Shukhov Tower

Vladimir Shukhov invented the world's first hyperboloid structure in the year 1890. Later he wrote a book "Rafters" where he proved that the triangular shapes are 20-25% heavier than the arched ones with a ray grating. After that, Shukhov filed a number of patents for a diagrid. He aimed not only to achieve greater strength and rigidity of the structure, but also ease and simplicity through the use of as little building material as possible.

The first diagrid tower was built for the All-Russia Exhibition in Nizhny Novgorod in 1896, and later was bought by Yury Nechaev-Maltsov, famous manufacturer of the city. Shukhov was responsible for constructions of a new types of lighthouses, masts, water and transmission towers.

Broadcasting tower at Shabolovka has become one of the diagrid structures in the form of a rotated hyperboloid. The Khodynka radio station, built in 1914, couldn't longer handle the increasing amount of radiograms. On July 30, 1919, Vladimir Lenin signed a decree of the Council of Workers' and Peasants' Defense, which demanded “to install in an extremely urgent manner a radio station equipped with the most advanced and powerful devices and machines”, sufficiently to ensure the security of the country and constant communication with other republics. Tower designing was started immediately across many bureaus. Later that year Shukhov’s Construction Office won a competition.

Shukhov’s engineering talents have become popular against the background of a shortage of metal in the country during the World War I and Civil War. Often Shukhov used materials of disassembled bridges and factories. The complexity of the work was also determined by the lack of qualified workers after the World War I, laborers had to be trained directly at the construction site.

The planned height of the new nine-sectioned hyperbolic tower was 350 meters (15 meters above the Eiffel Tower, which was taken into consideration when creating the plan) with an estimated mass of 2,200 tons (the Eiffel Tower weighs 7,300 tons). However, in the context of the Civil War and the lack of resources, the project had to be revised: the height was reduced to 148.5 meters, the weight — to 240 tons.[1] New project was approved by Lenin personally.

Tower construction was carried out without any cranes and scaffolding, but only with winches. 240 tons of metal that was required for construction, was allocated by Lenin’s personal decree from the stocks of the Military Department. For lifting five wooden winches were used, which were moved to the upper sections.

The tower is composed of six sections, one above the other. Each section is an independent hyperboloid based on a larger one. Installation of each section was carried out inside the contour and then lifted up to a predetermined height. In order for the base of the section to pass, the bottom diameter was tightened, and after stretching into the installed section, it was loosened, attached and mounted. The initial project implied that the bearing ribs located in the vertical sections of the tower would contact the imaginary surface of the hyperboloid only at the nodal points located on the horizontal belts of the hyperboloid. The lower supporting ring was attached to the foundation with an anchor bolts on both sides from the nodal supporting gusset plates.

On June 29, 1921, during the uplifting of the fourth section, an accident occurred — cable broke, as a result whole fourth section fell from a height of 75 meters and damaged the fifth and sixth sections, which were assembled on the ground. During the investigation, the real cause of the accident was confirmed - metal fatigue, after that work was resumed. The report on the inspection of the tower’s construction in 1937 states: “... metal of the Shukhov Tower can be attributed to the steel St - 1, St - 2 and St - 3. Samples have an overestimated content of harmful impurities: either sulfur or phosphorus, in some samples — both of them."

The sixth section was installed and finally secured on February 14, 1922. On February 28 they put a mast on the tower, after that Shukhov's job was done. On March 19, broadcasting transmitters were installed on the tower and the radio broadcasting began. The first was a concert of Russian music with the participation of Nadezhda Obukhova and Boris Evlakhov. Transmitter power on the tower was 100 kW, and the range - around 10000 km. It was more powerful than the radio stations of Paris, New York and Berlin.