Coralville Dam on Iowa River near Coralville, IA

(Satellite)

Street View, Oct 2015

USACE, Rock Island District posted two photos with the comment:

Today's edition of 'Then & Now' takes us over to Coralville Lake! The first photo, taken in 1957, shows construction of the dam and spillway. The area looks much different today as the reservoir has filled in to help with flood control in the area.

Coralville is one of three lakes/reservoirs in the District that help with flood control, in addition to two "dry" reservoirs we have as well!

1

2

The emergency spillway is a parking lot for the boat ramp and beach when the lake is at its normal level.

Street View, Oct 2015

The spillway waters flow over some very old rocks.

Street View, Oct 2015

They are from the Devonian Period.

uiowa, p2
This bedrock was exposed by the floods in 1993 and 2008.
"The limestone rocks exposed at the Devonian Fossil Gorge are of middle Devonian age (about 375 million years old) and include the Rapid and Solon members of the Little Cedar Formation. During this time, Iowa and much of North America lay at tropical latitudes just south of the equator, and the Devonian sea covered most of what is now the United States."

The record 2008 flood:

By United States Army Corps of Engineers - Photo, Public Domain, Link
"View of Coralville Dam at floodstage, Sunday June 15, 2008. The spillway fully open with water about 5 feet deep -- the record for the dam"

1884,1890-1965+1965,2012 Washington Avenue Bridges over Mississippi River in Minneapolis, MN

1965,2012: (Archived Bridge Hunter; John A. Weeks III; Satellite)

"The first bridge at this location was built in 1884. The 1884 structure was reconstructed in 1890 to accommodate streetcars. Streetcar service ended in 1952, and the bridge was determined to be obsolete shortly after that time and was dismantled in 1965." [JohnWeeks]

The bridge was strengthened so that light rail could be added in 2012.
 

Robert Swann commented on a post
Washington Avenue Bridge, about 1885.

Photo via umn
1940

JohnWeeks
This photo "is from a historic display located on the University of Minnesota campus. It shows the original Washington Avenue Bridge circa 1905. This iron truss bridge was in place from 1884 to 1965."
[Note the number of people that used to live on the Bohemian Flats flood plain.]

Photo via umn
Campus Views. View from SW showing Washington Ave Bridge under construction, 1965

.

1965 Bridge

Street View, Sep 2013

The upper deck is dedicated to pedestrian traffic because the University of Minnesota built an expansion of the campus on the west bank of the Mississippi River. Because the winters get cold in Minnesota, the students have the option of an enclosed walkway. Unfortunately, according to the Google search results, this is a popular suicide bridge.

Street View, Sep 2014

Street View, Oct 2023

The traffic capacity was reduced by half to add the light rail.

Street View, Oct 2008

"So, when is a bridge a girder--and a steel stringer--and a deck truss--all in one? This bridge started out in 1965 as a plain deck girder bridge and remained as such until 2010, when a massive project began to upgrade the bridge to carry light-rail traffic. The plan was to add stringers to increase the load-carrying capability, but the original stucture's rigid cross-members didn't allow it. The design engineers came up with a very creative and innovative way to address this--instead of solid stringers, trusses were designed and installed, one member at a time, to fit around the existing sway bracing without having to remove any of it! And so, as a result, the main spans still retain their full original girder system, with multiple 'stringer-trusses' to support the light rail vehicles." [BridgeHunter]

This view caught the construction after the trusses had been added to the east lanes, but before they were added to the west lanes. So we get a good before-and-after view of the stringers. And since the Warren trusses had not been painted, we can easily see the trusses.

Street View, Jun 2011

MNDOT
"Design and construction of a double-deck, welded, haunched, continuous plate-girder bridge using A441 high-strength steel."
"This bridge was one of the first in the nation to use A441 high-strength, low-alloy steel in its superstructure, which allowed for the structural connections to be welded rather than riveted."

