to the designated shop of the repair activity. After the shaft has been repaired, or a new one has been made, it is picked up and brought back to the ship by the ship’s force. The pump is reassembled, inspected, and tested by  the  ship’s  force  to  make  sure  it  is  operating satisfactorily. An important thing to remember is that the repair facility  is  responsible  for  ensuring  that  its  personnel repair  or  manufacture  this  this  to  the  manufacturer’s specifications,  perform all  tests  required  by  quality assurance  (QA),  and  fill  out  properly  all  the  required forms. You, however, are responsible for witnessing any test required by QA, monitoring the status of the job at all  times,  and  reassembling  and  test  operating  the  pump properly.  The  end  results  will  produce  a  reliable, operating piece of equipment. EQUIPMENT TESTS As  an  EN2,  you  will  assist  in  scheduling  and performing  various  tests  on  your  equipment.  The purpose  of  those  tests  is  to  determine  how  your equipment  is  performing  and  if  there  are  any  equipment malfunctions. The tests are performed at various times, such  as  (1)  before  the  ship  goes  to  the  shipyard  for overhaul, (2) after post deployment, (3) during a tender availability,  or  (4)  as  required  by  PMS.  The  tests  are performed  by  the  ship’s  force,  IMA  personnel,  shipyard personnel,  or  an  inspection  team  (such  as  a  Board  of Inspection  and  Survey  [INSURV]).  Detailed  types  of inspections   are   described   in  COMNAVSURFLANT Maintenance   Manual,   COMNAVSURFLANT   INST. 9000.lC   or   COMNAVSURFPAC   Ship   and   Craft Maintenance   Manual,  Volumes  1  and  2,  Planned Maintenance, COMNAVSURPAC INST. 4700.lB. Two types of inspections and tests that can be used to “spot” impending trouble in an internal combustion engine  are  called  trend  and  spectrographic  analyses.  We will now discuss and explain their importance and use in detecting problems in internal combustion engines. ENGINE TREND ANALYSIS Preventive  maintenance  receives  a  great  deal  of attention  from  everyone  in  the  field  of  diesel  engine operation, since letting an engine run as long as it will run and fixing it only after a breakdown occurs is not only foolish, but extremely costly. On the other hand, you would be just as foolish to constantly tear down an engine just to inspect it. You should know that vital parts of an engine last longer and operate better if they are not tampered   with   unnecessarily.   Therefore,   an   attempt must be made to find a happy medium between these two forms of maintenance. One way to determine the condition of an engine is by monitoring its operation. This is done by regularly obtaining certain engine operating data and by studying, analyzing,  and  comparing  it  with  previous  data.  This information   is   then   reduced   to   a   form   that   all engineering personnel can interpret and decide whether the engine needs to be overhauled or just temporarily shut down for simple maintenance. For more detailed p r o c e d u r e s ,    r e f e r    t o    N A V S E A    S 9 2 3 3 - C 3 - HBK-010/010,  Diesel  Engine,  Over  400  BHP,  Trend Analysis   Handbook SPECTROGRAPHIC  ANALYSIS Spectrographic  analysis  is  a  method  of  determining engine or equipment wear by analyzing engine oil and hydraulic  oil  samples  for  chemicals  and  particles  not found in new oil or hydraulic fluid. This analysis is done in laboratories on samples provided by ships according to  instructions  given  in  their  sampling  kits. Ships must maintain accurate records of operating hours since major overhauls, oil changes, and samplings to  provide  the  testing  facility  with  the  information requested in the sampling kit. (COMNAVSURFLANT uses  the  services  of  the  Charleston  Naval  Shipyard,  and COMNAVSURFPAC  uses  intermediate  maintenance activities  (IMAs)  for  analyzing  oil  samples  from machinery   employing   closed   lube   oil/hydraulic systems.) In addition, ships must maintain a record of conditions  found  and  repairs  made  as  a  result  of laboratory recommendations. When the shipyard or IMA laboratory receives the oil sample, a physical test and a spectrometric analysis are   performed.   The   physical   test   consists   of   the following  actions: 1.  All  samples  are  tested  for  fuel  dilution,  and  a report by percent volume is provided to all concerned. 1-19