Sunday, June 29, 2014

Excitation Current

Synchronous AC generators such as those in large power plants need a DC current flowing through the rotor windings to create a steady magnetic field. Mechanically rotating this magnetic field through the stator windings induces the AC current generated by the plant.

Modern facilities produce the DC current by rectifying power from the grid. That is why they cannot darkstart. But hydro-electric plants in the early 20th century had auxiliary generators to create their excitation current because there was no grid to tap. They were the sole source of power for their market.

The Keokuk Powerhouse has two of the following 2,200 horsepower AC Generators spinning at 125 rpm, each connected to a bus that serves half the units. The apparatus in front is part of a specially designed oil-pressure governor. These generators are dynamically excited and the casing on top houses the exciter circuitry, which is part of the rotating machinery.

Used with permission from Jim Rabchuk
Each main AC generator, below is 13 of the 15 units, has a motor that taps that bus to drive a DC generator. The output of the DC generator is connected to the field windings using brushes. So the main AC generators use static excitation.

Used with permission from Jim Rabchuk

Below are the two 220 hp auxiliary DC generators that were installed in the Lockport Powerhouse of the MWRD in 1934. These replaced the original 3 units installed when the plant went operational in 1907. The original exciters would generate 632 hp at 300 rpm.

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The 1907 Crocker-Wheeler AC generator below is statically excited by the auxiliary units and can produce 4,000kw at 6.6kV.

These units are no longer used, but they were left in as museum pieces because now only 1,500 cfs can be used after the other Great Lake states and Canada sued Chicago in the 1930s for drawing too much water out of Lake Michigan. The plant was designed for 10,000 cfs, and ran at 5,000 cfs until the lawsuit. Here is an overview of the "old half."

And a closeup of the three remaining 1907 units.

I could not figure out how a horizontal shaft would work until I found the following diagram.

US Goverment, HEAR IL-197-C

This diagram depicts the turbine with just 4 stages, which were installed in 1945. The original turbines had 6 stages. A turbine would generate 5,092 hp at 165 rpm. 5 of the turbines contained Wellman-Seaver-Morgan wheels with 54" Jolly-McCormick runners. Two of the units used S. Morgan Smith wheels. Unfortunately, I don't know what a wheel vs. a runner is.

The last horizontal unit retired was in 1976, and it was left in situ. Where they removed the old generators, you can see the hole they plugged up through which the 12-inch shaft used to go. In addition to these two units, the turbine has also been removed from the unit on the far end even though it still has its generator.

These three units that no longer have their turbines have had their intake gates replaced with 3 sluice gates per unit that are controlled from the MWRD headquarters in Chicago to help regulate the canal level in response to an influx of storm water.

Update: 1912 ComEd Power Station.

By the mid 1900s, there were enough different power stations in the country that the gnerators derived their excitation current from the grid. No one dreamed (more accurately, nightmared) that the entire grid might go out. But it did in the Northeast in 1965. I remember that ComEd had a big plant near the East River. This allowed them to bring a naval ship near the plant. They used a generator on the ship to provide the excitation current to get one of the power plant's units running again. (I always wondered what the "jumper cables" that they strung from the ship to the generator looked like.) Then they could use power from that unit to provide excitation current to start up the remaining units and power plants in the Northeast. But before they started that first unit, they had to isolate a service area that was big enough to provide load for the generator but not so big as to overload it. And as they brought more units on line, they had to adjust the service area to keep the supply and demand of electricity balanced. New York had blackouts in 1977 and 2003 as well. I assume by then that at least some units had gone back to using auxiliary generators rather than the grid so that they no longer had to find a navy ship to restart the grid. (It appears the Brooklyn Navy Yard is no longer a navy yard. It is a couple of development projects and a museum.)

