In March 2008 the ACCIONA and Sacyr consortium were awarded the contract to design and construct the Mularroya dam in La Almunia de Doña Godina, Chodes and Ricla (Zaragoza). The contract included construction of the diversion dam and pipeline, which involves constructing more than 12.6 km of tunnel with an internal diameter of 2.9 m.  

To construct the tunnel, Acciona has modified one of its double-shield TBM to the needs of the project, which requires a single-shield rock TBM due to the geological complexity of the route. By adapting the machine it is now possible to use a belt conveyor for the muck. This enhances the feasibility of the project and delivers a highly significant environmental benefit thanks to the use of more efficient electric-powered machinery, generating emissions savings of up to 219 tons of CO2.  

The revision of the TBM has also meant manufacturing a new cutter head to fit the diameter required by the project. The original machine had a drilling diameter of 4,100 mm but the project needs to be 3,556 mm. Click here for further information on the project  and also visit https://www.acciona.com/.45/20.