NONE BIGGER: TUNNEL BORING MACHINE FOR ORLOVSKI TUNNEL BRINGS NEW WORLD RECORD.

For many years now, diameters in mechanized tunnelling have been gradually expanding, with Herrenknecht regularly setting and breaking world records. In early July 2011, the Russian operator company NCC (Nevskaya Concession Company) placed an order with Herrenknecht – the TBM manufacturer, based in Schwanau, Germany – for the construction of a Mixshield. The tunnel boring machine (TBM) for the Orlovski Tunnel will surpass all previous TBMs. With a diameter of 19.25 m, the tunnelling shield, designed to link both halves of the center of St. Petersburg under the River Neva, sets a new world record.

St. Petersburg, Russia / Schwanau, Germany, 17 August 2011. On the occasion of the contract signing for the world’s largest tunnel boring machine, entrepreneur Martin Herrenknecht recently met the Russian Prime Minister, Vladimir Putin, in St. Petersburg. In a high-level business meeting, Mr. Putin wanted to find out at firsthand about the gigantic automobile tunnel project – an extremely challenging construction project under the River Neva, which will be carried out using the world’s biggest tunnel boring machine. The contract for the manufacture of a 19.25 m diameter Mixshield, which smashes all previous diameter records, had previously been signed by the Russian operator company, NCC (Nevskaya Concession Company) and Herrenknecht AG. For Herrenknecht, this is the biggest single order in the company’s history and represents a huge technical challenge, which has been well prepared by extremely thorough, intensive preparatory engineering collaboration between the customer and the contractor.

Including the backup, the Herrenknecht Mixshield will be a total of 82 meters long. On its own, the tunnelling shield will weigh around 3,800 tons and deliver 8,400 kW drive power to the cutting wheel. The leap in diameter to 19.25 m will enable the machine to excavate 600 cubic meters of soil hourly. The excavation area is more than 50% larger than that for the largest TBM currently in operation in the world (see list of record holders below). A Mixshield is the quickest and safest solution for driving the around 1 km long tunnel bore under the Neva in the face of the high groundwater pressures. An extremely ambitious timetable has been set for implementation of the project. Tunnelling is set to begin in St. Petersburg in the spring of 2013, with the tunnel due to be taken into operation in 2016. The aim of this new and world’s largest mechanically bored tunnel is to provide significant relief in the center of St. Petersburg and allow a continuous traffic flow in the city divided by the river.

Until today, vehicles have had to use the various bridges in order to cross the River Neva from the city center to the northern districts and the orbital freeway. Valentina Matviyenko, Governor of St. Petersburg, explained why this tunnel was so urgently required: The city needed a Neva crossing for motor vehicles round the clock, especially during the shipping season. In addition to linking the banks of the Neva with one another, the Orlovski Tunnel would make a contribution to the economic development of Russia. Allowing longer bridge opening times would allow the intensity of shipping on the Volga/Baltic waterway and the River Neva to increase. The mega-tunnel, with two three-lane carriageway levels, would considerably improve the traffic capacity.

The Orlovski Tunnel project is a pioneering German-Russian project, setting new engineering and constructional standards in large diameter tunnelling.

Herrenknecht world record TBMs

1995 Adler Tunnel, Switzerland; Single Shield TBM; 12,535 mm
1997 Elbe Tunnel, Germany; Mixshield; 14,200 mm
2001 Lefortovo Tunnel, Russia; Mixshield; 14,200 mm
2004 Silver Forest Tunnel, Russia; Mixshield; 14,200 mm
2005 M30, Spain; EPB Shield; 15,200 mm
2006 Shanghai Changjiang Under River Tunnel, China; 2 x Mixshield; 15,430 mm
2010 Sparvo, Italy; EPB Shield; 15,550 mm
2011 Orlovski Tunnel, Russia; Mixshield; 19,250 mm