FFG-7

                FFG 7 CLASS ADVISORY NO. 06-95                                  

                                                                                

                    SUPERSTRUCTURE WELDING                                      

                                                                                

 REF/A/LTR/NAVSEA/-//                                                           

                                                                                

 REF/B/DOC/NAVSEA/-//                                                           

                                                                                

 NARR/REF A IS FFG 7 AER N0. 13-94, PASSIVE COUNTERMEASURES (PCMS)              

 MATERIAL AND NON-SKID REMOVAL FOR SUPERSTRUCTURE CRITICAL WELD                 

 INSPECTION, SERIAL NUMBER 335TH/9940 OF 19 DEC 94.  REF B IS NAVSEA            

 DRWG 150-5604994 REV E, QUALITY ASSURANCE REQUIREMENT FOR SHIPALT              

 146K.//                                                                        

 POC/P. J. REGIS/LCDR/-/LOC: ARLINGTON VA/TEL: DSN 332-1304 X113                

 /TEL: (703) 602-1304 X113//                                                    

                                                                                

 RMKS/1.  THIS CLASS ADVISORY PROVIDES GUIDANCE CONCERNING WELD                 

 REPAIR OF CRITICAL AREAS ON FFG 7 SUPERSTRUCTURES.                             

                                                                                

 2.  BACKGROUND                                                                 

      A.  HISTORICALLY, THE SUPERSTRUCTURE ON FFG 7 CLASS SHIPS HAS             

 EXPERIENCED EXTENSIVE CRACKING.  THE CAUSE OF THE CRACKING HAS BEEN            

 DETERMINED TO BE A COMBINATION OF HIGH DESIGN STRESS COUPLED WITH              

 POOR QUALITY WELDING.  IN SEVERAL CASES CRACKS HAVE SPREAD ACROSS THE          

 02 LEVEL WEATHERDECK.  THE MOST PREVALENT CRACKING OCCURS AT FRAME             

 200.5 ON THE 02 LEVEL.                                                         

      B.  SHIPALT FFG 7-86K WAS FIRST INTRODUCED TO ALLEVIATE                   

 CRACKING PROBLEMS.  THIS SHIPALT WAS NOT COMPLETELY SUCCESSFUL,                

 THEREFORE, SHIPALT FFG 7-146K WAS DEVELOPED AND IMPLEMENTED.                   

 SHIPALT 146K INCORPORATES MORE STRINGENT QUALITY ASSURANCE MEASURES            

 AND WELDING PROCEDURES.                                                        

      C.  DUE TO CONCERN THAT THE HIGH STRESSES AND POOR QUALITY                

 WELDING MAY PRODUCE CRACKING AT OTHER AREAS OF THE FFG 7 CLASS                 

 SUPERSTRUCTURE, POST SHIPALT 146K INSTALLATION SHIP CHECKS HAVE BEEN           

 UNDERTAKEN BY NSWCCD-SSES AND LBNSY TO MONITOR THE EFFECTIVENESS OF            

 THE ALTERATION.  TO ASSIST NSWCCD-SSES AND LBNSY AND ALLOW FOR                 

 SHIPS FORCE INSPECTION OF CRITICAL WELD AREAS, REF A WAS DEVELOPED.            

 THIS AER CALLS FOR THE PERMANENT REMOVAL OF PCMS AND NON-SKID FROM             

 CRITICAL WELD AREAS IDENTIFIED DURING POST SHIPALT 146K INSTALLATION           

 SHIP CHECKS.  REMOVAL OF THE SPECIFIED PCMS MATERIAL WILL NOT                  

 ADVERSELY AFFECT THE PERFORMANCE OF THE REMAINDER OF THE COATING.              

