Marine Sheathing

Marine sheathing refers to the protective layers of insulation, lagging, and cladding installed on pipes, bulkheads, boilers, turbines, and other surfaces aboard ships to control heat, dampen noise, and resist fire. For most of the twentieth century, this sheathing was heavily reliant on asbestos-containing materials, including block insulation, pipe-covering, sprayed coatings, gaskets, and woven cloth wrapped around steam and exhaust lines. The term covers both the insulating core and the outer cloth or metal jacket that held it in place.

Origin

"Sheathing" derives from the Old English scēath, meaning a covering or scabbard, and was adopted into naval architecture to describe protective layers on hulls and machinery. The marine application of asbestos sheathing expanded dramatically during World War II shipbuilding programs in the 1940s, when U.S. Navy and merchant marine specifications mandated asbestos insulation throughout vessels.

Significance in Asbestos Context

Marine sheathing is one of the most heavily documented sources of occupational asbestos exposure, particularly for Navy veterans, shipyard workers, merchant mariners, boiler tenders, machinist's mates, pipefitters, and insulators. When sheathing was cut, ripped out, replaced, or simply deteriorated with age, it released large quantities of amosite and chrysotile fibers into confined shipboard spaces with poor ventilation. Identifying which sheathing products were aboard a specific ship, and which manufacturers supplied them, is often central to building a case, because shipyard and Navy procurement records, MILSPEC documents, and product specifications can tie particular brands (such as Unibestos, Marinite, or Thermobestos) to the exposure history.

Example Sentence

His decades aboard destroyers as a boiler technician brought him into daily contact with damaged marine sheathing around the steam lines, which his expert linked to his later mesothelioma diagnosis.

Related Terms

Amosite, Pipe Covering, Lagging, Shipyard Exposure, Unibestos, MILSPEC

Notes

• If you or a loved one served in the Navy, Coast Guard, or merchant marine, gather DD-214 records, ship assignments, and rate/MOS information. These establish which compartments and equipment you worked around.
• Ask family members about specific ships, hull numbers, and dates of service; product-identification experts can match these to known sheathing manufacturers and overhaul yards.
• Preserve any photographs, logbooks, or yearbooks showing engine rooms, fire rooms, or insulation work. These can corroborate exposure to damaged or disturbed sheathing.
• Shipyard civilian workers (Brooklyn Navy Yard, Norfolk, Long Beach, Bath Iron Works, and others) should document trade, dates, and tasks; secondary exposure to family members from work clothes is also a recognized pathway.