Friday, June 27, 2014

Typewriter vs. Keypunch vs. Keyboard

20140812 584c, sorry about the blur.
The ISO was up to 800, but I see the shutter speed was 1/6.
The posting on Tank Car Safety and a post I have been working on for the Keokuk Dam and Powerhouse are effectively small research papers. And I have been thinking about why I'm having trouble writing them. The last time I wrote a research paper, I used a typewriter and 3x5 notecards. On the other hand, I did not have spell check, a web search engine, and satellite maps. My current issue is that I have to invent an electronic version of notecards.

Another problem is that the monitor provides such a small window into what I have written. For years I had a monitor that was 1600x1200 pixels from work. But I had to surrender that monitor when I retired. And now all of the monitors that I could buy are shorter. The monitor I'm currently using is 1920x1080. It is interesting how much impact loosing a couple of inches of height has had on my comfort level when editing a post. But the "research" posts grow large enough that even a larger monitor would not help.

So I printed what I had written so far so that I could spread it out on a table and see what I had and try to figure out a new structure for the post. In the past, when learning another persons program (or relearning one of my own), I would print it and go find a conference room table to lay it out on. Think about how many more pixels are on several pages of paper compared to a monitor. No wonder it is so hard to see the "big picture" with a monitor.

And then I thought about cutting apart the various paragraphs and pictures so that I could physically rearrange the content. This reminded me that the origin of cut&paste is not ctrl-X/ctrl-V but rather newspaper editors cutting up columns of typeset text to paste them on pages.

And my use of a typewriter for research papers reminded me of a meeting I had at work in the late 70s. Keep in mind that the PC was not developed until the mid-80s so keyboards did not exist. We had terminals that integrated the input (keys) and output (CRT) as one unit. In that meeting I mentioned that I had keypunched a memo. A colleague asked me "When was the last time I used a keypunch?". He thought I should have used the verb typed instead of keypunched. I turned to him and asked when was the last time he used a typewriter. I had certainly used a keypunch more recently than a typewriter, and so had he. Fortunately the introduction of the keyboard in the 80s also introduced the verb keyboarding so that I now don't have to choose between antique terms for the activity of banging on keys.

So we don't have to go back to the 1800s and early 20th century to do Industrial Archeology of relics. Typewriters and keypunches became relics in the 1970s with the advent of text processing (troff and TeX are the two I used) and then word processing (What You See Is What You Get or WYSIWG) programs. In fact, the text processing programs have also become relics.

Concerning punch cards, during grad school, you could tell who was doing some serious programming because they needed a box (2000 cards) to carry their program. In fact, I had a program that required me to use a drawer (3600 cards). And I remember that I could grip about 700 to 800 cards.

We got rid of our typewriters years ago. I used to have punched cards and a 1200-foot reel of magnetic tape from college up in the attic. But they got thrown out several years ago. So there are no pictures for this post.

To scrape or not to scrape

Last Fall I did two visits to Mississippi Lock and Dam #18. During the first visit, I did not see any tows at the dam, from the bridge in Burlington, nor from the bridge in Fort Madison. And then my wife remembered that the federal government was shutdown. We concluded that the Corps is one of the services that was suspended.

When I arrived for the second visit, an unusual locking operation was in progress. Unfortunately, this was BC (before camera), so I'm going to use satellite pictures to illustrate the procedure.

The upstream tow was five barges in a single file. And the barges were wide enough so that only two fit side-by-side in the lock. Normally 3 barges can be fit side-by-side. When I arrived, the towboat was shoving the first 3 barges into the starboard side of the lock. After they tied those barges to the slip anchors, they untied the fourth barge from the third barge. The tow of two barges backed up and moved over so that it could enter the lock on the port side. Actually, it didn't back up that far. It first swung the front end over. It could do that by running its starboard propeller forward while running its port propeller in reverse. And then it pushed its rear end over. I still haven't figured out how it did that. I wondered if he had sideways thrusters. But I did not see any prop wash coming from the side of the towboat. Thrusters are powerful enough to create a visible wash?

The second half of the tow entered the lock very slowly. There were just inches on each side, but it never touched the other barges or the lock's wall as it entered the lock. Below, the red indicates the position of the 5 barges and the blue is the position of the towboat.

