The Knox class consisted of 46 destroyer escorts (initially DE-1052 through DE-1097, reclassified FF in 1975) commissioned between 1969 and 1974 at Todd Pacific Shipyards, Avondale Shipyard, and other yards. The Knox class used a distinctive single-screw, single-shaft steam turbine propulsion system — a departure from the twin-shaft design of earlier destroyer escorts — that concentrated the steam plant engineering in a compact machinery space. The Knox class served as anti-submarine warfare escorts through the Cold War, with the ships transferred to allied navies through the 1990s as they were replaced in the US fleet. These 1969-era frigates were among the last Navy surface ships built with full steam turbine propulsion and asbestos pipe covering in the engineering spaces.

Single-Screw Steam Plant Asbestos

Knox-class frigates used a compact single-screw steam plant with asbestos insulation:

  • Boiler plant — the two Combustion Engineering boilers aboard Knox-class frigates used asbestos boiler lagging on exterior surfaces and asbestos refractory brick in combustion chambers in the 1969-era construction specifications. BT ratings maintaining the Knox-class boiler plant worked in the compact single-boiler-room arrangement with the asbestos-containing boilers as the dominant engineering feature
  • Main steam piping — the main steam piping from Knox-class boilers to the single-screw propulsion turbine and to auxiliary steam loads used asbestos pipe covering in the engineering spaces consistent with the late-1960s construction specifications that still included asbestos pipe covering on Navy frigate steam systems
  • ASROC launcher and engineering combination — the Knox class combined the ASROC anti-submarine rocket launcher and the engineering plant in a compact hull, with engineering ratings maintaining the steam plant in close proximity to ASW system components

VA Claims for Knox-Class Veterans

VA presumptive service connection under 38 CFR § 3.309(d) covers asbestos exposure aboard steam-powered destroyer escorts and frigates. Engineering ratings who served aboard Knox-class destroyer escorts 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 Knox-Class Destroyer Escorts (DE/FF)

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 Presumptive Benefits — No Filing Deadline

The U.S. Department of Veterans Affairs recognizes mesothelioma, asbestos-related lung cancer, asbestosis, and pleural disease as conditions presumed to be service-connected for Navy veterans with documented asbestos exposure under 38 CFR § 3.309(d). No statute of limitations applies to VA disability compensation claims.

Available benefits may include monthly disability compensation, Dependency & Indemnity Compensation (DIC) for surviving spouses, priority VA healthcare enrollment, and Special Monthly Compensation for severe cases. Parallel claims against the asbestos bankruptcy trust funds established by the manufacturers of these products do not reduce VA compensation.

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.