US Navy ocean minesweepers (MSO class) — approximately 65 vessels built in the 1950s at various yards — were purpose-built for mine countermeasures operations, using wooden and fiberglass-reinforced hull construction to minimize magnetic signature in order to safely operate in mine fields. MSO class ships were powered by diesel engines rather than steam turbines to minimize magnetic field generation. Despite their non-magnetic construction, MSO crew members accumulated asbestos exposure from diesel engine exhaust system insulation and from asbestos-containing materials in the ship’s accommodation and mechanical systems in 1950s-era construction.

Diesel Engine System and Asbestos

MSO class minesweepers used diesel-electric propulsion with diesel engine maintenance by Enginemen (EN) and Machinist’s Mates:

  • Diesel exhaust system insulation — the diesel engine exhaust piping, exhaust manifolds, and exhaust silencers on MSO class minesweepers used asbestos insulation on the hot exhaust system components in the confined engine room of these small ships. Enginemen performing exhaust system maintenance worked in proximity to asbestos-insulated exhaust components throughout their engineering maintenance
  • Diesel engine gaskets — diesel engine maintenance on the main propulsion diesels and ship’s service diesel generators involved asbestos-containing head gaskets, exhaust manifold gaskets, and turbocharger gaskets in standard diesel engine overhaul maintenance
  • Generator set maintenance — the diesel generators providing electrical power used asbestos-containing engine gasket materials during scheduled overhaul

Accommodation and Mechanical System Asbestos

MSO ships built in the 1950s used asbestos-containing materials in accommodation and mechanical system insulation:

  • Ship’s accommodation spaces — crew berthing, mess, and working spaces in MSO class ships used asbestos-containing materials in deck tile and accommodation space construction consistent with 1950s-era naval construction standards
  • Freshwater and heating system piping — fresh water heating and accommodation heating systems used asbestos-insulated piping in some MSO class ship configurations

Mine Warfare Operations

MSO class minesweepers operated in mine fields sweeping for moored and influence mines using mechanical sweep gear and influence sweep systems:

  • Mine warfare crew members aboard MSO vessels worked in the confined accommodations of these small ships — approximately 172 feet long with crews of around 75 — with continuous exposure to the ship’s interior construction throughout each deployment

VA Claims for MSO Veterans

VA evaluates asbestos-related disability claims on a case-by-case basis. Veterans generally need evidence of in-service asbestos exposure, a current asbestos-related diagnosis, and a medical link between them. Engineering ratings who served aboard ocean minesweepers and have since been diagnosed with mesothelioma, asbestosis, or asbestos-related lung cancer may qualify for VA disability benefits.

Product & Manufacturer Reference

The asbestos-containing products documented on U.S. Navy vessels and at shipyards are catalogued by manufacturer on AsbestosIndex. These records cross-reference which companies supplied which materials and to which facilities.

Pipe Covering & Block Insulation Thermal insulation applied to steam lines, valves, and equipment in engine rooms and fire rooms Marine Products Insulation, gaskets, and packing products specified for naval and commercial marine applications Boilers & Steam Equipment Boiler manufacturers and insulation products — central to the fire room exposure pathway Gaskets & Packing Sheet and ring gaskets used throughout piping flanges, valve bonnets, and pump housings Electrical Products Wire insulation, switchgear arc chutes, and panel liners used throughout electrical spaces Full Product Index Search all 200+ manufacturers and 1,500+ documented asbestos products on AsbestosIndex™

Navy Ratings Most Exposed to Asbestos Aboard Ocean Minesweepers (MSO)

The U.S. Department of Veterans Affairs and the public asbestos litigation record document that the following Navy ratings worked routinely in spaces where ACM was installed, maintained, ripped out, and replaced:

VA Disability Claims for Asbestos-Related Disease

The U.S. Department of Veterans Affairs evaluates asbestos claims individually. A veteran generally needs medical evidence of a current asbestos-related disease, service evidence supporting in-service asbestos exposure, and a medical opinion connecting the two. Ship assignments, Navy ratings, and equipment records can help document the exposure history but do not create automatic service connection.

Approved claims may provide monthly disability compensation and related benefits. Survivors may separately qualify for Dependency & Indemnity Compensation when the applicable requirements are met. Civil lawsuits and asbestos-trust claims use different standards; claimants should obtain individualized advice about how the processes interact.

How to file a VA disability claim: VA claims are filed directly with the U.S. Department of Veterans Affairs — not with a law firm. Start at VA.gov › Hazardous Materials Exposure, call 1‑800‑827‑1000, or get free help filing from a Veterans Service Organization: DAV, VFW, or American Legion.

VA Claims Guide on This Site › Compare: VA vs. Civil Lawsuit

Source notes: equipment-manifest entries (where shown) are sourced from public-record BUSHIPS (Bureau of Ships) documentation, NARA archives, and the public asbestos litigation record. Manufacturer attributions link to documented asbestos-product histories on AsbestosIndex.com where available. Nothing on this page constitutes medical or legal advice.