On March 12, 2018, local time in Ecuador, HEI completed slip form concreting for the key works — the ventilation and cable shaft of the Ecuadorian Minas Hydroelectric Project. The large-diameter ventilation and cable shaft with a vertical length of 440m, known as “the key works”, serves as the channel for ventilation of underground powerhouse chambers and 230KV HV cables of the entire project.

The Minas Hydroelectric Project is the third largest hydropower plant in Ecuador and HEI’s first hydropower EPC project. The power plant is a diversion hydroelectric plant with three impulse turbines, each having a capacity of 90MW. The main construction scope includes the civil construction and electromechanical construction of 78m high compacted concrete dam, 13.8km water headrace tunnel, 452m pressure shaft, underground powerhouse, 440m ventilation and cable shaft, ground switch station and 43km 230kV power transmission lines. Among them, the ventilation and cable shaft is involved in complex geological conditions, a large number of fracture zones, slurry mingled layers and drift sand formation, and severe groundwater seepage. Since the construction commencement of the ventilation and cable shaft, substantial difficulties have been met at each stage. All the staff of the Minas Hydroelectric Project of HEI have fearlessly confronted the difficulties, given full play to their managerial advantages, led their subcontractors to overcome numerous difficulties and eventually completed the slip form concreting for the key path — the ventilation and cable shaft of the project.

Completion of slip form concreting for the ventilation and cable shaft is an important milestone of the Project. It is the first instance in Ecuador and can be said to be a model in the deep shaft construction field in the world. At present, the project is at the installation stage of the nine 230KV cables aiming at the desired power generation target.