The Knox class (FF-1052, originally designated DE-1052) comprised 46 ships built between 1967 and 1974, primarily at Todd Shipyards, Avondale Shipyards, and Lockheed Shipbuilding. Knox-class frigates were designed for anti-submarine warfare (ASW) and served through the late 1980s and early 1990s, with many units transferred to foreign navies through the Foreign Military Sales program. The class used a single-shaft steam turbine propulsion plant — a compact and powerful system that concentrated all high-temperature steam equipment and its associated asbestos insulation in a single fireroom and single engine room arrangement.

Single-Shaft Steam Plant and Asbestos Concentration

The Knox class’s single-screw propulsion arrangement meant that all engineering spaces were more compact than two-shaft destroyer designs. A Combustion Engineering (CE) or Babcock & Wilcox boiler generated steam at approximately 1,200 psi — higher pressure than earlier destroyer designs — feeding a single main propulsion turbine and all ship’s service systems.

This high-pressure, single-plant configuration used asbestos insulation throughout:

  • Fireroom with the main boiler covered in asbestos block insulation; the compact space concentrated asbestos fiber in an enclosed environment
  • Main steam line from the fireroom to the engine room carrying 1,200 psi steam under the most demanding asbestos insulation requirements of any Navy steam system
  • Engine room with the main turbine, reduction gearing, and all auxiliary machinery insulated with asbestos-containing materials
  • Ship’s service turbine generators and feed systems served by the same high-pressure steam with asbestos-insulated distribution piping throughout
  • Exhaust and bleed steam systems for heating hotel loads — crew spaces, galley, and machinery spaces — all using asbestos pipe covering

Engineering Ratings Aboard Knox-Class Frigates

Boiler Technicians (BT) assigned to Knox-class frigates operated and maintained the single-boiler plant under sustained at-sea conditions, with routine maintenance cycles requiring close work with asbestos-covered boiler casings and steam system components. Machinist’s Mates (MM) in the engine room maintained the turbine plant in the same asbestos-laden environment. The single-plant configuration meant that most engineering watch duties brought crew members into direct contact with insulated steam systems.

Knox-class ships extensively documented in asbestos litigation include USS Knox (FF-1052), USS Roark (FF-1053), USS Gray (FF-1054), USS Hepburn (FF-1055), USS Connole (FF-1056), and the full 46-ship roster built across Todd, Avondale, and Lockheed facilities.

VA Claims for Knox-Class Veterans

Veterans who served in engineering billets aboard Knox-class frigates before the early 1980s and have since been diagnosed with mesothelioma, asbestosis, or asbestos-related lung cancer may qualify for VA presumptive service connection under 38 CFR § 3.309(d). DD-214 records or service records identifying a Knox-class frigate (FF-1052 through FF-1097) as a duty station document the qualifying assignment.

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 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.