Navy Sonar Technician (ST) Asbestos Exposure: Sonar Rooms, Keel Spaces, and Exposure Below the Waterline

If you held the ST, STS, or STG rating and you’ve just been diagnosed with mesothelioma, lung cancer, or asbestosis — this article is written for you. Navy Sonar Technicians worked in compartments that, by design, were sealed from ambient ship noise. That same design trapped airborne asbestos fibers released from deteriorating pipe lagging, hull insulation, and acoustic panels. The exposure was real, the manufacturers knew, and legal options remain open today.

Under federal maritime law — 46 U.S.C. § 30106 — you have three years from the date of diagnosis to file a civil lawsuit against the manufacturers who supplied asbestos-containing products to the Navy. Separately, VA presumptive service connection under 38 CFR § 3.309(d) carries no filing deadline and requires no proof of causation. These are not competing options. Veterans should pursue both simultaneously. Manufacturers including Johns-Manville, Owens-Corning, Eagle-Picher, Garlock Sealing Technologies, Armstrong World Industries, W.R. Grace, Georgia-Pacific, Celotex, Crane Co., and Combustion Engineering supplied asbestos-containing products to the Navy for decades and face civil liability regardless of any VA award.

The ST Rating: Three Subspecialties, Three Distinct Exposure Profiles

The ST rating covered sonar operations across surface and subsurface platforms:

ST (General Sonar Technician) — primary enlisted designation for sonar-qualified personnel
STS (Surface Sonar Technician) — assigned to destroyers, cruisers, frigates, and escort vessels
STG (Submarine Sonar Technician) — assigned to attack and ballistic missile submarines

Each subspecialty placed personnel in different compartments, hull depths, and maintenance environments — all of which allegedly contained asbestos-based materials in the construction and repair era through the 1970s and into the 1980s.

What Navy Sonar Technicians Did: Duties That Created Exposure

Surface Sonar Technician (STS)

STS personnel aboard surface combatants reportedly performed the following duties that may have exposed them to asbestos:

Standing 8–12 hour watch periods at sonar consoles in sealed, acoustically isolated compartments where pipe lagging from Johns-Manville and Owens-Corning products — including Kaylo, Thermobestos, and Aircell — allegedly deteriorated overhead and along bulkheads
Calibrating hydrophone transducers and acoustic arrays mounted on the hull exterior
Troubleshooting and repairing sonar electronics surrounded by equipment racks wrapped in thermal insulation
Maintaining cable runs, power distribution, and signal conditioning equipment insulated with thermal wrap products
Accessing and servicing hull-mounted sonar domes and below-waterline transducer housings enclosed by Crane Co. and Combustion Engineering thermal protection systems
Performing preventive maintenance on sonar cooling loops, valve systems with Garlock gaskets, and acoustic isolation mounts sealed with W.R. Grace compounds

Submarine Sonar Technician (STG)

STG personnel serving aboard submarines reportedly carried additional exposure risk from confined space access and pressure hull proximity:

Standing sonar watch in forward compartments surrounded by pressure hull insulation containing Johns-Manville and Owens-Corning products
Repairing and adjusting towed-array cable systems and towed-hydrophone equipment
Accessing torpedo room passages and forward void spaces during extended deployments
Maintaining forward sonar domes and transducer arrays in keel voids where insulation was often deteriorated and friable
Routing signal cables through Eagle-Picher electrical insulation throughout the pressure hull
Entering confined spaces for acoustic impedance matching material repairs and replacement

Where ST Personnel Worked Aboard Ship

Primary Sonar Operating Spaces

ST personnel spent the majority of their watch hours in dedicated sonar equipment rooms on lower decks near the bow or keel — exactly where hull insulation and pipe lagging concentrations were highest. These compartments were enclosed by design for acoustic isolation, creating sealed environments where disturbed asbestos fibers may have remained suspended and breathable throughout an entire watch rotation.

Reported exposure characteristics of sonar operating rooms:

Limited ventilation by design — acoustic isolation requirements prevented air exchange
Overhead and bulkhead insulation containing Kaylo, Thermobestos, or Aircell thermal wrap
Cable trays with Armstrong World Industries and Eagle-Picher jacket material
Piping with Johns-Manville or Owens-Corning thermal protection running to adjacent machinery spaces
Access panels and equipment hatches with Garlock gaskets and W.R. Grace sealant compounds
Sound-dampening wall panels allegedly containing asbestos-based acoustic material from Georgia-Pacific and Celotex

Secondary Compartments — Routine Access During Maintenance

ST personnel routinely entered compartments adjacent to or supporting sonar systems. Each entry point expanded the exposure profile.

Keel and Bilge Spaces — During transducer maintenance and dome inspections:

Corroded, friable pipe lagging containing Thermobestos and Aircell products
Bilge insulation wrapping from Unibestos and Cranite products deteriorating from saltwater exposure
Garlock and Superex valve packing in seawater cooling and auxiliary systems
W.R. Grace sealant and joint compound on hull penetrations and pipe connections

Below-Waterline Equipment Voids — Housing sonar dome mechanisms and hydrophone arrays:

Spray-applied Monokote fireproofing on structural members
Unibestos thermal wrap on piping and equipment mounts
Hull insulation blankets from Combustion Engineering and Eagle-Picher
Accumulated insulation debris from prior maintenance and years of material deterioration

Main Machinery Spaces — When tracing power supply cabling and pneumatic lines:

