DDG-51 DDG-51
DDG 51 CLASS ADVISORY NR 14-94
CIWS MAGAZINE AMMO HANDLING SYSTEM SLACK CHAIN BRAKING DEVICE RESET
REF/A/DOC/NAVSEA/-//
REF/B/DOC/NAVSEA/-//
NARR/REF A IS TECHNICAL MANUAL, NAVSEA S9DDG-BT-SSM-030/DDG51 CLASS
CIWS AMMUNITION AND MK 36 DECOY LAUNCHING SYSTEM, HANDLING,
STOWAGE,STRIKE-UP AND REPLENISHMENT SYSTEM FOR THE DDG 51 CLASS. REF
B IS TECHNICAL MANUAL, NAVSEA SG420-CJ-MMA-010/88733 - CIWS AMMUNITION
AND DECOY LAUNCHING SYSTEM CARTRIDGES HANDLING EQUIPMENT FOR THE
DDG 51 CLASS.//
RMKS/1. THIS ADVISORY PROVIDES DIRECTION TO REDUCE THE TRAVEL SPEED OF
THE PNEUMATIC CHAIN HOISTS IN THE FWD AND AFT CIWS MAGAZINES. IT ALSO
PROVIDES GUIDANCE IN THE EVENT THAT THE SLACK CHAIN BRAKING DEVICE ON
THE HOISTS IS ACTUATED AND MUST BE RESET.
2. BACKGROUND. DURING ALL OF THE DDG 51 CLASS ACCEPTANCE TRIALS,
INSURV HAS NOTED OPERATIONAL DISCREPANCIES WITH THE CIWS HOIST
SYSTEM. SEVERAL CHANGES HAVE BEEN IMPLEMENTED TO CORRECT
DEFICIENCIES, INCLUDING:
A. REPLACING MAC-AIR VALVES WITH MAROTTA VALVES (DDG 51 AND FOLLOW),
B. RELOCATING THE VALVES SAFELY AWAY FROM THE HOIST (DDG 51 AND
FOLLOW),
C. REDUCING THE TRAVEL SPEED OF THE HOISTS (DDG 53 AND FOLLOW),
D. TAMPER-PROOFING THE SPEED CONTROL VALVES (DDG 53 AND
FOLLOW), AND
E. INSTALLING SAFETY PLACARDS WITH SLACK CHAIN BRAKING DEVICE
RELEASE PROCEDURES AND WARNINGS ABOUT THE SYSTEM SPEED SETTINGS
(DDG 53 AND FOLLOW). THIS ADVISORY APPLIES TO DDG 51 AND 52 AS AN INTERIM
MEASURE PENDING BACKFIT OF ITEMS C, D AND E AND THE INCLUSION OF THESE
INSTRUCTIONS IN REF A.
3. ACTION.
A. ADJUSTMENT OF HOIST SPEED - THE PNEUMATIC CHAIN HOIST IN THE FWD
MT 21 CIWS MAGAZINE SHALL BE ADJUSTED SUCH THAT THE PLATFORM, WHEN
EMPTY, TRAVELS ITS FULL LENGTH FROM THE 02 LEVEL TO THE 03 LEVEL IN NOT
LESS THAN 15 SECONDS. THE HOIST IN THE AFT MT 22 CIWS MAGAZINE SHALL BE
ADJUSTED SUCH THAT THE PLATFORM, WHEN EMPTY, TRAVELS ITS FULL LENGTH
FROM THE 01 LEVEL TO THE 02 LEVEL IN NOT LESS THAN 20 SECONDS.
ADJUSTMENT OF THE PLATFORM SPEED SHALL BE ACCOMPLISHED USING THE
PROCEDURE GIVEN IN SECTION 6-3.3 OF REF B WITH THE FOLLOWING EXCEPTION -
IN STEP M., RATHER THAN USING SPEEDS LISTED IN TABLE 1-1, THE SPEED
CONTROL VALVES SHALL BE ADJUSTED TO PRODUCE THE PLATFORM SPEEDS
LISTED ABOVE.
WARNING: ONCE THE SPEED OF THE HOISTS HAS BEEN CALIBRATED, THE SPEED
CONTROL VALVES SHALL NOT BE TAMPERED WITH. UPON COMPLETION OF HOIST
SPEED ADJUSTMENT, TORQUE STRIPE PAINT SHALL BE APPLIED ACROSS THE SET
SCREW AND VALVE BODY OF THE SPEED CONTROL VALVES. NO ATTEMPT SHOULD
BE MADE TO INCREASE THE SPEED OF THE SYSTEMS ABOVE THEIR CALIBRATED
AND RATED SPEED. IF, SUBSEQUENT TO CALIBRATION, THE TORQUE STRIPE
PAINT ON THE VALVES IS OBSERVED TO BE CHIPPED IN ANY WAY THE SYSTEM
SHALL NOT BE USED UNTIL RECALIBRATED BY MAINTENANCE PERSONNEL TO THE
SAFE SPEED RANGE.
