1950 25.5mw Narrows Dam and Lake Greeson on Little Missouri river near Murfreesboro, AR

(Satellite)

The dam was completed in 1950, and it was built to mitigate flooding in Murfreesboro and to provide hydropower. The 941' (287m) long dam rises 183.5' (56m) above the river. "The powerhouse of the dam is located adjacent to the east abutment and has three 8,500-kilowatt-hour (KWh) [should be kw instead of kwh] generating machines, the third one having been installed in 1969. The average power annually generated is 28,000,000 KWh. Its maximum discharge is 42,300 cubic feet per second." The spillway has been used in 1968 and 2009. "Each time, the areas below the dam along the river were flooded, but not nearly as badly as in the days before the dam was built." [encyclopediaofarkansas]

Street View, Jan 2024

Those are some big outlet pipes.

Street View, Oct 2013

 

encyclopediaofarkansas_media

USACE, this is their idea of hi-res photo
All three generating units operating at full capacity release 2.2kcfs.

"The U.S. Army Corps of Engineers, during recent maintenance activities on the trash racks at Narrows Dam at Lake Greeson, Arkansas, identified a need for repairs to the metal structure supporting the trash racks. Trash racks are metal grates preventing large debris from entering and damaging the turbans used for creating hydropower, and do not affect the integrity or effectiveness of Narrows Dam." [Dec 22, 2023, USACE News Release]

ArkansasOnline, May 2009 file photo. (Arkansas Democrat-Gazette file photo)
To put the 28 million kWh production of this dam in perspective, the "Arkansas Nuclear One near Russellville produced 13.55 billion kWh in 2021."

Over one year after they stopped generating power because of a defective trash rack support, they are going to repair the dam. I presume it is the trash rack support that they are fixing.

USACE, Vicksburg District posted

🚧 Notice: Narrows Dam Area Closure 🚧

Beginning February 16, 2025, the Narrows Dam Day Use Area pavilion and swim beaches will be closed to the public. Access to this area will be restricted until repairs are completed.

⚠️ The 'No Boats' area in front of the dam will be extended to include the entire work area for both worker and visitor safety. 🚫 🚤

Additionally, a 'No Ski' area will be established to help reduce wave action within the area for worker safety.

We appreciate your understanding and cooperation during this time as we work to maintain this important site.

Stay safe and stay tuned for updates!

USACE,Vicksburg District posted 0:25 video
May is Dam Safety Awareness Month! Be sure to check out Narrows Dam at Lake Greeson in Murfreesboro, Arkansas – this dam has helped reduce flood risk to portions of the Ouachita River Basin and provided recreational opportunities since 1950. Lake Greeson is the only lake with an all-concrete dam within the Vicksburg District. Want to know more about this or other dams near you? Learn more by visiting the National Inventory of Dams (https://nid.sec.usace.army.mil/#/).

@ 0:11, cropped

This is what a more normal flow looks like.

Street View, Oct 2013

1966 I-80 Tunnel Feb 14, 2025, Crash and Fire near Green River, WY

(Satellite)

The crash was in the westbound tunnel.

6:09 video @ 0:30
"At least two people were killed and several more were injured."

@ 2:39

A follow-up video. The plan was to have 2-way traffic flowing in the remaining tunnel on Feb 19. Also, no word yet from WDOT as to the cause of the crash and of the fire.

6:26 video @ 4:21

1833 Allegheny Portage Railroad Staple Bend Tunnel

(Satellite)

Allegheny Portage Railroad National Historic Site posted

Anniversary Hike for the opening of the Allegheny Portage Railroad!

Join a park ranger for a hike to the Staple Bend Tunnel on Sunday, March 16 at 2:00 p.m. for the 191st anniversary of the railroad's opening. The hike is approximately 4.5 miles in length. 

Please call the Visitor Center at 814-886-6150 to sign up and for meeting location details. Plan for uncertain weather due to the time of year. Please prepare for snow, ice, mud, rocks, rain, and roots. The hike takes place rain or shine. 

The Allegheny Portage Railroad opened on March 18, 1834. Participants will learn about Staple Bend Tunnel construction and how the Allegheny Portage Railroad moved people and goods over the Allegheny Mountains. (es)

Image: Staple Bend Tunnel.

Scott Reynolds: Is this a section of rail that served the area prior to the horseshoe?

