Thursday, 16 June 2016

MUSKRAT: HYDRO ENGINEER NOTES QUALITY CONTROL PROBLEMS

Guest Post by James L. Gordon, P.Eng. (Retired)

There have been two recent incidents at Muskrat which indicate that there is an inadequate quality control process at the construction site. 

The first was the announcement by Andritz, the spillway gate contractor, that they were suing NALCOR and Astaldi. The contractor cited changes in the schedule by NALCOR and errors by Astaldi in their work on the spillway concrete, as stated on the CBC news on May 25. The second, and far more serious incident, was the collapse of a concrete form in the powerhouse on May 30.

To comment on the Andritz situation first: Andritz base their claim on two factors, the delay in the schedule, and defective work by Astaldi. Their claim states “However, by the first half of 2014 it was obvious to Muskrat and Andritz that the civil works performed by Astaldi were delayed,". The construction delays are well known, but their impact on Andritz required “(an) aggressive and in Andritz's view, likely unattainable on Muskrat's stated budget."

Work on the spillway concrete was completed in November last year. This work included the placement of the gate primary spillway gate anchors within the concrete, to protrude through the formwork. The primary anchors are then used for installation of the secondary anchors required to align the spillway gate guides to within a few thou (a thou is equal to 0.0254 millimetre) by Andritz. The late completion of the concrete work required changes in the gate installation schedule, forcing Andritz to work during cold winter weather instead of in the summer, resulting in extra cost for heating the work site.

The other allegation is contained in this statement: “it determined that Astaldi's civil works remained incomplete and, in certain cases, defective, contributing to further disruption and delay." The “defective” work is most likely due to misalignment of the primary anchors, requiring corrective measures by Andritz. This indicates a lack of quality control. The defective anchors should have been corrected before Andritz arrived on site.

The lawsuit also indicates a lack of understanding by NALCOR management on how to work with contractors. NALCOR issued a “Notice of Default” and threatened to call in a $20.5M letter of credit Andritz had provided when awarded the contract. This just poured gasoline on the fire (dispute) instead of trying to work with Andritz to resolve the issues. All contractor claims, and there will be many, should be resolved on site within a week of the claim being submitted, otherwise they eventually escalate into an expensive lawsuit.

The other far more serious incident was the collapse of a concrete form during a concrete pour in the lower part of the powerhouse. Again, as reported by the CBC on May 30, “Concrete was being poured to construct the lower draft tube, essentially a large pipe that will return water to the Churchill River”.

Concrete forms do not collapse. During my 64 year career in the hydro industry, I have never encountered such an incident. Their collapse is so serious, that formwork design is rigorously verified, since a collapse will endanger worker safety, and if a worker is drowned in the heavy wet concrete, retrieval is impossible. NALCOR was very fortunate that no lives were lost, and only seven workers were injured.

The draft tube is located below the hydraulic turbine and returns the water to the river through a right angled bend. The bend is an extremely complicated shape, changing from vertical and circular at the beginning below the turbine, to almost rectangular around the bend and almost horizontal to the exit at the river.

Author inside large draft tube bend
The photograph (above) places the author inside a large draft tube bend. Streaks are from water leaking out of the concrete form during repairs at the top of the draft tube.

The formwork for the bend used to be made out of wood, with a shipwright in charge of the carpenters – a time-consuming task. Current practice calls for the form to be fabricated off-site in steel, designed for permanent placement within the concrete, one form per unit. Alternatively, the form can be designed to be dis-assembled from the interior and re-used on the other turbines.

NALCOR states that “the piece of failed of equipment was manufactured in the United States, but assembled on site by the project's main contractor, Astaldi”. The failure could then be due to inadequate design, incorrect installation by Astaldi, or even a fault in the manufacture.

The question is: who was responsible for the work? It could be either Astaldi or the manufacturer. Nevertheless, the work has to be verified, and since the component is so critical to the progress and safety of the work, the design, manufacture and installation should have been verified by NALCOR engineers, again indicating a lack of quality control.
These incidents clearly indicate that the quality control measures currently used by NALCOR, need to be revised to place more control within the jurisdiction of the NALCOR design team.

