Machinist's Mate

A Machinist's Mate is a U.S. Navy enlisted rating responsible for operating and maintaining a ship's propulsion machinery, auxiliary equipment, and steam systems, including turbines, pumps, valves, condensers, evaporators, and air compressors. Because this work was performed in engine rooms, fire rooms, and auxiliary spaces dense with asbestos-insulated equipment, Machinist's Mates are among the Navy ratings with the highest documented rates of asbestos-related disease.

Origin

The Machinist's Mate (MM) rating was formally established in the U.S. Navy in 1904, evolving from earlier engineering ratings tied to the transition from sail to steam propulsion. The rating expanded enormously during World Wars I and II as the fleet grew, placing hundreds of thousands of sailors into asbestos-laden engineering spaces between the 1930s and 1970s.

Significance in Asbestos Context

For a veteran diagnosed with mesothelioma, lung cancer, or asbestosis, service as a Machinist's Mate is often by itself strong evidence of heavy occupational asbestos exposure. MMs worked hands-on with asbestos gaskets, packing, lagging, and pipe insulation every day, ripping out old insulation during repairs, replacing gaskets on flanges, and repacking valves and pumps, frequently in confined, poorly ventilated spaces. This rating creates a well-documented exposure pathway that connects the veteran's disease to specific manufacturers of pumps, valves, turbines, boilers, and insulation supplied to the Navy, which is the basis for claims against those companies (the Navy itself is generally immune from suit). Defendants frequently argue exposure cannot be tied to their specific product, so identifying the equipment a Machinist's Mate worked on (by ship, hull number, and engineering space) is central to the case.

Example Sentence

His DD-214 showed he served as a Machinist's Mate Second Class aboard a destroyer from 1962 to 1968, which his attorneys used to identify the specific pump and valve manufacturers whose asbestos products he handled daily.

Related Terms

Navy Veteran Exposure, Boiler Tender, Pipefitter, Gasket and Packing Exposure, Engine Room Exposure, Bystander Exposure

Notes

• Request a complete copy of your military service record (DD-214 and full OMPF) from the National Personnel Records Center in St. Louis; these documents establish your rating, ships, and dates of service.
• Make a written list of every ship you served on, the engineering spaces you worked in (forward/aft engine room, fire room, auxiliary machinery room), and the equipment you remember handling, pumps, valves, turbines, evaporators, and their manufacturers if you recall them.
• Ask family members to look for old photographs, letters home, cruise books, and rate manuals; these can corroborate duties and equipment when memory fades.
• File a VA claim for service connection in parallel with any civil claim. Mesothelioma and asbestos-related lung cancer are recognized as service-connected for qualifying Navy veterans, and the two processes do not interfere with each other.
• If you also performed shipyard overhauls or worked at a Navy yard between deployments, document those periods separately; overhaul work often involved the most intense asbestos exposure of a Machinist's Mate's career.