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

Moscow Moscow is the Capital city, capital and List of cities and towns in Russia by population, largest city of Russia, standing on the Moskva (river), Moskva River in Central Russia. It has a population estimated at over 13 million residents with ...

'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 (, ) is a types of inhabited localities in Russia, city and the administrative center of Kaluga Oblast, Russia. It stands on the Oka River southwest of Moscow. Its population was 337,058 at the 2021 census. Kaluga's most famous residen ...

and

Ryazan Ryazan (, ; also Riazan) is the largest types of inhabited localities in Russia, 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 C ...

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

Moscow Metro The Moscow Metro) is a rapid transit system in the Moscow Oblast of Russia. It serves the capital city of Moscow and the neighbouring cities of Krasnogorsk, Moscow Oblast, Krasnogorsk, Reutov, Lyubertsy, and Kotelniki. Opened in 1935 with one l ...

and in

elevator An elevator (American English) or lift (Commonwealth English) is a machine that vertically transports people or freight between levels. They are typically powered by electric motors that drive traction cables and counterweight systems suc ...

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 1,000,000 (one million), 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 ...

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

Kapotnya district Kapotnya District () 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 Refinery, one of the few remaining industrial facilities ...

. 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 (), or MKAD (), is a ring road running predominantly on the city border of Moscow with a length of 108.9 km (67.7 mi) and 35 exits (including ten interchanges). It was completed in 1962. The speed lim ...

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 Union of Soviet Socialist Republics. (USSR), commonly known as the Soviet Union, was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 until Dissolution of the Soviet ...

. 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 in Russia Industrial accidents and incidents in Russia