Asbestos products were used throughout the ships of the U.S. Navy Pacific Fleet, particularly in the propulsion plant. On steam-powered vessels, high-pressure steam powered not only the main turbines that powered the ship through the water, but all of the other machinery and equipment needed to run the ship.
As a result, all of the turbines, valves, and machinery required asbestos insulation to protect the Navy seamen from being injured by the hot surfaces. Insulation was also needed to keep the temperature within the machinery spaces low enough that the men could work in the engine and boiler rooms.
Shipyard workers and Navy seamen were exposed to asbestos when this equipment was repaired and overhauled at Pearl Harbor Naval Shipyard. Navy seamen were also exposed to asbestos during routine on-board maintenance and repairs.
Asbestos Insulation on Turbines and Boilers
On steam-powered ships, the boilers created high-pressure steam used to turn the high and low pressure turbines. Asbestos insulating block lined the inside walls and sides of these boilers. Asbestos pads and asbestos felt covered the steam drum, and countless asbestos gaskets of all sizes were used on boiler doors, hand holes and inspection ports. The large propulsion turbines, the heart of the ship, were heavily insulated with asbestos pads, asbestos felt, asbestos cloth, and asbestos cement. There were also asbestos gaskets on the turbines.
Asbestos on Steam-Powered Machinery
All of the other machinery and equipment related to the operation of the ships was also steam-powered. Feed pumps, forced draft blowers, lubricating systems, fire and bilge pumps, and the like were driven by their own steam-driven turbines, called auxiliary turbines. These were always insulated with asbestos. In addition to the auxiliary turbines, many pieces of the equipment ran hot and were likewise insulted with asbestos. Feed pumps, distilling plants, and de-aerating feed tanks were all covered with asbestos pads, asbestos felt, asbestos cloth and asbestos cement.
Asbestos Molded Pipe Covering
These ships had miles of piping that were also insulated with asbestos. Not only were the high-pressure steam lines insulated with asbestos, but the cold water lines, such as the fire main, were often insulated with asbestos to prevent condensation and sweating. The Navy’s Bureau of Ships had extensive Technical Manuals detailing the way in which ships were to be constructed and maintained, with an entire chapter devoted to “Thermal Insulation”.
The types of pipe covering approved by the Navy for use on its ship included amosite asbestos pipe covering, called Unibestos, that was almost 100% asbestos fibers held together with a binder. Another product, called 85% magnesia was widely used in the 1940s and 1950s. It contained 15% asbestos. Calcium silicates that typically contained 15% asbestos were also used to insulate pipes. All of these products released deadly asbestos fibers when the pipe covering was cut, handled, manipulated, removed and/or replaced. These small and mostly invisible fibers were inhaled by the seamen who served on these Navy ships.
As a result of all the insulating materials used on Navy ships, Pearl Harbor Naval Shipyard workers and Navy seamen who worked on or around the ships’ machinery and equipment were routinely exposed to asbestos. They were unaware of the dangerous nature of the asbestos dust and the fact that it could lead to an asbestos-related cancer. Galiher DeRobertis & Waxman has represented hundreds of Hawai‘i residents who developed mesothelioma from the asbestos used on Navy equipment at Pearl Harbor.