They then lashed the two halves together so that when the lock filled, the towboat could shove all the barges out of the lock. They exited very slowly so that nothing scrapes the walls. They then unlashed the front half and backed up the rear half to the following configuration assuming that the upstream gates are opened.

The backing up was very slow so that nothing scraped the wall or the other barges. Or if something did hit, I did not notice (hear or see) even though I was watching closely for contacts.

He then twisted the front of the second half to the right behind the first half by going forward with the port prop and backwards with the starboard prop. I was able to watch the prop wash and confirmed that he was pushing hard with the port prop and pulling hard with the starboard prop. The prop wash in the following webcam picture of a tow leaving Mississippi Lock #15 illustrates that the props are near the edges of the boat to maximize the distance between them to maximize the torque that they can apply to the tow.

And then he moved the rear over. Again, I can't figure out how he did that maneuver because he did not move forward or backwards, just sideways. It took a while to lash the back half to the front half. After the deckhand cranked the winch as hard as he could, he would stand on the cable, and it would go down to the deck. Then he would crank that slack out and stand on the cable again. He repeated the stand/crank cycle until the cable would not go do down; he could jump up and down on the cable and it just bounced.

When I arrived, there was already a 15-barge tow moored upstream waiting to use the lock. And while this 5-barge tow was locking, a little tow arrived on the downstream side. After the 5-barge tow was clear of the lock, the water was lowered to let the little tow lock through before the lock was tied up with the 15-barge tow. I'm glad to see that they make exceptions to the first-come-first-served rule because the small tow had plenty of room on either side so it locked through quickly because it was able to remain intact and it entered and left the lock quickly since it did not have to worry about scraping the walls.

Note that the 5-barge towboat maneuvering slowly to avoid scraping the walls or barges was costing 3 crews precious time. I had assumed it was important to avoid scraping until I saw the 15-barge tow approach the lock. As explained in The Force of Outdraft, a second towboat was used to keep the tow tight against the guide wall. So the barges were scraping the wall during their approach.

So we have two extremes, one tow using a lot of time to avoid scraping something and another tow deliberately scraping the guide wall with quite a bit of force.

The guide and lock walls do wear out, but it is not clear if scraping is the issue compared to weathering. Below is the input bay to the Lockport Powerhouse on the left and the approach to the Lockport Lock on the right. The "circles" are fenders that should catch any barges that get in trouble because of the outdraft caused by the flow through the powerhouse.

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You can see that the wall on the right has been refurbished. The wall on the left has not. But note that there is no shipping activity along the old wall. All of that deterioration is due to weathering. A closeup of the refurbished wall indicates that it has already been scrapped quite a bit even though this part is still a ways from the Lockport Lock.

And the outside wall of the old 1907 lock, which is no longer used, also shows that walls can deteriorate even if nothing has scraped them. (When it was built, it had the highest drop in the world---38 feet.)

So it seems that a captain going very slowly to avoid any scrapes is more of an ego/pride thing than a real need. And the slow speeds reduce the capacity of the locks.

A video of the 641' Tecumseh rubbing the fenders while entering the Iroquois Lock (Satellite). Judging from the paint, this is not the first time the Tecumseh has scraped its side.

Screenshot from video

Thursday, June 26, 2014


The title of the NTSB report on the Marseilles Dam accident is "Allision of the Dale A. Heller Tow with Marseilles Dam" (new URL). I looked up Allision in my regular dictionary and did not find it. So I got the bigger dictionary off the shelf. Still no joy. I know the NTSB avoids using terms like "accident" or "crash". I've seen "incident" as one of their favorite euphemisms. So I was wondering of "allision" is a new euphemism or if it really means "running barges into a dam". A web search quickly determined that it is a maritime law term that means a moving vessel violently running into a stationary vessel or an object. It is distinguished from "collision", which means two vessels running into each other. So a ship does not collide with a bridge, it allides with it. Furthermore, an allision is a violent contact. For example, a ship scraping a bridge pier fender as it passes under the bridge is not an allision.

