First Ashore!

The 887-ton Cutter Head was the first piece of Seattle's SR99 Tunnel Boring Machine (TBM) to be landed at Pier 46 from Jumbo Fairpartner.

The massive 17.48 m (57.5 ft) diameter Cutter Head was carefully placed on two Goldhofer self-propelled mega axle/mega tired transporters.

The configuration of cutting heads is matched to the type of material being bored through. For example, the TBM gnawing through the Alps is designed to cut through hard rock - old hard rock.

Designated as an Earth Pressure Balance TBM, this type of cutting head was developed in Japan in the 1970's to deal with silt and clay, sand and gravel, and glacial till. This is the very soil structure Seattle lays upon.

 

The upper body of one of three support cars was unloaded on Tuesday the 9th and parked on screw jacks, awaiting it's succession in the TBM re-assembly procedure.