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.
Friday, August 28, 2015
1932,1942,2016+2016 Eggner Ferry Bridges (US-68, KY-80) over Kentucky Lake
The old (truss) bridge was rebuilt in 1943 to raise it 25' to make room for Kentucky Lake [B&T-1932] and a span was replaced in 2012 because the Rocket Ship/Delta Mariner allided with the replaced span.
Satellite, I saved an image to show how far behind the updates can be. This shows construction has just started, yet the bridge has been open for a while. In fact the old bridge is now gone. (Update: May, 2017 has the same image.)
20150826 4282c, north elevation from west shore
South elevation from the west shore
The bridge with steel through trusses was completed on March 25, 1932, before the Tennessee River was dammed downstream to create the Kentucky Lake. It was initially a toll bridge, but the toll was removed after just a few years. I wish Illinois would learn from Kentucky as to how to retire tolls. Many of their current parkways were originally tollroads. The bridge was closed on July 10, 1943, to raise the bridge 22 to 25 feet. A temporary ferry was run until it was reopened in February 1944 just in time for the impounding of Kentucky Lake. (Explore)
Preliminary work began in 2011 to replace it with a 4-lane bridge in 2017. But on January 26, 2012, just before 8:00pm, the Delta Mariner destroyed the span over the recreational channel. It should have passed under the span over the shipping channel, which was a couple of spans to the west. An archive page has several more photos of the wreck. I picked this one because it reminds me that a truss is designed to be supported at the two ends, not the center. It is also interesting how steel beams will bend rather easily if subjected to too much stress. No one was injured during the accident. But at least four drivers of cars on the bridge had a very scary night.
(Update: the ship has been renamed as R/S RocketShip. Those notes have more photos of the ship that allided with this bridge.)
A new 322' span was assembled and floated on a barge to install on the bridge's piers. Nathan Holt's banner picture has a nice view of the new truss. The bridge was reopened on May 25, 2012, for use by the Memorial Day weekend traffic. This is impressive considering the Kentucky Transportation Cabinet dithered about what to do before awarding the contract to Hall Contracting on March 8, 2012. The pier on the eastern side of the span was moved out of position. Sensors were mounted to monitor its tilt and movement. They did not provide a ferry service because too many cars, 3000/day, used the bridge. (Another source indicates the bridge carried 6,250/day.) So commuters, for example to Murray State University, had to drive an extra hour each day. (Wikipedia)
The Delta Mariner is a cargo ship that can travel in as little as 9' of water. It can travel on rivers and oceans to carry rockets and other parts from Boeing's factory in Decatur, AL to the Gulf of Mexico, and then to Cape Kennedy or Vanderburg. (Comment by Bill in BridgesTunnels.)
Originally, the bridge consisted of four 10-panel Parker through trusses with a 5-panel Pratt through truss on either side. Because of the 2012 allision, the eastern Parker truss was replaced by a Warren through truss without verticals. The longest span of the truss bridge is 368'.
As we approach the bridge, you can see the replacement bridge is being built just to the north of the old bridge except for the tied arch. The tied arch span is being built on a barge.
Obviously, about the last construction step of the bridge is to move the arch span and lift it in place. Note that the false work is still erected. The arch will provide a navigation channel that is 502'x60' (LakeBridges).
On Aug 27, Web Camera 3 shows they are getting ready to build the superstructure of the big pier that will hold the west end of the tied arch.
As someone else drove across the bridge, I was able to grab some additional shots including a profile view of the arch that shows the arches "lean in" to improve lateral stability.
Given how low the sun was when I took this and that it was from a moving car, it is rather remarkable that the auto-focus was able to grab this photo. I was trying to get a shot that would indicate the depth of the girders. Since the safety wires are probably about four feet high, the girders are probably about twelve feet high. The cylinder of welding gas on the left is another reference point. The next time I see one, I'll have to try to measure how high it is.
The photo also caught a side view of the double-boom crane. I zoomed in to the cab of the crane to highlight the big pile of counterweights that are stacked on the rear of the cab.
A picture of the end of the east-end girders also shows the new truss.
I zoomed into the first visible top-chord junction to note that, according to Historic Bridges, truss bridges are built with nuts-and-bolts instead of hot rivets since the 1970s.
I zoomed in on another arch bridge picture after I noticed the falsework includes a beam under the arch and each of the cross members. Also note that safety netting has been installed under all of the beams.
I took this picture to capture the new and old truss work. But I also like the play of the crane booms and sunset clouds.
I caught a view of the double-boom crane that shows it is a tracked crane and the view includes the top of the counterweight pile.
After crossing the bridge and coming back, we went to an amphitheater south of the bridge where we had a clear (no trees!) view of the bridge.
When I took some overview pictures including the one near the top of this posting, a towboat was approaching a barge next to a pier near the middle of the river. I then took a sequence of telephoto pictures, which I'm not including because they don't had much new info. Then I noticed that the towboat was backing up with the barge attached. I got a clear shot of the towboat (below). But the neat "action shot" of it generating a lot of exhaust was not taken because it happened with the boat was behind a pier.
We then went to the end of the Cherokee Lane to get the north elevation picture at the top of the posting. The telephoto pictures are not very useful because I did not have enough sunlight for a decent shutter speed.
But the barge that was parked in the Billie Branch bay was interesting. At one end it had a control house and a conveyor belt.
I assume the angled white area at the bottom of the barge is the water line. They must carry material in just the end away from the control house because it appears that only that end goes lower in the water.
Diane Thiede Photo
Update: my sister sent me this photo of them raising the arch section into place. They stayed just 10 minutes. She said it was like watching paint dry. This would have been at the end of November, 2015.
Zooming In
Google May, 2016 Street View from Bridge Hunter
I saved this view because the old truss bridge is gone now.
Note that in many of the scenes you can clearly see the new truss that replaced the one wrecked by the 2012 allision. So is the steel going to be fished out of the lake or are they going to call it an artificial reef?
As we approach the bridge, you can see the replacement bridge is being built just to the north of the old bridge except for the tied arch. The tied arch span is being built on a barge.
Given how low the sun was when I took this and that it was from a moving car, it is rather remarkable that the auto-focus was able to grab this photo. I was trying to get a shot that would indicate the depth of the girders. Since the safety wires are probably about four feet high, the girders are probably about twelve feet high. The cylinder of welding gas on the left is another reference point. The next time I see one, I'll have to try to measure how high it is.
The photo also caught a side view of the double-boom crane. I zoomed in to the cab of the crane to highlight the big pile of counterweights that are stacked on the rear of the cab.
I zoomed in on another arch bridge picture after I noticed the falsework includes a beam under the arch and each of the cross members. Also note that safety netting has been installed under all of the beams.
But the barge that was parked in the Billie Branch bay was interesting. At one end it had a control house and a conveyor belt.
I assume the angled white area at the bottom of the barge is the water line. They must carry material in just the end away from the control house because it appears that only that end goes lower in the water.
I zoomed in on another arch bridge picture after I noticed the falsework includes a beam under the arch and each of the cross members. Also note that safety netting has been installed under all of the beams.
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