April 4 - Jumbo Shipping has transported what is claimed to be the world's largest tunnel boring machine (TBM) from Japan to the USA on board its ship, Fairpartner.
The earth pressure balance shield TBM - consisting of 48 pieces and weighing a total of 7,777 tonnes - was constructed by Hitachi Zosen Corporation and loaded at Osaka, Japan.
The entire consignment had a volume of 31,606 cu m; the heaviest single piece weighed close to 900 tonnes. The shield TBM itself has a diameter of 17 m and is almost 100 m in length.
The TBM will be used to dig a highway tunnel for state route 99, beneath Downtown Seattle. The tunnel is expected to be complete by 2015. The TBM has been named Bertha after Seattle's first female mayor, Bertha Knight Landes.
