Thorndale Interlocking
CTA Purple Line Express run 520 threads its way from Tracks 2 to 4 at Thorndale Interlocking, a new set of universal scissors crossovers installed just south of Thorndale station on the North Side Main Line. This marks the north end of the RPM (Red-Purple Modernization) project to completely rebuild the 4-track main line- embankment, stations, and all- between here and just south of Lawrence. In the project section, tracks 1 and 2 are currently in use for all trains while tracks 3 and 4 get rebuilt on new viaduct sections. To accommodate the work, certain stations (Berwyn and Lawrence) have been closed completely, while others (Argyle and Bryn Mawr) have been partially closed, with their former island platforms serving only northbound Red Line trains; new, temporary platforms have been built to serve southbounds, which currently use what was southbound express track 1. Amazingly, Purple Line Express service has been preserved throughout all this work, a feat no doubt made easier by the fact that train frequencies have been somewhat reduced due to the pandemic and ongoing crew/staff shortages.
Thorndale Interlocking
CTA Purple Line Express run 520 threads its way from Tracks 2 to 4 at Thorndale Interlocking, a new set of universal scissors crossovers installed just south of Thorndale station on the North Side Main Line. This marks the north end of the RPM (Red-Purple Modernization) project to completely rebuild the 4-track main line- embankment, stations, and all- between here and just south of Lawrence. In the project section, tracks 1 and 2 are currently in use for all trains while tracks 3 and 4 get rebuilt on new viaduct sections. To accommodate the work, certain stations (Berwyn and Lawrence) have been closed completely, while others (Argyle and Bryn Mawr) have been partially closed, with their former island platforms serving only northbound Red Line trains; new, temporary platforms have been built to serve southbounds, which currently use what was southbound express track 1. Amazingly, Purple Line Express service has been preserved throughout all this work, a feat no doubt made easier by the fact that train frequencies have been somewhat reduced due to the pandemic and ongoing crew/staff shortages.