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Machinist's Mate Auxiliary (MMA)
Torpedoman's Mate (TM)




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General Description

Auxiliary Maintenance, Diesel Engine Technician, Fire Fighting, Torpedo Systems Specialist, Refrigeration Systems Technician, Air/Hydraulic Systems Technician

Machinist’s Mates (Submarines) receive extensive training in the operation and maintenance of hydraulic power plants, hoists and cylinders, oxygen generators, atmosphere control equipment, refrigeration systems, emergency diesel engines, pressurized air systems, plumbing systems, and submarine weapons and weapons delivery systems.  Responsible for the operation, routine care, and repair of submarine auxiliary and weapons systems and fire fighting and damage control equipment, these mechanical specialists are a vital element in the day-to-day operation and combat survivability of the submarine.

Job Categories.  Machinist’s Mates (Submarines) specialize in one of two areas: weapons or auxiliary systems. 

Weapons systems specialists (TM) operate and maintain underwater weapons launch systems (including air and hydraulic systems).  They are responsible for the safe loading, unloading, shipping, and storage of these weapons and conduct limited maintenance on torpedoes and missiles. TMs are also responsible for the storage, maintenance, and instruction of small arms. 

Auxiliary systems specialists (MMA) operate and maintain submarine non-nuclear mechanical systems in hydraulic, air, refrigeration, atmosphere control, plumbing, and diesel engines.

 The Machinist’s Mate (Submarines) focuses on mechanical work.  Typical duties include:

  • removing airborne waste products such as carbon dioxide, carbon monoxide, and hydrocarbons
  • manufacturing and storing oxygen
  • Cleaning, adjusting, testing, and performing preventive maintenance on submarine emergency diesel engines, mast and antenna hoists, hatches, and watertight doors;
  • Repairing or replacing valves, filters, pumps, compressors, and hydraulic or pneumatic control devices;
  • Operating, troubleshooting, and repairing ship’s refrigeration systems using specialized equipment after receiving EPA certification;
  • Removing and installing as well as securing and reinstalling weapons components from containers;
  • Testing equipment using voltmeters, ammeters, mergers, and ohmmeters;
  • Testing and replacing portable cable, self-contained relays, lamps, and fuses;
  • Locating and identifying components and assemblies of electronic equipment using technical maintenance publications;
  • Checking weapons storage, security, and alarm systems;
  • Maintaining equipment work logs and torpedo record books;
  • Identifying torpedo components, tools, and test equipment as well as ordering replacements;
  • Using and caring for common hand tools, special tools, and soldering equipment;
  • Performing preventive and corrective maintenance on hydraulic and pneumatic systems and components associated with launching systems;
  • Serving as team members performing inspections and final close-out checks on weapons;
  • Tracing mechanical/electrical circuits on schematics and drawings.
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