New York Navy Yard Report of Test of Marinite and Marine Sheathing as Furring for Heat Insulation (1941)

Test No. 4360 of the Material Laboratory at the Navy Yard, New York, dated November 29, 1941: a "Report of Test of 'Marinite' and 'Marine Sheathing' Asbestos Furring for Heat Insulation," submitted by Johns-Manville. It is signed by the laboratory's test engineer, supervisor, test officer and its laboratory officer, Commander C. F. Swanson. It is marked Plaintiff's Exhibit 1728.

What it shows

At the Bureau of Construction and Repair's request, the Navy tested Marinite and Marine Sheathing from April 1939 to October 1941 as furring strips and chair supports to insulate aluminum sheathing from steel bulkheads, and to write specifications for a lightweight class (like Marinite) and a heavyweight class (like Marine Sheathing). It rated both "incombustible," and reports their density (Marinite about 46 pounds per cubic foot as received), strength, hardness, water absorption, heat conduction and screw-holding power, including after 48 hours of vibration.

Workers in the yard's Joiner, Shipwright and Boat Shops worked the materials in shop fabrication tests "to determine the workability." The report concludes that the proposed use "was abandoned on account of considerations of relatively high weight and cost, possibility of splitting ... and uncertainty as to the behavior of the material under impact loads or the shock due to gun fire."

It says nothing about dust or health.

Related

• Marinite and the SS Morro Castle disaster, our guide to the product