Balao Class Submarine (SS-285) — Asbestos in WWII Fleet Submarines

The Balao class fleet submarines — 122 boats commissioned between 1943 and 1946, hull numbers SS-285 through SS-416 — constituted the largest American submarine class of World War II and the backbone of the Pacific Fleet submarine force that devastated Japanese shipping. Balao submarines used diesel-electric propulsion with four main diesel engines — Fairbanks-Morse opposed-piston diesels or General Motors Cleveland diesels depending on the building yard — driving four main generators and four electric propulsion motors. The Balao class was dimensionally similar to its predecessor Gato class but incorporated a thicker pressure hull allowing operations to 400-foot test depth versus the Gato class 300-foot limit. Balao submarines built at Portsmouth Naval Shipyard, Electric Boat (Groton), Manitowoc Shipbuilding, and other Navy yards used asbestos-containing pipe insulation throughout the submarine hull piping systems, asbestos-containing gasket materials in diesel engine exhaust and hull connections, asbestos-containing materials in the torpedo room and crew berthing construction, and asbestos packing in the numerous sea valves and hull valve assemblies throughout each submarine.

Diesel Engine Exhaust and Gasket Asbestos

Balao class diesel propulsion systems incorporated asbestos throughout:

• Diesel engine exhaust manifold and cylinder head gaskets — the Fairbanks-Morse 38D8-1/8 opposed-piston diesels and General Motors 16-278A diesels in Balao submarines incorporated asbestos-containing cylinder head gaskets, exhaust manifold gaskets, and engine end cover gaskets throughout the diesel engine assembly. Machinist’s Mates performing cylinder head maintenance, exhaust manifold work, and diesel engine overhaul operations in Balao submarine engine rooms encountered and replaced asbestos gasket materials throughout the engine maintenance work
• Diesel engine exhaust system insulation — the exhaust piping routing diesel engine exhaust through the Balao submarine hull to the muffler and exhaust discharge systems incorporated asbestos-containing insulation on exhaust piping components in the submarine hull. Machinist’s Mates working in Balao submarine engine rooms accumulated background asbestos exposure from the asbestos exhaust piping insulation in the confined engine room spaces

Submarine Hull Valve and Sea Valve Asbestos

Balao submarines incorporated asbestos in the numerous hull penetration valve assemblies:

• Sea valve and Kingston valve packing — Balao class submarines incorporated numerous sea valves, Kingston valves, and hull stop valves providing control of seawater flooding and venting for ballast tank operations and hull system services. These submarine hull valves used asbestos-containing braided packing in the valve stem stuffing boxes, with Machinist’s Mates and Torpedomen performing valve packing maintenance on the hull valve assemblies encountering asbestos packing materials throughout the submarine hull valve maintenance work
• Torpedo tube outer door and flooding valve packing — Balao submarine torpedo tubes incorporated flooding valves and vent valves with asbestos-containing packing in valve stem glands. Torpedomen maintaining torpedo tube flooding and drain valve assemblies encountered asbestos packing materials in the torpedo tube valve stems during routine torpedo tube maintenance

Crew Berthing and Interior Construction Asbestos

Balao submarine interior construction incorporated asbestos-containing materials:

• Crew berthing and forward torpedo room construction — Balao submarine crew berthing spaces, forward torpedo room, and after torpedo room incorporated asbestos-containing materials in the submarine interior construction consistent with WWII-era Navy submarine construction specifications. Submarine crews living and working in these spaces accumulated background asbestos exposure from the interior construction throughout their patrol deployments
• Control room and conning tower construction — the control room and conning tower of Balao submarines incorporated asbestos-containing materials in equipment mounting, pipe insulation on hydraulic and air system piping, and electrical cable insulation in the submarine control spaces

VA Claims for Balao Class Veterans

VA presumptive service connection under 38 CFR § 3.309(d) covers asbestos exposure aboard Navy submarines. Machinist’s Mates, Torpedomen, and crew members who served aboard Balao class submarines and have since been diagnosed with mesothelioma, asbestosis, or asbestos-related lung cancer may qualify for VA disability benefits.

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.