CMC to Use Two Lovat TBMs for Algerian Water Scheme Cooperativa Muratori e Cementisti (CMC) has placed and order with Lovat for twin hard rock 3.7 m-diametre TBMs, ancillary equipment and services to drive 11 km of tunnel for the water transfer project from Taksebt dam to Tizi Ouzou and Algiers in northern Algeria. CMC is tunnelling subcontractor for the general contractor SNC-Lavalin. Within this project, the first TBM will be boring 2,377 m for the Tizi Ouzou tunnel and 2,600 m for the Naciria tunnel. The second TBM will be boring 1,208 m for the Draâ-Ben-Khedda tunnel followed by a bore of 4,768 metres for the Thenia tunnel. The maximum depth of tunnel is 95 m, all above the water table. The geology of the tunnel alignments consists of primarily hard, compacted and very compacted blackish grey marl with an RQD typically from 75-90% and a UCS up to 70 MPa. Visit www.lovat.com and www.cmcra.com The TBMs will be built with pressure relief gates for face isolation of the cutting head. The cutting head drive is powered by 524 kW hydraulic drives and operates from 2.5 rpm to 9.5 rpm. Also included will be an auxiliary ventilation system and Lovat's PLC systems. The TBMs will be erecting a primary lining made up of 15 cm-thick expanded concrete segments. Each ring will be composed of three segments and an invert base. As each ring leaves the trailing shield, the ring will be expanded hydraulically to the cut diametre of the TBM. The resulting expansion joint will be kept open by means of spacer blocks that are manually inserted. Expanding the ring allows for a significant cost savings in terms of materials such as grout and associated products. The secondary lining will be a grouted-in-place concrete pipe. The segments will be produced by CMC using moulds supplied by Milan-based Same. For mucking-out, CMC will design its own muck cars, to be produced in China, and a set of brand new GIA locomotives. Visit www.gia.seThe first TBM is to be delivered from the Lovat plant in Toronto on 30th September, 2005 while the second follows on 28th October, 2005. Lovat will now have three hard rock TBMs in use for water transfer tunnels in Algeria, including a 4.2 m-diameter machine for the Beni Haroun aqueduct project, also under contract. Click dz/13. 30/05.