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

“hands-on with anything that contained asbe[stos]…” — testimony from a Machinist’s Mate specifically describing hands-on work with asbestos-containing products appears in the publicly filed asbestos litigation corpus. The “hands-on” characterization of MM asbestos work — as distinct from simply being present near asbestos-insulated equipment — establishes that Machinist’s Mates physically handled asbestos-containing products as part of their standard rating duties. Hands-on asbestos work by MMs included replacing asbestos gaskets on turbine steam lines, replacing asbestos packing on pump and valve stems, and handling asbestos-containing replacement parts for engineroom machinery.

“asbestos-containing products… machinist’s mate…” — formal documentation of Machinist’s Mates working with asbestos-containing products appears in the corpus in multiple independent documents, consistent with the standard engineroom maintenance work of the rating.

Specific Rank References — MM2 and MM3

“second-class machinist’s mate when you rem[oved/replaced asbestos]…” — testimony specifically from a Machinist’s Mate Second Class (MM2) describing asbestos removal or replacement work during his time at that rank appears in the corpus. The specific rank reference — MM2 rather than simply “machinist’s mate” — is consistent with the detailed interrogatory and deposition process used in naval asbestos litigation to establish exactly when in a veteran’s career asbestos exposure occurred.

“Port Command, Machinist’s Mate 3 & 2 Manua[l]…” — formal training manual documentation for Machinist’s Mate 3rd and 2nd Class appears in the corpus in the asbestos litigation context. MM rating training manuals described the maintenance procedures — including gasket and packing replacement — that constituted the hands-on asbestos work of the rating.

Retired MM Testimony — Career-Long Exposure

“Steward is a former machinist mate and ret[ired]…” — testimony from a former Machinist’s Mate who subsequently retired, describing Navy service and asbestos exposure, appears in the corpus. Retired MM testimony is a primary form of documentary evidence in naval asbestos claims, establishing the career-long asbestos exposure pattern typical of the rating.

“Steward is a retired Machinist Mate who served in the…” — the same retired MM appears in multiple independent corpus documents, confirming that this testimony was used across separate proceedings — a hallmark of significant asbestos litigation testimony.

“a retired Machinist Mate who served in the…” — retired MM service testimony appears in additional independent corpus documents, consistent with the pattern of senior retired MMs providing expert and lay testimony in naval asbestos proceedings.

“his father was a Machinist’s Mate in the Navy…” — family testimony from the child of a deceased Machinist’s Mate describing the father’s Navy service and asbestos exposure appears in the corpus, consistent with wrongful death and survivors’ claims arising from MM asbestos exposure.

Deposition Dialogue — Where MMs Were Exposed

“SAY, A MACHINIST MATE, WHERE THEY A[re/were exposed to asbestos]…” — formal deposition dialogue specifically addressing the locations and circumstances of Machinist’s Mate asbestos exposure appears in the corpus in a question-and-answer format consistent with expert or fact witness deposition testimony. Depositions addressing where Machinist’s Mates were exposed to asbestos covered the main engine room, auxiliary machinery rooms, and the steam system throughout the ship.

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 presumptive service connection under 38 CFR § 3.309(d) — the MM rating’s engineroom duties place Machinist’s Mates among the Navy’s highest-exposure ratings for the VA presumptive 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

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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.