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VLF Transmitter Lualualei Lualualei, Hawaii 458m -1,503ft VLF transmitter Lualualei is a facility of the United States Navy near Lualualei, Hawaii transmitting orders to submerged submarines in the very low frequency (VLF) range. VLF transmitter Lualualei, which operates under the callsign NPM on 21.4 kHz and 23.4 kHz, uses as antenna two guyed masts, each 458 metres (1503 feet) tall. Both masts, which were built in 1972, are not only the tallest towers in the Western hemisphere used for military purposes, they are also the tallest towers used for long wave transmissions in the Western hemisphere and since the collapse of Warsaw Radio Mast perhaps the tallest structures electrically insulated against ground.
BREN Tower Nevada Test Site 465m - 1,516ft Despite its immense size, the tower has actually been moved from its original location. Built by the Dresser-Ideco Company for the U.S. Atomic Energy Commission, it was first erected in 1962 in the atomic bomb test area at Yucca Flat, where it was used for an experiment intended to improve understanding the effects of radiation in the atomic bombing of Hiroshima.
After the Nuclear Test Ban Treaty banned open-air nuclear testing, the tower was dismantled and moved to Jackass Flats in Area 25 of the Nevada Test Site, where it was used for Operation HENRE (High Energy Neutron Reactions Experiment), a series of radiation measurement experiments using a small linear accelerator to provide neutrons.
Constructed of 51 thirty-foot (9 m) sections of high tensile steel, the structure is higher than the 1,472 ft (449 m) Empire State Building. The tower is equipped with an outside hoist to lift scientific equipment, and a two-person elevator inside the tower moves at 100 ft (30 m) per minute. The tower weighs 345 tons.
Access to the tower area has been closed since July 2006. No reason for the closure has been given.
 Guyed Mast KVLY-TV Blanchard, N.D. 630m - 2,063ft The tower is located three miles west of Blanchard, North Dakota, which is roughly halfway between Fargo and Grand Forks. It became the tallest artificial structure upon the completion of its construction on August 13, 1963. The tower was built by Hamilton Directors and Kline Iron and Steel, and took thirty days to complete, at a cost of $3.3 million.
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