CG-47 CLASS ADVISORY NO. 05-85
RADHAZ/HERO GUIDANCE
COMNAVSEASYSCOM WASHINGTON DC MSG 242232Z JAN 85
REF: A. NAVSEA SPDLTR 04H2/RAV/SER 643 OF 28 JUN 82, ACN 4/3 TO
3565
B. COMNAVSEASYSCOM WASHINGTON DC 302110Z NOV 83, ACN 15/3
TO OP 3565
C. COMNAVSEASYSCOM WASHINGTON DC 261326Z JUN 84, ACN 19/3
TO OP 3565
D. NAVSEA OP 4154, VOLUME 2
1. HAZARD AVOIDANCE. THIS CLASS ADVISORY PROVIDES GUIDANCE FOR
PREVENTING RADIATION HAZARDS (RADHAZ) TO PERSONNEL AND HERO
PROBLEMS DURING CG-47 CLASS SHIP OPERATIONS.
2. CG-47 CLASS SHIPS HAVE SEVERAL RADAR SYSTEMS CAPABLE OF GENER-
ATING HIGH LEVELS OF RF ENERGY. SUSTAINED RF POWER DENSITY IN EXCESS
OF 10 MW/SQ CM IS CONSIDERED HAZARDOUS TO PERSONNEL. THE NAVY IS
CONSIDERING ADOPTING THE MORE STRINGENT RADHAZ CRITERIA OF ANSI
C95.1-1982. SOME ELEMENTS OF ORDNANCE USED IN CG-47 CLASS SHIPS ARE
SUSCEPTIBLE TO RF ENERGY.
3. THROUGH A COMBINATION OF PERSONNEL ACCESS CONSTRAINTS, RADI-
ATION ZONE CONTROL, OUTPUT POWER CONTROL AND MAINTENANCE OF SAFE
SEPARATION DISTANCES, RADHAZ AND HERO PROBLEMS CAN BE PREVENTED.
CONTROL FEATURES INHERENT IN THE VARIOUS RADAR SYSTEM DESIGNS, WITH
STRICT PROCEDURE IMPLEMENTATION, CAN PROVIDE EFFECTIVE RF SAFETY
WITH MINIMAL OPERATIONAL IMPACT.
4. THE FOLLOWING PRECAUTIONS SPECIFY RADAR MAIN BEAM RADHAZ
SAFE DISTANCES FOR BOTH THE 10 MW/SQ CM CRITERION AND THE MORE
STRINGENT ANSI CRITERIA. RADHAZ SAFE DISTANCES FOR THE ANSI CRITERIA
SHOULD BE USED WHEN OPERATIONALLY FEASIBLE.
5. RADHAZ PRECAUTIONS INPORT:
A. AN/SPY-1A. HIGH POWER OPERATION SHALL BE IN THE MAINTEN-
ANCE MODE UNDER LOCAL CONTROL ONLY. THIS MODE PLACES THE BEAM AT
THE ZENITH POSITION. NESTED SHIPS SHOULD BE ADVISED TO KEEP PERSONNEL
MORE THAN 45 FEET FROM ARRAY FACES AND BELOW LEVELS EQUIVALENT TO
23 FEET ABOVE ARRAY (APPROXIMATELY TOP OF FORWARD DIRECTORS AND
TOP OF NUMBER 3 DIRECTOR AFT). PERSONNEL MUST BE WARNED NOT TO
LEAN OVER RAILS ABOVE THE ARRAY FACES. THE HELICOPTER LIGHTING
MAINTENANCE PLATFORM ALLOWS PERSONNEL ACCESS TO A RADHAZ ZONE
DIRECTLY IN FRONT OF THE AFT ARRAY FACE. THE ACCESS IS NORMALLY
BARRICADED, BUT STRINGENT PROCEDURAL CONTROLS MUST BE IMPLEMENT-
ED TO PREVENT PERSONNEL FROM INADVERTENTLY ACCESSING THE AREA
WHEN THE RADAR IS ACTIVE. IN LOW POWER OPERATION, THE MAIN BEAM
MINIMUM SAFE DISTANCE IS 30 FEET (50 FEET USING ANSI CRITERIA).