Johns-Manville pipe lagging on steam and hot water lines
Owens-Corning thermal insulation on main propulsion equipment
Georgia-Pacific and Celotex duct insulation in HVAC trunks
W.R. Grace products on valve packing and seals throughout engineering systems

Electronics Equipment Rooms (EER) — Containing switchgear, junction boxes, and control panel wiring:

Armstrong World Industries and Eagle-Picher electrical insulation
Garlock Sealing Technologies gaskets in electrical equipment penetrations
Crane Co. transformer and capacitor insulation
Asbestos-containing products throughout cable routing and conduit sealing

Forward Berthing and Passageways — Adjacent to sonar spaces, where overhead and bulkhead insulation was disturbed during watch turnovers and routine foot traffic:

Kaylo and Thermobestos insulation board overhead
Deck tile and adhesive containing Johns-Manville or Gold Bond asbestos materials
Bulkhead insulation wrap with Unibestos or Aircell products
Personnel movement generating airborne dust from deteriorated overhead materials

Cable Trays and Trunk Runs — Connecting sonar equipment to engineering and combat information center spaces throughout lower decks:

Owens-Corning electrical jacket material on signal and power cables
Conduit routing with Johns-Manville sealant and bonding compounds
Support structure with Monokote spray-applied insulation
Garlock gaskets at cable entry points and equipment penetrations

Ventilation and HVAC Trunks — Cooling sonar spaces through lower-deck routing:

Georgia-Pacific and Celotex duct insulation
Garlock gasket materials at duct joints and equipment connections
Asbestos-containing mastic for duct sealing and vibration isolation
Armstrong World Industries products in acoustic dampening applications

Asbestos-Containing Materials ST Personnel Allegedly Encountered

Naval vessels constructed and maintained through the 1970s — and many repaired into the 1980s — reportedly contained asbestos throughout installed systems. ST personnel may have encountered the following materials during routine maintenance, repair, and watch-standing.

Thermal Insulation Products

Pipe Lagging and Thermal Wrap — Applied to steam and hot water lines running through and adjacent to sonar spaces:

Kaylo (Johns-Manville) — rigid block insulation with asbestos fiber binder; friable when aged or disturbed
Thermobestos (Johns-Manville/Owens-Corning) — thermal wrap product for piping; commonly deteriorated aboard older vessels
Aircell (Johns-Manville) — cellular insulation product containing chrysotile asbestos fiber
Cranite (Combustion Engineering) — marine thermal insulation for high-temperature piping

Hull Insulation Blankets — Applied to interior hull surfaces in lower-deck compartments:

Unibestos (Unimat Products) — asbestos-containing thermal blanket material applied to hull structure throughout lower decks
Cranite thermal protection — Combustion Engineering product for hull insulation in machinery and sonar spaces
Johns-Manville block insulation — applied directly to steel hull structure for condensation control and thermal management

Spray-Applied Insulation and Fireproofing — On structural members in machinery spaces accessed during maintenance:

Monokote (W.R. Grace) — spray-applied asbestos-containing fireproofing applied throughout vessels for fire protection and thermal stability; highly friable once dry

Fiberglass Pipe Insulation with Asbestos Binder — On critical systems carrying high-temperature or high-pressure media:

Georgia-Pacific and W.R. Grace products — fiberglass insulation with asbestos fiber bonding material encountered during equipment maintenance and repair

Mechanical Seals, Gaskets, and Packing Materials

Gasket and Packing Material — In valves and mechanical penetrations near sonar dome flood/drain systems:

Garlock Sealing Technologies — asbestos-reinforced gaskets in valve bonnets, flange connections, and equipment penetrations throughout lower-deck compartments
Superex packing — rope-form asbestos packing in valve stems and rotating equipment seals

Rope Gasket Material — In watertight door frames and compartment bulkheads:

Celotex asbestos fiber products — rope gasket material in watertight doors and bulkhead penetrations requiring frequent inspection and replacement

Joint Compound and Sealant — On pipe connections and hull penetrations:

W.R. Grace and Armstrong World Industries products — asbestos-containing sealant and joint compound for pipe thread sealing and penetration closure
Johns-Manville and Owens-Corning mastic and bonding compounds — used for insulation securing and panel installation

Flooring, Overhead, and Wall Materials

Deck Tile and Adhesive — In sonar operating rooms and adjacent berthing spaces:

Gold Bond, Sheetrock, and Johns-Manville products — asbestos-containing vinyl composition tile and asbestos-laden adhesive installed on lower decks
Acoustic ceiling tile — asbestos-containing material in sonar rooms for sound dampening

Overhead Insulation Board — In sound-dampening applications in sonar rooms:

Pabco chrysotile or amosite products — insulation board applied to overhead structure for acoustic isolation
Georgia-Pacific and Celotex products — asbestos-containing board material for thermal and acoustic applications

Mastic and Bonding Adhesive — Securing tiles and panels throughout compartments:

Johns-Manville and Owens-Corning products — asbestos-laden mastic for securing deck tile, bulkhead panels, and insulation boards
W.R. Grace compounds — elastomeric sealant containing asbestos fiber for vibration isolation and acoustic dampening

Electrical and Cable Materials

Electrical Cable Insulation and Jacket Material — Throughout electronics spaces and equipment connections:

Eagle-Picher products — asbestos-containing electrical cable jacket material on power and signal cables running through sonar compartments and adjacent spaces
Armstrong World Industries — asbestos-insulated wire and cable in high-temperature applications
Johns-Manville electrical tape and conduit sealant