Ballard Siphon replacement project
Herrenknecht VSM (vertical shaft machine)
31 October, 2013: Construction work to replace wood-stave wastewater siphons built in 1935 under the Lake Washington ship canal in Seattle, Washington, is entering its final phases with the final 84in (2m) diameter fiberglass reinforced liner pipe being installed into the completed 2,000ft (610m) long x 2.6m diameter tunnel excavated by an EPBM at about 18m beneath the bed of Salmon Bay. Application of innovative shaft sinking technology is one of the highlights on the successful job as explained by Marty Noble, Project Representative for owner King County, and Rich Mascarello, Project Manager for contractor JW Fowler. The new CSO wastewater tunnel is on schedule to begin operation in early 2014.