The Knox class frigates — 46 hulls (FF-1052 through FF-1097) built between 1965 and 1974 at Todd Shipyards (Seattle) and Avondale Shipyards (Louisiana) — were the primary US Navy ocean escort frigates of the Cold War, designed for convoy escort and anti-submarine warfare in the North Atlantic against Soviet submarines. Knox class frigates used a single-shaft steam turbine arrangement with two Combustion Engineering boilers producing 35,000 shaft horsepower, and the single-shaft design concentrated all propulsion plant and engineering asbestos exposure in a single engine room and two firerooms. Their propulsion plant was an evolution of the destroyer-era steam turbine technology requiring the same comprehensive asbestos insulation in the engineering spaces.

Steam Plant and Asbestos in Knox Engineering Spaces

The Knox class two-boiler, single-turbine arrangement required asbestos insulation throughout the engineering spaces identical in type to destroyer-era steam plants:

  • Two Combustion Engineering boilers in two firerooms with asbestos block, sectional covering, and cement on boiler casings, steam drums, superheater sections, and uptakes
  • Westinghouse steam turbine set in the single engine room — asbestos block insulation on turbine casings, reduction gear connections, and high-temperature exhaust piping
  • Main steam piping at Cold War-era steam pressures from the boiler rooms to the engine room — asbestos block lagging and lagging cloth throughout the engineering spaces
  • Auxiliary steam systems including feedwater heaters, deaerators, and auxiliary turbines with asbestos insulation on all high-temperature surfaces

Single-Shaft Concentration of Exposure

The Knox class single-shaft propulsion arrangement concentrated the entire engineering plant into fewer spaces than twin-shaft destroyer designs, meaning that engineering watch standers in the single engine room were in a space with the full propulsion turbine set — and all its asbestos-insulated casings and steam piping — in a single enclosed compartment. Machinist’s Mates standing engine room watches had sustained exposure to all asbestos-insulated surfaces of the complete turbine installation.

Knox Class Service Record

Knox class frigates served as the workhorse ocean escort throughout the 1970s and 1980s, conducting ASW operations in the North Atlantic and Mediterranean and serving with Battle Groups in the Pacific. The class remained active into the early 1990s, with the last hulls decommissioned or transferred to allied navies. Several Knox class frigates were transferred to Taiwan, Turkey, Greece, Mexico, and other allied navies under Foreign Military Sales.

VA Claims for Knox Class Veterans

VA presumptive service connection under 38 CFR § 3.309(d) covers asbestos exposure aboard Navy frigates. Veterans who served aboard Knox class frigates (FF-1052 through FF-1097) and have since been diagnosed with mesothelioma, asbestosis, or asbestos-related lung cancer may qualify for VA disability benefits. DD-214 records identifying a Knox class hull number 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

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.