SHIPYARD OVERHAUL

To review the mechanics of the 3-M system, refer to “The Ships’ 3-M Systems” chapter of the Military Requirements for Petty Officer Third Class, NAVED- TRA 12044. Although that chapter provides an excel- lent description of the 3-M systems, the official ref- erence for the 3-M systems is the Ships’ Maintenance and Material Management (3-M) Manual, OPNAV - INST 4790.4. You may also wish to read Introduction to 3-M Systems, NAVEDTRA 13092, which gives a short but very informative explanation of 3-M sys- tems and procedures. AVAILABILITY TYPES An availability is an assignment of a ship to a repair facility for repairs beyond the capability of the ship’s force. Besides regular overhaul, several types of availabilities are assigned, according to the needs of the individual ship or the fleet. These are restricted, technical, and intermediate-level maintenance activity availabilities. Restricted Availability A restricted availability (RAV) is normally as- signed for emergency repairs of prime systems that prevent the ship from fulfilling its mission. When emergency repairs to primary systems cannot be made by the ship’s force, the commanding officer may request the TYCOM to assign a restricted availability for the repair of a specific system. During an RAV, the ship is incapable of performing its mission. Technical Availability A technical availability (TAV) is assigned when repairs on noncritical systems or equipment must be made by a repair facility or yard. These repairs do not affect the ability of the ship to complete its mis- sion. If necessary, the ship can get under way without the system or equipment being repaired. Intermediate-Level Maintenance Activity Availability An intermediate-level maintenance activity avail- ability (IMAV) involves repairs made by either afloat repair activities (tenders and repair ships) or shore intermediate maintenance activities (SIMAs). Its pur- pose is to accomplish as much intermediate-level maintenance and repair work as possible within the workload limitations, the available funds, and the rela- tive priority of the required work. Although the primary emphasis of a SIMA effort is on repair work, authorized ship alterations and alter- ations equivalent to repair are undertaken as SIMA workloads permit. UPKEEP PERIOD The upkeep period is time in a port where the facilities of a yard or a tender are available for routine maintenance that cannot be completed while the ship is under way. Upkeep scheduled with the assistance of a tender or a repair ship is sometimes referred to as tender availability. SHIPYARD OVERHAUL Ships are assigned availabilities at shore-based repair activities as directed by the CNO. The first scheduled overhaul is normally granted to a ship after an initial operating period of approximately 2 years. Thereafter, scheduled overhauls depend on the ship type. The amount of time in the shipyard for these over- hauls varies. For example, if the shipyard works on a one-shift basis, the overhaul often requires 6 months or longer. The employment schedule, an operating directive furnished by the TYCOM, indicates when a ship is scheduled for overhaul. 2-13