Machinist's Mate
Encyclopedia
Machinist's Mate is a rating in the United States Navy
's engineering community.
and air conditioning
equipment, windlasses, elevators, and laundry equipment. Operate and maintain (organizational and Intermediate level) marine boilers, pumps, forced draft blowers, and heat exchanger
s; perform tests, transfers, and inventory of lubricating oils, fuels, and water. Maintain records and reports, and may perform duties in the generation and stowage of industrial gases." Enlistees are taught the fundamentals of this rating through on-the-job training or formal Navy schooling. Advanced technical and operational training is available in this rating during later stages of career development. -- NAVPERS 18068F
Machinist's Mates (Submarine) and Machinist's Mate (Surface) generally fall into one of three roles:
s), potable water, and service steam to the ship. MMs operate the boilers that generate the steam (this job was previously done by Boiler Technicians, but the BT rating merged with Machinist's Mates in 2000) and use it to operate main engine (propulsion turbines), turbo generators, distilling units, and various auxiliary turbines. MM's working in the propulsion plants are often referred to as Pit Snipes, hole snipes or Snipes for short.
Machinist's Mates responsible for the propulsion plant are found in Machinery Division (or Main Engine Division, Main Propulsion Division, etc. in some ships), commonly referred to simply as M-Division or MP-Division. On surface nuclear ships, propulsion mechanics are found in Reactor Propulsion Division (commonly still referred to as M-Div), Reactor Mechanical Division (RM), Reactor Laboratories Division (RL). The USS Enterprise is the exception, in that M-Division is still part of Engineering Department, as opposed to Reactor Department.
and nitrogen
) units, hydraulic lifting and hoisting gear, hydraulic power plant components and mechanisms, chilled and fresh water, atmosphere control, ventilation, emergency diesel and corresponding sub-systemes, ballast control, auxiliary drain, compressed air and gases, plumbing, trash disposal & other equipment as designated by the Engineering Officer (Chief Engineer, or CHENG). Members of "A-Gang" may also help DC Men
, Gunner's Mate
s, or other ratings. Some listed attributes apply to submarine warfare to include SUBSAFE requirements for work authorization. All systems listed apply to a minimum of valve, pump maintenance repair.
and six months at one of four Nuclear Power Training Units (prototypes). Two NPTUs are moored training ships (MTS) using S5W reactors located at the Naval Weapons Station in Charleston, South Carolina
, and two additional NPTUs are land-based prototype units using an S5W reactor and an S8G reactor located in Ballston Spa, New York
. This course of instruction is commonly referred to as "the nuclear-power pipeline."
MMNs earn a 3385 NEC
(surface) or 3355 (submarines) upon completion of prototype. Along with the normal duties of a propulsion mechanic, they are responsible for the operation, maintenance, and repair of the auxiliary equipment in support of the naval reactors under their care. Later in his career, the MMN will qualify his/her Senior In-Rate watchstation (Chief Reactor Watch for surface MMNs in Reactor Mechanical division, Chief Machinery Operator for those in Machinery Division, and Engine Room Supervisor for submariners).
Additionally, some MMNs are designated as Engineering Laboratory Technicians (NEC 3386 for surface, 3356 for submariners) following successful completion of an additional 13 weeks of training. ELTs are water chemistry and radiological controls experts for their commands. Upon qualification of one of the above-mentioned Senior In-Rate watches, they are awarded NECs 3396 or 3366.
Also, on submarines, some MMNs are designated as Submarine Nuclear Propulsion Plant Emergency Welders (NEC 3351). They go through a two month school learning welding, brazing, and soldering from Hull Maintenance Technician
senior enlisted welders. Each submarine is required to have at least one of them to go underway. They are on board to provide emergency repairs to the reactor plant if necessary to get the ship back to port where professional welders can complete a certified repair.
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...
's engineering community.
