Saturday, June 28, 2014

Amazing Engineering Still in Use: Lock & Dam 15, Mississippi River

This post will be a bit different than previous ones in Urban Decay. Here we will highlight engineering and infrastructure that is still is regular use and has been maintained eight decades after construction. Lock & Dam 15 are on the Mississippi River at Rock Island, Illinois.

First, a short introduction. A river flows downhill towards the sea or a lake. In flat terrain, it flows slowly, and, provided water depth is adequate, vessels can traverse both upstream and downstream.  But, as the terrain becomes steeper, a vessel has more and more trouble moving upstream because of the increasing current. Therefore, to aide navigation, engineers build dams across the river to create a series of lakes or pools. The river ends up looking like a series of terraces with dams marking the lower (downstream) edge of each pool. To let ships pass, a lock or boat lift must be built at each dam. Locks are also used to bypass an area of dangerous water, such as cataracts or waterfalls.

Click the link for an excellent Corps of Engineers brochure on Upper Mississippi River locks and dams.  "The Upper Mississippi River – Illinois Waterway System includes 37 locks and 1,200 miles of navigable waterway in Illinois, Iowa, Minnesota, Missouri, and Wisconsin. The 9-foot Channel Navigation Project was largely constructed in the 1930s and extends down the Upper Mississippi River from Minneapolis-St. Paul to its confluence with the Ohio River and up the Illinois Waterway to the Thomas J. O’Brien Lock in Chicago. "The maintenance needs of the aging infrastructure are increasing at a rate much greater than the operations and maintenance funding provided for the system." This is a polite way of saying that Congress has been grossly underfunding maintenance for decades.  It is a symptom of our race to the bottom.

"9-foot Channel Navigation Project" means that barges with a draft of 9 feet can transit the system. In the south, the 9-ft channel begins at Baton Rouge. Ocean-going ships can travel up the Mississippi as far as Baton Rouge, but further north, cargo must be transferred to barges. I do not know haw a depth of 9 ft was selected in the 1920s, when the ambitious project was conceived.
Here is the Lock & Dam 15, with the dam, lock, and railroad bridge spanning the Mississippi River (undated photograph from U.S. Army Corps of Engineers). Across the Mississippi River is Davenport, Iowa.
This is the newly-built project in 1933.
Today, the scene looks almost the same, with the elegant Clock Tower building serving as the office for the U.S. Army Corps of Engineers on Arsenal Island (2009 photograph courtesy U.S. Army Corps of Engineers).
The main lock is 110 feet wide by 600 feet long. A lock is a basin of water that allows boats to change their elevation and pass from one water level to another. Gates open and the boat enters. The gates close and the water either drops if they are heading downstream or rises if they are moving upstream. Then the gates open and the boats proceed on their way. In this example, the barges contain coal and are moving upstream. The top photograph shows the gates opening on the downstream side. Coal is an example of bulk cargo that is most economically and safely carried by barge. Rock, gravel, petroleum, cement, wheat, soybeans, and extra-large machine parts or steel constructions are other examples of materials that can be carried by barge. As long as there is a nearby waterway, barges are much more efficient than trains or trucks.
This is a 1936 photograph of the dam at Rock Island. The water flow can be blocked by a series of roller gates that roll down a track to a specified elevation. "The 1,203-foot-long movable dam is the largest roller dam in the world consisting of 11 non-submersible 100-foot-long roller gates with 11 control houses. Nine gates are 19 feet 4 inches in diameter and two are 16 feet 2 inches."
These photographs show how the roller gates operate. They fit in an inclined slot and literally roll up or down the track to the specified elevation in the river. The advantage of this design is the cylinder is strong and can withstand impact from ice and logs. Also, a relatively low-power electric motor can roll the cylinder up or down. I do not know how they seal the ends, or what happens if debris lodges on the track.
These are photographs of hydraulic physical models at the famous Iowa Institute of Hydraulic Research at the University of Iowa in Iowa City (Mavis 1939). The Iowa River flows through campus, dividing it into east and west sections. In the 1930s, the river provided the water that was used for the models. My father noted in his diary that sometimes the river flooded the subbasement, and work was suspended until the water level dropped again. Also, sometimes the model froze in winter (he noted a period of almost two weeks in February of 1937 when morning temperature was -17˚ F.). In that era, many of the students showered in the laboratory - they must have rented rooms in rooming houses without bath facilities. How times have changed; can you imagine contemporary students living like that?

In the first photograph, the template for the bed is made of wood. Fifty years later, the construction process was almost identical, except that the templates were cut from aluminum.
This shows a model with three roller gates, of which the center unit is raised (Morang 1937).
This shows the flow pattern based on a time exposure photograph of confetti. This method of visualizing was used at least through the 1990s.
This is a flume with a model of the Marmet Dam on the Ohio River. Notice the turbulence downstream of the gate. A flume is a long glass box which allows the technicians to see the flow from the side. Flumes are still in use in laboratories around the world.
Here are students and faculty of the Hydraulics Laboratory in 1936 or 1937. My father noted that in some classes, there were many Chinese students. Even back then, the government of Chiang Kai-shek was sending technical students to the United States to learn about engineering and science.

This was the era before electronic computing machines, and all observations were recorded manually on graph paper. We built much of the nation's infrastructure like this, based on sound engineering by hard-working engineers, scientists, and technicians. And we are letting it crumble away through neglect, political infighting, corrupt politicians, and national stupidity.

References

Mavis, F.T. (editor). 1939.  Two Decades of Hydraulics at the University of Iowa, Abstracts of Theses, Publications, and Research Reports. University of Iowa Studies in Engineering, Bulletin 19, Iowa City, IA.

