1940 Fort Peck Dam Danger

Dam: (Satellite)

Spillway: (Satellite)

Power Plant: (Satellite)

 

The earthen dam suffered two landslides during construction. The first one happened early with a designed slope of 1:1. The slope was changed to 1:3, and construction continued. The second happened near completion because the weak shale bedrock failed. They convened the design committee, and they concluded that the dam should be fixed and completed. These screenshots are of the second landslide.

28:04 video @ 23:34
Fort Peck Dam Construction

@ 23:50

The power plant is on the left. I don't know why the buildings are so tall. If they are surge tanks, they are awful big.

Street View, Jun 2023

The consulted expert blames the big landslide during construction on the use of hydraulic fill rather than on the shale that deteriorated when exposed to weather. Thus, he says the dam could fail again. If Fort Peck Dam breaks, the deluge of water could break the big downstream dams. This would flood St. Louis with a lot more water than the 1993 flood.

4:44 video @ 2:12
When the dam breaks: 'Flawed' dam may threaten St. Louis area
"BECAUSE OF DAMAGE FROM EARTHQUAKES IN THE 1970, THE STATE OF CALIFORNIA REQUIRED ALL HYDRAULIC FILLED DAMS BE TORN DOWN OR REBUILT. NO OTHER LARGE DAMS HAVE BEEN BUILT THAT WAY SINCE."

Mark Sepolio Photography posted two photos with the comment: "This the Spillway... Although The Fort Peck Dam in Montana: It is the largest hydraulically filled dam in the United States and creates Fort Peck Lake, the fifth largest artificial lake in the U.S. The dam is over 250 feet [76m] in height and 21,026 feet [6.4km, 4 miles] in length. What’s more, the dam was constructed not only for flood control but also to create jobs during the Great Depression. At its peak in 1936, it provided 10,456 jobs. Isn’t that fascinating?"

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Gus Copenhaver commented on the above post
Now you're in my familys' part of Mt.

Jo, Nov 2022

Jo, Nov 2022

Shreya07 posted

Fort Peck Dam

Fort Peck Dam is one of the largest earth-fill dams in the world, located in northeastern Montana on the Missouri River. Built during the Great Depression, it stands as a landmark of American engineering and New Deal–era public works.

Construction and History

Construction began in 1933 and was completed in 1940 as part of large federal projects designed to create jobs and modernize infrastructure. Thousands of workers came to the remote plains to build the massive structure, turning the project into a major historical chapter for the region.

At the time, it was among the biggest dam projects ever attempted in the U.S.

Size and Engineering

Fort Peck Dam is over 21,000 feet (6,400 m) long and about 250 feet (76 m) high. Unlike concrete dams, it is made primarily of compacted earth and rock, which required enormous volumes of material and careful design.

Fort Peck Lake

The dam created Fort Peck Lake, one of the largest man-made lakes in the United States. The lake stretches for more than 130 miles and has a shoreline longer than California’s coast.

Purpose

Fort Peck Dam serves multiple roles:

Hydroelectric power generation

Flood control along the Missouri River

Water storage and river management

Recreation and tourism

Recreation and Wildlife

The area around the lake is known for outdoor activities such as:

Fishing for walleye, pike, and bass

Boating and camping

Wildlife watching

It is managed in part by the U.S. Army Corps of Engineers, which oversees dam operations and recreation areas.

Why It Matters

Fort Peck Dam is both an engineering achievement and a historical symbol of the New Deal era. Today it continues to provide power, manage water, and support recreation in the northern Great Plains.

This image is small because it may be AI generated.

History Old Photos posted
It was a crisp autumn day on October 10, 1936, at the massive construction site of Fort Peck Dam in northeastern Montana. Dozens of workers swarmed over the enormous circular steel liner — a giant diversion tunnel section designed so that one-fourth of the mighty Missouri River would eventually flow through it during the dam’s construction. Men in work clothes and caps balanced on scaffolding and internal spokes, welding, bolting, and guiding the massive structure into place with ropes and tools. The huge steel cylinder dominated the scene, dwarfing the workers and highlighting the incredible scale of this New Deal engineering project. Built to tame the Missouri River, provide jobs during the Great Depression, and bring flood control and navigation to the region, Fort Peck Dam was one of the largest earth-filled dams in the world. This iconic photograph by Margaret Bourke-White captured both the raw power of American industry and the human effort behind it.

Cayla Jasske commented on the above post
This is a real photo……don’t think this post is…another AI

1925+2004 US-24,65 Bridge over Missouri River at Waverly, MO

1925: (Archived Bridge Hunter; Bridge Hunter; no Historic Bridges; HAER)

2004: (Satellite)

The 1925 bridge was 1,942' (592m) long with a main span of 419' (127m). The deck was just 20' (6m) wide. [BridgeHunter]

Waverly, MO, is up on a river bluff, so the bridge descends down to the floodplain.

1932 photo via BridgeHunter, Credit: Missouri State Archives
Md Nurujjaman Sarkar posted

The old Waverly Bridge spanning Hwy 24/65 across the Missouri River. The view is looking toward the river bottoms between Carrollton and Waverly. 