Description
According to the Bureau of Naval Personnel (BUPERS), the job of an MM is to "operate, maintain, and repair (organizational and intermediate level) ship propulsion machinery, auxiliary equipment, and outside machinery, such as: steering engine, hoisting machinery, food preparation equipment, refrigerationRefrigeration
Refrigeration is a process in which work is done to move heat from one location to another. This work is traditionally done by mechanical work, but can also be done by magnetism, laser or other means...
and air conditioning
Air conditioning
An air conditioner is a home appliance, system, or mechanism designed to dehumidify and extract heat from an area. The cooling is done using a simple refrigeration cycle...
equipment, windlasses, elevators, and laundry equipment. Operate and maintain (organizational and Intermediate level) marine boilers, pumps, forced draft blowers, and heat exchanger
Heat exchanger
A heat exchanger is a piece of equipment built for efficient heat transfer from one medium to another. The media may be separated by a solid wall, so that they never mix, or they may be in direct contact...
s; perform tests, transfers, and inventory of lubricating oils, fuels, and water. Maintain records and reports, and may perform duties in the generation and stowage of industrial gases." Enlistees are taught the fundamentals of this rating through on-the-job training or formal Navy schooling. Advanced technical and operational training is available in this rating during later stages of career development. -- NAVPERS 18068F
Machinist's Mates (Submarine) and Machinist's Mate (Surface) generally fall into one of three roles:
Propulsion Mechanics
The core job of an MM is the engine room. A mechanic's job in the engine room is to operate the steam plant that provides propulsion, electric power (along with Electrician's MateElectrician's Mate
Electrician's Mate is a United States Navy and United States Coast Guard occupational rating.Electrician's Mates stand watch on generators, switchboards, control equipment and electrical equipment; operate and perform organizational and intermediate maintenance on power and lighting circuits,...
s), potable water, and service steam to the ship. MMs operate the boilers that generate the steam (this job was previously done by Boiler Technicians, but the BT rating merged with Machinist's Mates in 2000) and use it to operate main engine (propulsion turbines), turbo generators, distilling units, and various auxiliary turbines. MM's working in the propulsion plants are often referred to as Pit Snipes, hole snipes or Snipes for short.
Machinist's Mates responsible for the propulsion plant are found in Machinery Division (or Main Engine Division, Main Propulsion Division, etc. in some ships), commonly referred to simply as M-Division or MP-Division. On surface nuclear ships, propulsion mechanics are found in Reactor Propulsion Division (commonly still referred to as M-Div), Reactor Mechanical Division (RM), Reactor Laboratories Division (RL). The USS Enterprise is the exception, in that M-Division is still part of Engineering Department, as opposed to Reactor Department.
Auxiliary Mechanics
The other major place to find Machinist's Mates is in the Auxiliaries Division of Engineering Department, often referred to as "A-gang". Mechanics in this role establish training & work on mechanical equipment within and outside of the engine rooms. To include the operation and preventive maintenance of: AC&R (Air Conditioning and Refrigeration) units, O2/N2 (liquid oxygenLiquid oxygen
Liquid oxygen — abbreviated LOx, LOX or Lox in the aerospace, submarine and gas industries — is one of the physical forms of elemental oxygen.-Physical properties:...
and nitrogen
Nitrogen
Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...
) units, hydraulic lifting and hoisting gear, hydraulic power plant components and mechanisms, chilled and fresh water, atmosphere control, ventilation, emergency diesel and corresponding sub-systemes, ballast control, auxiliary drain, compressed air and gases, plumbing, trash disposal & other equipment as designated by the Engineering Officer (Chief Engineer, or CHENG). Members of "A-Gang" may also help DC Men
Damage Controlman
Damage Controlman are the Navy's and Coast Guard’s maintenance and emergency repair specialist.Coast Guard Damage Controlmen assigned to cutters are responsible for maintaining watertight integrity, emergency equipment associated with firefighting and Shipboard flooding; plumbing repairs; welding...
, Gunner's Mate
Gunner's Mate
The United States Navy occupational rating of gunner's mate also known as gunsmens mate is a designation given by the Bureau of Naval Personnel to enlisted sailors who either satisfactorily complete initial Gunner's Mate "A" school training, or who "strike" for the rating as a deck seaman by...
s, or other ratings. Some listed attributes apply to submarine warfare to include SUBSAFE requirements for work authorization. All systems listed apply to a minimum of valve, pump maintenance repair.
