Sunday, July 1, 2012

American Integrity Go-Around

Late last evening at 20:45, as the Duluth Aerial Lift Bridge was lifting for the 1000 foot American Integrity, the bridge lost power and the alert crew of the Integrity made a go-around and re-entered once the power was restored.
Had the crew and Bridge Operator not done a superb job in dealing with this emergency, a catastrophe would have occurred in front of a crowded Canal park.
This video will show the first attempted entry and the go-around.


AIS track (From boatnerds.com)

9 comments:

  1. Ken,

    Fascinating video! Do you know how close to the piers the Integrity was when she veered off her approach? This is of some interest, considering the closing of the Park Point fire station and the resulting necessity of getting downtown engines across the bridge during a Park Point emergency. How close can a 1000-footer be to the piers and still safely abort her approach, at "normal" speed (whatever that is), in order that the bridge can stay down?

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  2. I guess you would have to talk the some eye witnesses or the boat captain to verify the distance.

    Of course, since the video is time lapse, it does look like a faster and more dramatic turn than it probably was. None the less, when you are turning a boat the size of a football field, it would make for a rather interesting maneuver.

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  3. Sorry, Dennis. I thought I was posting on Ken's DSN blog, where he has a link to your video. I didn't realize I was on duluthharborcam.com Anyway--nice video, thanks.

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  4. Alan: Here is an AIS plot of the incident, posted to boatnerd.com:

    http://newsearch.boatnerd.com/download/file.php?id=3934&mode=view

    For reference, the Murphy dock (last dock before the Integrity turned into the river) is very close to 700 meters (~2300 feet) long.

    Given that, it looks like she started her turn about a half mile out, and executed it within a circle of radius about 3/4 of a mile.

    I have no idea if that's the "best" she can do, but it's what happened. I'd also imagine that there is a very well known point at which the bridge must be fully up or the boat will throw it hard to port.

    While I'm sure it made for a few intense minutes for those involved, the photos make it look a lot closer than it was.

    (And thanks for the video, Dennis)

    -Dan

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  5. Capt. Ed MontgomeryJuly 8, 2012 at 11:20 AM

    Hi Folks -- By and large, the 'point Of No Return' for a 1,000 footer or full size 'Salty' is generally a half nautical mile. That is why the bridge requests a second 'Confirmation' radio call at a mile and a half, announcing the vessel's intentions and requesting an opening. Situations occasionally arise like with the AMERICAN INTEGRITY, but rarely. This also one of the primary reasons the ships slow down to 'bare steerageway' when approaching the bridge. Much easier to slow or stop a ship doing 5 knots, instead of 15-20 knots service speed. By the way, thousand foot ships like the AMERICAN INTEGRITY are actually more like three football fields long!

    Capt. Ed M.

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  6. Very informative Capt. Ed. These are monstrous ships and take special skill to operate.
    Thank you very much!
    Dennis

    . p.s. I stand corrected on the football field comparison.

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  7. It won't play for me!

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  8. Nevermind ... Sorry

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