Not my picture so not sure when it was taken - I only saved it because I grew up in the river bottoms about a mile from that bridge.

The bridge was built in the 1920’s I believe and was very narrow. Many people were extremely anxious about driving over it because it was so narrow, but it saw a lot of traffic in spite of its narrowness. 

It had at least one large chunk of pavement fall out of it from the amount of traffic it saw. Such was the case in 1967, when the river had flooded there and one of my brothers and I walked across the bridge. I remember getting to that big hole in the middle and was so freaked out! Maybe 12 years later, I road my 10-speed across that bridge. That was a bit scary too, but not as scary as walking up to the hole in it!

And that floodplain does get wet.

Apr 24, 1952, photo via BridgeHunter, Credit: MDOT, Missouri State Archives

MDOT squeezed every ounce of life out of the old bridge. I believe those holes in the steel caused by rust are called section loss.

Photo by Stan Baughn via BridgeHunter

"Significance: The Waverly Bridge (Bridge No. G-54R) is a monumental, multispan structure with two Pennsylvania through-truss spans, three Parker truss spans, one deck approach span, two plate girder approach spans, and one steel stringer approach span. The total length of the bridge is 1,945', and it has undergone only minor alterations since its completion in 1925. The bridge was built as part of a multi-structure program sponsored by the Missouri State Highway Commission to span the Missouri River at several locations. The Waverly Bridge ultimately had a tremendous long-term impact on the local and regional economy, eliminating a natural barrier to commerce within west-central Missouri." [HAER_data]

 HAER MO-112-7
7. Overall ground-level view to the northwest - Waverly Bridge, Spanning Missouri River at State Route 65, Waverly, Lafayette County, MO

HAER MO-112-15
15. Overall view to the northwest 

2004 Bridge

Street View, Jul 2024

Street View, Jul 2024

US-77 1981,83 Siouxland Veterans Memorial Bridge over Missouri River at Sioux City, IA

1896: (Archived Bridge Hunter; Bridge Hunter; HAER)

1981: (Archived Bridge Hunter; Bridge Hunter; John Weeks III; Satellite)

Until 1979, these bridges also carried US-20. It now carries  BUS-20 as well as US-77.

Street View, Sep 2023

John Weeks
This 1,502' (458m) long bridge has a main span of 425' (130m).
The navigation channel is 400' (122m) by 80' (24.4m).
"An inspection in early May, 1982, found a fracture across the full width of the downstream horizontal tie girder. The fracture was heavily corroded, suggesting that the fracture happened just after the bridge was opened. Further investigation revealed that the strength of the steel varied considerably, with some of the steel not meeting minimum strength specifications. The bridge was closed on May 6, 1982. It remained totally closed for 7 months, with 2 lanes reopening on December 9, 1982. The repairs were completed and the bridge was fully reopened on May 9, 1983."
[When I had seen the rehabilitation date of 1983, I wonder what went wrong in less than two years. Now I wonder which country provided the steel.]
"Highway US-77 once ran north and south from border to border. The northern section of the road became redundant when Interstate I-29 was completed. As a result, US-77 was truncated at the interchange located at the north end of the Siouxland bridge."

Street View, Jun 2024

Street View, Nov 2021

Street View, Sep 2022

Sujit Ingle, Apr 2023

 

This shows that the tie-arch bridge was built with falsework in the river rather than with tie-backs. I wonder how far north the 9' navigation channel went in 1980 on the Missouri River.

HAER IOWA,97-SIOCI,1--1
1. General View of the Bridge from the South Shore, looking WNW.

"The Siouxland Veterans Memorial Bridge, from Sioux City, Nebraska, to Sioux City, Iowa, was opened to traffic in January 1981. In May 1982 Iowa Department of Transportation personnel discovered a fracture across the full width of the top flange on the down stream tie girder. The investigation into the cause of the fracture included chemical and physical testing and fractographic and metallographic examinations. Results of the latter examinations showed that the fracture originated at a gas-flame-cut edge of the 2 3/4-in.-thick A588 flange plate. It arrested at least once at a depth of 0.37 in. and possibly earlier at a depth of about 0.05 in. before propagating in a brittle mode across the flange. The fracture surface was heavily corroded, indicating that the fracture had occurred long before its discovery. The physical tests indicated that the plate in which the fracture occurred did not meet the specified toughness requirements. Additional tests on samples of material extracted from other parts of the girders revealed highly variable toughness properties, some of which did not meet the requirements of the specifications either." [pubsindex]

"Steel for the bridge was provided by two suppliers, one who furnished most of the flange plates, and the other who furnished the remainder of the flange plates and all of the web plates....A number of locations were found where the toughness did not meet the specified requirement. Locations where 21 /2-in.-thick plates did not meet the requirement were also found. At this point in the investigation, an offer was made to IDOT by the supplier of the fractured plate to replace all flange plates that had been furnished by the supplier. This offer was accepted. Work to replace these flange plates was completed in spring 1983." To replace the flanges, they had to remove the dead load off of the tie girders. To do this, they built falsework and then jacked up the superstructure. The bridge was opened to limited traffic while the flanges were being replaced. [onlinepubs]

This photo has been moved to the Combination Bridge. 

