Last Updated on November 16, 2023
This guide provides helpful information for those looking to join the Navy as a Machinist’s Mate (MM) during the Fiscal Year 2024.
Navy ships regularly navigate the ocean, covering extensive distances to reach the shores of all continents on Earth.
As a Machinist’s Mate, your role is crucial in maintaining the propulsion and auxiliary systems that enable the ship to arrive safely for its mission.
Your responsibilities encompass various tasks throughout the entire vessel, including repairing steam turbines and adjusting aircraft elevators.
This will provide you with comprehensive mechanical knowledge of ship systems found on cruisers and destroyers.
Job Description
Machinist’s Mates (MM) are Navy enlisted Sailors who handle the operation, maintenance, and repair of ship propulsion machinery, auxiliary equipment, and external machinery. This includes equipment such as steering engines, hoisting machinery, food preparation equipment, refrigeration and air conditioning equipment, windlasses, elevators, and laundry equipment.
They also operate and maintain marine boilers, pumps, forced draft blowers, and heat exchangers.
They perform tests, transfers, and inventory of lubricating oils, fuels, and water, maintain records and reports, and generate and stow industrial gases.
MMs fulfill their duties in diverse settings aboard Navy ships, which may include fire rooms, boiler rooms, engine rooms, or shops.
As an MM, physical work and teamwork are expected during the daily work routine. These environments can be hot and noisy.
Around 6,300 individuals carry out responsibilities in the MM rating on traditional steam-powered vessels and at land-based stations.
Specific Responsibilities
The responsibility of Machinist’s Mates includes the operation and maintenance of ship propulsion machinery, auxiliary equipment, and machinery located outside the primary systems.
Specifically, the job responsibilities of an MM may include:
- Positioning piping systems for oil, water, air, and steam in proper alignment.
- Conducting the operation of ship boilers and steam turbines employed in ship propulsion.
- Conducting the operation of turbo generators used for generating electrical power.
- Performing cleaning, adjusting, testing, and maintenance on boilers, engines, and generators.
- Taking care of auxiliary machinery, which comprises steering engines, elevators, winches, pumps, and valves through maintenance and upkeep.
- Conducting the operation and maintenance of water desalination plants.
- Maintaining galley equipment and A/C systems.
- Conducting repairs on valves, pumps, compressors, turbines, and hydraulic devices.
- Generating and evaluating reports and records pertaining to machinery operation.
Different Roles
Steam Plant Auxiliary Systems Maintainer
Steam Plant Auxiliary Systems Maintainers operate and maintain steam turbines and reduction gears.
These professionals also maintain auxiliary machinery, such as turbo-generators, pumps, and oil purifiers.
This includes supplementary machinery situated outside of the primary machinery areas.
Machinery such as steering engines, elevators, refrigeration plants, air conditioning systems, and desalination plants.
These Sailors align piping systems for oil, water, air, and steam, control the operation of ship boilers and steam turbines, and operate turbo-generators for electrical power.
Maintainers also clean, adjust, test, and perform preventive maintenance on boilers, main engines, and other machinery.
They maintain desalinization plants, refrigeration plants, air conditioning systems, and galley equipment.
Maintainers perform repairs or replacements on valves, pumps, and heat exchangers.
They also perform repairs on compressors, steam turbines, and control devices.
These experts examine records and reports related to machinery operation.
Maintainers are supervised by a mentor while learning a trade or skill.
Steam Plant Auxiliary Systems Manager
Steam Plant Auxiliary Systems Managers operate and maintain steam turbines and reduction gears.
These professionals also maintain auxiliary machinery, such as turbo-generators, pumps, and oil purifiers.
This includes machinery outside of main machinery spaces like steering engines, elevators, refrigeration plants, air conditioning systems, desalinization plants, and compressed gas producing plants.
Managers align piping systems for oil, water, air, and steam.
These Sailors control the operation of ship boilers and steam turbines for propulsion and service systems.
These professionals also control the operation of turbo-generators for electrical power production.
Managers clean, adjust, test, and perform preventive maintenance on boilers, engines, turbo-generators, and other auxiliary machinery.
This includes steering engines, elevators, winches, pumps, and associated valves.
Other responsibilities include operating and maintaining desalinization plants, refrigeration plants, air conditioning systems, and galley equipment.
