Railway tracks require periodical and constant maintenance work. COMSA has the latest technology in equipment that enables it to carry out the setting up and maintenance of tracks without interrupting the circulation of trains, acting on adjacent tracks or during the night. Below you will find some of the work carried out by COMSA. The works marked with a have further information available in PDF format. PORTUGAL-Fergrupo Maintenance work over the entire rail network. REFER. CHILE-COMSA de Chile Track maintenance of the San Rosendo-Mariquina section of the Central to South Line. EFE-Chile Maintenance of the Talca-Constitución branch line. Maintenance of the Coihue-Nacimiento branch line. Maintenance of Rome - Naples High Speed Line. Operation and maintenance of 22 level crossings. Chimbarongo-Chillán Sector. Integral maintenance of the La Encina-Salou section. Integral maintenance in the Tarragona area. Integral maintenance in the Barcelona area. Integral maintenance on the Venta de Baños-Palencia and Madrid-Irún lines. Urgent actions and maintenance in the Asturias area. Urgent actions and maintenance in the Zaragoza area. Maintenance and repair of infrastructures on the Calatayud-Lleida section. Track maintenance Maintenance Base in Calatayud. Madrid-Saragossa-Barcelona-High Speed Line Trambaix. Maintenance on installations (25-year concession)   Trambesós. Maintenance on installations (25-year concession) Maintenance of the High-Speed Train Ciudad Real-Adamuz (Base de Catatrava) Section Maintenance of the Corredor Mediterráneo (Mediterranean Corridor)