Most of the 3,000 people who worked on the project were unskilled. Foremen specialized in every domain were selected for their training. In fact, in the case of the Boyati Tunnel, English foremen were chosen, as they have had experience in the London and New York subways. The company also established a premium system, which was very popular, especially among Greek workers. The insurance of all staff against accidents and diseases was mandatory, as was the quinine’s provision on a daily basis in order to prevent malaria. The company particularly emphasized the robustness of the employee, and therefore applied for a rich nutrition program, creating the corresponding facilities. Also, the workers coming from other regions were installed in settlements near the construction site in order to avoid the temporary installation in the countryside.