Finally, it was announced that “Pike (Astaldi) said work in the draft tube area of the powerhouse has been suspended while an investigation is underway by the company, Nalcor Energy and Occupational Health and Safety officials”. (CTV News May 30.) 

What is not mentioned is that the wet concrete from the formwork collapse should have been immediately removed before it had time to set. Now, the failure investigation will be compromised by the inability to verify that the formwork was manufactured correctly, since part of the formwork will be embedded in solid concrete, and can only be inspected after it has been carefully chipped out of the concrete – an almost impossible task. This indicates a complete lack of foresight by those involved.

Jim Gordon, P.Eng. (Retired)
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Editor's Note:

Jim Gordon has authored or co-authored 90 papers and 44 articles on a large variety of subjects ranging from submergence at intakes to powerhouse concrete volume, cavitation in turbines, generator inertia and costing of hydropower projects. He has worked on 113 hydro projects, six of which received awards "for excellence in design" by the Association of Consulting Engineers of Canada. He was also awarded the Rickey Gold Medal (1989) by the American Society of Civil Engineers "for outstanding contributions to the advancement of hydroelectric engineering...". As an independent consultant, his work assignments have ranged from investigating turbine foundation micro-movements to acting on review boards for major Canadian utilities. He has also developed software for RETScreen and HydroHelp.

21 comments:

  1. Thanks for the explanation Jim. The tube collapse is much more serious than I thought. The cleanup and (re)design of the form looks like it will be difficult and take a lot of time. Why the wet cement was not removed baffles the mind.

    It appears Nalcor is just as arrogant with the contractors as they are with the NL rate/taxpayer. It is a symptom of Nalcor being beyond the scrutiny of the "sole shareholder" or any competent regulation. This must change. Adding a few chairs to the corporate deck of the HMC Nalcor will not avoid the iceberg ahead. The now discredited managers have been left in control of the dam construction. What exactly has changed?

    This latest scrap between Astaldi and Nalcor lingers. Now Andritz is suing both. What a mess!

    In the mean time another summer season slips away and construction delays mount. Meanwhile Stan Marshall's promise of full consideration of the stop or go option is his first broken promise. Marshall is showing the same contempt for the "sole shareholder" that the Martin/Bennett team have displayed to date.

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    1. I would suggest to you Bruno that Wet cement versus concrete to remove would have been much less expensive. Now whoever gets the contract to remove the concrete will have a much more lucrative contract. Everything concerning Muskrat Falls contracts is BIG, the overseers of this project don't give a hoot what this is going to cost the taxpayers and hydro consumers of Newfoundland and Labrador. They only care about the Millions of dollars they are going to personally pocket.

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  2. Stop being an idiot Bruno. Stan Marshall has only been on board less than a month. Before you slag him off, he at least deserves an opportunity to wrap his head around the whole set of Nalcor issues.

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  3. Last fall I had aconversation with a carpenter who worked at Muskrat saying that he had never been on a job so poorly managed as this, and he has worked on many large projects. He advised of special forms that came from Germany that no one knew how to put them together. Not likely this form work, but having heard that last year, I was not surprised by this situation.
    Winston Adams

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  4. Where is Stan Marshall's promised "full review"?

    So far, instead of a comprehensive, cohesive review, we have:

    --- a separate (unsubstantiated) pronouncement that cancellation of the project is "very unlikely";

    --- an essential dismissal of a peer reviewed Harvard study confirming the methyl mercury poisoning of Labradorians' food supply;

    --- a soon to be updated cost and completion schedule, even though it is unknown what impact the recent concrete form failure and dispute with Astaldi will have on the project;

    --- still no court decision with respect to whether Nalcor controls the river waterflow;

    --- as Mr. Gordon confirms, potentially inadequate Quality Control by Nalcor.

    What does that then say about the quality and the design/construction of the North Spur/Kettle Lakes mitigative measures?