Speaking of allisions, I came across a video of a ship entering the Panama Canal's Gatun Locks on an angle and smashing one of the mules.

Wednesday, June 25, 2014

The Force of Outdraft

Outdraft is a current that moves across a lock or channel entrance towards a dam's spillway. The higher the flow rate through the dam, the stronger the outdraft current.

My first exposure to  outdraft was the Marseilles Dam accident. Four tow boats were working together to try to get a 14-barge tow out of a flood current and into the safety of a canal as illustrated below.
US Government

The Dale A. Heller towboat was 128 ft, 596 gross tons, and 5,600 hp. The Loyd Murphy was from a 15-barge tow that had already been tied up to a mooring to ride out the flood waters. The Creve Coeur and City of Ottawa towboats were from the Coast Guard.

The Marseilles Dams' gates were almost all of the way open to avoid flooding Marseilles. The four towboats were not successful in fighting the resulting outdraft. And Marseilles ending up getting flooded anyhow.

US Government

US Government

And even after the flood subsided, shipping had to evacuate the pools above and below the dam while a rock cofferdam was being built to allow repairs of the damaged trunnions.

US Government
Note that half of the 8 gates could not be used to pass river flow while the repairs were being made.

The second demonstration of the force of an outdraft was when I visited Lock and Dam #18 on the Mississippi River last Fall. Unfortunately, it was BC (before camera), so I don't have any pictures. So I'll use a satellite picture. Below is the upstream guide wall and upstream gate.

The red rectangle represents the leading part of a 15-barge tow. The blue oval highlights a towboat that is normally parked near the upstream gate of the lock. The blue rectangle illustrates where the "blue" tow boat positions itself while the tow approaches the lock entrance. As soon as the front of the tow is past the end of the guide wall, the auxiliary towboat pushes the tow against the wall so that it is not pulled away from the lock entrance by the outdraft. I left when the tow was close to the lock because I had to leave for a meeting. I assume that as soon as the front of the tow entered the lock, it pulled away and went back to its parking spot.

Tuesday, June 24, 2014

Marseilles Dam Accident

US Government
I was researching the Marseilles Hydro Plant, and I discovered that the NTSB released their report (new URL) today. When I first read about the accident last April, 2013, I wondered why the captain would try to navigate into the canal during river flood conditions. It turns out, he got in trouble because he was conservative. He held up 0.75 miles upstream on April 17, 2013, when the gates were open to 31% of the full capacity to wait for better conditions. The problem was that the conditions got worse. By the next afternoon the gates were open to 92% of capacity. The captain wanted to tie up, but another tow got the only mooring in the area. A conference call was held with the River Industry Action Committee, Illinois River Carriers Association, the Coast Guard, the Corps, and others to determine how to help the 14-barge tow. It was decided that the towboat for the other tow and two Coast Guard towboats would help shove the tow into the safety of the navigation canal. The plan included temporarily reducing the flow rate through the dam during the maneuver. However, when they reduced the flow, they increased the flood threat of the town Marseilles. So the flow was increased and the maneuver failed. Seven of the barges broke away from the tow and crashed into the dam.

The damages were almost $4 million for the barges and cargo, $10 million for temporary repairs, and $35 or $50 million (I've seen both numbers) for permanent repairs. And shipping was sometimes shutdown on the river after the accident to lower the pool to reduce the pressure on the broken gates and the cofferdam that was being built to help with the repairs.

The Corps had created a slide presentation that describes the incident, both the barge allision and the earthen dike damage, and the temporary repairs.

Water Intake Trash Screens

We began a tour of the Lockport Powerhouse by going up the stairs on the side of the powerhouse to the upstream side. 

20140614 0340c

When I got to the top of the stairs, I noticed the following:

And the view off to the right was:

Walking around this gizmo to see what was on the other side, I saw water intake gratings and more of that "vertical thing". The purpose of the gratings is to prevent trash from flowing through the turbines.

