Asbestos Use on Navy Ships
Literally tons of asbestos insulating materials were used on all classes of US Navy vessels–ranging from asbestos pads, felt and cloth to asbestos pipe covering and cement to asbestos gaskets and packing. Until the 1980s, a Navy ship's machinery and piping would be covered with asbestos insulation from stem to stern.
Throughout the life of the ship, these asbestos materials would be removed and replaced dozens or hundreds of times. Each time, huge numbers of toxic asbestos fibers would be released into the surrounding air.
Shipyard workers involved in the construction, repair, and overhaul of Navy ships were exposed to the asbestos dust released from these materials. Likewise, Navy seamen of all ranks were exposed to the asbestos dust as they operated and maintained these vessels at sea and in port. These ships were their jobsites as well as places they called home while at sea and on duty.
Asbestos pads were used to insulate equipment and machinery on US Navy ships. These pads were also used on the thousands of flanges and valves found throughout the ship. They were designed to be easily removable for routine maintenance of the ship's equipment.
Asbestos pads were formed by putting amosite fiber inside of asbestos cloth, like one would stuff a pillow. Amosite was a trade name for a type of asbestos that was highly favored by the US Navy. Based on the US Navy's Insulation Schedules, over 85% of all of the asbestos fiber used in the insulation on a typical US Navy ship was amosite. The pads were used with asbestos cloth, thread, and tape to insulate the equipment and machinery operating at high temperatures. These asbestos pads were called "removable pads" or "removal insulation". They were installed in such a way that workers could easily remove the asbestos pads to get to the equipment or valves they were trying to repair. When incorporated into these pads, amosite was used in its pure form. Amosite asbestos is a highly toxic fiber that causes mesothelioma. Because these asbestos pads were routinely removed and replaced, their handling generated asbestos dust. Each time the pads were removed and replaced, shipyard workers and seamen were exposed to this dangerous dust.
Asbestos Pipe Covering
Rigid pre-formed asbestos pipe covering was used around regularly shaped pipes. These rigid forms of insulation came in a variety of round sizes and were typically three feet in length. The asbestos pipe covering was covered with asbestos cloth, troweled with asbestos cement, and painted to act as permanent insulation.
Unibestos was the trade name of a pipe covering that was nearly pure amosite asbestos. This type was used extensively by the US Navy in its World War II construction of ships. Other types of pipe covering used chrysotile asbestos, another fibrous form of asbestos imported from Canada.
The cutting and sawing of this rigid pre-molded pipe covering exposed shipyard workers to dangerous asbestos dust and fibers. Exposure to the asbestos dust coming from the pre-molded pipe covering can cause mesothelioma.
Asbestos Cloth, Asbestos Tape and Asbestos Thread
Asbestos cloth, tape, and thread were used in conjunction with asbestos pads and pre-molded pipe covering to build out the insulated surfaces. Asbestos cloth was wrapped around pre-molded pipe covering and was typically installed over the asbestos pads that covered the equipment, machinery and valves.
Asbestos Gaskets and Asbestos Packing
Almost all of the equipment and machinery, valves, fittings, and pipe connections on a Navy vessel used asbestos-containing gaskets. Asbestos gaskets were generally cut from compressed asbestos sheet materials that contained 80% or more asbestos fiber. In later years, some pre-formed gaskets were used in specific applications. There were literally thousands of asbestos gaskets used throughout US Navy ships.
Asbestos packing was used in valve stems to prevent leaking. To repair a leaking valve, the valve was opened and rings of deteriorated asbestos packing were removed. This was typically accomplished with a tool that looked like a cork-screw. New packing was installed and packed down tightly into the valve to prevent leaking.
Before new asbestos gaskets could be installed, the metal surface had to be perfectly cleaned and all of the old gasket material removed so that the new gasket could adequately adhere. Asbestos gaskets were subject to extreme heat and pressure. This caused many gaskets to stick firmly to the metal surface and made them difficult to remove. The removal of old asbestos gaskets caused the release of asbestos fibers as the surfaces were sanded by hand or with pneumatic tools and wire brushes. Similarly, all of the old and deteriorated asbestos packing had to be dug out of valves before new asbestos packing could be installed.
Shipyard workers were exposed to the asbestos dust generated from the installation of asbestos gaskets and packing during new ship construction. In addition, during the overhaul and repair of Navy ships, workers were exposed to the asbestos fibers from the gaskets and packing.
Navy seamen assigned to the machinery spaces of US Navy ships also worked with asbestos gaskets and packing on a routine basis. This regular and routine task exposed thousands of Navy Veterans to toxic asbestos dust during their Naval service and puts them at risk for contracting mesothelioma.
Asbestos cement was used over all of the various insulating materials to fill cracks, form an extra layer of insulation, and provide smooth surfaces for painting. Asbestos cement was typically mixed dry to form a slurry that was troweled over asbestos pads, pipe covering, and other insulated surfaces. The surface was then painted to complete the smooth damage-resistant finish. Significant amounts of asbestos fibers became airborne each time asbestos cement was used.
If you believe that you were exposed to asbestos in the Navy, you should be sure to inform your physician and have regular physical exams.