The Most Asbestos-Heavy Space Afloat

On a steam-powered merchant ship, the engine and boiler rooms were the hottest, most confined, and most heavily insulated spaces aboard — and the men who worked them absorbed the most asbestos. Everything that carried heat was wrapped in it: main and auxiliary steam lines, boiler casings, superheaters, turbines, evaporators, feed pumps, and the valves and flanges between them. Insulation was applied as asbestos block, cloth, rope, cement, and preformed pipe covering, and it had to be cut, fitted, torn off, and rebuilt every time a fitting underneath needed service.

Who Worked There

  • Oilers moved constantly among running machinery, oiling bearings and wiping down equipment sheathed in asbestos lagging.
  • Firemen / watertenders tended the boilers directly — the single most asbestos-intensive station on the ship.
  • Wipers — the entry-level engine rating — cleaned the spaces where asbestos dust settled and often assisted with insulation work.
  • QMEDs (Qualified Members of the Engine Department) and licensed engineers supervised and performed the repairs that disturbed insulation as a matter of routine.

How the Dust Got Into the Air

Asbestos aboard ship was not a sealed hazard — it was a working material. Every voyage brought leaks, blows, and breakdowns that had to be fixed at sea, by the crew, with no replacement insulation but whatever was in the storeroom. A repair meant tearing off old lagging (dry, friable, and dusty), grinding gaskets off flanges, cutting new asbestos cloth or block to fit, and mixing asbestos cement by hand. In a sealed engine room with forced ventilation, that dust did not settle and disappear — it recirculated through the space and up into the berthing and mess areas above.

Gaskets, Packing, and Valve Work

Beyond insulation, the engine room ran on asbestos gaskets and packing. Every flange, pump, and valve was sealed with asbestos-based gasket material or packing that had to be scraped, cut, and replaced during maintenance — releasing fibers directly into a mariner’s breathing zone. Products used aboard ship for these purposes were, according to publicly filed asbestos litigation records, allegedly manufactured with asbestos well into the 1970s and beyond.

Decades of Cumulative Exposure

Because merchant mariners often spent entire careers in the engine department — voyage after voyage, ship after ship — the exposure was cumulative and prolonged. That pattern of heavy, repeated, unprotected exposure is consistent with the mesothelioma, asbestosis, and lung-cancer diagnoses that surface decades later. If you served in a ship’s engine or boiler room and have been diagnosed with an asbestos-related disease — or lost a loved one who did — an experienced asbestos attorney can review the exposure history and the civil claim that may be available against the companies that allegedly supplied the asbestos aboard.