These input screens are for the two generators that are still operational in the powerhouse.

Later, I remembered to ask what that "conveyer belt thing" was all about. It is for cleaning out the trash that accumulates against the intake screen. They place a dumpster at the end of the conveyer belt that you see in the third photo. Then the vertical arm is extended so that the scraper at the end reaches down below the trash. And then the arm is retracted to pull the trash up and over the top of the screen so that it falls onto the belt. The arm is on rails so that it can work its way across the face of the screens.

A view of the conveyer belt from the screen side. You can see the roof of the powerhouse in the background.

As another example of water intake screens, this is the gate room of the Keokuk Powerhouse.

On the right side just beyond the metal hand rails are the tops of the intake screens. They extend 40 feet down.

In this closeup of one end of the intake chamber, it looks like all but one of the screens has been replaced.
Used with permission from Jim Rabchuk
Four of the intake screens feed water to the scroll chamber for one turbine.

Monday, June 23, 2014

Sluice Gate

A sluice gate is one of the designs for how to control the flow of water in water control facilities such as dams and powerhouses. It consists of a flat panel on the upstream side of an opening. The panel is pulled straight up to let water flow. Below is the spare gate for the Lockport Powerhouse.

Because of the water pressure on the upstream side, the panel would have a lot of friction against the sides of the opening. So the wheels are added to make it easier to move the gate up and down.

In the background is the storage of the bulkheads that they can slide down on both sides of a sluice gate so that they can do maintenance in place. Below is a view of the bulkhead storage from the other side.

In this powerhouse, there is a threaded rod connected to the top of the gate that goes up through an actuator above the gate. Below are the actuators for three of the gates. You can see just a few inches of the rod above the first actuator because the gates are closed. If they were open, there would be about 14 feet of the threaded rod sticking up through the top of the actuator. The gates are normally operated by the electric motor on the left from a control office in Chicago. But notice that there is a hand crank in case of an emergency.

A structure upstream from the Lockport Powerhouse is nothing but a set of seven sluice gates in the side of the Sanitary and Ship Canal.

These gates are opened about 6 times a year after heavy rains in the area when the flow in the canal is more than the powerhouse can handle. I understand I would not want to be where I'm standing to take that picture if the gates are open!

Below is the gate room in the Keokuk Powerhouse.

I had assumed that the metal panels sticking up through the floor grate would be the top of open sluice gates. But the scroll chamber for a turbine is supposed to be fed from four gates, each of which is 7.5x22 feet. So I don't know why one, instead of four in a row, gates appears to be open. The 75-ton traveling crane that is used to pull the gates up must be parked above the photographer because I don't see it near the top of the room. The gates have brakes so the crane is not needed to lower them.

The Keokuk Dam has 119 spillways. (The building on the left side of the picture is the powerhouse.)

And at the top of each of those spillways is a sluice gate.

On top of the dam are two gate gantry cranes that roll along the top of the dam on rails. They hook to a gate to raise or lower it.

Saturday, June 21, 2014

Glass Making

I came across notes on glass making in the Buffalo region while researching the Niagara Power Stations. Not only were the notes interesting, it occurred to me that glass making is an important part of our industrial heritage. Below is a summary of the notes.

Glass containers were first produced in Egypt about 2,000 B.C. The blowpipe was invented around 300 B.C.

In the Lockport and Lancaster factories, the ingredients for glass were melted in a furnace in large pots at 2,500 degrees Fahrenheit for thirty to forty hours and then cooled to about 1,800 degrees to a more workable consistency. The furnaces were originally wood fired. Until 1820, glass was made with a blowpipe. However molds might be used to give the glass its shape. In 1820 the "pressed glass" method was invented. "A glob of glass was gathered on an iron rod by a workman, dropped into a pieced mold on a machine, and a plunger forced the glass into all parts of the mold." In 1903 the glass blowing machine was invented. "Although furnaces are now heated by natural gas rather than wood or coal, the same technique of blowing is used in the modern automatic machines which turn out thousands of bottles or jars an hour.

