As we mentioned a few days ago, construction crews were pretty busy on our property over the past few weeks. Specifically, they were pulling a string of pipe about 500 feet long beneath the road just to the east of us. Our property was the staging area for this activity. And if it weren’t for some potentially frustrating line list violations, we kind of enjoyed watching the fascinating process and learning about it from the workers, a generally nice bunch of people. (For the record, we’ve spoken with more than 20 workers on our property. So far, we’ve met only 3 who are from Michigan. We don’t know whether that’s a representative sample, but it does cause one to be a little skeptical of all of Enbridge’s claims of creating lots of local jobs.)
Anyway, we took photos and video of the process and thought some of you might be interested. So here’s a slideshow. Click on the first image to start it:
And then they start pulling. It took a few hours to pull it all.
I wonder if the coating is substantial enough to withstand contact with rock and other objects within the boring. Think of the Titanic–much worse damage was done as the momentum of the ship dragged along the iceberg, causing the initial puncture to become an elongated tear.
Now, don’t get me wrong… should the pipe be punctured during the pull through the bore it would be easily detected by a subsequent pressure test or pig inserted into the pipeline. But, suppose the coating is only abraded enough to expose the underlying pipe to contact with the earth–wouldn’t this allow for corrosion to take place–all entombed in an underground bore where it can’t be detected until it causes pipeline integrity failure?
Is the coating designed to provide electrical resistance to allow a post-pull pipe to ground resistance test which could theoretically detect a coating abrasion? I’m hoping this is the case. And, if it is, I imagine there are “standards” in place that specify an acceptable threshold of current leakage which, if exceeded, would be cause to pull the pipe back out of the bore to remediate the issue.
Would a pipeline guru (Mr. Holmstrom?) be so kind as to enlighten us on this practice?
I just saw this. Yes, pulling pipe trough a bored hole does run the risk of coating damage. Finding coating damage in a bored situation after the fact? I’m not sure when that would show up, & the only way to fix it is to replace it.