These are notes that I am writing to help me learn our industrial history. They are my best understanding, but that does not mean they are a correct understanding.
Wednesday, July 14, 2021
1929,1997 and 2014 US-421 Milton-Madison Bridges over Ohio River
Milton, the smaller town, is first because the bridge was owned by Kentucky. But evidently Indiana took the lead on the replacement and now owns the bridge. But they didn't change the name back to putting the larger town first.
Historic Bridges explains that Kentucky DOT not only destroyed another cantilever bridge, the bridge contained some unique features including a 600' through Baltimore truss. Historic Bridges identifies the replacement as a continuous truss bridge, and it is fracture critical. Normally, fracture critical is one of the reasons given for getting rid of old trusses.
"The bridge now has a severe weight restriction of 3 tons. We tried to cross in an F-350 pickup and a cop came up and made us back up" [1929 Bridge Hunter comment by Gary posted Dec 12, 2012] It carried 10,000 vehicles per day. [mbakerintl]
"The new bridge opened at 9:30pm on June 3, 2013. Demolition of the previous bridge will begin soon." [Mark Gish comment on 1929 Bridge Hunter] This opening was on temporary piers and it had a weight restriction. The truss slide was done Apr 10, 2014, and the permanent opening was on Apr 17, 2014. [2014 Bridge Hunter] They got it off the temporary piers none too soon because a bearing popped just a month before the slide. [wdrb]
The new bridge is owned by INDOT instead of KDOT and the contract was for $111m.
Somebody quit paying for the domain name for the project, miltonmadisonbridge.com, so it has now been highjacked and all of the bridge information has been lost. I guess only a bridge nerd like me really cares.
WALSH fabricated the trusses on barges near the river bank, floated them into place, strand lifted them 90' above water onto temporary piers, blew up the old trusses to get them out of the way and slid the new trusses into place. "The Milton-Madison Bridge is 1/2-mile long, weighs more than 16,000 tons, and was moved 55 feet laterally into place - making for a record-breaking construction feat." [WALSH-project, video]
BurgessNiple I got this link from a comment by Fred Dieter on an IC post: About 10 years ago [2012] and 275 miles up river in Madison Indiana replaced a highway bridge in the same manor. It was one of only 2 crossings between Louisville and Cincinnati and neither state wanted to shut it down for replacement. "The 2,428-foot-long structure was slid along steel rails and plates into place, making it the longest bridge slide in North America."
Madison, IN, was founded in 1809 and was an important river town. The closest alternative crossing is over the Markland Dam, which is 26 miles upriver. These are the only two crossings between Louisville and Cincinnati. The bid process included a $25,000/day closure component capped at 365 days. WALSH was the only one of the five bidders that offered less than 365 days of closure. Good information about the construction process starts at 12:17. Sliding the truss onto the refubished piers reduced the closure to 10 days. I have not seen a figure for how long the truss demolition stopped river traffic. Lifting the 720' span, the longest on the Ohio, took less than 24 hours. A pair of rare falcons that used the bridge as a nesting site was able to raise chicks each year during the construction. They used lubricant on a Teflon pad on polished steel girders to get the coefficient-of-friction low for the slide. They got it so low that wind started sliding the bridge an unexpected quarter of an inch! Since they were supposed to maintain an alignment within 3mm over the 2400' length of the truss, they had to shut down during the wind event. Within a day, they added equipment to resist wind pushing and continued the slide. The falcons were setting on eggs while the bridge was moving. I skipped the "great cooperation" stuff at the end.
mbakerintl The existing piers had no rebar. The above video shows how they added rods along the perimeter down to the bedrock and wrapped and widened the piers with rebar concrete. Reusing the piers and alignment saved $50m. The trusses were prefabricated while the piers were being reinforced.
I've had trouble finding photos of the old bridge before their was construction activity. Notably, none of the 21 photos for the HAER have been digitized!
Two of the photos posted by Roger Green with the comment: "Here is the latest and greatest towboat to hit the water. Made a trip from New Albany to Madison, IN to get this one today. The new 'Bowling Green'... Took photos from both sides of the river. It was picking up something or someone and I was there about an hour and a half. At one point it went backward downriver. That was a strange sight."
a
b
This view shows how each span of the old bridge was different.
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