The primitive-looking building on the right was the interlocking tower at Lawrence that controlled the switches that narrowed the four-track main line north of here into just two tracks on the approach to Wilson station. The photographer is standing on the connecting track to the Milwaukee Road interchange yard at Buena. For a larger view, click here. (CTA Photo)
Leland Avenue and Broadway, Uptown
North Side Main Line
Established: circa 1922
Original Line: Northwestern Elevated Railroad
Lawrence Tower was installed as part of the elevation of the North Side Main Line from Lawrence to Howard, which was completed in 1922. The tower, located between Tracks 2 and 3 south of Lawrence station, controlled the convergence of the four-track main line north of Leland Avenue into just two tracks on the north approach to and from Wilson station. The tower also controlled access from Track 1 to the connector track to the Buena Interchange Yard south of Montrose Avenue. However, the switch between the connector and the gauntlet track along Track 1 was hand-throw.
On July 24, 1955, hours of attended operation of Lawrence Tower were reduced to 0630 to 1000 hours and 1430 to 1900 hours Monday through Friday only, when Evanston Express trains had to be switched to and from Tracks 1 and 4. During other times, all North-South trains used Tracks 2 and 3, allowing the switches to simply be left aligned for those tracks. However, on November 28, 1955, coverage was restored to Lawrence Tower during Monday through Friday middays.
Because the four-track main line allowed a high level of service north and south of Wilson but narrowed to just two tracks through Wilson station, Lawrence Tower (as well as Wilson Tower south of Wilson station) represented a choke point on the North Side "L" for many years. By the late 1950s, the CTA decided it was finally time to correct the bottleneck that the track configuration through Wilson presented. The merging of trains in each direction down to one track was not only beginning to cause intolerable delays to service but the mingling of so many trains on so few tracks was one cause cited in the investigation of a 1956 accident at Wilson.
In 1958, the CTA embarked on a $1.8 million project to reconstruct about 1,500 feet of right-of-way through Wilson station into a continuous four-track system. Once complete, Evanston Express and North Shore Line trains would run on the outside tracks (Tracks 1 and 4 on the southbound and northbound, respectively) and North-South Route trains would remain on Tracks 2 and 3 on the inside. Because trains would stay on their respective tracks the whole way through Wilson, Lawrence Tower would no longer be needed once the project was complete. The project took several years to complete and involved some complicated phasing to allow service to continue through the site during the project. To make the job easier, Track 1 would use part of the existing concrete elevated structure used by CTA freight trains connecting to the Milwaukee Road.
With the project reaching completion, Lawrence Tower was closed on January 11, 1961, concurrent with the new Track 3 being placed in service. The new Track 4 completed and placed in service on April 19, 1961. When completed, there were four tracks through Wilson served by four platforms, allowing for smoother operation without switching delays. By the end of the project the arrangement of the switches at Lawrence had been significantly changed as well. In January 1961, at the time the tower closed, there was a universal crossover between Tracks 1 and 2 a short distance south of the Lawrence platform -- a right-hand crossover on the north and a left-hand crossover immediately to the south. There was also a right-hand crossover between Tracks 3 and 4, closer to Leland Avenue than Lawrence. There were, however, no longer any switches between Tracks 2 and 3, so there was no ability to cross trains between the north- and southbound sets of tracks. In January 1961, the universal crossover between the local and express southbound tracks were hand-throw switches, but the crossover from Track 3 to Track 4 was still interlocked, probably because Track 4 through Wilson was still being reconstructed, so northbound trains sharing Track 3 needed to be sorted out at Lawrence, putting consistent usage on the switch. By January 1962, the next track map edition, the right-hand switch was shown as being hand-throw as well, no doubt a result of the end of the Wilson track realignment project in April 1961 and the regular use of the switch ending.
The switches remained in this configuration for over 30 years until the 1990s. On September 15, 1994, the right-hand crossover from Track 3 to 4 was permanently removed from service. This was most likely done in anticipation of a project undertaken the next year to replace the steel structure under Tracks 3 and 4 between Lawrence and Leland with a solid-fill embankment. (In the block between Lawrence and Leland, Tracks 1 and 2, the west half of the four-track line, was supported by a solid-fill embankment like the rest line to the north, while Tracks 3 and 4 were supported by a steel elevated structure like the alignment to the south.)
By 1999, the remaining two switches were labelled on track maps as being at Leland, and were thereafter known as Leland Crossover. See Leland Tower for more information on the crossovers at this location.
An interlocking was added back in the same general location as Lawrence Interlocking, just north of Lawrence station, in 2015. These switches were needed to control the movement of trains between tracks for various phases of the Wilson Station Reconstruction Project, which were removed one track at a time through the station for reconstruction resulting in the services through the area being consolidated from four tracks to three. However, this interlocking plant was named after Leland Avenue, which is closer to the actual location of the switches and tower than Lawrence Avenue is. (See Leland Tower for more information.)