The first glass factory in Lockport, NY, was opened in 1840. It went through a series of owners, but it grew before it went out of business in 1908. Another glass factory was started in 1900. In 1919 this plant was bought by the Thatcher Manufacturing Company and concentrated on milk bottles. "The introduction of paper milk containers forced them to switch to jelly, pickle and coffee jars, and they closed the factory in 1942."

The glass works in Lancaster was started in 1849 by eight blowers from Pittsburgh. It also went through a series of owners, but it operated until 1904. In 1907 a new factory was started to produce food and beverage containers. The notes state that in 1965 it consolidated with another plant in Pennsylvania. I gather that the Lancaster plant was shutdown as part of this consolidation.

There are quite a few pages describing the products produced by these factories in detail for the benefit of collectors such as
A very rare Lockport half-pint flask in pale yellow-green and aquamarine has a duck swimming with the words above, "Will you take a drink?" and the answer, "Will a [duck] swim"? with a plain reverse side.
The notes end with a discussion of why the factories closed. "Continental Can Co. with a branch in Lancaster was forced to dissolve its glass container operations in 1963 by federal anti-trust laws. To achieve economy in operations smaller plants often consolidated or moved nearer to the customer who purchased the containers."

Keokuk-Hamilton Bridge

The Keokuk-Hamilton Bridge is a 4-lane road bridge that opened in late 1985, and it retired the road bridge on the Keokuk Municipal Bridge. Below is a view of the bridge from the Iowa, upstream side.

20140613 0038

The concrete walls are the downstream walls for Lock #19. And John Weeks III has a nice downstream side view.

Note that the Iowa side is high to clear the barge traffic that uses the lock on the west side of the river. But the Illinois side of the bridge meets the shore below the bottom of the old bridge. Since there is a natural bluff on the Illinois side as well as the Iowa side, if they had made the bridge a little longer and kept the pier heights higher, they could have avoided the flood problems of 1993 and 2008. (I could not find info for 2011 for Keokuk. Was that just a lower Mississippi flood?) During the 1993 flood, the bridge was closed for two weeks before 26000 tons of limestone was piled on the access road and it was opened again. But the speed limit was 5 mph instead of the usual 35 mph. During the two weeks of road closure, a trolley car across the maintenance track on the dam was used by 4000 commuters each day. Even with the low access road in Illinois, this bridge opened sooner after the flood than the bridges at Hannibal, Quincy, and Fort Madison making it the only open bridge in a 230 mile stretch of the Mississippi. In 2008, they learned there lesson in 1993 and piled rock on the road sooner rather than later to keep the road open. A video that shows the water is almost to the bottom of the railroad bridge. A video that shows water on the access road and the bad traffic jams. Skip to timestamp 1:30.

I had noticed that the steel beams for this bridge were huge. And on the Iowa side they are also curved.

The beams are fabricated in the field, and we can see the two joints in the full span.

Friday, June 20, 2014

Keokuk Municipal Bridge

Just downstream of Lock #19 on the Mississippi is a 3800 foot long bridge with a swing span of 380 feet (Wikipedia, Bridge Hunter, Facebook). John Weeks III indicates that the original 1870 bridge was one of the first 15 bridges built across the Mississippi. When constructed in 1915-16 using the piers of the 1870 bridge, it carried a railroad as a through truss and a road, US-136, as a deck truss. In 1985, a 4-lane road bridge just downstream from this bridge opened, and the west end of the old road bridge became an observation deck. Below is a view from the Iowa side of the downstream elevation.

20140613 0039

In the following closeup of the Iowa side, the upper deck on the left is now the observation deck. Note the old stone wall for the railroad approach.


I got a view of the upstream elevation when I got lost looking for the observation deck.

This is where I should have turned for the observation deck. The little building is the old toll booth. And the old road is now a parking lot for the deck.

A view of the swing span from the end of the observation deck.

A close up of the gear reduction train and the top of the drum.

