‘World’s longest’ metro tunnel section completed in Rio

Contractors have blasted the final section of a five kilometre tunnel segment on Rio Metro’s Line 4 extension.

The Rio de Janeiro government said the tunnel, which connects two of the line’s six future stations – Leblon and Sao Conrado – is the longest individual subway section in the world.

On Monday, December 9, officials attended an event in a cavern beneath the 2016 Olympic host city to celebrate the final blast.

In a statement issued through the state communication’s agency, Governor Sérgio Cabral said that more work was currently being carried out on the subway system than at any other time since the system first opened in 1979.

The Rio Barra Construction Consortium, which is delivering the line west of Gávea to Barra where it will terminate at the new Oceanico Garden station, has used the New Austrian Tunneling Method (NATM) – ‘drill and blast’. However, a tunnel boring machine (TBM) will be used to construct the Ipanema-Gávea segment.

Officials in Rio expect the TBM to reach the site of the first new station – Our Lady of Peace – in early 2014 before ending its journey in Gávea in September 2015.

Around 300,000 people are expected to use Line 4 when it opens in 2016.