914 m of 2.44 m-diameter soft ground tunnel along two separate alignments in downtown Charleston including pump shaft, work shafts, and connections to existing stormwater tunnel. Under design by URS Greiner Woodward Clyde for City of Charleston, SC for bid late-1999. April 1999.Affholder won a USD40 million contract, awarded by the Charleston Commissioners of Public Works (CPW), for the third phase of the sewer tunnel replacement project. The third phase, or Cooper tunnel, is the longest section of tunnel and involves replacing some 5,490 m of tunnel some 40 m below ground along the east side of the peninsula. The excavated diameter will vary from 1.52 m to 2.13 m. The inner diameter varies from 50 cm to 1.22 m. A 1.95 m-diameter Lovat TBM will be used in open mode, as well as a 1.83 m Decker in open mode and an Alpine F6A roadheader. Excavation is entirely in the Cooper marl, a hard dry claylike material. The tunnel will be lined with fiberglass pipe manufactured by Hobas and backfill grouted by Pacific International Grout. Primary support will be steel ribs and wood lagging. Locomotives and muck cars for haulage will be used. All equipment is used or homemade. The contract also includes 1.32 m ID concrete caissons and 1.12 m drilled shafts. The Cooper tunnel will connect to the ongoing 3,660 m Ashley tunnel to complete the peninsula tunnel system. The third phase is slated for completion by September 2007. Visit www.lovat.com, www.vab.sandvik.com, www.charlestoncpw.com/tunnel/sewer_tunnel_project.htm and www.insituform.com/corporate/corp_affholder.html 31-32/05.Charleston Water System's board on 28th March, 2006 approved a USD24.4 million contract to extend Charleston's sewer tunnel system to Daniel Island to handle the 37.8 million litres of daily sewage expected when the area is eventually built out. The water and sewer system's Daniel Island treatment plant has a capacity of 1.9 million litres per day and Charleston Water System is seeking a permit to double that. The long-term plan is to pipe the waste from Daniel Island, Cainhoy and Thomas Island under the Cooper River, through the sewer system on the Charleston peninsula, and under the Ashley River to the Plum Island treatment plant.Consequently, Charleston Commissioners of Public Works plans to build a new USD40 million Daniel Island wastewater tunnel that would join the existing Charleston Peninsula tunnel system, which consists of the Ashley tunnel, Cooper tunnel and Harbour tunnel. These currently carry an average 37.8 million litres of wastewater to the Plum Island treatment plant every day. The new tunnel will go online in 2008. The length of the sewer tunnel is 5.8 km. The excavated diameter is 2.44 m, with a 1.4 m carrier pipe as the final lining. The method of excavation will be with a 2.44 m-diameter Lovat TBM. The initial lining will be steel ribs with hard wood lagging. Final lining will be a 1.4 m carrier pipe. The annulus space will be grouted with low density cellular concrete after carrier pipe installation. Mucking-out with electric locos and muck trains. Two shafts will be constructed by the caisson method, each 6 m ID and 7.3 m OD and approximately 36.6 m deep. The contractor is Affholder. Black & Veatch designed the project and is now providing the construction management. Construction started on 1st May, 2006 and is due for completion 15th December, 2007. Site preparation is nearly completed and the first shaft is under construction. Tunnelling is still a few months away. Visit www.charlestonwater.com/about_capital_tunnel_overview.htm, www.lovat.com, www.bv.com and www.insituform.com/corporate/corp_affholder.html 25/06.