Ridge Spur service to 8th and Market streets began on December 21, 1932. As part of that project, a tunnel shell running south under 8th Street then west under Locust Street to 18th Street (reusing parts of the never-completed Center City loop constructed in 1917) was completed in 1933 but not outfitted for service. Bridge Line service from 8th and Market to Camden began on June 7, 1936, sharing the Ridge Spur platforms at 8th and Market and splitting off from the Ridge Spur just south of Chinatown station.