B. FIRE CONTROL SYSTEM MK 99. EXTERNAL CW ILLUMINATOR RADI-
ATION MUST ALWAYS BE UNDER CONTROL OF C&D: E.G., SIMULATED ENGAGE-
MENT. THE BEAM MUST NOT BE DIRECTED TOWARD ANY SHIPYARD OR SHIP
STRUCTURE, I.E., CRANES, BUILDINGS, TOWERS AND ADJOINING SUPERSTRUC-
TURES. BY SELECTIVE TARGET DESIGNATION IN CLEAR AREAS AUTHORIZED BY
THE SHIPYARD SUPERINTENDENT, LIMITED ILLUMINATOR OPERATION CAN BE
ACCOMPLISHED. THE ILLUMINATOR GENERATES HAZARDOUS MAIN BEAM RF
LEVELS OUT TO 1310 FEET (1850 FEET USING ANSI CRITERIA).
C. EW SYSTEM AN/SLQ-32(V)3. THE SLQ-32 SYSTEM SHALL HAVE THE
TRANSMITTER OUTBOARD SPECIAL TEST EQUIPMENT (TOSTE) INSTALLED TO
SUPPRESS RADIATION WHILE OPERATING INPORT.
D. RADAR SYSTEM AN/SPS-49. SPS-49, WHILE ROTATING, DOES NOT
CREATE ANY RADHAZ AREAS, BUT EMI EFFECTS TO COMMERCIAL TV AND
RADIO RECEIVERS MAY LIMIT ITS USE INPORT. CONTACT THE SHIPYARD
SUPERINTENDENT PRIOR TO OPERATION. IF SPS-49 IS RADIATING WITH THE
ANTENNA STATIONARY, THE MAIN BEAM MINIMUM SAFE DISTANCE IS 200 FEET
(440 FEET USING ANSI CRITERIA).
E. RADAR SYSTEM AN/SPQ-9A. DURING NORMAL OPERATION WITH THE
ANTENNA ROTATING, SPQ-9A DOES NOT CREATE A RADIATION HAZARD. IF
SPQ-9A IS RADIATING WITH THE ANTENNA STATIONARY, THE MAIN BEAM
MINIMUM SAFE DISTANCE IS 65 FEET (85 FEET USING ANSI CRITERIA). IN THIS
MODE THE ANTENNA SHALL BE DIRECTED ONLY TO CLEAR AREAS AS
AUTHORIZED BY THE SHIPYARD SUPERINTENDENT.
F. CLOSE IN WEAPON SYSTEM (CIWS). CIWS SHALL BE DIRECTED ONLY
TO CLEAR AREAS AS AUTHORIZED BY THE SHIPYARD SUPERINTENDENT. IN
THE TRACK MODE, THE BEAM GENERATES HAZARDOUS MAIN BEAM RF LEVELS
OUT TO 90 FEET (140 FEET USING ANSI CRITERIA).
G. RADAR SYSTEM AN/SPS-55. DURING NORMAL OPERATION WITH THE
ANTENNA ROTATING SPS-55 DOES NOT CREATE A RADIATION HAZARD. IF SPS-
55 IS RADIATING WITH THE ANTENNA STATIONARY, THE MAIN BEAM MINIMUM
SAFE DISTANCE IS 25 FEET (50 FEET USING ANSI CRITERIA).
H. AN/WSC-3 SATCOM. WSC-3 CAN CREATE HAZARDOUS RADIATION
LEVELS OUT TO 4 FEET FROM THE WSC-1 ANTENNA (15 FEET USING ANSI
CRITERIA).
I. LN-66. LN-66 DOES NOT PRODUCE HAZARDOUS RADIATION LEVELS
USING THE 10 MW/SQ CM CRITERION. HAZARDOUS LEVELS EXIST OUT TO TWO
FEET FROM THE ANTENNA IF ANSI CRITERIA ARE USED.
J. OTHER RADIATION RESTRICTIONS MAY BE SPECIFIED BY THE PAR-
TICULAR PORT OF CALL. ADVANCE CONTACT WITH PORT AUTHORITIES
SHOULD BE ESTABLISHED.
6. RADHAZ PRECAUTIONS AT SEA:
A. RADHAZ SAFE DISTANCES. MAIN BEAM RADHAZ SAFE SEPARATION
DISTANCES SHOWN BELOW MUST BE MAINTAINED IN A MULTIPLE SHIP ENVIRON-
MENT. RADIATING ELEMENTS NOT SHOWN DO NOT CREATE RADHAZ CONDI-
TIONS BEYOND THE SHIP BOUNDARIES IN THEIR NORMAL OPERATING MODES.
