where did the steel to make tokyo tower come from
Tokyo Tower The new construction project attracted hundreds of tobi (鳶), traditional Japanese construction workers who specialized in the construction of high-rise structures. The Takenaka Corporation broke ground in June 1957 and each day at least 400 laborers worked on the tower.[5] It was constructed of steel, a third of which was scrap metal taken from US tanks damaged in the Korean War.[9][10] When the 90-metre antenna was bolted into place on 14 October 1958, Tokyo Tower was the tallest freestanding tower in the world, taking the title from the Eiffel Tower by 13 metres.[5] Despite being taller than the Eiffel Tower, Tokyo Tower only weighs about 4,000 tons, 3,300 tons less than the Eiffel Tower.[11] While other towers have since surpassed Tokyo Tower's height, the structure was still the tallest artificial structure in Japan until April 2010, when the new Tokyo Skytree became the tallest structure in Japan.[8] It was opened to the public on 23 December 1958 at a final cost of ¥2.8 billion ($8.4 million in 1958).[10][12] Tokyo Tower was mortgaged for ¥10 billion in 2000.[13]
Downtown The skyscraper would become the hallmark of the downtown area. Prior to the invention of the elevator – and later the high-speed elevator – buildings were limited in height to about six stories, which was a de facto limit set by the amount of stairs it was assumed that people would climb, but with the elevator, that limit was shattered, and buildings began to be constructed up to about sixteen stories. What limited them then was the thickness of the masonry needed at the base to hold the weight of the building above it. As the buildings got taller, the thickness of the masonry and the space needed for elevators did not allow for sufficient rentable space to make the building profitable. What shattered that restriction was the invention of first the iron- and then the steel frame building, in which the building's load was carried by an internal metal frame skeleton, which the masonry – and later glass – simply hung off of without carrying any weight.[7]