Nikolai Ryzhkov, so little known in the Soviet capital that his biography does not list a birthplace, has catapulted from the job of general manager of a machine factory in Sverdlovsk to premier of the Soviet Union in a decade, a rise through the bureaucracy that took his predecessor, Nikolai Tikhonov, 25 years.

Appointed chairman of the Council of Ministers by the Presidium of the Supreme Soviet on the eve of his 56th birthday, Ryzhkov is an engineer by education with a reputation as a skillful manager and a sound knowledge of economics.

Elected to the 300-member Soviet Central Committee at the 26th Communist Party congress in 1981, Ryzhkov, a protege of the late Soviet leader Yuri Andropov, began his meteoric rise in 1982, when Andropov replaced Leonid Brezhnev.

Under Andropov, Ryzhkov became a secretary and chief economic expert of the Central Committee in 1982. He most likely had close association with Gorbachev, also a Central Committee secretary and economic expert at that time. Last April Gorbachev ushered Ryzhkov into the ruling Politburo, along with Egor Ligachev, widely recognized as the second-ranking Politburo member.

A tall, commanding figure with dark, graying hair, Ryzhkov began his career as a mining foreman in Sverdlovsk after graduating from the Ural Polytechnic Institute. He became deputy director of the Uralmashzavod heavy machine building plant in Sverdlovsk in 1959 and rose to become general director of the plant, where he remained until 1975, when he moved to Moscow to work at a Soviet government planning and budget commission.

Ryzhkov became a party member in 1956 but is one of few top Soviet officials who has never held a full-time party job. He has traveled widely in Eastern Europe and once to Vietnam but never in the West.