RF SOURCE MINIMUM SAFE DISTANCE
10 MW/SQ CM CRIT. ANSI C95.1-1982 CRIT.
AN/SPY-1 (HIGH POWER) 360 FT 520 FT
AN/SPY-1A (LOW POWER) 30 FT 50 FT
AN/SPG-62 (FCS MK 99) 1310 FT 1850 FT
AN/SLQ-32 90 FT 130 FT
CIWS 90 FT 140 FT
B. MAN ALOFT. ALL AREAS ABOVE THE 05 LEVEL AND THE HELICOPTER
LIGHTING MAINTENANCE PLATFORM ON THE 04 LEVEL ARE MAN ALOFT AREAS.
PROCEDURES SHALL BE ESTABLISHED TO ENSURE RADAR AND RADIO
TRANSMITTERS FOR THESE AREAS ARE SECURED WHILE MEN ARE ALOFT.
C. WEATHER DECK. THE 03 LEVEL FORWARD OF THE AN/SLQ-32 AND
THE BOAT STORAGE AREAS AFT OF THE AN/SLQ-32 ARE HAZARDOUS WHEN THE
ACTIVE EMITTERS ARE RADIATING. PERSONNEL SHOULD BE RESTRICTED FROM
THESE AREAS WHEN RADIATION IS POSSIBLE. AREAS OF THE BRIDGE WINGS
ARE EXPOSED TO RF LEVELS WHICH EXCEED THE ANSI CRITERIA, BUT ARE LESS
THAN 10 MW/SQ CM, DURING TRANSMISSION BY THE 10-30 MHZ TWIN WHIP
ANTENNA ATOP THE PILOT HOUSE, ANTENNA 2-3. THE HAZARD CAN BE
MINIMIZED BY LIMITING HF TRANSMITTER POWER TO 500 WATTS OR BY RE-
STRICTING ACCESS TO THE BRIDGE WINGS DURING TRANSMISSION BY THE TWIN
WHIP.
7. HERO PRECAUTIONS:
A. CIWS. CIWS IS CONSIDERED HERO SUSCEPTIBLE IN SEVERAL FRE-
QUENCY RANGES. THE HERO RESTRICTIONS ARE SPECIFIED IN OP 3565
ADVANCED CHANGE NOTICES 4/3, 15/3, AND 19/3, REFERENCES A, B AND C
RESPECTIVELY. HERO RELATED AMMUNITION HANDLING PRECAUTIONS FOR
CIWS ARE PROVIDED IN REFERENCES A AND D. CIWS HERO RESTRICTIONS ARE
SUMMARIZED BELOW.
(1) TOUCHING OF THE 20MM ROUND PRIMER SHOULD BE AVOIDED
AT ALL TIMES. DURING OPERATION REQUIRING ON DECK HANDLING OF BARE
(WITHOUT RADHAZ LINKS) 20MM ROUNDS, TRANSMITTERS IN THE 2 MHZ TO 1400
MHZ FREQUENCY RANGE SHOULD BE SECURED.
(2) WHEN TRAVELING IN COMPANY WITH OTHER SHIPS, PRE-
CAUTIONS SHOULD BE TAKEN TO AVOID DIRECT ILLUMINATION OF 20MM
AMMUNITION (ON DECK, IN LOADERS OR MOUNTS) WITH FIRE CONTROL OR
SURFACE/AIR SEARCH RADARS IN THE 2.7 GHZ TO 8.4 GHZ FREQUENCY RANGE
WITHIN THE SPECIFIED SAFE DISTANCES. SAFE DISTANCES ARE SPECIFIED IN
REFERENCES A AND B. THIS RESTRICTION APPLIES TO RADIATION OF CG-47
CLASS SHIP CIWS BY OTHER SHIPS AND TO CG-47 CLASS SHIP RADIATION OF
OTHER SHIPS CIWS. THE SAFE DISTANCE SPECIFIED IN REFERENCE B FOR
AN/SPY-1A IS 1462 YARDS. THERE ARE NO RESTRICTIONS ON ILLUMINATION OF
THE MOUNT IF LIVE AMMUNITION IS TOTALLY CONTAINED WITHIN THE DRUM
MAGAZINE. (SEE REFERENCE C FOR DETAILED INSTRUCTIONS).
