Video: How a double-deck highway is built inside the Seattle tunnel – with enough concrete to fill 9 football stadiums
GeekWire » The Washington State Department of Transportation (WSDOT) takes viewers on a behind the scenes construction tour of the new double-deck State Route 99 tunnel. WSDOT’s Deputy Administrator explains how the tunnel boring machine, known as Bertha, works to dig through the ground and place concrete rings to form the tunnel wall as she goes. Watch as the tunnel takes shape and construction crews build the framework and pour concrete for the roadway. It is estimated the new tunnel will use enough concrete to fill nine football stadiums. Click here for the video.
GeekWire » Seattle Tunnel Partners (STP) has released a video of construction crews performing routine maintenance on Bertha, the tunnel boring machine, which includes power washing the cutting head and replacing cutting tools that weight 75 pounds each. Bertha is outfitted with 700 cutting tools (or teeth). During this maintenance stop STP has inspected 400 teeth, replacing 25, and remains on schedule to resume digging at the end of July.