On 29 January, the second tunnel boring machine for Line 2-Green departed from the port of Taicang, China, aboard the ship Chipol Taihu, bound for Brazil. Considered the largest machine in metro construction in the country, the new ‘Tatuzão’ is 133 metres long, 11.67 metres in diameter and weighs 2,600 tonnes.

The tunnel boring machine will be responsible for excavating approximately 7 km between the future Penha and Dutra stations, on the border with Guarulhos. It is scheduled to arrive in Brazil in March, with excavation work beginning in the second half of the year.

The Dual Mode – EPB (Earth Pressure Balance) and Open Mode machine ensures safety and efficiency in varied soils, with an advance capacity of up to 15 metres per day in soil and 10 metres per day in rock.

In addition to the cutting wheel, which breaks through the wall upon reaching each future station, the tunnel boring machine has a ‘backup’: a support structure consisting of conveyor belts for removing earth, a hyperbaric chamber, a ventilation system and a mechanism for installing the concrete segments that line the tunnel.

(Source: Portal ABC do ABC, on 30 January)