From 10:00 25 May 2005 to 16:00 26 May 2005,

Moscow Moscow ( , US chiefly ; rus, links=no, Москва, r=Moskva, p=mɐskˈva, a=Москва.ogg) is the capital and largest city of Russia. The city stands on the Moskva River in Central Russia, with a population estimated at 13.0 million ...

's power supplies were the centre of a major incident, which resulted in the supply being outed for several hours in many of City of Moscow districts, as well as

, Tula,

Kaluga Kaluga ( rus, Калу́га, p=kɐˈɫuɡə), a city and the administrative center of Kaluga Oblast in Russia, stands on the Oka River southwest of Moscow. Population: Kaluga's most famous resident, the space travel pioneer Konstantin Tsiol ...

and

Ryazan Ryazan ( rus, Рязань, p=rʲɪˈzanʲ, a=ru-Ryazan.ogg) is the largest city and administrative center of Ryazan Oblast, Russia. The city is located on the banks of the Oka River in Central Russia, southeast of Moscow. As of the 2010 Census ...

provinces. Some tens of thousands of people were trapped in stranded underground trains in the

Moscow Metro The Moscow Metro) is a metro system serving the Russian capital of Moscow as well as the neighbouring cities of Krasnogorsk, Reutov, Lyubertsy and Kotelniki in Moscow Oblast. Opened in 1935 with one line and 13 stations, it was the first unde ...

and in

elevator An elevator or lift is a wire rope, cable-assisted, hydraulic cylinder-assisted, or roller-track assisted machine that vertically transports people or freight between floors, levels, or deck (building), decks of a building, watercraft, ...

s, railway signaling was put out of action and many commercial and governmental organisations were paralysed.

Occurrence

The accident, which some accounts state affected more than 2

million One million (1,000,000), or one thousand thousand, is the natural number following 999,999 and preceding 1,000,001. The word is derived from the early Italian ''millione'' (''milione'' in modern Italian), from ''mille'', "thousand", plus the au ...

people, started in powerstation no. 510 Chagino, situated in the south-east of Moscow in the

Kapotnya district Kapotnya District (russian: Капотня райо́н) is an administrative district (raion) of South-Eastern Administrative Okrug, and one of the 125 raions of Moscow, Russia. Kapotnya is best known as the site of Moscow oil refinery, one of ...

. Here, the high voltage (500 kV) current, going into the capital along the main power lines, is lowered via transformers for city usage to 220 kV and 110 kV. The Chagino substation, built in 1964, is equipped with six high-to-low transformers. Another six substations situated around the

MKAD The Moscow Automobile Ring Road (russian: link=no, Московская кольцевая автомобильная дорога, Moskovskaja koltsevaya avtomobilnaya doroga), or MKAD (), is a ring road running predominantly on the city borde ...

carry out the same functions, and form the Moscow energy ring, which supply Moscow and neighbouring provinces with electricity.

Theories of cause

The immediate cause of the incident, some state, was a mixture of several factors, among which feature: equipment wear-and-tear, absence of back-up powers, the fact that Moscow had endured temperatures above for a number of days. Moreover, Moscow is a very complex region and has the most complex electrical schemata, or "copper board", as it is known by those in the business. It is the only region in which there has been no automatic shut-off system installed since the fall of the

Soviet Union The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen national ...

. This increased vulnerability of Moscow's electrical network played an important role in what happened.

References

External links

BBC report on the blackout

{{in lang, ru Moscow, 2005 2005 in Moscow Moscow power blackouts Moscow Power Blackouts, 2005 Electric power in Russia May 2005 events in Russia