A 100-ton hydraulic drill rig toppled over on Chicago Transit Authority elevated tracks near the Bryn Mawr station on Chicago's North Side on Oct. 6 around 3:30 P.M., falling into an alley at street level. Disassembly and removal of the collapsed drill rig was underway on Oct. 7. The drill rig was being used as part of an ongoing CTA modernization project.
No injuries were reported, but power lanes were damaged and CTA service at the Bryn Mawr station was suspended for several hours. The CTA restored normal service the evening of Oct. 6 including stops at the Bryn Mawr station. An 18-unit residential building directly east of the station was evacuated and contractor Walsh-Fluor is paying for residents' stays in hotels until it's determined that it is safe to return.
A spokeswoman for the CTA said the cause of the incident is under investigation and a spokesman for the Chicago Fire Dept. said CFD personnel responded and helped with the evacuation. The drill rig, an IMT International AF 300 mounted to a Cat 349D hydraulic excavator base, is typically used for foundation piles, and can work at depths of up to 75 meters.
Construction on the $2.1-billion CTA Red/Purple line modernization has been underway by Walsh/Fluor for the last two years. A 285-ft-long gantry crane will be used to place concrete replacement sections of track structure in a longitudinal way in the Edgewater and Uptown neighborhoods near the site of the incident. The CTA spokeswoman said it is too soon to know what, if any, impact there will be on the construction schedule from the accident. Walsh-Fluor began assembly of the gantry in late September.