Big Bertha Tunnel-Boring Machine

Big Bertha wakes from one-year nap, begins to chew her way into repair pit
Excavation stopped on Big Bertha repair pit due to major ground sinkage in area
Drilling delays a problem for tunnel-boring machine Big Bertha even as she slumbers below ground
Repairs to Big Bertha will include 86 tons of steel reinforcement to tunnel-boring machine's bearing, cutter drive
equipment damage From our partners
Repairs to Big Bertha will require a 12-story pit and removing the tunnel-boring machine's cutterhead
Tunnel-boring machine Big Bertha shut down for "months" due to complexity of needed repairs
No. 6 in 2013: Big Bertha digs in before being stopped in her tracks