B. SRBOC. AN/SLQ-32 RADIATION SHOULD BE INHIBITED WHEN CON-
DUCTING SRBOC HANDLING AND LOADING OPERATIONS.
C. STANDARD MISSILE 1 (SM-1). SM-1 IS CONSIDERED HERO SUSCEPTIBLE
AND SHOULD NOT BE EXPOSED TO MAIN BEAM HIGH POWER ILLUMINATION BY
THE AN/SPY-1A PRIOR TO LAUNCH.
D. ASROC. ASROC CONFIGURED WITH ISA MK 4 MOD 0 IS HERO SAFE
AND THERE ARE NO HERO RESTRICTIONS ON OPERATIONS WITH THIS MISSILE.
ASROC CONFIGURED WITH ISA MK 3 MOD 2 IS HERO SUSCEPTIBLE AND SHOULD
NOT BE EXPOSED TO MAIN BEAM HIGH POWER ILLUMINATION BY THE AN/SPY-
1A OR TO MAIN BEAM ILLUMINATION BY THE AN/SPG-62. ADDITIONALLY, HF
TRANSMISSION BY THE 10-30 MHZ TWIN WHIP ANTENNA ATOP THE PILOT HOUSE
SHOULD BE DISCONTINUED DURING HANDLING, LOADING OR PRESENCE OF
ASROC CONFIGURED WITH ISA MK 3 MOD 2 IN THE VICINITY OF THE FORWARD
GMLS MK 26 LAUNCHER.
8. HELICOPTER OPERATIONS - FOUR PROBLEM AREAS MUST BE CON-
SIDERED:
RADHAZ - ELECTROMAGNETIC RADIATION FROM THE SHIP'S SENSORS COULD
BE SUFFICIENTLY INTENSE TO CREATE A RADIATION HAZARD TO THE
HELICOPTER AIR CREW.
HERO - ELECTROMAGNETIC RADIATION FROM OWNSHIP RADARS MIGHT
TRIGGER THE DETONATION OF ORDNANCE AND PYROTECHNICS ON THE HELI-
COPTER.
EMI/EMC - FRIENDLY JAMMING COULD RESULT FROM INTERFERENCES
BETWEEN THE SHIP AND HELICOPTER SENSORS.
INTERCEPT BY OWNSHIP WEAPONS - THE HELICOPTER COULD BE INTER-
CEPTED BY OWNSHIP WEAPONS EITHER AS A RESULT OF BEING INADVERTENTLY
INTERCEPTED BY A WEAPON INTENDED FOR A THREAT PLATFORM OR A
RESULT OF BEING IMPROPERLY DECLARED A HOSTILE TARGET.
A. PEACETIME, NON-OPERATIONAL EXERCISES GREATLY REDUCE THE
PROBLEMS. WEAPONS SHALL BE SECURED AND SENSORS INHIBITED OR RE-
DUCED TO LOWER OUTPUT POWER SO THAT CONVENTIONAL RECOVERIES AND
LAUNCHES MAY BE ACCOMPLISHED.
B. UNENGAGED OPERATIONS CONSTITUTE ANY OPERATIONAL ENVIRON-
MENT WHEN THE SHIP IS NOT DEFENDING ITSELF. IF AN ATTACK IS IMMINENT
OR EVEN POSSIBLE (WARTIME CONDITIONS), IT WILL BE NECESSARY TO LIMIT
THE PERIOD OF TIME DURING WHICH THE OPERATION OF SENSORS WOULD BE
INHIBITED TO THE SHORTEST TIME POSSIBLE.
C. RECOVERY AND LAUNCH OPERATIONS DURING AN ACTIVE ENGAGE-
MENT ARE NOT RECOMMENDED; BUT SHOULD AN EXIGENCY ARISE, COMMAND
DECISIONS MUST BE MADE USING RISK TRADEOFFS, E.G., DIVERSION OF
HELICOPTER TO ANOTHER PLATFORM, HOLDING PATTERN. EACH AEGIS SHIP
SHALL DEVELOP A DOCTRINE FOR HELICOPTER OPERATIONS IN VARIOUS
COMBAT POSTURES.
9. THIS INFORMATION WILL BE INCLUDED IN THE AEGIS CSTOM.
CG-47