      D.  GOOD WELD QUALITY IS MANDATORY IN THE PRESENCE OF THE HIGH            

 DESIGN STRESS AREAS SUCH AS FOUND ON THE FFG 7 02 LEVEL.  ACHIEVING            

 GOOD QUALITY WHEN WELDING ALUMINUM REQUIRES METICULOUS ADHERENCE TO            

 CLEANLINESS AND PROCEDURES.  POOR ALUMINUM WELDING WILL CRACK.                 

                                                                                

 3.  ACTION.                                                                    

      A.  ALL FFG 7 CLASS SUPERSTRUCTURE WELD REPAIR WORK SHALL                 

 CONFORM TO REF B OR NSWCCD-SSES EQUIVALENT QUALITY ASSURANCE                   

 PROVISIONS.                                                                    

      B.  TACK WELDING ON CRITICAL WELD AREAS OF THE SUPERSTRUCTURE             

 AND CORRESPONDING INTERIOR OVERHEADS AND BULKHEADS IS PROHIBITED.              

 SUPERSTRUCTURE CRITICAL WELD AREAS ARE DEFINED AS ANY STRUCTURAL               

 WELD BETWEEN FRAMES 180 AND 230.                                               

      C.  NSWCCD-SSES (CODE 6233) SHALL BE CONTACTED PRIOR TO ANY               

 WELDING WITHIN 24 INCHES OF ANY CRITICAL WELD AREA TRANSVERSE BUTT             

 WELD.                                                                          

      D.  SHIPS FORCE SHALL REPORT TO ORIG AND NSWCCD-SSES THE                  

 FOLLOWING ITEMS IF FOUND IN THE SUPERSTRUCTURE CRITICAL WELD AREA              

 DURING NORMAL ROUTINE INSPECTION:                                              

           (1) ANY CRACK IN AN EXISTING TRANSVERSE BUTT WELD.                   

           (2) ANY DECK CRACK OVER A LONGITUDINAL STIFFENER.                    

           (3) ALL PREVIOUSLY REPAIRED CRACKS.                                  

           (4) ANY CRACK OVER 6 INCHES IN LENGTH.                               

           (5) ANY CRACK WITHIN 24 INCHES OF A TRANSVERSE BUTT WELD.            

      E.  SHIPS FORCE SHALL ACCOMPLISH REF A AT THE EARLIEST WINDOW OF          

 OPPORTUNITY.                                                                   

                                                                                

 4.  FOR COMNAVSURFLANT/COMNAVSURFPAC - RECOMMEND:                              

      A.  TASKING FFG 7 CLASS SHIPS TO ADHERE TO PARA 3 ACTIONS.                

      B.  TASKING IMA ACTIVITIES TO ADHERE TO PARA 3 ACTIONS.                   

                                                                                

 5.  FOR LBNSY (CODE 250.1) - ENSURE ALL SHIP ALTERATIONS UNDER                 

 DEVELOPMENT, WHICH REQUIRE SUPERSTRUCTURE WELDING, CONFORM TO REF B            

 OR EQUIVALENT WELDING QUALITY ASSURANCE PROVISIONS.                            

                                                                                

 6.  FOR SUPSHIPS - ENSURE REF B IS ADHERED TO PRIOR TO AND DURING              

 INSTALLATION OF SHIPALT FFG 7-146K.                                            

                                                                                

 7.  THIS CLASS ADVISORY HAS NO IMPACT ON EOSS, PMS, OR CMP.  IT WILL           

 BE CANCELLED AT THE DISCRETION OF THE ORIG AND CNSL/CNSP.                      

                                                                                

 8.  NAVSEA POC IS JOHN STONE, PMS335TH, DSN 332-1304 X115 OR COMM              

 (703) 602-1304 X115.  NAVSEA WELDING POC IS JOHN DORN, SEA 03M2, DSN           

 332-0206 OR COMM (703) 602-0206.  NSWCCD-SSES STRUCTURES POC IS                

 MARTIN COHEN, CODE 625, DSN 443-7651 OR COMM (215) 897-7651.//                 

                                                                                

 BT