B. RESETTING THE SLACK CHAIN BRAKING DEVICE - IN THE EVENT THAT THE
CIWS MAGAZINE AMMO HANDLING SYSTEM SLACK CHAIN BRAKING DEVICE
ACTUATES, THE FOLLOWING PROCEDURE SHALL BE USED TO SAFELY RESET THE
SLACK CHAIN BRAKING DEVICE. ALL MAGAZINE PERSONNEL SHALL BE FAMILIAR
WITH THE SAFETY NOTICES LISTED IN TECHNICAL MANUAL
S9DDG-BT-SSM-030/DDG 51 CLASS.
EQUIPMENT/TOOLS REQUIRED:
TWO 6 INCH MACHINE CLAMPS
ONE 12 FOOT (MIN) TAPE MEASURE
PORTAPOWER (OR SIMILAR) JACK
CROSSCUT SAW
ONE 6 INCH ADJUSTABLE WRENCH
CONTAINER OF TORQUE STRIPE (1/2 OZ PLASTIC TUBE - 1476T11)
SHORING (4 X 4) - MINIMUM OF 8 FT
PROCEDURE:
(1) OPERATE AIR SUPPLY VALVES (FWD: ALP-V-222 OR AFT: ALP-V-361) TO
THE OFF POSITION (CW ROTATION).
(2) LOOSEN THE AIR REGULATOR LOCK NUT AND ADJUST THE AIR
REGULATOR FOR THE MINIMUM AIR PRESSURE -OFF- (CCW ROTATION).
(3) DEFLECT MOISTURE SEPARATOR BLEED VALVE TO BLEED OFF SYSTEM.
OBSERVE AIR PRESSURE GAUGE INDICATES A PRESSURE REDUCTION.
(4) REPEAT STEPS (2) AND (3) UNTIL AIR PRESSURE GAUGE READS ZERO (0)
P.S.I.
CAUTION: DO NOT PROCEED UNTIL AIR PRESSURE GAUGE READS "0" PSI. INJURY
COULD RESULT FROM SUDDEN INADVERTENT PLATFORM MOTION. GAUGE MUST
READ "0" PSI.
(5) INSTALL A MACHINE CLAMP ONTO EACH OF TWO RAIL SURFACES AT THE
LOW POINT OF THE PLATFORM STRONGBACK. THIS IS A BACKUP PRECAUTION TO
PREVENT INADVERTENT DOWN MOVEMENT OF THE PLATFORM.
(6) OFFLOAD ALL BOXES OF AMMO FROM THE PLATFORM AND RETURN AMMO
TO MAGAZINE STOWAGE.
CAUTION: THE SLACK CHAIN BRAKING DEVICE RESET SHOULD NOT BE
PERFORMED ON A PLATFORM CONTAINING AMMO.
(7) IF THE SLACK CHAIN BRAKING DEVICE ACTIVATION WAS CAUSED BY A
CHAIN FAILURE (BREAKAGE) THE CHAIN MUST BE REPAIRED BEFORE CONTINUING
TO RESET CHAIN BRAKING DEVICE.
(8) DETERMINE AND ASSESS THE QUANTITY OF STANDARD LINKS AND
MASTER LINKS REQUIRED TO RESTORE CHAIN TO ORIGINAL LENGTH.
(9) REASSEMBLE CHAIN AND SPOOL CHAIN THROUGH THE LIFT
SPROCKET ASSEMBLY ATTACHED TO CYLINDER PISTON ROD.
(10) ATTACH END OF REPAIRED CHAIN TO FLAT (REF B, FIG AND INDEX NR.
7-2-36 IN TABLE 7-2) USING CHAIN MASTER LINK.
(11) ATTACH FLAT TO PLATFORM LIFT TUBE USING 1/2" QUICK RELEASE PIN.
(12) IF CHAIN FAILURE WAS NOT THE CAUSE OF SLACK CHAIN BRAKING
DEVICE ACTIVATION, THEN FAILURE MODE MUST BE ISOLATED AND REPAIRED.
CAUTION: DO NOT APPLY AIR TO SYSTEM UNTIL JACKING APPARATUS HAS BEEN
SET UP AND IN PLACE FOR READY USE.
(13) ENSURE ALL PERSONNEL NOT DIRECTLY NEEDED OR INVOLVED IN RESET
OF BRAKING DEVICE ARE CLEAR OF THE AREA/MAGAZINE.
CAUTION: SECURE ALL PLATFORM RETAINER CHAINS TO THEIR NORMALLY
ATTACHED POSITION. LOOSE DANGLING CHAINS CAN WHIP AND INJURE
PERSONNEL OR DAMAGE EQUIPMENT.
(14) OBTAIN JACKING DEVICE TO BE USED TO RELEASE THE
LOCKING DEVICE.
(15) LOCATE THE JACK ON THE DECK AT THE CENTER POINT OF THE TWO
VERTICAL RAILS.
