The Bratsk Hydroelectric Power Station (also referred to as The 50 years of Great October Dam) is a concrete gravity dam on the Angara River and adjacent hydroelectric power station. It is the second level of the Angara River hydroelectric station cascade in Irkutsk Oblast, Russia. From its commissioning in 1966, the station was the world’s single biggest power producer until Krasnoyarsk Hydroelectric Power Station reached 5,000 MW (at 10 turbines) in 1971. Annually the station produces 22.6 TWh. Currently, the Bratsk Power Station operates 18 hydro-turbines, each with capacity of 250 MW, produced by the Leningrad Metal Works ("LMZ", , ) in the 1960s. Design and specifications Dam Components: concrete wall 924 m long and 124.5 m high at its maximum (stationary part 515 m long, waterdrop part 242 m long, dumb part 167 m). by-wall house 516 m long riverbank concrete walls all 506 m long right bank ground wall 2,987 m long, left - 723 m long. On the top of the dam are the track of the Taishet-Lena railway line and a vehicle road. There are no navigational channels, because the Angara has no through ship routes. Nevertheless, the construction project includes the possibility to build a ship elevator. Bratsk dam is often referred to as the second largest in the world by reservoir storage capacity. Power plant The Turbine Hall contains 18 Francis hydroturbine units, ca. 250 MW each, with 106 m of operating head. A 5,140 m-long penstock forms the Bratsk Reservoir. With a 4,500 MW capacity, and 22.6 TWh of annual output, it is Russia's second largest single producer of hydroelectricity. Output is distributed into five 500 kV power lines and twenty 220 kV lines. The plant was designed by the Moscow-based Hydroproject () institute, and is operated by the joint-stock company Irkutskenergo (), although all the buildings themselves belong to Russia's federal government. A reconstruction project includes increasing the output towards 5,000 MW. At present, Irkutskenergo together with JSC Silovii Mashini () is modernizing the aging turbines. Economics The plant powers hundreds of factories. It became a part of the Bratsk territorial-production complex () About 75% of the output is consumed by the Bratsk Aluminium Plant. History The plan to build the hydroelectric plant was approved in September 1954 and later that year the first workers and machines arrived at Bratsk. On December 21, 1954 preparation works were initiated by the Nizhneangargasstroy