has not determined the specific defensive armament of the Site, but it was typical for site like this to be defended soldiers equipped with small arms and light machine guns for perimeter defense and .50 caliber machine guns.

Ms. Susanna Danner, Conservation Project Manager for the Big Sur Land Trust is familiar with the site and has stated that there are remnants of concrete "bunkers" on the site. Parcel one of 10 acres was located between Joshua and Dowd Creeks while the second parcel was located 1,000 feet north of Granite Canyon. The Corps of Engineers Warning Notice dated 7 July 1947, states that the station was declared surplus to the needs of the Army effective 30 June 1947. By 31 March 1948, all equipment had been removed by the newly formed U.S. Air Force and the post was turned over to the Army Corps of Engineers for disposal.

Realty Control File Summary (Eng Form 1603), states that the property was leased under number W-3460-ENG-3979 and that the station consisted of 25 buildings that were sold on 16 December 1948. The lease was terminated 30 September 1949.

 
 
Radar Sets Used at Point Sur
 
 
SCR-270-D Mobile Long Wave Aircraft Warning Set
 
 
Description: Six-vehicle mobile, long wave early warning aircraft detector. Azimuth and range supplied. Set is equipped with "A" scope.
Uses: To establish a screen of warning which provides information of approaching aircraft as early as possible but with a sacrifice of accuracy in range, azimuth and elevation. IFF equipment RC-150 is used.
Performance and Siting: Maximum range on a single bomber flying at indicated heights, when set is on a flat sea level site:
 
 Altitude, feet  1000   5000  20,000  25,000
 Range, miles  20  50  100  110
Set should be sited at a height between 100' and 1000' above an unobstructed reflecting surface.
Transportability: Complete set is carried in 6 vehicles, the largest of which measures 30'4" x 9'10" x 8'. Total weight of shipment is 101,790 lbs; total volume 11,485 cu. ft.
Installation: Operates from trucks in which mounted. Can be placed in operation about 6 hours after arrival at site.
Personnel: Seven men comprise operating crew. For 24 hour operation about 50 men are required to run radar, communication radio, and camp.
Power: 15.3 KW, supplied by PE-74, 25 KVA gasoline-driven generator, having fixed consumption of 4 gal. per hour, non-leaded gasoline.
 
 
SCR-271-D and SCR-271-E Fixed Long Wave Aircraft Warning Set
 
Description: Fixed long wave early warning aircraft detector. Azimuth and range supplied on "A" scopes. 271-D has a 100' tower; 271-E, a 50' tower.
Uses: To establish a screen of warning which gives data on aircraft as early as possible, but with a sacrifice of accuracy in range, azimuth and elevation. IFF equipment RC-151 is used.
Performance and Siting: Maximum range on a single medium bomber flying at indicated altitudes, when set is on a flat sea level site:
 
 Altitude, feet  1000  5000  20,000  25,000
 SCR-271-E Range, miles  20  50  100  110
 SCR-271-D Range, miles  25  60  120  135
Sets should be sited so that the mean antenna height is between 100 and 1000 ft. above an unobstructed flat surface. The 100' tower should be used when it is desired to get additional low coverage, or to insure clearance above surrounding trees or other obstructions.
Transportability: Sets are packed in 106 units, weighing a total of 42,279 lbs. Largest unit is 176" x 25" x 20". Total volume is 4008 cu. fit.
Installation: Requires a weatherproof building approx. 20' x 40' for housing radar components and a building approx. 20' x 20' for housing the power units and switchboard. A 100 foot tower on concrete footings is required for an SCR-271-D and a 50-ft. tower for an SCR-271-3. Buildings and tower are built by engineers in about 3 weeks. Radar can be installed by five men in about two weeks.
Personnel: 7 men are operating crew. For 24 hour operations, about 50 men are required for radar, communication radio, and camp.
Power: 15.3 KW supplied by PE 74, 25 KVA gasoline-driven generator. Consumption is 4 gal. per hour, non-leaded standard commercial gas.

 

SCR-588 Long Wave Aircraft Detector and Ground Control Intercept Radar

 
Description: Fixed medium-range, long wave aircraft detector and GCI. Provides azimuth, range, and altitude data. Type HR and PPI scopes.
 
Uses: To give continuous plan position and accurate relative height of enemy plane and friendly fighter plane for GCI. Set can also be used for early warning and to give increased coverage at low angles of search. IFF equipment RC-188 is used. When operating as GCI, VHF equipment SCR-624 is required.
 
Performance and Siting: Maximum range on a medium bomber, with set on flat sea level site:
 Altitude, feet

 1,000

5,000

10,000

 25,000
 Range*, miles

 20

 50

 95

 105
*Range of PPI limits GCI operation to about 45 miles.
 
When operating as GCI, set must be sited so that a flat unobstructed surface extends at least 1/4th mile in the height-finding sector. Good GCI sites are extremely rare. For early warning, sets should be sited between 100 and 1,000 feet above an unobstructed surface.
Transportability: Set is packaged for shipment in 55 units, weighing a total of 54,000 lbs. Largest unit measures 15.3' x 3.8' x 1.8'. Total shipping space is 3500 cu. ft.
 
Installation: Requires a weatherproof building approximately 20' x 40' for housing radar components and a building approximately 20' x 20' for power units and switchboard. A 25' tower on concrete footing is required for support of antenna. Buildings and tower can be built by Engineers in about 3 weeks. Radar can be installed by 5 men in 2 weeks.
 
Personnel: 8 men are operating crew. For 24-hour operation about 54 men are required to run radar, communication radio, and camp.
 
Power: 4 KW at 230 volts and 1 KW at 115 volts, from three PE-198 electric diesel units, supplied with set. (Two units operate simultaneously). Fuel consumption is 21/2 gals. of Diesel fuel oil per hour.

 

AN/CPS-1 Air Transportable; Microwave Early Warning Radar


Manufacturer: General Electric

IEEE Band: S Band

NATO Band: F Band

Exact Frequency: 3200 MHz

Maximum Instrumented Range: 200 miles

Power Required: 23 kw from portable generator

Antenna Weight: 5 tons

Scanning Rate: 10 rpm

Notes: Complete installation weighs 66 tons. When it is necessary to make it mobile, 10 trucks are required for MEW gear and 6 more for VHF installation. Ready for travel in 1.5 days.

 

AN/CPS-5 Air Transportable Ground Control Interception Radar


Manufacturer: General Electric & Bendix

IEEE Band: L Band

NATO Band: D Band

Exact Frequency: 1300 MHz

Pulse Repetition Frequency: 400 pps

Pulse Width: 2 microseconds

Peak Power: 750 kilowatts

Maximum Instrumented Range: 60 miles (in operation aircraft were picked up as far as 210 miles)

Maximum Altitude: 40,000 feet

System Weight: 40,000 pounds

Operators: Five men required: PPI operator, A-Scan operator, Plotter teller, Recorder and radar repairman
 
Notes: Production began January 1945. Used with AN/TPS-10.

 

 
 
 
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Updated 8 February 2016