Tunnel boring machine for the Orlowski Tunnel achieves new world record

The diameters in mechanised tunnelling have been increasing steadily for years – now a leap to over 19 m has been achieved.

The Russian operating company NCC (Nevskaya Concession Company) have placed an order with Herrenknecht AG for the production of a Mixshield with a diameter of 19.25 m. The machine will bore the Orlowski Tunnel in the centre of St. Petersburg and provide a continuous connection of the two halves of the city divided by the River Neva.

The Mixshield will be 82 m long including backup. The cutterhead shield alone will weigh about 3,800 t with a drive power of 8,400 kW at the cutting wheel. Mixshield technology is the best solution to quickly and safely bore the tunnel about 1 km long under the high prevailing groundwater pressures under the Neva. The tunnel drive in St. Petersburg should start in early 2013 and the tunnel is to open for traffic in 2016. The new tunnel will have two carriageway levels each with three lanes and will considerably improve the traffic capacity in the city centre of St. Petersburg and permanently join up the parts of the city on the two sides of the river.

Book recommendation: Mechanised Shield Tunnelling