Senior church officials and some engineers had expressed concerns that the Cathedral would be affected by the new line that will run underneath the downtown section of Avenida Alcalde/16 de Septiembre.
Constructors say they will erect a 1.5-meter wide contention wall, with a depth of 32 meters below the sidewalk on Alcalde, to reinforce the Cathedral against vibrations caused by passing trains.
The wall will also protect other historic buildings along the avenue.
Studies show the Cathedral’s foundations are far from solid, church leaders say, with the north tower leaning slightly ever since the construction of the Hidalgo road tunnel in the 1980s.
The Archdiocese of Guadalajara says it will take the opportunity of the Line Three construction process to undertake a full rehabilitation of the Cathedral in coordination with the Instituto Nacional de Antropología e Historia (INAH) and Jalisco Secretaría de Infraestructura y Obra Pública.