United States Navy Machinist’s Mates (MM rating) were the enlisted sailors responsible for operating and maintaining the main propulsion machinery — the steam turbines, reduction gears, condensers, pumps, and associated equipment — that drove Navy ships through the water. Machinist’s Mates worked in the main engine room (forward and after enginerooms on larger ships), directly operating and maintaining the main propulsion turbines supplied by Westinghouse Electric and General Electric, and the extensive network of auxiliary steam machinery throughout the ship. Because main propulsion turbines and their associated steam systems were insulated with asbestos throughout the engineroom, and because every flanged steam connection used asbestos gaskets and every valve stem used asbestos packing, the MM rating was among the most heavily asbestos-exposed occupations in the Navy’s engineroom workforce. Publicly filed asbestos litigation records document Machinist’s Mates with personal testimony about hands-on asbestos product work, specific rank references, training manual documentation, and retired MM testimony about career-long asbestos exposure.

Documented Asbestos Exposure — Machinist’s Mate Rating

Personal Testimony — Hands-On Asbestos Work

Specific Rank References — MM2 and MM3

Retired MM Testimony — Career-Long Exposure

Deposition Dialogue — Where MMs Were Exposed

How Machinist’s Mates Were Exposed to Asbestos

Main propulsion turbine operations: Westinghouse and GE main propulsion turbines were insulated with asbestos block and blanket on their casings and steam chests. MMs operated and maintained these turbines continuously during sea operations, working in direct proximity to asbestos-covered equipment.

Gasket and packing replacement: MMs replaced asbestos gaskets on steam turbine casing flanges, throttle valve flanges, and all other flanged connections in the main steam system. Every pump in the engineroom — feedwater pumps, lube oil pumps, condensate pumps — used asbestos-packed valve stems and stuffing box packing, replaced by MMs during routine maintenance.

Condensers and auxiliary machinery: Main condensers, air ejectors, feed heaters, and auxiliary steam machinery throughout the engineroom used asbestos gaskets and packing that MMs serviced regularly. Condensers from manufacturers including Foster Wheeler and Worthington used asbestos gaskets on all heat exchanger heads.

Turbine overhaul at shipyards: During ship overhaul, all turbine insulation was removed by shipyard insulation workers in the engineroom — generating extreme asbestos fiber concentrations in the confined space where MMs worked alongside the insulation trades.

Navy veterans who served as Machinist’s Mates (MM), whether aboard steam-powered destroyers, cruisers, carriers, or submarines, who subsequently developed mesothelioma, asbestos-related lung cancer, asbestosis, or pleural disease may qualify for:

  • VA service connection under VA asbestos-claim guidance — the MM rating’s engineroom duties place Machinist’s Mates among the Navy’s highest-exposure ratings for the VA asbestos asbestos service connection claim
  • Civil claims against main propulsion turbine manufacturers (Westinghouse, GE), auxiliary machinery manufacturers, and asbestos insulation product manufacturers

Key documents for an MM asbestos claim:

  • DD-214 — documenting MM rating and ship assignments
  • Service records — documenting engineroom duty stations aboard specific ships
  • Diagnosis — mesothelioma, asbestos-related lung cancer, asbestosis, or pleural disease

Free, confidential case evaluation: Speak with O’Brien Law Firm — (314) 936-2956

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Exposure documentation derived from publicly filed asbestos litigation records including personal Machinist’s Mate testimony describing hands-on asbestos product work, specific rank-level documentation (MM2, MM3), Machinist’s Mate training manual references, and retired MM testimony identifying career-long asbestos exposure in the Navy main engineroom. This does not constitute legal or medical advice.