2. All samples are tested for solids by being spun in a centrifuge. Solids will settle at the bottom of the sample. 3. Allowable “use limits” are tested and recorded. When   the   physical   test   is   completed,   the shipyard/IMAs  will  make  a  spectrometric  analysis  of each used oil sample, then report to all concerned the concentrations  of  the  following  elements  in  parts  per million  (ppm). Additional  information  on  trend  analysis  and  oil spectrometric a n a l y s i s    i s  c o n t a i n e d    i n COMNAVSURFLANTINST 9000.1C or COMNAVSURFPACINST   4700.lB. POTABLE WATER SYSTEMS The   potable   water   system   supplies   scuttlebutts, sinks,  showers,  sculleries,  and  galleys  and  provides makeup water for various freshwater cooling systems. This system is often called the freshwater system. The term fresh water is not correct because fresh water is not potable unless it is safe for human consumption. Potable   water   may   be   contaminated   during production,  handling,  storage,  or  distribution.  Treatment with a halogen, such as chlorine or bromine, is the only approved   method   of   disinfecting   potable   water. Submarines and servicecraft are not equipped to use the halogen   treatment   method.   They   are   provided   with emergency  methods  to  treat  fresh  water.  The  ship’s engineering  and  medical  departments  are  responsible for   the   receipt,   distribution,   and   quality   testing   of potable   water.   For   more   in-depth   information concerning   potable   water   systems,   refer   to   NSTM, Chapter   533,   “Potable   Water   Systems.”   Additional references related to potable water systems are shown in the following list. NSTM,  Chapter 090, “Inspections, Tests, Records, and  Reports” NSTM, Chapter 220, “Boiler Water/Feedwater” NSTM,   Chapter   9580,   “Distilling   Plants   Low Pressure Submerged Tube Steam Plants” NSTM, Chapter 9480, “Piping Systems” NSTM,   Chapter   631,   “Preservation   of   Ships   In Service (Surface Preparation and Painting)” NSTM,  Chapter  670,  “Stowage,  Handling,  and Disposal of Hazardous General Use Consummables” Manual of Naval Preventive Medicine for Potable Water Shore-to-Ship Delivery, NAVMED P-5010-5 Manual of Naval Preventive Medicine for Potable Water Ship-to-Ship Delivery, NAVMED P-5010-6 Potable Water Standards, BUMEDINST 6240.3 TRAINING By  the  time  you  have  reached  the  EN2  level  of experience,  you  have  acquired  many  skills  and  a considerable  amount  of  theoretical  knowledge.  As  an EN2, you will be responsible for passing these skills and knowledges   on   to   other,   lower-rated   Enginemen. Success  in  training  others  requires  that  you  have  or develop  certain  additional  skills  as  an  instructor. TRAINING  RESPONSIBILITIES You must be technically competent before you can teach  others,  but  your  technical  competence  must  be supplemented by the ability to organize information, to present it effectively, and to arouse and keep the interest of  your  trainees. You  will  find  excellent  general  information  on  how to plan, carry out, and evaluate an instructional program in   Military   Requirements   for   Petty   Officer   Second Class,   NAVEDTRA   12045,   and   in  Military Requirements  for  Petty  Officer  First  Class,  NAVED TRA 12046. Our  discussion  does  not  include  the  basic information given in these references. Instead, it deals with some of the difficulties peculiar to the training of the engine-room and auxiliary personnel and some of the ways in which you can overcome or minimize these difficulties. What kinds of things cause special problems in the training of engine-room personnel? For one thing, the interrelationship  of  propulsion  plant  operations.  Each person  must  be  trained  to  perform  not  only  as  an individual  but  also  as  a  member  of  a  team.  Take  for instance the duties of the watch standers. They are very closely  related,  and  the  actions  taken  by  one  person depend in some way upon the actions taken by other persons. From a long-range point of view, however, the teamwork   required   for   engine-room   operations   can actually be turned to a training advantage. As a person is  being  trained  for  one  specific  duty,  he  or  she  will naturally learn something about the other duties. As a rule, therefore, the first part of a person’s engine-room training may take quite a while, but the last part will take much  less  time. 1-20