Bertha (tunnel boring machine) - Wikipedia

Micro tunnel shield method is a digging technique used to construct small tunnels, and diminish in size of general tunnelling shield. Micro tunnel boring machine is quite similar to general Tunnelling shield but on a smaller scale. These Tunnel boring machine generally vary from 1 to 1.5 metres (3.3 to 4.9 ft).

Tunnel boring machine - Wikipedia

The World's Largest Tunnel-Boring Machine Must Be Saved. Bertha has stalled deep beneath Seattle, leaving the city's planned waterfront renaissance hanging in the balance.

The World's Largest Tunnel-Boring Machine Must Be …

Bertha, the world’s largest tunneling machine, has been stuck under downtown Seattle since it broke in December 2013. Engineers have had to concoct a massive and expensive rescue plan—essentially a whole construction project in itself. And yesterday, the Bertha’s broken cutter head was finally hoisted out of the Earth.

The World's Largest Tunneling Machine Is (Finally) …

On Saturday,the world's largest tunnel boring machine was dedicated in the city of Seattle. “Bertha,” as it’s known, will spend the next 14 months boring a 1.7 mile (2.7 km) tunnel under the city to replace a viaduct damaged in a 2001 earthquake. Gizmag took a look inside the giant machine.

Gizmag goes inside the world's largest tunnel boring machine

Watch video · Contractors building a highway tunnel under Seattle are preparing to remove the world's largest boring machine so that it can be repaired. The gigantic drill, known as Bertha, stopped working in December 2013 after digging just 1,000ft of its two-mile journey to replace the aging Alaska Way, which was damaged in 2001 by an …

The world's biggest boring machine Bertha is taken out …

Digging an Enormous Tunnel Under Downtown Seattle To replace a decaying viaduct under downtown Seattle, the state of Washington ordered the world's largest tunnel-boring machine.

Digging the World's Widest Tunnel Under Downtown …

Jul 13, 2012 · How a Tunnel-Boring Machine Drills Underground NYCEDC. Loading ... Tunnel excavation with NFM Technologies TBM (tunnel boring machines) - …

How a Tunnel-Boring Machine Drills Underground - YouTube

World's largest tunneling machine still stuck - CNN Video. Feb 12, 2015 · CNN's Thom Patterson explains how engineers plan on getting Bertha, the world's largest tunnel machine, digging again in Seattle.