Hong Kong West Drainage Tunnel (2007 - 2012) Tunnel Construction by TBM method The break through of the tunnel TBM assembly chamber Intake tunnel from river channel and maintenance chamber construction Adit tunnel construction by drill and blast method 點擊圖片放大 +8 Drop shaft construction by Raise Boring Method Drop shaft and Stilling Chamber at the end of adit tunnel Precast tunnel segment delivered by locomotive Concrete mixer After blasting at East Portal Intake construction at ground level