Allegheny Portage Railroad National Historic Site: Scott Reynolds Hi Scott! Yes, the Allegheny Portage Railroad was 36 miles over the Allegheny Mountains from Hollidaysburg to Johnstown. The Portage used 10 inclined planes and 11 levels. The Staple Bend Tunnel was only about 4 miles from Johnstown at the top of Inclined Plane No. 1. Pictured is the western end of the tunnel. From the parking lot to the eastern end, walkers and bikers are walking along what was known as the Long Level! (es)

Metrotrails posted two photos with the comment:

Then and Now Series: Historic 1880s view of the Staple Bend Tunnel on the Allegheny Portage Railroad from John Fritz Collection, National Canal Museum of Easton PA, compared to the tunnel on our January 2019 hike.

Clearly, some reconstruction has taken place, which included a widening of the Roman Revival facade. Based on topography, the historic photo is likely the west portal, although it is believed the east portal once had a similar facade.

Completed in 1834, it is believed to be the oldest railroad tunnel in America. Part of the Main Line of Public Works, a series of canals and rails connecting Philadelphia and Pittsburg, the route shortened travel time from twenty some odd days to only four.

Today, this section of the historic Portage can be followed between Franklin, just east of Johnstown, and Mineral Point PA.

Michelle Craig: No widening. Count the stone (bricks). Looks like they just added fill dirt and raised the ground through the tunnel. I count 27 stones from the keystone in the old pic and only 25 in the new.

Pete Bailis: Looks like the original photo has some major vignetting making it seem narrower also the people are most likely close to the camera and not standing in the portal. It looks like the original facade that has just been cleaned nicely. All the stones seem to match in both photos like Michelle Craig mentions below. Tunnels do silt up after time and this one has had 185 years to do just that. GREAT photo comparison.

Metrotrails: It was filled a bit at the base for draining.

Metrotrails shared

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Allegheny Portage Railroad National Historic Site posted

A big thank you to the wonderful group that joined us for our Heritage Hike to the Staple Bend Tunnel to celebrate the 191st anniversary of the Allegheny Portage Railroad a few days ago! (es)

Image: A group of hikers in front of the Staple Bend Tunnel.

The Pennsy crossed the peninsula at a lower elevation and was able to use a cut instead of a tunnel.

1907/07 Johnstown Quad @ 62,500

Not only did the Pennsy cut through the peninsula, but so did the river. And it looks like a mining operation has removed a lot of land.

Satellite

Since this cut is upstream of Johnstown, PA, was the it formed by the Johnstown Flood or by a mining operation? Since the flood was in 1889, this river cut is man made.

The tunnel was the first railroad tunnel the US. It was the third tunnel, but the first two were canal tunnels. It is 901' (275m).

Facebook Reel

1926,1938+1971 10mw+50mw Mormon Flat Dam on Salt River and Canyon Lake

(Satellite)

Bureau of Reclamation posted
Located east of Phoenix, Mormon Flat Dam impounds Canyon Lake, a favorite recreation area for boating and fishing. It was the first dam constructed under Salt River Project’s hydroelectric expansion program in the 1920s. Mormon Flat Dam was named after nearby Mormon Flat, a place where pioneers from Utah stopped to camp on their way to the valley

clui
"The Mormon Flat Dam was completed in 1926, the first of three dams along the lower Salt River, between Theodore Roosevelt Lake and Phoenix, two of which have powerhouses with reversible turbines, enabling pumped storage functions. The Mormon Flat hydroelectric plant has a conventional turbine, producing 10 megawatts, and a reversible unit that was installed in 1971, adding another 50 megawatts to the plant’s generating capacity, and enabling the plant to pump water backwards through the Salt River Project system, a network of several hydropower plants and reservoirs that provide electricity to the Phoenix region."

 

usbr
"Mormon Flat Dam, a 224-foot high concrete thin-arch structure,...creates a 57,852 acre-foot reservoir.
"In 1938, Reclamation completed construction of a new gate structure and a concrete-lined spillway discharge channel, and installed two 50-foot-square stoney regulating gates, hoists, motors, two 25-kilovolt-ampere gasoline-engine driven generators, and a new road to the powerhouse."

 

Jake Taraj, Dec 2022

 

LoC

LoC

Trail Bridges at Ionia, MI

Grand Trunk: (Satellite)

Gateway Overpass: (Bridge Hunter; Satellite)

1881 Pere Marquette: (Bridge Hunter)

1914 Pere Marquette: (Bridge Hunter; Satellite)

While studying the GTW depot in Ionia, I discovered that they have some non-trivial trail bridges. The former GTW right-of-way is now the Fred Meijer Grand River Valley Trail, and the former Pere Marquette RoW is now the Ionia River Trail. Both of the railroad bridges go over the Grand River. Some significant money was put into the trail system around Ionia.

