Back Channel: (Satellite)
"This facility stands at the head of the Ohio River navigation system and forms a 24-mile pool on the three rivers around the city of Pittsburgh." It was built between 1919-22 and replaced three wicket dams that were built between 1877-1915. It was rebuilt as a gated structure between 1935-38.
Judging by the scale on a satellite image, the main lock is 600' x 110' and the auxiliary lock is 200' x 5?'. During the summer months there are almost as many lockages for pleasure craft as there is for commercial traffic. So the smaller auxiliary lock makes sense.
On Jan 13, 2018, 27 barges broke free and allided with the dam and two USACE workboats causing $12.5m in damages. A record rainfall caused the river to rise 12' in a little over a day. And ice formations accumulated at the head of the barge fleet. Instead of the usual 600hp towboat used to attend the fleeting area, a 1,050 hp and a 1,800 hp towboat had been assigned to the area. But they were unable to adjust the mooring lines to accommodate the rising river and the steel-pile mooring cell gave way. The entire fleet started drifting downstream. Both towboats tried to stop the fleet, but the current was too strong. "The Pittsburgh area has a long history of barge breakaways caused by high water and ice buildups." The NTSB recommended more regulation and inspection of fleeting areas by the Coast Guard. But neither the Coast Guard or the USACE have the resources to inspect fleeting areas for structural integrity. [WaterwaysJournal-ntsb, paycount of 2/week] I could not find a link to the NTSB report itself. It sounds to me that what they really need is a mooring cell that holds a floating bollard.
|U.S. Coast Guard Photo via WaterwaysJournal-ntsb|
|USACE via WaterwaysJournal-news|
More than 60 barges broke loose on Jan 13, 2018. 37 of them were at another location. But 27 of them were upstream of this dam. All but two of those 27 barges were found by Jan 18. There was no significant damage to this facility and no environmental concerns from pollution.
|US Coast Gaurd via WaterwaysJournal-news|
Corps works to remove ice from Emsowrth Lock.
This is a photo of the original wicket dam and we see a wicket tender in action.
It looks like this dam uses sluice gates instead of roller or Tainter gates.
[They were going to use in-the-wet technologies to rehabilitate the dam. That was the technology that caused such a dramatic cost overrun for the Olmsted Dam. I wonder how it worked on this project.]
I've never seen a long apron like that on a USACE river dam. Since the work by Bergmann involved scour protection, I assume scouring was a known issue and that this apron was part of the original design to address that issue. But an extended scour protection solution was needed to avoid undermining the dam in case a gate breaks. [synthetex]
|Stephanie Strasburg/Tribune-Review via TribLive|
The Olmsted Dam in-the-wet technology was building modules on the shore and then floating them into place. This sounds like they were actually pouring concrete under the water.
They did build concrete armor units and drop them into place.
Look at the struts needed to hold the walls when there is no water pressure on the inside. They used 14 struts about 6' in diameter that were built with 1" steel.
|Army Corps of Engineers gives tour of Emsworth Locks and Dams in advance of major rehabilitation project|
"An auxiliary chamber at Emsworth will eventually be replaced by a chamber the size of the one being inspected as part of an estimated $2.1 billion Upper Ohio River Navigation Project at the Emsworth, Dashshields and Montgomery locks and dams....Lenna Hawkins, deputy district engineer for USACE Pittsburgh District, said they are getting close to about 30% of the design of the navigation project, which was authorized by the federal government in 2016."
[I wish I had more confidence in the USACE's judgement concerning construction projects.]
Another view of the sluice gates.
|post-gazette, Emily Matthews|
A primary lock chamber is being dewatered as part of the inspections and maintenance procedures of the Emsworth Locks and Dams' downstream lock draining closure system on Wed, Oct 14, 2020, in Emsworth.
U.S. Army Corps of Engineers Pittsburgh District posted six photos with the comment:
🗺️ “It’s tough to make decisions around #Engineering and the Pittsburgh District without data from surveyors,” said John. “I love the boots-on-the-ground work. I get opportunities to see things most people don’t know exist. I get to feel and breathe our projects.”💻 John has been with the district since August 2020, and with the #USACE since 2010. Bob has been with the district since 2014.🧭 “I love my job. It’s a great gig. You can get a mix of field time and office time, which is what I’ve been striving for my whole career, which I love. I’m not stuck in either world. It’s nice being able to have the option to do research but also go out and conduct surveys. It involves problem-solving, and it’s a great job,” Bob said.
[It looks like quite a few fill values need to be fixed.]
And the Mar 2022 satellite image shows a previous dewatering with all of those wall braces.
The smaller lock can handle only one barge at a time and it is creating a big "traffic jam."
|Clayton Adams posted|
It's become a river parking lot with single barge locking..both locks, 6 miles a part. We'll be tied off to the bridge before its all said and done..lol!!!
Heather Brown Hensch: Emsworth and Dashields locks below Pittsburgh. We're pulling cuts at Emsworth now.
2 of 11 photos posted by Fort Loudoun Lock with the comment: "A few recent pics from Emsworth Locks & Dam just a few short river miles downstream from Pittsburgh, PA. The very first L/D facility on the upper end of the Ohio River owned, operated, and maintained by the U.S. Army Corps of Engineers Pittsburgh District."
Cathy Selber: So much bigger than our dam! Very cool!
Fort Loudoun Lock: Cathy Selber You are correct that both lock chambers are much larger. However the dam is much smaller with a lower lift. Also, Emsworth has no hydropower plant whereas Fort Loudoun does have hydropower.
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