This photo has been moved to the Combination Bridge.

2009 photo by Jack Schmidt via BridgeHunter

safe_image for The Bridges of Sioux City, Iowa, Photo by Jack Schmidt
The second bridgehunting tour takes us to Sioux City, Iowa. In 2022, a museum curator did a presentation on the city's bridges, dating back to the first crossing in 1865. That presentation is now available for viewing. Enjoy the tour: 

This is that presentation:

51:11 video

1888+1982 BNSF/(CB&Q+GN) Bridge over Missouri River at Sioux City, IA

1888: (Archived Bridge Hunter; Bridge Hunter; HAER)

1982: (Archived Bridge Hunter; Bridge Hunter; Satellite)

 

Street View, Sep 2024

Street View, Sep 2024

Photo provided by the Smithsonian Institution via BridgeHunter_1888, Public Domain

I found this bridge while researching how the CB&Q Railroad that was south of Sioux City connected with the Great Northern Railroad that was north of Sioux City. It looks like the bridge also helped C&NW connect some of its routes.

- Burlington Northern Railroad (BN)

- Chicago & North Western Railway (CNW)

- Chicago, Burlington & Quincy Railroad (CBQ)

- Chicago, St. Paul, Minneapolis & Omaha Railway (CMO)

- Great Northern Railway (GN)

[BridgeHunter_1888]

Except for the navigation span, the new bridge is a steel girder bridge.

2018 photo by John Bernhisel via BridgeHunter_1982

The BNSF is made up of four routes in the Sioux City area. The CB&Q was the unlabeled routes on the south and west side of the area. The middle route in the upper-right corner was the Great Northern. And BNSF bought the Milwaukee route to the northwest. (The Milwaukee to the southeast is abandoned.)

1955/67 Sioux City Quad @ 250,000

This BNSF system map summarizes the four routes.

BSNF_network

It is interesting that the former-CB&Q route to the west is omitted from this map.

BNSF_subdivision

1952+1975 I-680 Mormon Pioneer Memorial Bridge over Missouri River at Omaha, NE

(Archived Bridge Hunter; Bridge Hunter; no Historic Bridges; Satellite)

2009 photo by Brad J Williams via BridgeHunter
"Eastbound bridge built 1952; westbound built 1975"

The skinny bridge on the right would be the 1952 bridge so we are looking East.

2009 photo by Brad J Williams via BridgeHunter

Eastbound (old bridge):

Street View, Jul 2023

Westbound (new bridge):

Street View, Oct 2024

Andrey Novikov posted three photos with the comment: "The Mormon Pioneer Memorial Bridge is a bridge composed of two cantilevers that crosses the Missouri River.   June 23, 2023."

Roger Deschner: This is the westbound I-680 bridge. The older eastbound bridge is quite a bit narrower, lacking breakdown lanes.

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1893,2013 Bellefontaine Bridge over Missouri River near the Mouth

(Archived Bridge Hunter; Historic Bridges; HAER; Satellite)

BridgeHunter also included this HAER, but that is of a bridge in Nebraska, not Missouri!

HistoricBridges rates this bridge as 9/10 national and 10/10 locally. It is one of the few bridges left that was designed by George Morison, who Nathan calls "one of the greatest engineers in American history...who built some of the first major river, long-span metal truss bridges in America. Visit the Frisco Bridge page to learn more about Morison."

HAER MO,95-SALU.V,1--3
3. EAST WEB, SHOWING PIERS AND SHORELINE; VIEW TO NORTH - Bellefontaine Bridge, Saint Louis, Independent City, MO

 

HAER MO,95-SALU.V,1--31zzz
31. Photocopy of historic photograph, photographer unknown, date unknown. TRAIN PASSING THROUGH SPAN AT NORTH END OF BRIDGE

Only two of the four cut-stone piers have needed reinforcement so far.

Street View, Jul 2022

The approach on the north side is a viaduct over a flood plain. According to a comment by Al Bertram on BridgeHunter, it was rebuilt and the piers were capped around 2014.

Street View, Oct 2022

Street View, May 2013

This view shows that the flood plain does get wet.

Street View, Jul 2015
Aug 2019 and Jan 2022 also have standing water in the field.

Given that the river was high in Jul 2015, I went back and got a view of the main channel back then.

Street View, Jul 2015

safe_image for 1893: A Newly Built Railroad Bridge in Missouri Passes a Crucial Test
Photo Credit: Library of Congress
"The Bellefontaine Bridge was one of the first bridges to incorporate what is known as the Baltimore truss design."

pdf, p 6 via archive via BridgeHunter
The Bellefontaine Bridge: a report to Charles E. Perkins, president of the Chicago, Burlington & Quincy Railroad [published 1894]