In an effort to keep maintenance costs down, the English introduced the concept of the fiberglass tower which was later adopted by the Coast Guard. The color of the tower is molded into the plastic with pigments, so painting is not necessary. Little if any metal is used in order to keep saltwater corrosion to a minimum. The light lens is plastic and no storm panes are required for protection. The result is very low maintenance light towers. The first use in the United States of a fiberglass tower was apparently in northern California in the 1960s. Three were built in New England in the early 1980s: Great Salt Pond Light, Block Island, Rhode Island; Deer Island Light, Boston Harbor, Massachusetts; and Cape Code Cannal Breakwater Light, Massachusetts. The first plastic lighthouse, Deer Island Light, a white tower built in 1982, replaced an iron tower on a caisson. It was replaced by a red-brown plastic tower in 1984.
The introduction of reinforced concert once again changed the direction of lighthouse construction. This material was in many ways superior to iron and steel. It was cheaper and required much less maintenance. Also, it was extremely strong. Many lighthouses built in places susceptible to earthquakes were made of reinforced concrete. Therefore, most major concrete towers are found on the west coast.
Reinforced concrete towers began to replace brick masonry towers at the beginning of the 20th century. The first reinforced concrete tower was built at Point Areas, California, in 1910. It is 115 feet tall, one of the two tallest towers on the West Coast. The tallest reinforced concrete tower is Navassa in the West Indies. This tower is 150 feet tall. A series of reinforced concrete towers of art deco design were constructed in Alaska during the 1920s and 1930s. One of these, Scotch Cap, was destroyed by a tidal wave in 1946; killing five men.
The newest reinforced concrete tower is Oak Island, North Carolina. This 169-foot tower was completed in 1958. This silo-style tower was erected by using a Swedish-developed moving slip-form method. Concrete was poured and once that section dried, the form was moved up and another section was poured. The color is integrated into the concrete. The lantern room is aluminum.
The skeleton tower, first made of iron and later steel, found great favor with the Lighthouse Board in the second half of the 19th century. The structure could be pre-fabricated and taken to the construction site in pieces. The height of the tower could be increased simply by adding sections to the bottom. Also, this type of tower offered low wind resistance, a definite asset at windy locations. It should come as no surprise that the tallest of these towers are found in areas frequented by hurricanes.
The tallest skeleton towers were Cape Charles and Hog Island, Virginia, built in the 1890s. These towers were 191 feet tall--just two feet shorter than the tallest tower in the country, the brick one at Cape Hatteras. The Cape Charles tower is still standing.
At least in theory, the skeleton tower could be disassembled and moved to a new location should the need arise. Many skeleton towers remain today. The one at Coney Island, New York, is given special notoriety by the presence of the last civilian lightkeeper, Frank Schubert.