Moscow prepares to open stretch of longest underground line

Moscow is getting ready to open a section of metro on the Big Circle Line – described as the world’s longest underground metro.

As of December 2021, passengers will have access to a newly-completed 20km section that has nine new stations plus one opened after refurbishment.

An ambitious project globally, the Big Circle Line (BCL) will have 31 stations and is expected to be completed in 2022. With a total underground length of 70km when finally completed, it is claimed to become the longest fully underground metro line in the world, surpassing that of Beijing by more than 10km.

To speed up the pace of construction on the BCL, Russian engineers used solutions deemed unconventional for Moscow, explained Anna Merkulova, CEO of the Mosproekt-3 Group of companies.

«We have put stations closer to the surface to increase the amount of work done by tunnel boring machines. Coupled with the unprecedented number of TBMs engaged on the project, such a solution offered the possibility of improving the time needed for constructing new underground infrastructure.»

Up to 23 TBMs have been used simultaneously to bore the BCL tunnels, helping the line enter the Guinness Book of World Records. Specialists from Mospromproekt – part of the Mosproekt-3 Group – designed six of the ten stations to be opened in December 2021.

The Big Circle line is part of the large-scale, off-street rail transport system development programme launched by Moscow authorities in 2011. By 2024, its size will have doubled, exceeding 1,000 km, and the number of stations will have increased by 120. The consolidated transport system includes the Moscow Metro, ground level interchange line (Moscow Central Circle) and several suburban railroads (Moscow Central Diameters).