Roger,
Those look like supplemental hanger rods that were added to provide either additional strength or protection for the tension members of the truss, and they would continue through the length of the members. The repair appears typical throughout the truss. What you were seeing were the ends of the rods and the nuts. I did not see them in my pre-rehab photo gallery so I assume they were added in the recent rehab: https://historicbridges.org/bridges/browser/?bridgebrowser=m...
I was just in Winona, and crossed the Mississippi River in both directions (in a heavy rain). The new westbound bridge has a higher deck than the historic eastbound bridge, giving a great close view of the upper chord of the old bridge.
I noticed some odd spike shaped structures on top of each upper chord gusset plate. You can easily see them from the new street view I just posted. What are these? Did they exist on the bridge before its rehab? None of the HAER photos show these, but they did not focus on the upper chord.
Are these for lightning protection? Are they for electronic stress monitoring?
Runner-up, Best Example of a Restored Historic Bridge US/Canada - 2019 Authors Choice Awards, The Bridgehunter's Chronicles. https://bridgehunterschronicles.wordpress.com/2020/01/11/201...
The bridge was reopened with appropriate pomp and ceremony on July 1, 2019. Article: https://www.postbulletin.com/news/local/winona-bridge-is-bac...
This has got to be a big win-win for both historic bridge preservation and infrastructure upgrades, proving that the concept of reusing the historic bridge as half of a one-way couplet is valid and working, with some compromises like losing parts of the approach spans to keep it within budget.
I was just in Winona. The project is nearing completion - with a significant improvement.
The only part of the approach spans that has been replaced is the westernmost portion, which I believe was originally steel stringer. The deck truss portions of both approach spans appear to have been preserved and rehabilitated, along with the main through truss span. On the west, the two highest deck truss approach spans, and the entire deck truss east approach, have been kept and rehabilitated. Though the westernmost section is now a UCEB, at least the new bents have a similar form to the rest of the original bridge. This should be regarded overall as a win.
This bridge will reopen soon to eastbound one-way traffic. A 78 year old steel truss bridge, renewed for another 78 years. I bet it outlasts the new concrete box girder bridge parallel to it.
Apparently good news here. After some uncertainty over cost, MNDOT will rehab the main steel truss spans of the old bridge after all, but they'll completely replace the approach spans in what appears to be a compromise to keep the overall project within budget. They will be replaced one at a time to maintain contractor access for rehabbing the main steel truss spans at the same time. First Minnesota end, then Wisconsin. So it will indeed wind up as an old/new couplet of 1-way bridges.
I was just through Winona, and I drove across the new westbound bridge. It has opened to 2-way traffic until work on the old bridge is completed and it's reopened for eastbound traffic in 2019. Demolition work has begun on the west (Minnesota) approach spans.
http://www.postbulletin.com/news/local/fixing-the-winona-bri...
Will Minnesota DOT renege on bridge promise?
http://www.winonapost.com/Article/ArticleID/47884/Will-MnDOT...
Here we see a fine two-bridge solution under construction. The new concrete box-girder bridge will carry westbound traffic, while the historic truss bridge will carry eastbound traffic. Temporarily, the new bridge will carry both directions, while the old bridge is closed for a thorough rehabilitation. The slim profile of the new bridge will not interfere much with sight lines of the historic truss bridge, especially from the south and the Downtown Winona riverfront.
I only wish such an arrangement could be worked out for a couple of other historic bridges facing demolition, such as Savannah-Sabula. http://bridgehunter.com/il/carroll/8600001777/
It's good they're keeping the old bridge. In MN, it's somewhat rare to see an old bridge and a new bridge side by side. The last old/newer bridge combo I can recall was the I-94 bridge over the St. Croix river that lasted till the mid-90's when the old bridge was demolished.
MnDOT project page:
Sounds like they want a two bridge solution here, with a new girder bridge taking some of the load off this historic bridge. http://www.dot.state.mn.us/d6/projects/winonabridge/docs/ea....
Truss bridges by their nature are considered "fracture critical" due to the lack of redundancy in the tension members. During the recent rehab, these bars were added to provide some redundancy to those members.