INTRODUCTION TO SONAR 



effectiveness, and reliability depends on how 

 well you perform the required maintenance. 



PLANNED MAINTENANCE SUBSYSTEM 



Preventive maintenance, when properly car- 

 ried out, reduces casualties and associated costs 

 and equipment downtime required for major re- 

 pairs. The PMS is designed to simplify main- 

 tenance procedures (insofar as possible) by 

 defining the maintenance required, scheduling 

 its performance, describing the tools and methods 

 to be used, and providing for the detection and 

 prevention of impending casualties. 



In establishing minimum equipment mainte- 

 nance requirements, the NavShips Technical 

 Manual , manufacturers' technical manuals, and 

 other applicable publications are reviewed criti- 

 cally. If planned maintenance requirements are 

 found to be unrealistic or unclear, they are 

 modified or completely revised before incorpora- 

 tion into the PMS. 



It is possible that the planned maintenance 

 specified in the PMS may differ from that 

 prescribed in other documents. Should some 

 variance become apparent, remember that, inso- 

 far as preventive maintenance is concerned, the 

 PMS supersedes and takes precedence over 

 existing requirements set forth in various tech- 

 nical publications. 



Planned Maintenance Subsystem Manual 



A master Planned Maintenance Subsystem 

 Manual (OpNav 43P1) is tailored to each ship. 

 It contains minimum planned maintenance re- 

 quirements for each maintainable component 

 installed in that particular ship. Normally, appro- 

 priate sections (engineering, electronics, weap- 

 ons, etc.) of the master manual are kept in the 

 office of the department concerned. Respective 

 sections are used by department heads in planning 

 and scheduling all maintenance requirements 

 in their departments. 



The departmental PMS manual contains a 

 section for each division or maintenance group 

 within a department. Each divisional section 

 includes a table of contents and a maintenance 

 index page (MIP) for each system, subsystem, 

 or component. Applicable portions of the PMS 

 manual are kept in the working space for the 

 equipment to which they pertain. These portions 

 serve as a ready reference to the required 

 planned maintenance. Each MIP contains a brief 

 description of maintenance requirements and 

 the frequency with which they are to be effected. 



The frequency code is; D — daily, W — weekly, 

 M — monthly, Q — quarterly, S — semiannually, A — 

 annually, C — overhaul cycle, and R — situation 

 requirement. Frequency codes for daily, weekly, 

 monthly, quarterly, semiannual, and annual 

 planned maintenance actions are self-explanatory. 

 Code C designates certain planned maintenance 

 actions performed in a specified quarter (i.e. 

 once) during the operational cycle between ship- 

 yard overhauls. Code R identifies planned main- 

 tenance actions that are to be performed before 

 getting underway, after a specified number of 

 hours of operation, or to meet other require- 

 ments that arise only during specific situations. 



Figure 9-1 shows a maintenance index page 

 from a typical PMS manual. Information entered 

 on the MIP includes the system or component, 

 a short description of each maintenance require- 

 ment, maintenance frequency code plus a consecu- 

 tive number starting with numeral 1 for each 

 frequency code assigned, rate(s) recommended 

 to perform the maintenance, average time re- 

 quired to perform the maintenance, and related 

 maintenance requirements. Related maintenance 

 represents additional planned maintenance that 

 can be completed before, in conjunction with, 

 or immediately after a scheduled maintenance. 



Shipboard application of the PMS varies slight- 

 ly from one ship to another. Clarification is re- 

 quired, therefore, of information found on MIPs 

 regarding rates recommended to perform main- 

 tenance and the average time required for the 

 task. Actually, maintenance tasks are performed 

 by personnel available and capable, regardless 

 of the rate listed on the MIP. As listed on the 

 MIP, average time required does not consider 

 time required to assemble necessary tools and 

 materials, to obtain permission to secure equip- 

 ment, nor to clean the area and put away tools 

 upon conclusion of a task. Always remember that 

 no maintenance is complete until all tools and 

 equipment are put away and the area is cleaned. 



Scheduling Planned Maintenance 



For each division or maintenance group, a 

 cycle schedule that provides a visual display of 

 planned maintenance requirements (based on the 

 operational cycle of the ship between shipyard 

 overhauls) is exhibited in the departmental office. 

 Information supplied on a cycle schedule for any 

 particular division or maintenance group includes 

 the MIP number from the PMS manual, a listing 

 of all equipment within that particular group for 

 which planned maintenance is required, and the 

 specific quarter in which the semiannual, annual. 



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