Underwater footage of the Mackinac Pipeline suspended across the Straits. By NWF

Concerns mount over Mackinac Pipeline – original welder speaks out.

Posted on Posted in Fortify, Restore, Sustain, Unite

The Record Eagle, out of Traverse City, Mich., has always done a phenomenal job covering the issues that surround the Straits of Mackinac Pipeline owned by Enbridge Energy. The latest Letter to the Editor is yet another example on their excellent ability to connect with their readers.

Bruce Trudgen, from Acme, Mich., has raised some critical questions about the integrity of the pipeline, all of which center around his personal interactions helping to install this pipeline over 61 years ago:

Pressure-check pipelines

The safety of the two Mackinac Straits oil pipes is becoming an issue. I was a member of the team that welded up those two four-mile-long pipes and dragged them across the straits back in 1953. At that time we were told that the pipes would last for 50 years. Well, that was more than 61 years ago.

Why worry? Design specifications called for a minimum bend radius of no less than 1,700 feet and unsupported spans of no more than 75 feet. The bottom is hilly; to meet these specifications dredging was required. Fifteen-foot-wide trenches were cut through the tops of the hills, but deep-water dredging was not an exact science using technology of the 1950s.

What about the bending stress in the pipes, added to the stress from the oil pressure, roughly 400 psi? The roughly 1,500 welded joints shouldn’t be an issue. Each joint was X-rayed twice.

Has external corrosion reduced the strength of the pipes? Before being filled with oil, the pipes were filled with water and pressurized to 1,200 psi for 10 hours.

Perhaps they should be filled with water and pressure checked again today.

Bruce Trudgen


Mackinac Pipeline covered in debris. Photo by NWF
Mackinac Pipeline covered in debris. Photo by NWF

Bruce has uncovered information about this pipeline that Enbridge and regulators prefer to keep to themselves. Information on the installation, original regulations and the long disputed lifespan of the line.

All of Bruce’s points are critical for this discussion but what he might not realize, which makes all his questions that much more important, is that Enbridge recently increased pressure on this pipeline by 10% to pump even more oil into Canada. So it not only appears that Enbridge continues to ignoring the perceived lifespan of the pipeline (by over 11 years), but it also appears that regulators are allowing for these changes in operation without requiring critical tests.

A new “We the People” petition to the President.

Please consider signing this new petition to President Obama asking that his administration require a new Presidential permit for this pipeline. A Presidential permit requires Enbridge to disclose the integrity of this pipeline, it puts the pipeline through environmental reviews and opens up the opportunity for public comment.



One thought on “Concerns mount over Mackinac Pipeline – original welder speaks out.

  1. Enbridge wants to increase the pressure on these pipes, it’s true, and I believe that they already have. And the bigger issue is that they are putting tar sands oil through the pipes, something they refuse to acknowledge by calling it by another name. (and not dilbit, I think they say ‘light crude’.) But you state here that they’re pumping the oil into Canada, and unless you know something I don’t, they’re pumping it from Canada’s Alberta tar sands mines across MN and then into various pipelines across the Midwest. I suppose there’s a pipeline that does re-enter Canada at Sarnia, but the flow is still going from Alberta, and it’s toxic goop that should be left in the ground. This info from the welder is really interesting though, thanks for posting.

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