Managers repair or replace valves, pumps, and heat exchangers.
They also repair or replace compressors, steam turbines, and control devices.
These Sailors also analyze machinery operating records and reports.
Managers have mastered a trade or skill and can mentor technicians and maintainers independently.
Steam Plant Auxiliary Systems Technician
Steam Plant Auxiliary Systems Technicians operate and maintain steam turbines and reduction gears.
These professionals also operate and maintain auxiliary machinery such as turbo-generators, pumps, and oil purifiers.
These technicians maintain machinery outside of main machinery spaces, including electrohydraulic steering engines, elevators, refrigeration plants, air conditioning systems, desalinization plants, and compressed gas producing plants.
These Sailors align piping systems for oil, water, air, and steam.
They control the operation of ship boilers and steam turbines for propulsion and service systems.
These professionals also control the operation of turbo-generators for electrical power production.
Preventive maintenance tasks include cleaning, adjusting, testing, and performing other maintenance on boilers, main engines, turbo-generators, and auxiliary machinery.
This includes steering engines, elevators, winches, pumps, and associated valves.
Technicians also operate and maintain desalinization plants, refrigeration plants, air conditioning systems, and galley equipment.
These Sailors repair or replace valves, pumps, heat exchangers, compressors, steam turbines, and hydraulic or pneumatic control devices.
These professionals are also responsible for recording and analyzing machinery operating records and reports.
Technicians are expected to work independently and mentor Steam Plant Auxiliary Systems Maintainers with limited supervision.
Training and Promotion Opportunities
Upon completion of initial training at Recruit Training Command Great Lakes (known as Navy Boot Camp), recruits will report for specialized training, including Basic Engineering Common Core and ” A” School (9 weeks) in Great Lakes, IL.
This training covers basic mechanical theory, technical documentation, safety programs, piping systems, tools and instruments, mechanical systems, the Maintenance Material Management System (3M), and basic watch-standing procedures.
Once their training is completed, recruits have the possibility of being assigned to ships and naval repair activities both at sea and at shore stations, both within the U.S. and overseas.
Promotion opportunities are consistently accessible but competitive, contingent upon individual performance.
Advanced Training
Promotion opportunities are consistently offered in the MM community but are subject to competition, contingent on individual performance.
Advanced training for Navy MMs includes specialized programs such as underwater welding, electrical and refrigeration systems training, and nuclear power plant operations.
These courses are aimed at providing a comprehensive understanding of the many technical aspects of working in the MM field.
Training also includes physical fitness programs, leadership skills development, and in-depth knowledge about naval ship construction and maintenance.
Participants who successfully complete advanced training will be eligible for promotion opportunities.
Individuals who have a college degree and aspire to be leaders may have the chance to become Naval Officers, which would allow them to lead and mentor others.
Post-Service Opportunities
The specialized training and work experience gained during service as a Machinist’s Mate in the Navy can lead to valuable credentials and job opportunities in related fields in the civilian world, such as industrial machinery, engineering, power plant operation, and more.
Qualifications to Join
To be eligible for Enlisted Sailor status and pursue a career as a Machinist’s Mate, candidates must have a high-school diploma or an equivalent qualification. Applicants must also be a U.S. citizen eligible for security clearance.
Prospective Machinist’s Mate candidates should possess effective communication skills and show an inclination for working with tools and mechanical devices.
Aspiring MM candidates should possess characteristics such as resourcefulness, a willingness to gain new knowledge and skills, and strong physical endurance.
Working well with others as part of a team is important. Applicants must also have good manual dexterity and normal hearing.
General qualifications may vary depending on your current or past military service.
ASVAB Requirement
Applicants must score the minimum ASVAB score below to qualify to join the Navy as a Machinist’s Mate (MM).
ASVAB for MM:
VE+AR+MK+AS=195; or
VE+AR+MK+AO=200
The enlistment qualification requirements above are current as of Fiscal Year 2024, per the Navy Personnel Command. This information is not readily available to the public.
So, contact your local Navy Enlisted Recruiter for the most current requirements to join the Navy as an enlisted Sailor.
More Information
If you wish to learn more about becoming a Machinist’s Mate (MM), contact your local Navy Enlisted Recruiter. They will provide you with more detailed information you’re unlikely to find online.
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