Diagrid in the context of "Hearst Tower (New York City)"

Steel frame is a building technique with a "skeleton frame" of vertical steel columns and horizontal I-beams, constructed in a rectangular grid to support the floors, roof and walls of a building which are all attached to the frame. The development of this technique made the construction of the skyscraper possible. Steel frame has displaced its predecessor, the iron frame, in the early 20th century.

The Hearst Tower is a building at the southwest corner of 57th Street and Eighth Avenue, near Columbus Circle, in the Midtown Manhattan neighborhood of New York City, New York, U.S. It is the world headquarters of media conglomerate Hearst Communications, housing many of the firm's publications and communications companies. The Hearst Tower consists of two sections, with a total height of 597 feet (182 m) and 46 stories. The six lowest stories form the Hearst Magazine Building (also known as the International Magazine Building), designed by Joseph Urban and George B. Post & Sons, which was completed in 1928. Above it is the Hearst Tower addition, designed by Norman Foster and finished in 2006.

The building's main entrance is on Eighth Avenue. The original structure is clad with stone and contains six pylons with sculptural groups. The tower section above has a glass-and-metal facade arranged as a diagrid, or diagonal grid, which doubles as its structural system. The original office space in the Hearst Magazine Building was replaced with an atrium during the Hearst Tower's construction. The tower is certified as a green building as part of the Leadership in Energy and Environmental Design (LEED) program.

Vladimir Grigoryevich Shukhov (Russian: Влади́мир Григо́рьевич Шу́хов; 28 August [O.S. 16 August] 1853 – 2 February 1939) was a Russian and Soviet engineer-polymath, scientist and architect renowned for his pioneering works on new methods of analysis for structural engineering that led to breakthroughs in industrial design of the world's first hyperboloid structures, diagrid shell structures, tensile structures, gridshell structures, oil reservoirs, pipelines, boilers, ships and barges. He is also the inventor of the first cracking method.

Besides the innovations he brought to the oil industry and the construction of numerous bridges and buildings, Shukhov was the inventor of a new family of doubly curved structural forms. These forms, based on non-Euclidean hyperbolic geometry, are known today as hyperboloids of revolution. Shukhov developed not only many varieties of light-weight hyperboloid towers and roof systems, but also the mathematics for their analysis. Shukhov is particularly reputed for his original designs of hyperboloid towers such as the Shukhov Tower.