LPD-1

                     SHIP SYSTEMS ISE ADVISORY NO. 059-82                       
                                                                                
                                                                                
                   LPD-1 CLASS STERN GATE EMERGENCY RIGGING                     
                                                                                
                  NAVSSES PHILADELPHIA PA MSG 212142Z MAY 82                    
                                                                                
                                                                                
 REF:            A.      SHIPALT LPD-405, REV 1, STERN GATE EMERGENCY RIGGING   
                 B.      NAVSEA DWG LPD 2-122-5500985, STERN GATE EMERGENCY RIG-
 GING MODIFICATION                                                              
                 C.      NAVSHIPYD PHILADELPHIA PA 061344Z MAY 82 (NOTAL)       
                                                                                
                                                                                
 1.      SUMMARY:  THE PURPOSE OF THIS MESSAGE IS TO ADVISE THAT THE            
 EMERGENCY STERN GATE RIGGING ARRANGEMENT CURRENTLY INSTALLED ON                
 USS RALEIGH (LPD-1) AND USS VANCOUVER (LPD-2), PER SHIPALT LPD-405, IS         
 SUBJECT TO POSSIBLE FAILURE DUE TO A MARGINAL FACTOR OF SAFETY                 
 ASSOCIATED WITH ONE OF THE SHEAVES USED ON THE STARBOARD SIDE.  A              
 RECOMMENDED MODIFICATION IS PROVIDED.  END SUMMARY.                            
                                                                                
 2.      REFERENCE A WAS ISSUED TO MODIFY THE EXISTING LPD CLASS STERN          
 GATE EMERGENCY RIGGING.  REFERENCE B WAS DEVELOPED BY SUPSHIP SAN              
 DIEGO AND WAS USED FOR THE INSTALLATION OF REFERENCE A ON USS                  
 VANCOUVER (LPD-2).  ALSO, NAVSHIPYD PHILADELPHIA PA RECENTLY USED              
 REFERENCE B FOR ACCOMPLISHING REFERENCE A ON THE USS RALEIGH (LPD-             
 1).                                                                            
                                                                                
 3.      REFERENCE C NOTED A PROBLEM WITH ACCOMPLISHING THE SHIPALT             
 PER REFERENCE B.  ONE OF THE EXISTING SHEAVE BRACKETS IS SUBJECTED TO          
 SUBSTANTIALLY MORE TORSIONAL LOADING WITH THE NEW RIGGING AR-                  
 RANGEMENT SHOWN IN VIEW EL 17-C OF REFERENCE B.  REFERENCE C                   
 FURTHER NOTED THAT NAVSHIPYD PHILADELPHIA WAS DEVELOPING A MOD-                
 IFICATION TO REFERENCE B WHICH WOULD BE ACCOMPLISHED ON USS                    
 LASALLE (AGF-3), CURRENTLY UNDERGOING ROH AT NAVSHIPYD                         
 PHILADELPHIA THE MOD BEING DEVELOPED BY NAVSHIPYD PHILADELPHIA IS              
 TO STRENGTHEN THE SHEAVE BRACKET SUBSTANTIALLY SO THAT IT WILL BE              
 ABLE TO HANDLE THE LOADING SAFELY.                                             
                                                                                
 4.      NAVSSES DISCUSSED THE ABOVE PROBLEM WITH SUPSHIP SAN DIEGO             
 DESIGN PERSONNEL AND IT WAS AGREED THAT THE BEST SOLUTION WOULD BE             
 TO CHANGE THE STARBOARD RIGGING ARRANGEMENT SO THAT IT IS SIMILAR              
 TO THE PORT ARRANGEMENT (SEE DETAIL 8-C ON REFERENCE B).  NOTE, THE            
 PORT ARRANGEMENT UTILIZES A SNATCH BLOCK VS A FIXED SHEAVE AND IS              
 NOT SUBJECT TO THE TORSIONAL LOADING.  THIS ALTERNATIVE FIX WAS                
 DISCUSSED WITH NAVSHIPYD PHILADELPHIA DESIGN PERSONNEL AND THEY                
 CONCUR WITH IT.                                                                
                                                                                
 5.      BASED ON THE ABOVE, NAVSSES RECOMMENDS THE FOLLOWING:                  
         A.      AT THE FIRST OPPORTUNITY MODIFY THE STARBOARD SIDE EMER-       
 GENCY STERN GATE RIGGING ON USS RALEIGH AND USS VANCOUVER SO THAT              
 IT IS THE SAME AS THAT ON THE PORT SIDE (DETAIL 8-C OF REFERENCE B).           
         B.      ACCOMPLISH THIS SAME MOD ON USS LASALLE WHILE IT IS STILL IN   
 ROH.                                                                           
         C.      UNTIL THIS MOD IS ACCOMPLISHED, EXTREME CARE SHOULD BE         
 USED IF THE EMERGENCY STERN GATE RIGGING MUST BE UTILIZED:  NO                 
 EXTERNAL LOADS (OTHER THAN THE GATE WEIGHT) SHOULD BE IMPOSED ON               
 THE RIGGING.                                                                   
         D.      UPON ACCOMPLISHMENT OF THIS MOD, THE EMERGENCY RIGGING         
 SHOULD BE TESTED.  TESTING IS TO INCLUDE A 200 PERCENT STATIC LOAD TEST        
 (THE GATE HORIZONTAL AND AN EXTERNAL LOAD OF APPROXIMATELY 80-90K              
 POUNDS PLACED ON THE GATE) AND A 150 PERCENT DYNAMIC LOAD TEST (THE            
 GATE HORIZONTAL AND AN EXTERNAL LOAD OF APPROXIMATELY 40-45K).                 
 DURING BOTH TESTS THE HYDRAULIC SYSTEM DOCKING VALVE MUST BE                   
 OPENED AND DURING THE DYNAMIC TEST APPROXIMATELY 2 FEET OF GATE                
 TRAVEL IN EACH DIRECTION IS REQUIRED TO VERIFY OPERATION.                      
                                                                                
 6.      FOR NAVSEA 5142/9413:  RECOMMEND APPROPRIATE ACTION BE TAKEN TO        
 MODIFY REFERENCE B TO DOCUMENT THE ABOVE MODIFICATION.                         
                                                                                
 REFERENCES A AND B SHOULD ALSO BE REVISED TO INCLUDE THE TESTING               
 REQUIREMENTS CITED IN PARAGRAPH 5.D ABOVE.                                     
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
 THIS ADVISORY APPLICABLE TO LPD-1 AND AGF-3 CLASSES OF SHIPS.