Mesothelioma & Military Frigates
The U.S. Navy defines a frigate as a kind of warship that is designed to perform anti-submarine warfare and act as an escort for other ships, such as merchant convoys.
The early U.S. Navy Relied on Frigates
The frigate used by the early American Navy was constructed of woods such as oak, pine and elm. It was square-rigged and had three masts.
The vessel was constructed with a number of decks, each of which had a different use. The upper deck, known as the spar deck, was outfitted with short-barreled guns that were used at close range. Directly below the spar deck was the gun deck. This carried heavy guns on both its sides. Below the gun deck was the berthing deck where the sleeping quarters and mess areas were located. The next deck down was a small storage deck, known as the orlop, which also served as the onboard hospital for crew members wounded in battle. The majority of the ship’s supplies, however, were stored in the lowest deck, or hold.
These early frigates were in constant use, protecting merchant shipping, fighting battles with enemy ships, and taking possession of enemy cargo.
The World War II Frigate Gets a New Design and Becomes More Focused in its Mission
During World War II, the British redesigned the frigate to be larger than a corvette, but smaller than a destroyer. The goal of this new design was to make the frigate an effective antisubmarine escort vessel.
The U.S. Navy used the British design for the River class frigates as a model for the 303- foot Tacoma class patrol frigates that joined the fleet in 1943. All of these frigates were manned by Coast Guard crews except for two.
The British Design Was Modified to Accommodate America’s Use of Welded Construction
The Tacoma class was constructed with a lighter bridge structure and a pole foremast, two features that distinguished it from the British River class. However, the real difference between the British and American designs was in the armaments the Tacoma carried.
It had three 3?/50 caliber dual purpose guns and four 40 mm guns in two twin mountings. Each frigate could also be outfitted with up to 10 single 20 mm Oerlikons. Given the number of missions these frigates performed during the war, the vibrations from this amount of artillery could easily loosen fibers from the asbestos insulation used throughout the ship and send them into the air to be inhaled.
The American Frigate’s Engine Was Another Place Where Asbestos Was Used
Although the U.S. Navy kept the British reciprocating engines with the same horsepower, it did use higher steam pressures so that the Tacoma class could travel up to 9,500 miles at 12 knots. This kind of steam pressure meant engines were lined with asbestos to protect against fires.
Another American Design Element Led to Dangerous Asbestos Exposure Levels
Frigates built in the U.S. used forced ventilation, which uses an air handler to condition and circulate air. Air handlers contain heating and cooling elements, filter racks, dampers, and ductwork through which conditioned air is circulated into the area to be ventilated and then returned to be cleaned. All of these parts of air handlers were areas where asbestos was heavily used.