Pennsy Bridges and Tunnel near Conemaugh Dam

Trail East Bridge: (Satellite)

Abandoned Tunnel: (It was between the two bridges. They can't use it for the trail because it is plugged so the tunnel doesn't drain the reservoir.)

Original Route: (Satellite, just the piers are left)

Trail West Bridge, First Bypass: (Satellite)

High Bridge, Second Bypass: (Satellite)

Dave Kuntz posted five photos with the comment: "The tops of the stone arches barely peek out above the Conemaugh Reservoir in rural Western PA.  The tunnel at the end of  the bridge is above water now but won't be come the spring rains.  This ex-PRR line was abandoned in the early 50's and relocated higher with the opening of the dam downriver.  It is also a primitive rail trail when not flooded - note the debris around and on the bridge.  Coming tomorrow: the other end of the tunnel and the stone arch bridge at the dam itself."

Bear Marshall: This particular grade is the second iteration of the line. Originally it followed the river in some spots. I don't remember all of the details but I did a bit of research on the area a while back.

1

2
[As a comment observed, this photo shows the plug that keeps the tunnel from draining the reservoir.]

3

4

5

Dennis DeBruler commented on Bear's comment
That explains why two abandoned routes have been documented. https://www.openrailwaymap.org/

Dave Kuntz posted four photos with the comment: "Different fates for 3 RR bridges by the Conemaugh Dam in Western PA:   The impressive stone arch bridge at the bottom is now a walking/biking trail; the modern steel bridge above it is still in service although one track has been removed, and the piers nearest the dam date to the earliest bridge that is long gone.  Both the unused bridges went to now abandoned tunnels covered by trees in the right of the top photo, one of which still has rails in front of it.  The tunnels traversed the hillside to the arched bridge on the other side, which I posted yesterday.  The creation of the dam in the background necessitated raising the entire line, hence the newest bridge also being the tallest."

Tim Shanahan shared

Jim Kelling: What is the nearest town or city?

Dennis DeBruler: Jim Kelling This is out in the wilderness. I dropped a pin on the high bridge: https://maps.app.goo.gl/DCafNxKQj29a64qL8.

1

2

3

4

 

Rob Oches commented on Dave's post
I’m a union Ironworker and collect memorabilia, I’ve owned this page ad out of time magazine for years but never saw the completed bridge.

Andy Hoyle commented on Dave's post, cropped
One of the last trains going through the tunnel to Livermore before the town was razed for flood land.

Gayle Donelson commented on Dave's post
So much to see here.

Joe Stobert commented on Dave's post

Joe Stobert commented on Dave's post

Joe Stobert commented on Dave's post

The original route.

1903/46 Latrobe Quad @ 62,500

I was shocked to learn that there is no high-res topo map between 1903 and 1964, so I had to use a low-res map to show the first bypass route, today's trail.

1954/54 Pittsburgh Quad @ 250,000

The current route.

1964/66 Blairsville Quad @ 24,000

1955-1979+1982 Dauphin Island Bridges

1955: (Archived Bridge Hunter; no Historic Bridges)

1982: (Archived Bridge Hunter; Satellite)

The 1955 bridge had a lift span, and it was destroyed in 1979 by Hurricane Frederic. [BridgeHunter_1955]

The 1982 bridge is 17,814 (5.4km, 3.4 mile) long bridge and has a 400' (122m) navigation span. [BridgeHunter_1982]

The vertical clearance of the main span is 83' (25m). [WaterwayGuide]

pci, p2

pci, p3

pci, p15

pci, p19

Alabama Memories posted
Dauphin Island Bridge in 1982

1977 Swinging (Pedestrian) Bridge over Toccoa River in Fannin County, GA

(no Bridge Hunter; no Historic Bridges; Satellite, 1,353 photos)

Street View, May 2017

 

Walter Bettencourt, Jul 2023

Paul Bridges posted seven photos with the comment: "Swinging Bridge on the Toccoa River, Fannin County Georgia. At 375' [114m] it is the longest suspension footbridge east of the Mississippi."

1

2

3

4

5

6

7