Башню в Джидде Ограничивает Не Бетон, а Канат

On the shores of the Red Sea, the first building in history taller than a kilometer is being completed. It seems that the limit to skyscraper height is concrete: sooner or later, the lower walls will give way to the weight of what's above. In reality, modern high-strength concrete can support far more than it's loaded with, and the first thing to hit the ceiling is a regular steel elevator cable. Popular science documentaries count floors and records, while extreme engineering here boils down to three things: what the ground can support, how far the concrete pump can reach, and how much the cable weighs in the shaft. The mechanics are simple. The cabin hangs on cables, the cable extends the entire height of the lift, and weighs at every meter. The higher the building, the longer and heavier the cable, which means more cables are needed—not for the cabin, but for the weight of the cables themselves. At about 500 meters, this spiral loses its purpose, which is why supertall buildings are equipped with transfer floors and sky lounges. The claimed six hundred and sixty-meter climb with a single cabin would require around twenty tons of steel cables; a cable with a carbon fiber core weighs about a fifth of that. There is no bedrock beneath the Jeddah site. Above lies silty sand, below lies a layer of porous limestone with shell imprints about fifty meters thick, and the groundwater is salty. The foundation was assembled from two hundred and seventy piles ranging in diameter from one and a half to almost two meters, the deepest reaching one hundred and five meters. Above lies a slab covering approximately seven and a half thousand square meters: over fifty-six thousand cubic meters of concrete and approximately eight thousand tons of rebar, protected from salt by an electric current. It was the soil that forced the original plan for a one-and-a-half-kilometer tower to be abandoned. In 2018, construction stalled around the sixty-third floor: the main contractor was suspended, then the pandemic struck, and the pause lasted five years. The cranes resumed operation in January 2025, and by December the tower had surpassed eighty floors, a floor every three to four days. Completion is scheduled for 2028. The three-wing, tapering design minimizes vortex shedding, which causes a steady wind to rock the high-rise building more violently than a rare storm. SOURCES: KONE - data on Jeddah Tower elevators and UltraRope technology, including rope weight calculations (kone.com, primary source); Thornton Tomasetti - structural diagram of the tower (thorntontomasetti.com); Engineering News-Record - reports on the foundation and construction progress (enr.com); The Skyscraper Museum - Supertall section (skyscraper.org); ArchDaily - reports on the resumption of work (archdaily.com).