Friday, May 5, 2017

1961 US-53+I-535 Blatnik Bridge over St. Louis River at Duluth+Superior

(Bridge Hunter, Historic BridgesJohn A. Weeks III3D Satellite, Birds-Eye View)

Bridge Hunter, photo provided by Hank Zaletel
License: Creative Commons Attribution-NonCommercial-NoDerivs (CC BY-NC-ND)
[In the background is the swing span of the Interstate Bridge.]

"Major reconstruction of the Blatnik bridge occurred in 1992 and 1993. The bulk of the work was to widen the bridges to add room to the shoulders, and to install a center divider. There was also a three year project to paint the bridge from end to end." [John Weeks] This is the first truss bridge that I know of where the deck was widened. The outsides of the piers seem to be lighter than the rest of the piers at the same vertical line. Was concrete added to the sides to widen them?

Bridge Hunter specifies a total length of 1,140.1'. But they must be talking about just the truss structure with its 600' long center span. John includes a photo taken from US-53 on Miller Hill that shows the bridge also crosses Howards Bay. And the bridge needs long approaches to achieve its 120' clearance. [DuluthNewsTribune]
John Weeks

While Minnesota has one entry in the National Bridge Inventory for the Blatnik Bridge, Wisconsin maintains 5 entries as follows: 

NBI #B16000500050000, 2,241 Feet, Girder Span, Crosses WI-35.
NBI #B16000500020000, 697 Feet, Girder Span, Crosses Howards Pocket.
NBI #B16000500030000, 1,884 Feet, Girder Span, Crosses Soo Line Railroad.
NBI #B16000500010000, 1,140 Feet, Arch Span, Crosses Saint Louis Bay.
NBI #B16000500040000, 2,022 Feet, Girder Span, Crosses Garfield Ave. 

If you add up these spans, you get 10,225 feet. This is 2,245 feet longer than what Minnesota reports in their NBI entry. Minnesota apparently does not count the bridge sections that cross WI-35 on the Superior end of the bridge. It is also possible that Minnesota recognizes a different northern endpoint for the bridge. As evidence, a photo below shows that there is landfill between the Blatnik Bridge and the Garfield Avenue Bridge. If Wisconsin considers the Garfield Avenue interchange to be part of the Blatnik Bridge, that could account for the 2,245 foot discrepancy.

[John Weeks]

I learned of this bridge from a video of a boat, Federal Yukon, that went under it on its way "to CHS to load wheat." Since the video was taken from the north side, some of the scenes show the grain elevators on the south side of the river. Given that the boat has three cranes rather than an unloading conveyor, I would not have guessed it would haul wheat. I was able to find CHS on the map:

Satellite
DuluthShippingNews
Federal Kumano
Just a few hours after I wrote the above text, I came across an article about the Federal Yukon. It and a sister ship, Federal Kumano, are taking loads of Durum wheat that was grown in North Dakota to Algeria where it will be milled and used to make couscous. The boat is a "salty." That is, it can go through the Welland Canal.

Update:
Christopher Rengo posted
The John G. Munson departed Duluth for the first time this Season with a load of taconite from CN Dock 6. Was a beautiful morning for a little Classic Laker action!
[Eastish Elevation]
The video at top of the Federal Yukan arriving for a load of Duram wheat from CHS to take to Algeria was May 4. On May 9, its sister ship, Federal Kumano, was back already for another load of wheat.

Gus Schauer posted
American Integrity departs Duluth with coal for Marquette while Federal Yukon waits to load at CHS. May 11, 2017.
[Federal Yukon is probably waiting because Federal Kumano is being loaded by CHS.]
Jason Kahler posted
American Integrity backing into Midwest Energy in Superior today.

Photo by Ed Hollowell via Bridge Hunter, License: Creative Commons Attribution-NonCommercial-ShareAlike (CC BY-NC-SA)

Maussman Construction posted seven photos with the comment:
In 1960, Massman completed the substructure of the new interstate bridge that connects the cities of Duluth, Minnesota, and Superior, Wisconsin. In order to meet a tight schedule deadline, construction progressed through the majority of winters that “come early and stay late,” according to old company newsletters. Massman built 30 piers to support a structure that rises nearly 120 feet above the water in order to accommodate the large vessels that call upon the local ports.
Now called the John A. Blatnik Bridge, the structure carries I-535 across the Saint Louis Bay, a tributary of Lake Superior.
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Federal Kumano leaves Duluth on the evening of 5/11/2017, and Federal Yukon leaves Duluth about 24 hours later.

In 2008, an analysis of the design was done because the modifications made in the 1990s were never analyzed. They discovered that 16 gusset plates did not have an adequate safety margin. Minnesota had learned the hard way with the I-35W bridge in Minneapolis that a weak gusset plate can bring down the entire bridge. So the "16 gusset plates were strengthened by adding angle iron strengtheners or plate doublers." [John Weeks] Additional gusset plates were strengthened in 2012 and 2016. In fact, corroding gusset plates have become an ongoing maintenance issue that has helped cause MnDOT to schedule a replacement by 2028 for an estimated cost of $460m. [DuluthNewsTribune]

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