Western Railroad Discussion > Bismarck Bridge Demo Update no. 2

This week we can actually see some trusses coming down. Two workers on lifts are cutting connections with a crane cable holding the truss, Then the pieces are lowered onto a barge. The barge will eventually be moved to the west shore where the trusses will be loaded onto trucks.

Bismarck Bill

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It's like the old saying "How do you eat an elephant? One bite at a time."

Question for all you closet structural engineers:

Can the bridge stand on it's own without any of the truss work?  I would be inclined to say yes - of course it wouldn't support a train at that point, but I would have to believe the deck would be self-supporting.

Just a curiosity - I have no idea if they're going to remove all the truss work piece by piece.

rbenko Wrote:
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> Question for all you closet structural engineers:
>
> Can the bridge stand on it's own without any of
> the truss work?  I would be inclined to say yes -
> of course it wouldn't support a train at that
> point, but I would have to believe the deck would
> be self-supporting.

see my first update regarding the supports placed beneath the center span
https://www.trainorders.com/discussion/read.php?1,6223203

>
> Just a curiosity - I have no idea if they're going
> to remove all the truss work piece by piece.

yes-piece by piece-no explosives 

BB



Edited 1 time(s). Last edit at 10/02/26 13:26 by bmarti7.

If you look at some of the other photos that Bill has shared, you can see what appears to be cofferdams adjacent to the bridge piers and cribbing that extends up to the deck girders. I couldn't quite tell from his other pictures, but I would suspect that rails, ties, ballast, etc., have all been removed to reduce weight. (I'd need to reread his posts.)

Given the age of the bridge and the fact that it appears to have pin-connected bridge trusses, I'd suspect that they will use cranes and cribbing to support the structure while dismantling it, as often times these older bridges lacked redundancy and had single points of failure. (For instance, the pins.) Mechanical and electrical engineering background here, however, and not civil/structural.

Edit: I see Bill responded while I was typing my post.

rbenko Wrote:
-------------------------------------------------------
> Question for all you closet structural engineers:
>
> Can the bridge stand on it's own without any of
> the truss work?  I would be inclined to say yes -
> of course it wouldn't support a train at that
> point, but I would have to believe the deck would
> be self-supporting.
>
> Just a curiosity - I have no idea if they're going
> to remove all the truss work piece by piece.



Edited 1 time(s). Last edit at 10/02/26 13:29 by broken_link.

A few thoughts--and I love railroad bridges alot--I bought a book about them.

1.  That's all pre-atomic steel---rare stuff.
2.  I wonder if those concrete piers will last 144 years like the beautiful, hand-set cut stone blocks did?  I just love all those old masonry bridges.  It's sad to know those piers will be destroyed.
3.  What made this steel last so long--144 years is a long time in railroad service, and highway bridges would beg for such longevity.  Did this steel have more base iron?  Other elements?  Or was the entire structure just "overbuilt" to last?

Road bridges are exposed to deicer..ie salt. But some rail bridges are very corroded ...remember acid rain?
RB