Morang, C.N. 1937.  The Effect of Symmetrical and Unsymmetrical Roller Gate Operation on Discharge Coefficients. M. S. thesis, State University of Iowa, Iowa City, IA, 68 pp. 


Photograph No. 1 is from the Library of Congress:  

TITLE: Mississippi River dam #15, general view of completed dam, view from top of Clock Tower building
SUMMARY: Photograph shows dam across the Mississippi River and Davenport, Iowa. The Government bridge, which carries railroad, automotive, and pedestrian traffic, is in the foreground. The Davenport city skyline is in the background.
DATE: 20 March 1934
This image is available from the United States Library of Congress's Prints and Photographs division under the digital ID ppmsca.17351

Friday, June 20, 2014

South Nags Head - the Condemned Beach Houses that Never Collapse

Dear Readers, some of you may remember my previous articles about the elevated cottages at East Seagull Drive in South Nags Head, North Carolina. They were condemned when they were in danger of collapsing into the Atlantic Ocean. Well, to confound the skeptics, they are still standing as a testament to convoluted U.S. real estate laws and property rights, and are serving as a rather macabre tourist attraction.
An odd feature: one of the houses has been reinforced with secondary new pilings, and there is a real estate sign underneath. Have the houses been un-condemned?
The northernmost house in the group is leaning rather ominously. Is this one for sale, too?

Let's move to  a more cheerful topic: one of the largest sand dunes on the east coast. This is Jockey's Ridge State Park. The high, unvegetated area of Jockey's Ridge is known as a medano—a massive, asymmetrical, shifting hill of sand lacking vegetation. (El Médano, in Spanish, is "the sand dune," as well as the name of a town on Tenerife.) According to the state park web page, "Jockey's Ridge is the tallest active sand dune system in the Eastern United States, and the most striking of the remaining dunes on the Outer Banks. Shifting winds are constantly reshaping the dunes. Because the Ridge is always changing, it is often referred to as "The Living Dune.""
It is really interesting to walk to the top and see the Atlantic ocean to the east and Albemarle Sound to the west. You can pretend for a few minutes that you are doing the Lawrence of Arabia march through the desert, except there are no camels.
When it rains, a sizable pond forms in a hollow to the east of the main part of the dune, demonstrating that barrier islands can have a high ground-water table if there is sufficient regular rainfall.
A popular activity is to slide/jump down the steep east side, sort of like running down a snow field. Well worth a visit!

Click the links for the 2010 article on the condemned houses. The 2012 article described the houses and the beach nourishment project.

Photographs taken with Fujifilm X-E1 and Panasonic G3 digital cameras.

Saturday, June 14, 2014

Coles, Mississippi - Not Much Left

If you drive from Baton Rouge, Louisiana, to Vicksburg, Mississippi, via the inland route rather than the 4-lane Hwy 61, you pass through a number of small lumber towns in the piney forest terrain. Driving north on Hwy 33 north of Gloster, you soon you enter the Homochitto National Forest. If you go too fast, you will zip by the junction where Mullins Road and McDowell Lane join 33. Oops, you just missed Coles.
Most of the buildings facing the road are abandoned. Whatever business once sustained this town has dried up.
There was an old cottage behind some trees. The porch had some of the old-fashioned outdoor chairs of the type I have seen in New Hampshire and the Adirondacks.
The former gasoline station had become an antique shop within the last few years, but I could not tell if it was open any more.
There was some great debris outside the antique store - my favorite photography subjects.

Photographs taken with a Fujifilm X-E1 digital camera, tripod-mounted, with the Fuji 27mm f/2.8 lens (an excellent and compact little optic). Raw files processed with PhotoNinja software.

Tuesday, June 3, 2014

Back to the Secret Playground of Vicksburg


My previous post on the Secret Playground of Vicksburg generated a lot of interest, so I thought I would take another look. This is early June, spring is in full blast, and the jungle is engulfing the site. It is a stroll down poison ivy lane to reach the playground equipment.
From what I can tell, no one has cut grass or done any other work for at least a year.
Just around the corner from the playground on Wisconsin Avenue, a fellow parked a classic Volkswagen Beetle on the grass about five years ago. And there it sat, year after year, slowly rusting and moldering. Originally it was in running condition. I once asked him about it, and he said he was going to restore it. Last week it was gone, and he said he had the tin man take it away. Pity.
He also had an old camper in the woods. He dismantled the camper part, leaving the cab as sort of an odd-looking pickup truck. You see a lot of unusual things like this in Vicksburg.  A few days later, even the cab and chassis were gone.
Just at the corner of Wisconsin and Confederate Avenues is Toots' Gro. This venerable establishment has been in business for decades and has an active lunch crowd. The CocaCola sign in the first photograph was identical to two or three others painted around town. The local bottler (now closed) may have been trying to invoke the old-time look to their advertisements. The sign is still there, but faded.
Confederate Avenue is worth exploring - park and walk around. This was once Military Park property, but many years ago, the City and the National Park Service exchanged land, and this part of Confederate Avenue is now city-owned. But the statues and plaques remain in place. Some are in the woods almost hidden.

The playground photos were with a Fuji X-E1 digital camera with a Leitz 50 mm f/2 Summitar lens. The automobile photographs were taken with a Panasonic G3 camera with 14-45 mm Lumix zoom lens. The odd red color on the VW came from the Kodachrome 25 simulation in  DxO Filmpack 3, with the intensity slider at 100%. The photographs of Toots' Grocery are scans of color slides, taken with a Leica M3 camera. The bearded soldier is a crop from a Kodachrome slide.

Update March 2017: Toots Grocery is closed and the building is for sale.