GTW Bridge:

Edward Gross, Dec 2015

2015 Gateway Overpass:

Street View, Aug 2023

1881 PM:

BridgeHunter_1881
[It is not obvious in this photo, but it is obvious in the photo below that they added new piers between the existing piers because the steel girder spans are shorter than the truss spans. I'm still trying to figure out how they added the steel girders under the trusses, but in this photo they are removing the trusses since the girders are now carrying the tracks. As expected given the 1881 date, the trusses appear to be pin connected.]

1914 PM:

Pamala Thurber, Apr 2021

The Gateway Overpass is a tied arch. It was probably built offsite and then moved to the abutments to minimize the closure of the state highway. Not only did they build a new bridge, they built the embankments needed to create an overpass. Here is a view back when the trail crossed at grade level.

Street View, Oct 2013

The GTW bridge is on the west side and the PM bridge is on the east side.

Dennis DeBruler

Replacing the Francis Scott Key Bridge over Patapsco River at Baltimore, MD

I'm seeing enough information about replacing the Francis Scott Key Bridge that was destroyed on Mar 26, 2024 that it is time to starts some notes about the replacement because I anticipate a lot of design and construction information.

Casey Jones Nov 23, 2024, video of 22:04: Why the Replacement Key Bridge Needs to be Antifragile! [The video includes a book review. He also talks about the new design for this bridge at 12:30]

Maryland via TruckDriverNews via Facebook
[I just skimmed the text because I was after a rendition of the design. For all of the talk about the economic impact of the destroyed bridge, one would think someone would have funded some better dolphins for the old bridge. I could not find an estimated completion date.]
Kiewit Corporation posted

In partnership with the Maryland Transportation Authority (MDTA), we've unveiled the design for the Francis Scott Key Bridge rebuild. 

This new bridge will be Maryland’s first cable-stayed bridge, set to modernize Baltimore's skyline. It will have a main span of 1,665 feet and an overall length of two miles. 

For more information on the new design: https://bit.ly/4hKoV63

Casey Jones found a better rendition of the preliminary design. The silver lining of destroying the old bridge is that the deck of the new bridge will be higher. This is important because the size of container ships keep growing. He also found an estimated completion date of 2028.

6:34 video @ 0:45

In fact, the height is increasing from 185' to 230'.

@ 1:08

The Practical Engineer (Grady Hillhouse) just posted a couple of days agon (Feb 14, 2025) an explanation as to why most new long-span bridges are cable-stayed bridges. It occurred to me that it is appropriate to include here.

20:18 video @ 12:06

Casey's Jul 14, 2025, update:

13:46 video

Key Bridge Rebuild posted three photos with the comment:

Baltimore here we come!

Six test piles have been loaded on a barge and are now en route. The large steel cylinder piles will be driven into the Patapsco riverbed for the test pile program.  Some of these piles will be evaluated for the potential to be incorporated into the permanent foundations for the new bridge.

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Sep 30, 2025:

WBAL-TV 11 Baltimore posted
Video from SkyTeam 11 shows the first pylon ready for installation at the site of the Key Bridge; https://www.wbaltv.com/article/key-bridge-site-video-pylon-ready-installation/68139613

Comments on above post

Oct 14, 2025:

Mike Sorrelle posted
View from plane flying over Baltimore, showing the Key bridge with the missing middle section.

John Mapguy: what is that pinkish area on the right hand shore [or left bank?]

Mike Sorrelle: John Mapguy Dredge material containment

[They just recently started the Test Pile program.]

Key Bridge Rebuild posted four photos with the comment: "Bridging the Facts: Learn more about the flotilla."

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Key Bridge Rebuild posted

Key Bridge REIMAGINED: Maryland’s first cable-stayed bridge will deliver:  

Massive pier protection: Main pylon fenders larger than a football field and a vessel-protection system supported by 276 concrete-filled steel piles, each 8-foot wide.  

A new, modern Key Bridge is on the way! 

Key Bridge Rebuild posted four photos with the comment:

We’ve completed driving all test piles at Pier 24 and Pier 25! These are the main span piers, critical for supporting the central portion of the bridge. Next, the static load testing will begin.  

The team placed the load frame on the piles and are preparing to simulate the forces the bridge will experience once constructed. This test helps verify that the foundation design can handle real-world loading conditions and deliver long-term safety and performance.  

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William Ater Jr. commented on a post:

Cost estimates of the replacement span have gone up.

Originally thought to cost around $1.9B USD, it’s now estimated to be somewhere between $4.3 & $5.2B USD.

Also, the new bridge’s original goal of being completed by 2028 has been pushed back to late 2030.

12:45 video @ 3:13
Kiewit will be out of Key Bridge Replacement Project