I know the American Recovery and Reinvestment Act (aka "the stimulus") is no longer a hot topic in most parts. But the stimulus is alive and well in my hometown of Madison, Indiana. Next week our new (replacement) bridge connecting us to Milton, Kentucky (and access to I-71) will open to traffic.
Our old bridge was an astounding 85 years old and had been in deteriorating condition for decades (it was last refurbished in 1997). It was rated structurally deficient after scoring only 33 out of 100 on the sufficiency scale. This for a bridge with an estimated 3,500 cars a day traversing it. I hated driving across it. It was way too narrow for modern traffic. In March 2012 the weight limit was lowered to 3 tons, which posed a significant hassle for tractor-trailers trying to get from the factories in Madison to I-71 in Kentucky (and vice versa) with the only other river crossings being either 26 miles upstream or 46 miles downstream.
The bridge was in such disrepair that there really was no other option but to replace it. Indiana and Kentucky officials had been negotiating the financing of a replacement project for nearly two years when in February 2010 the project was awarded $20 million in stimulus funding.
Here is how the grant's impact is described on the project website:
Ironically, efforts to replace a bridge born of the Great Depression gained sudden momentum as a result of the Great Recession of 2009. With new federal stimulus funding available for infrastructure projects, INDOT and KYTC aggressively pursued and obtained a $20 million grant toward the estimated $131 million cost of replacing the bridge. SourceThe project was estimated to create or preserve 1,400 jobs. I've lived in Madison off and on over the last 3 years. It was nice to see all those welders, steelworkers, engineers, etc. out there earning paychecks (of which a good portion would be spent in local stores and restaurants like the Dairy Queen just off the bridge in Milton that is owned by my cousin). It was even better knowing that Democrats had made it possible by fighting for the stimulus.
One last word on the political aspects of this project. Indiana's governor is Mike Pence. Pence was a well-known critic of the stimulus while holding a leadership position in the House GOP. That, of course, has not stopped him from making a couple of photo-op appearances at the bridge with all those construction workers in the background. I haven't heard of any plans for him to make an appearance when the bridge reopens but if he does, I'll just have to go down there with a sign to remind everyone of his hypocrisy. (Secretary of Transportation Anthony Foxx is going on a bus tour next week to highlight the need for infrastructure investment. He will be stopping in Louisville, about an hour away, where they are gearing up to build two new bridges. I contacted his office to see if he could stop by and help us celebrate the completion of our project but they were not able to work it into his itinerary.)
That's the economic/political part of the story. The engineering part of the story is equally awesome. Follow below the fold for more details and a really cool time-lapse video.
Because a large number of Madison residents work in factories on the Kentucky side of the river, minimizing the amount of time the bridge was out of commission was a top priority. Walsh Construction Co. out of La Porte, IN came up with the really cool idea for a "superstructure replacement" using a construction method called "truss sliding" that would only require 10 days of downtime instead of a year (see below about unexpected delays).
With truss sliding, instead of tearing down the old bridge and then building a new one in its place, a new bridge superstructure was built and placed on temporary piers next to the old bridge. The old bridge could still be used while the new superstructure was being built. Then once the new superstructure was in place on the temporary piers, traffic could be diverted across the new bridge while the old bridge was demolished and the permanent piers refurbished.
And that brings us to this awesome time-lapse video. Once the piers had been refurbished, it was time for the slide. This meant literally sliding a 2,428 foot bridge superstructure, weighing 7,230 tons, 55 feet. It is the longest truss sliding project in North America - and quite possibly the world. It was a project that was being watched by engineers all around the world.
The Milton-Madison Bridge Project – a joint effort between the Indiana Department of Transportation and the Kentucky Transportation Cabinet – has received numerous awards. It was named one of the top 10 bridge projects in the country by Roads & Bridges magazine, received a 2012 Best of What’s New Award from Popular Science magazine and received several state and national engineering awards for innovation. SourceLike most projects of this size and complexity, things did not go perfectly. One worker was killed early in the project. Mother Nature did not play nicely, we had one of the coldest and snowiest winters I can remember. And then, as they were preparing to do the slide, a steel bearing dislodged, injuring a worker and causing part of the superstructure to drop nearly a foot. As a result the bridge was immediately closed to all traffic for the remainder of the project. The slide itself ended up taking two days due to high winds. The bridge will end up having been closed to traffic for about 45 days instead of the hoped-for 10 days, which thanks to American ingenuity is still a lot better than being closed for a full year.
This time-lapse video shows the slide from two angles. The first gives you an idea of the total size of the bridge. The second gives you a better feel for just how far the bridge had to be slid.