This project included construction of launch and retrieval shafts and 2,100 feet of 114-inch segmentally lined tunnel with an 85.5-inch diameter final liner. Additionally, two existing 36-inch wood stave pipelines were slip-lined with steel liners. Common when the siphon was originally constructed, the original pipes were similar to wooden barrels with metal compression bands holding the … Continue reading Ballard Siphon Replacement Rebid
For any tunnel project, gaining access to the underground is a critical – if sometimes overlooked – component. The building of vertical shafts is the most common method of getting men and material into and out of the tunnel, but shaft construction is no easy matter due to challenging soils, the presence of groundwater, conflicting … Continue reading Reaching New Depths
King County is getting ready to use a shaft excavation machine that will be the first of its kind in North America. James W. Fowler Co., the general contactor, is using it to build a 30-foot diameter, 145-foot deep launching portal for a tunnel boring machine. It’s all part of a $38 million project to … Continue reading Use of German excavation machine on Ship Canal tunnel a first for U.S.