GCI--Ground or Ship Control of Interception Sets

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SCR-588 Long Wave Aircraft detector and GCI

SCR-588
SCR-588

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 1000 5000 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.

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SCR-527 Mobile Long Wave Aircraft detector and GCI

SCR-527-A in Operating Position
SCR-527-A in Operating Position

DESCRIPTION: Seven-truck mobile long wave medium-range aircraft detector and GCI. Gives azimuth, range and altitude on PPI and HR scopes.
USES: To provide necessary 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-127 is used. When operating as a GCI station, VHF equipment SCR-624 is required.
PERFORMANCE
AND SITING:
Maximum range on a single medium bomber flying at indicated altitudes when set is installed on a flat sea level site:

Maximum range on a medium bomber, with set on flat sea level site:
Altitude, feet 1000 5000 10,000 25,000
Range*, miles 17 35 90 100
*Range of PPI limits GCI operation to about 45 miles.

When operating as GCI, set must be sited so that a flat unobstructed reflecting surface extends at least 1/4th mile in the sector in which height-finding is desired. Good GCI sites are extremely rare, and workable sits are found only with difficulty. When used for early warning, these sets should be sited at a height between 100 and 1,000 feet above an unobstructed reflecting surface.

INSTALLATION: Operates from trucks in which mounted. Can be placed in operation in approximately 6 hours after arrival at proper site.
TRANSPORTABILITY: Set consists of 7 vehicles weighing a total of 97,610 lbs. Largest vehicle measures 26'21/2" x 8'11/2" x 10'.
PERSONNEL: 8 men are operating crew. For 24-hour operations, about 54 men are required for operation of radar, communication radio, and camp.
POWER: Supplied by two PE 137-A 25 KW, 120/208 V gasoline generators, one of which serves as a spare. Supplied with set in separate trucks. Fuel consumption is 2.4 gal. per hour of non-leaded standard commercial gasoline.

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SCR-615-A and SCR-615-B Microwave Aircraft Detectors for GCI

SCR-615
SCR-615

DESCRIPTION: Fixed, microwave aircraft detector for GCI. Gives range, altitude and azimuth data on planes. Has 2 "A" scopes, one PPI.
USES: Adjunct to a search radar to give accurate height data, thus permitting GCI operation from sites not suitable for other GCI sets which need flat sites. Also gives low-angle coverage when operated as search set. IFF equipment RC-215 is used.
PERFORMANCE
AND SITING:
Range on a single, medium bomber flying at indicated altitudes:

Altitude, feet 1000 5000 10,000 25,000
615-A, range, Miles. 25 35 35 35
615-B, range, Miles. 25 50 50 50

For height finding, set is sited near search set so objects which may cause ground clutter are screened from set by nearby hills.

For low angle early warning, set is sited as high as possible in coastal areas overlooking sea. When sited overlooking land, the site should be as high as possible. Back radiation is negligible.

TRANSPORTABILITY: When packed for shipment by freight the total weight is expected to be approximately 10,000 lbs.
INSTALLATION: Antenna and transmitting and receiving components are installed on a wooden tower 30', 55', or 105' high, depending on site. Operating controls and presentation unit are installed in a separate weatherproof building approximately 20' x 20'. If used as adjunct to a search type set, controls and presentation can be installed in same building with search set equipment. A 20' x 20' building is required for power units and switchboard. Tower and buildings must be built by engineers and require approx. 2 weeks. Radar components can then be installed by 5 men in about 5 to 6 days.
PERSONNEL: 8 men comprise an operating crew. For 24-hour operation about 54 men are required to operate radar, communication radio and camp.
POWER: 12 KW, 120/208 V 3 phase supplied by electric diesel generator.

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*SCR-627 Long wave GCI

SCR-627
SCR-627

DESCRIPTION: Fixed, long wave medium-range GCI that supplies azimuth, altitude, and range data on planes. Two PPI and one HR scope supplied.
USES: To provide 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-207 is used with this set. When operating as a GCI station, VHF communication equipment SCR-624 is required.
PERFORMANCE
AND SITING:
Maximum range on a single medium bomber flying at indicated altitude, when set is installed on a flat sea-level site:
Altitude, feet 1000 5000 10,000 25,000
Range*, miles 25 60 120 135
*Range of PPI limits GCI operation to approx. 45 mi.

When operating as GCI, set must be sited so that a flat unobstructed reflecting surface extends at least 1/4 mile in the sector in which height-finding is desired. For early warning, set should be sited between 100 and 1000 feet above an unobstructed reflecting surface.

TRANSPORTABILITY: Set when crated is expected to weigh about 75,000 lbs.
INSTALLATION: Requires a weatherproof building about 20' x 40' for housing radar components, and a building 20' x 20' for the power units and switchboard. Antenna structure is approximately 30' L x 30' H x 20' D and mounts on turning gear installed in a concrete pit approx. 11' x 11' x 7' D. Buildings and tower must be built by engineers in about 3 weeks. Radar components can be installed by 5 men in about 3 or 4 days.
PERSONNEL: 8 men comprise an operating crew. For 24-hour operation about 54 men are required to run radar, communication radio, and camp.
POWER: Power is supplied by two PE-137 A, 25 KW, 120/208 volt gasoline generator sets (one spare). Fuel consumption is 2.4 gal. per hour, and non-leaded standard commercial gasoline is needed.

* Available for issue in latter part of 1943.

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*SM Microwave Shipborne CG Set

SM on Aircraft Carrier
SM on Aircraft Carrier

DESCRIPTION AND USES: Microwave set with three axis stabilized antenna, installed on aircraft carriers to search for enemy planes, particularly low-flying and shadow planes, and to supply height, speed and course data so that a Fighter Director Officer can direct fighters to an interception. Can also be used to search for ships and periscopes. SM is correlated with search sets, such as SK, and with radio communication to planes. Has provisions for A and G band IFF, and a built-in BO antenna. For night interception, AIA is required in planes.
PERFORMANCE: SM has a reliable detection range of 35 miles on a medium bomber 500 ft. above optical horizon. surfaced submarines can be followed to horizon. Periscopes can be seen 6 miles or more, and buoys can be seen up to horizon. Range can be determined to ± 200 yds., or 1/4%, whichever is greater. Bearing can be determined to ± 1/2°. Elevation can be determined to ±1/3° if airplane is 21/2° or more above optical horizon. If plane is lower, data is less reliable. Accuracy of range difference between two targets is ± 50 yds. for separation of 500-10,000 yds. Elevation limit is 90°.
TRANSPORTABILITY: Spares, testing equipment and separate generator supplied.
INSTALLATION: SM has 23 components weighing a total of about 9 tons. Largest unit is the antenna mount -- 131" high, with a diameter of 67" at base, and weighing about 4,600 lbs. The antenna is 6 ft. in diameter; 8-foot antennas will be installed on later sets. The console (76" x 65" x 24" -- 1,800-2,000 lbs.) splits into 3 parts for installation.
PERSONNEL: Minimum operators per shift required are two, plus one assistant radar officer. Recommended personnel: 15 per day.
POWER: Power required is 45-65 KW, 440 V. 3-phase 60 cycle, supplied by motor generator set, or, in emergencies, from ship's supply.

* Available for issue in latter part of 1943.

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