    All of these (and many others --- lowest cost, other options, etc.) should be "fully reviewed" IN A COMPREHENSIVE, COHESIVE MANNER, and NOT trotted out in small, one-by-one, politically palatable, digestible chunks. Maurice Adams, Paradise

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    1. So Gilbert Bennett, second in command to the disgraced CEO Ed Martin gets a promotion instead of a boot out the door. Go figure.

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  5. I sincerely hope that the assiation representing professional engineers in this province is rigorously investingated this "near tragedy". It is well within thier mandate.

    On the subject of Mr. Marshall's public comments so far, should we be surprised? Anyone pondering the future of this project as well as the future of this province would do well to Google "kleptocracy". It is becoming obvious that the filching of the public purse will not stop until every credit facility this province has is exausted and the bond markets declare "no more". Insolvency, default, and territorial status is looming: no one knows this better than Ed Martin, P.Eng., hence, the cashing in of the pension.

    If this brief harangue sounds bleak and desperate it is not by accident. Newfoundland emerged from commission of government and entered Canada with every intent of being an equal among the confederation. Instead, We face the grim prospect that within the foreseeable future that dream will have died and we will return to being a "ward of the state". Thanks a lot.

    John D Pippy, B. Eng. (civil), MBA

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    1. I am having a chuckle at my spelling mistake in the first sentence. I, of course, meant "association" and apologize for any offense taken. Des is welcome to edit out my careless and calous blunder.

      Jp

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    2. Are you certain that Mr. Martin is a P.Eng?

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    3. No, I am not certain at all. It was an assumption on my part but I will check and get back.

      Jp

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    4. There is no Ed Martin on the registry of the association so i can only assume he is not a P.Eng. my sincere apologies to Mr. martin and members of the association.

      Jp

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    5. Ed Martin is an accountant, as I recall. So no engineering skills.

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  6. MethylMercury issues,collapsing concrete,escalating project cost,higher consumer/buisness electricity costs.What else can or will go wrong? Maybe Mr.Sullivan's fellow blogger Ed Hollet is onto something when he writes making the best of a bad deal,top right hand corner of this page.

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    1. With a shrinking volume of electricity sales on the island going forward, I feel it is difficult to even justify the transmission line tie in. Unless to satisfy also the legal commitments to Nova Scotia. Nfld Power is now forecasting well below that used to justify MF, at least for 2016 and 2017, and no reason to think it will turn upwards as needed. All goes back to the first question DO WE NEED THE POWER.... certainly not that much power and not at that cost. Misled from day one. We would be getting a 9 percent reduction in electricity rates July 1, from the Holyrood fuel component.... not exactly where they were forecasting for this time frame. Forecasting...not a hard science!

      Winston Adams

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  7. The latest CRA shows support for Muskrat down 11 points since last year (now 54%). It should be noted that the poll was taken when support for the project may have received a bump due to Ed Martin's departure and Stan Marshall's appointment. The poll would also not have included the impact of the Harvard methyl mercury study, and the 4.9% margin of error means that potentially less than half of those polled now support the project. Maurice Adams

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    1. Goes to show ... the public is still not well informed.... so does 54 percent think that electricity rates of 20 cents per kwh is acceptable to pay for this? There will be no outrage from them once there is a price shock, or is it just gas prices and pickles that upsets them!
      WA

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    2. "Why didn't ANYONE tell us about the cost on our power bills because of Muskrat Falls" I can hear it now from the public after the first rate shock post-MF power bill..

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  8. Germany had so much renewable energy on Sunday May 8th that it had to pay people to use electricity.
    http://qz.com/680661/germany-had-so-much-renewable-energy-on-sunday-that-it-had-to-pay-people-to-use-electricity/

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  9. NTV news this evening confirmed that Astaldi will be bringing in special drills to drill out the hardened concrete. Maurice Adams

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  10. And now a fiasco with the Chinese-made transmission lines??!?!?!?

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  11. This is a sad predicament we lost our way Churchill Falls was finished on budget and ahead of schedule!!! Hopefully this great endeavor can proceed and not at the cost of life and safety of our men and women

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