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Statue of Liberty Construction

The creator of the Statue of Liberty, Frédéric-Auguste Bartholdi, thought well beyond the image of what would be the world's tallest monument. He considered such practical matters as how to support 100 tons of copper plate and how to make the 151-ft-tall statue able to withstand the forceful winds of New York Bay. However, for the solution to these problems he turned to Gustave Eiffel, the engineer famous for his innovative bridge designs who would subsequently build the Eiffel Tower. Eiffel anticipated skyscraper construction when he designed the Statue of Liberty's supporting frame.

He produced a 94-ft-high wrought-iron square skeleton whose chief structural members are four posts that work in compression. The skeleton supports a secondary iron frame that, in turn, carries a system of flat wrought iron bars. These members carry the copper plates that form the statue's exterior skin. Extending from the main frame are a smaller frame supporting the head and a slim 47-ft, 7-in. skeleton carrying the arm that holds the torch. The frame is braced with diagonal members and was designed to withstand a wind load of 58 psf. In a 50-mph wind, the monument moves 3 in.

In Egypt, at twenty, Bartholdi had gazed with deep emotion upon the colossal, centuries-old "granite beings, in their imperturbable majesty ... whose kindly and impassible glance seems to disregard the present and to be fixed upon the unlimited future." He said that he learned then that the treatment of a colossal statue must be entirely different from that of heroic, life-size, or smaller sculpture. "The details of the lines ought not to arrest the eye ... the surfaces should be broad and simple, defined by a bold and clear design, accentuated in the important places ... it should have a summarized character such as one would give to a rapid sketch." Starting with the 1.25-meter model, a complete statue 2.85 meters high was built, followed by another four times as high, this latter being about one-fourth the size of the completed masterpiece. At each stage, the sculptor made changes in order to conform to the principle of the utmost simplicity in the final work. Bartholdi's final modifications in design had to be made in the one-fourth-size model of plaster supported by its wooden frame. No further changes were possible.

The statue was divided into about 300 sections, and each section enlarged to four times its size by the painstaking, mathematical process of "pointing up," in this case involving many thousands of measurements and as many verifications. Against the plaster surface of each of these enlarged sections was built and fitted precisely a stout mould of laminated wood. Into each wooden mould, a sheet (one square meter or larger) of virgin copper, 2.5 milli- meters or about one-tenth of an inch in thickness, was pressed by means of rammers, levers, and mallets large and small. In the case of complicated shapes, the copper had to be heated. Wrought iron bands and rods gave rigidity to each of the copper sections, which were feather-edged and held together with one-fifth-inch flush- headed copper rivets.

The "noble rust," as Italians call it, which gives copper and bronze so beautiful a surface color, has covered the Statue of Liberty with a malachite green that does not disintegrate the metal as rust devours iron.

Galvanic action was avoided by insulation between all iron and copper parts. (This now consists of asbestos, soaked in shellac.) Folds of the statue's drapery gave ample opportunity for expansion or contraction of the copper re- sulting from changes in temperature. Lightning is conducted by copper rods into the earth.

The sheathing of the statue is made up of 3/32-in. copper plates. In Paris, Bartholdi constructed full-scale plaster models of all parts of the statue. From these, large wooden molds were made of the statue's surface. Using the repousse method, copper sheets were hammered within these molds to reproduce the statue's contours on the the plates. In all, 350 plates make up the statue's surface. Two inch-wide straps of iron were forged to fit inside each plate. Although the copper plates overlap and are riveted to each other, they are supported entirely by these iron bars. The bars are angled upward at about 60° and act like springs. The design allows the skin to bend without being damaged by high winds or extreme fluctuations in temperature.

Bartholdi assembled the statue in Paris, using temporary rivets to link the copper plates. Then it was disassembled and shipped in 210 crates to New York in 1885. On Bedloe's (now Liberty) Island in New York Bay, an 89-ft-high granite-faced reinforced concrete pedestal was built--one of the first instances of the large-scale use of reinforced concrete. The statue was reassembled on the pedestal without any exterior scaffolding. As the framework rose, the workmen attached the copper skin with 300,000 copper rivets in precisely drilled holes.

The 150-foot pedestal was designed by Richard M. Hunt and built by Gen. Charles P. Stone, both Americans. It contains steel underpinnings designed by Alexander Eiffel of France to support the statue. The $270,000 cost was borne by popular subscription in this country. President Grover Cleveland accepted the statue for the United States on Oct. 28, 1886. On Sept. 26, 1972, President Richard M. Nixon dedicated the American Museum of Immigration, housed in structural additions to the base of the statue. In 1984 scaffolding went up for a major restoration and the torch was extinguished on July 4. It was relit with much ceremony July 4, 1986 to mark its centennial.

Other Statue of Liberty topics: Auguste Bartholdi, Construction, Copper, Corrosion, History, Head, Introduction, Model, Picture, Postcard, Restoration, Symbolism

Other landmarks: Christ the Redeemer, Colossus, Delhi pillar, Eiffel tower, Golden Gate bridge, Great Buddha, Guggenheim Museum (Bilbao), Guggenheim Museum (NYC), Normandy bridge, Oresund crossing, Quebec Bridge, Statue of Liberty, Thames Barrier, Titanic, Tower of the Orologio