Careers Career Paths Navy Enlisted Machinist's Mate Job These sailors work with all manner of machines and parts Share PINTEREST Email Print Chloe Giroux © The Balance Career Paths US Military Careers Technology Careers Sports Careers Sales Project Management Professional Writer Music Careers Media Legal Careers Government Careers Finance Careers Fiction Writing Careers Entertainment Careers Criminology Careers Book Publishing Aviation Animal Careers Advertising Learn More By Rod Powers Rod Powers Air Force NCO Academy Rod Powers was a retired Air Force First Sergeant with 22 years of active duty service. Learn about our Editorial Process Updated on 01/04/20 Machinist's Mates (MMs) in the Navy are responsible for maintaining and operating a variety of complex machinery, and assisting machinists in keeping all Navy craft in top working order. Most of the work they do is conducted on machines and engine parts within the hulls of Navy ships and submarines. For instance, these sailors operate and maintain steam turbines and reduction gears used for ship propulsion and auxiliary machinery such as turbogenerators, pumps, and oil purifiers. They also maintain auxiliary machinery outside of main machinery spaces, such as electrohydraulic steering engines and elevators, refrigeration plants, air conditioning systems, and desalinization plants. And, they may also operate and maintain compressed gas producing plants. Duties Performed by Navy Machinist Mates Some of the more technical responsibilities of machinist's mates include: Aligning piping systems for oil, water, air, and steam, and controlling the operation of ship boilers and steam turbines used for ship propulsion and service systemsCleaning, adjusting, testing and performing other preventive maintenance on a ship's boilers, main engines, turbogenerators and other auxiliary machinery including steering engines, elevators, winches, pumps, and associated valvesOperating and maintaining desalinization plants (distilling plants) to make freshwater from seawaterMaintaining refrigeration plants, air conditioning systems, and galley equipmentRepairing or replacing valves, pumps, heat exchangers, compressors, steam turbines, and hydraulic or pneumatic control devicesMaking entries in and analyzing machinery operating records and reports Working Environment for Navy Machinist's Mates Machinist's mates work within the hull of a ship in fire rooms, boiler rooms, engine rooms or shops. These locations are sometimes hot and noisy. Machinist's mates may be required to perform heavy physical work. They must be able to work closely with others and, in some cases, with limited supervision. Qualifying as a Navy Machinist's Mate After Navy basic training, these sailors spend eight weeks in technical training (or as the Navy calls it "A school") at the Naval Recruit Training Command in Great Lakes, Illinois. To be eligible to serve as a Navy machinist's mate, you'll need a combined score of 195 in the verbal (VE), arithmetic (AR), mathematical knowledge (MK) and auto and shop (AS) segments of the Armed Services Vocational Aptitude Battery (ASVAB) tests. You also can qualify with a combined 200 on the VE, AR, MK and assembling objects (AO) segments of the ASVAB tests. There is no Department of Defense security clearance needed for this job. Normal hearing is required, however, and will be tested prior to granting this rating. Vision must be correctable to 20/20 and normal color vision (no colorblindness) is required to serve as a machinist's mate. Sea/Shore Rotation for Machinist's Mates First Sea Tour: 54 monthsFirst Shore Tour: 36 monthsSecond Sea Tour: 36 monthsSecond Shore Tour: 36 monthsThird Sea Tour: 36 monthsThird Shore Tour: 36 monthsFourth Sea Tour: 36 monthsForth Shore Tour: 36 months Sea tours and shore tours for sailors that have completed four sea tours will be 36 months at sea followed by 36 months ashore until retirement.