(16) MEASURE FROM THE TOP OF THE JACK TO THE BOTTOM MEMBER OF THE
PLATFORM STRONGBACK.
(17) CUT A PIECE OF 4" X 4" MINIMUM SHORING ONE INCH LESS THAN THE
MEASURED DISTANCE ABOVE IN STEP (16).
(18) PLACE THE SHORING ON THE TOP SURFACE OF THE JACK.
(19) SUPPORT SHORING AS REQUIRED TO HOLD CAPTIVE WHILE PERFORMING
JACKING OPERATION.
(20) SNUG-UP SHORING BY OPERATING JACK IN THE UP DIRECTION.
(21) REMOVE THE MACHINE CLAMPS FROM EACH RAIL.
WARNING: SHORING MUST BE MADE CAPTIVE TO PREVENT "KICKOUT" WHILE
CONDUCTING THE JACKING OPERATION.
(22) SECURE VERTICAL SHORING IN PLACE TO PREVENT FROM
FALLING WHEN BRAKING DEVICE RELEASES.
(23) ADJUST AIR SUPPLY VALVES (FWD ALP-V-222 OR AFT
ALP-V-361) ON (FULLY CCW).
(24) ADJUST AIR REGULATOR (CW ROTATION) UNTIL AIR PRESSURE GAUGE
READS 50 PSI.
(25) JOG THE RAISE CONTROL VALVE TO REMOVE SLACK IN THE LIFT SYSTEM
CHAIN.
(26) AGAIN JOG THE RAISE VALVE TO APPLY THE FULL 50 PSI ON THE CHAIN
AND HOIST SYSTEM.
(27) OPERATE THE JACK IN THE UP DIRECTION UNTIL THE LOCKING DEVICE
DISENGAGES FROM THE LOCKED POSITION.
(28) THE PLATFORM SHOULD COME TO REST AND THE CHAIN TENSION
SHOULD RETURN AND HOLD THE LOCKING DEVICE TO A NEUTRAL POSITION.
(29) DEPRESS THE RAISE CONTROL LEVER AND POSITION THE
PLATFORM TO THE FULL UP POSITION.
(30) REMOVE ALL JACKING AND SHORING APPARATUS MATERIALS FROM
INSIDE MAGAZINE.
CAUTION: IF BELL SHOULD RING AT ANY TIME, IMMEDIATELY MOVE CLEAR OF THE
PLATFORM WHICH COULD BE IN MOTION.
(31) CYCLE PLATFORM THROUGH AT LEAST TWO (2) COMPLETE
CYCLES TO ASSURE REDUCED PRESSURE SYSTEM OPERATION.
(32) RETURN SYSTEM TO FULL DOWN OR STOW POSITION.
(33) ADJUST AIR REGULATOR FOR 100 PSI AS INDICATED ON THE AIR
PRESSURE GAUGE.
(34) APPLY TORQUE STRIPE ACROSS REGULATOR ADJUSTMENT
STEM/LOCK NUT/REGULATOR BODY FOR VISUAL TAMPER PROOF INDICATION.
NOTE: IF THE SLACK CHAIN BRAKE DEVICE WAS ACTIVATED DUE TO A LOAD CHAIN
OR OTHER LIFTING COMPONENT FAILURE AND THE CHAIN OR COMPONENT WAS
EITHER REPAIRED OR REPLACED, THE AMMO HANDLING SYSTEM WILL REQUIRE A
WEIGHT TEST IAW SECTION 700-4.5.2 OF NAVSEA TECHNICAL MANUAL
S9086-XG-STM-010, CHAPTER 700 (SHIPBOARD AMMUNITION HANDLING AND
STOWAGE) PRIOR TO USE.
4. FOR COMNAVSURFLANT - RECOMMEND DDG 51 AND 52 BE TASKED TO ADHERE
TO THE PROVISIONS OF PARA 3 ABOVE AND TO SUBMIT OPNAV FORM 4790/2K FOR
FABRICATION AND INSTALLATION OF PLACARDS TO CONTAIN TEXT OF PARA 3.B.
5. FOR SUPSHIP BATH - REQUEST YOU ENSURE THAT PARA 3 PROCEDURES ARE
INCLUDED IN THE NEXT CHANGE TO REF A AND THAT REF B IS REVISED
ACCORDINGLY.
6. THIS ADVISORY HAS NO IMPACT ON EOSS, CSOSS, PMS OR CMMP. IT WILL BE
CANCELLED WHEN HOISTS HAVE BEEN ADJUSTED AND PLACARDS HAVE BEEN
INSTALLED IN DDG 51 AND 52 AND REF A HAS BEEN UPDATED TO INCLUDE PARA 3
PROCEDURES.
7. POC IS MR. N. S. SMITHSON, PMS400F511, DSN 332-5981 (EXT 133) OR COMM (703)
602-5981. TPOC IS MR. F. WEIDNER, NAVSEA 03W46, DSN
332-9391 (EXT 406) OR COMM (703) 602-9391.//