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Large Steel Water Main Project Pushes Static Bursting Envelope
“We weren’t sure how the machine was going to pull,” Meadows related. “We really didn’t know because of this material – welded steel; there are no joints and the coating inside of the pipe created an issue. On the first couple of pulls, coal tar coating built up in front of the expander. We ended up having to excavate and clean the material out before we could continue pulling. So, we made some adjustments to the cutter wheels and used some pipe soap. We put the soap on the front of the expander head and it prevented the tar from sticking to itself and balling up in front of the expander.”
Ultimately, Global Underground crews completed runs of 466, 517, 496, 430 and 620 feet. The Colorado Springs Utilities in-house crews completed the excavation and backfill. Global Underground and CSU crews worked together on the tie ins. The two organizations worked simultaneously to keep the project moving forward and on schedule. Actual bursting time was eight to 10 hours for the first sections because of the issues with the coal tar coating. Bursting times dropped significantly to three hours per run after the crews made adjustments to compensate for the coal tar coating.
“We knew there would be a lot of challenges with this project and that it was the largest project ever done for this size material. The teamwork between Global Underground and Colorado Springs Utilities was tremendous. And the technical support from TT Technologies through this challenging burst was exceptional,” Meadows said.