Asbestos on Naval Ships: Why use Amosite Fibers?

I am beginning my path towards writing articles and (hopefully) a book on asbestos issues arising from shipbuilding, seafaring, and ship breaking. This will be a tremendous opportunity for me to personally better understand and then discuss the history and remaining legacy issues. I hope that you come along for the ride and participate with questions.

The topic for today will focus on the use of amosite asbestos fibers on United States war ships. As the availability of amosite is limited to mining in South Africa, the mandatory use for military applications on the other side of the globe would seem to be out of the norm. You know, “Buy American”, especially for ships being built during World War II and the logistics of shipping fibers? Someone must have thought this to be important, and so what makes the amosite fibers so special?

First, is it important that amosite was used on Navy ships? Yes, history has shown that inhalation of amosite asbestos fibers is significantly more dangerous than chrysotile asbestos. As such, this decision in the context of history has made a difference, and not a good one, to those who built, worked aboard, and broke up the ships. Although important to the war effort, it has caused significant pain and suffering to those who served (and others) for sixty or so years.

This question is best answered through the historical literature. Specifically, the January 1946 edition of The Journal of Industrial Hygiene and Toxicology in the article entitled “A Health Survey of Pipe Covering in Constructing Naval Vessels.” This article by Walter Fleischer, Frederick Viles, Robert Gade, and Phillip Drinker is often cited and discussed for a number of asbestos related issues (including its conclusion that “pipe covering is not a dangerous occupation” concerning asbestos pipe covering in shipyards), but for today we will just focus on the article’s discussion on the use of amosite fibers on the ships. As stated in the article:

“An important ingredient of pipe covering material used on U.S. Navy vessels is amosite. This mineral is a magnesium iron silicate of variable composition. The name is the generic used for an asbestos type of fiberous mineral mined in South Africa.

The chief reasons for the wide use of amosite felt and pipe covering in naval work are its low thermal conductivity, light weight, strength, and refractoriness.

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Amosite pipe covering weights about 14 pounds per cubic foot, with a temperature limit of 750 degrees F, as compared to magnesia with a weight of 16 pounds per curbic foot, and a temperature limit of 500 degrees F.”

Some additional details are discussed in the above material. If you want the entire article, please just message or send me an email.

However, amosite needed to be blended which chrysotile fibers, and not used alone. As stated in the article:

“Therefore amosite alone will not comply with Navy Specification because of he low magnesia content and must be mixed with chrysotile asbestos to equal or exceed the 6.0 per cents minimum value for magnesia … The two types of asbestos fibers must be mixed together in the proper proportions to satisfy the values set for magnesia and silica. The amounts of these materials used to form this mixture therefore would be 6-43 per cent chrysotile asbestos and 94-57 per cent amosite asbestos.”

A good question to ponder is whether the U.S. Navy would have still required amosite fibers over chrysotile fibers during ship construction in World War II, knowing that it (1) would save lives and the usefulness of the ships during battle, but (2) would be catastrophic long term to many of the people exposed. Although operating procedures and warnings might have helped minimize some exposure, my Navy friends tell me that when the big guns go off, the result includes dust all over many areas of the ship, including the crew quarters.

Remember my prior blog discussing the potential for South Africa to have joined the Axis instead of the good guys in World War II? https://theasbestosblog.com/?p=1760. Good thing that they made the right choice.

For those of you really into World War II history, this is also a good time to mention those amazing World War II asbestos drawings by Arthur Szyk. They are still available on EBay periodically. https://www.reddit.com/r/PropagandaPosters/comments/2gnhgj/what_no_asbestos_magazine_ad_with_art_by_arthur/

Please let me know if you have any comments or questions concerning this blog, or would like an electronic version of the 1946 article. My email is TheAsbestosBlog@gmail.com. Thanks. Marty