Nuclear Mechanics
Some MMs are qualified to work on nuclear propulsion plants. They are designated as MMN (Machinist's Mate Nuclear), though the N is generally only used for the purposes of billeting and advancement exams. These mechanics go through a rigorous training program consisting of three months at the Nuclear Field "A" School, six months of Naval Nuclear Power Training CommandNaval Nuclear Power Training Command
The Naval Nuclear Power Training Command is the parent organization within the division that is responsible for educating enlisted and commissioned personnel of the US nuclear naval program. NNPTC's mission is to train officer and enlisted students in science and engineering fundamental to the...
and six months at one of four Nuclear Power Training Units (prototypes). Two NPTUs are moored training ships (MTS) using S5W reactors located at the Naval Weapons Station in Charleston, South Carolina
Charleston, South Carolina
Charleston is the second largest city in the U.S. state of South Carolina. It was made the county seat of Charleston County in 1901 when Charleston County was founded. The city's original name was Charles Towne in 1670, and it moved to its present location from a location on the west bank of the...
, and two additional NPTUs are land-based prototype units using an S5W reactor and an S8G reactor located in Ballston Spa, New York
Ballston Spa, New York
Ballston Spa is a village in Saratoga County, New York, United States. The population was 5,556 at the 2000 census. It is the county seat of Saratoga County. The village is named after Rev. Eliphalet Ball, a Congregationalist clergyman and an early settler. The village lies on the border of two...
. This course of instruction is commonly referred to as "the nuclear-power pipeline."
MMNs earn a 3385 NEC
Navy Enlisted Classification
The Navy Enlisted Classification system supplements the rating designators for enlisted members of the United States Navy. A naval rating and NEC designator are similar to the Military Occupational Specialty designators used in the U.S. Army and U.S. Marine Corps and the Air Force Specialty Code ...
(surface) or 3355 (submarines) upon completion of prototype. Along with the normal duties of a propulsion mechanic, they are responsible for the operation, maintenance, and repair of the auxiliary equipment in support of the naval reactors under their care. Later in his career, the MMN will qualify his/her Senior In-Rate watchstation (Chief Reactor Watch for surface MMNs in Reactor Mechanical division, Chief Machinery Operator for those in Machinery Division, and Engine Room Supervisor for submariners).
Additionally, some MMNs are designated as Engineering Laboratory Technicians (NEC 3386 for surface, 3356 for submariners) following successful completion of an additional 13 weeks of training. ELTs are water chemistry and radiological controls experts for their commands. Upon qualification of one of the above-mentioned Senior In-Rate watches, they are awarded NECs 3396 or 3366.
Also, on submarines, some MMNs are designated as Submarine Nuclear Propulsion Plant Emergency Welders (NEC 3351). They go through a two month school learning welding, brazing, and soldering from Hull Maintenance Technician
Hull Maintenance Technician
Hull Maintenance Technician is a United States Navy occupational rating.Hull Maintenance Technicians plan, supervise, and perform tasks necessary for fabrication, installation and repair of all types of shipboard structures, plumbing, sheet metal fabrication, carpentry and piping systems;...
senior enlisted welders. Each submarine is required to have at least one of them to go underway. They are on board to provide emergency repairs to the reactor plant if necessary to get the ship back to port where professional welders can complete a certified repair.
Various MM ratings
(Reference: http://www.history.navy.mil/faqs/faq78-2.htm#anchor13179)- MM - Machinist's Mate
- MM/SS - Machinist's Mate - Submarine Qualified
- MM(A) - Machinist's Mate (Aviation)
- MM(A)(GE) - Machinist's Mate (A) (Bombing)
- MM(A)(H) - Machinist's Mate (A) (Hydrogen)
- MM(A)(P) - Machinist's Mate (A) (Photographic)
- MM(CBE) - Machinist's Mate (Construction Battalion) (Equipment Operator)
- MM(MB) - Machinist's Mate (Motor Boat)
- MM(N) - Machinist's Mate (Nuclear)
- MM(O) - Machinist's Mate (Optician)
- MM(SRE) - Machinist's Mate (Ship Repair) (Engine Operator)
- MM(SRI) - Machinist's Mate (Ship Repair) (Instrument Maker)
- MM(SRO) - Machinist's Mate (Ship Repair) (Outside Machinist)
- MM(SRS) - Machinist's Mate (Ship Repair) (Inside Machinist)
- MM(W) - Machinist's Mate (Weapons)
- MME - Machinist's Mate (Engineman)
- MMG - Machinist's Mate (Industrial Gas Generating)
- MML - Machinist's Mate (General)
- MMR - Machinist's Mate (Refrigeration Mechanic)
- MMS - Machinist's Mate (Shop Mechanic)