Scaling is a critical activity in tunnel construction that significantly affects both safety and maintenance costs. Recognized as a high-risk mining operation, it poses substantial dangers to operators, with a notable incidence of accidents and fatalities in the tunneling industry. Large-scale projects such as hydroelectric power plants (HPP) present significant challenges, including substantial vertical elevations and the constraint of a single heavily trafficked main road. These conditions often necessitate semi-mechanized work methods for tunnel construction, which can be labor-intensive, time-consuming, and pose significant safety risks. To address these challenges and improve efficiency, an alternative mechanized method was evaluated and implemented. This approach involved deploying a fleet of excavators equipped with hydraulic hammers and advanced protection systems. Considering local regulations, the Caterpillar M313D wheel excavator and Atlas Copco SB452SC hydraulic hammer were selected for their superior operational performance and ability to mitigate risks associated with scaling activities. The standard scalers and their subsystems were evaluated for their reliability and availability, using data from underground mining operations to guide the configuration and decision-making process. This approach aimed to address operational challenges while being constrained by investment costs, high depreciation expenses due to the shorter project duration, and demanding work conditions. The proposed solution was implemented in tunnel construction for an HPP in Chaglla project over three years. A fleet of six-wheel excavator systems demonstrated effective performance, successfully adhering to the project's safety policies and operational goals pursuing zero fatalities, and high availability and reliability.