Unfortunately, the lock blocks the view of the rollers and rack at the bottom of the drum. But the HAER has a picture of the foundation of the drum.

After I came back from the van to get my 55-200mm lens for a closeup of Dam #19, I was excited to see that the span had closed. First of all, that meant the bridge was still used for trains. And secondly, it meant that one should be coming.

Of course, I was disappointed that I missed the closing. But Steve Conro caught the closing of the bridge on video. So I went back down and got another downstream elevation shot with the span closed.

 A westbound covered-hopper train did arrive 27 minutes later. Jeffrey Dobek also caught a westbound tank-car train, probably for corn syrup, on the bridge; and Matthew Chapman caught an eastbound covered-hopper train. The KJRY services a corn syrup plant in Keokuk twice a day, 365 days a year. So that would explain covered-hopper cars carrying corn and tank cars carrying syrup.

Update: Keokuk, Iowa Historians posted five images with the comment:
Keokuk's First Bridge
After the 1865 close of the Civil War, the businessmen of both Keokuk & Hamilton, Illinois began to believe that expansion of both cities could be accomplished by bringing rail traffic through the area.
For the next three years, The leading businessmen & politicians of both cities met often to lay out plans to bring the railroads here.
In December, 1868 these men established the Keokuk - Hamilton Mississippi Bridge Company to raise capital to build a railroad bridge across the river
On January 19, 1869 The Keokuk - Hamilton Mississippi Bridge Company entered into contracts with the Indiana Central Company, the Peoria Company, the Des Moines Company, and a fourth railroad company, (the Toledo, Wabash & Western Railway Company,) whose railroad connected with the bridge at Hamilton. By that contract the Bridge Company agreed to begin to construct forthwith across the Mississippi river, at Keokuk, and to complete by January 1, 1870, 'a substantial wrought-iron bridge, suitable for the running of railway trains;' 'to lay a track upon said bridge, and connect the same with railways belonging to the parties hereto, in such manner, and at such points, as may hereafter be agreed upon;' and 'to maintain and keep in repair in perpetuity the said bridge and tracks, so that trains may safely cross at all times, except when repairs make it necessary that crossing should be temporarily suspended, or when it shall be necessary to have the draw open for the passage of boats;' and granted to those four railroad companies, in perpetuity, the right to use the bridge for the purpose of passing their trains across the Mississippi river; and they agreed to pay monthly stipulated rates for the transportation of passengers and freight, and, if the gross amount of the rates for freight for any year should fall below the sum of $80,000, making up the deficiency, each of the four railroad companies contributing in proportion to the tonnage passed by it over the bridge; for which, by a subsequent modification of the contract in June, 1871, was substituted one-fourth of such deficiency.
This was to be the first combination roadway and railway bridge built across the Mississippi River. The construction contact was awarded to the Keystone Bridge Company of Pittsburgh which was one of Andrew Carnegie's first business ventures at a cost of $850,000.
Carnegie invested heavily in stock of the Keokuk-Hamilton Mississippi Bridge Company & became its president. Of course steel from Carnegie's steel mills was used in its construction
The new "Iron Bridge" furnished another link for commerce between east and west and for freight and immigration. It was said that this bridge was one of the wonders of the nineteenth century - at least to the people of Keokuk. The total length of the bridge was 3800 feet and accommodated railroad cars, horse and wagon teams, and foot passengers.
Keokuk was the terminus of five different railroads: the Toledo, Wabash & Western, the Toledo, Peoria & Warsaw, the Keokuk & St. Louis, the Keokuk & St. Paul, and the Des Moines Valley Railroad. A locomotive named the "Iowa" was the first to cross the Keokuk - Hamilton Bridge on April 19, 1871. The bridge was opened to the public on June 14, 1871.
On the night of Friday, November 4, 1881, the steamboat War Eagle crashed into the bridge taking out one span of it. This span was temporarily replaced by a covered wooden span.
When the steel span was replaced, the wooden span was disassembled, numbered & rebuilt on the Hamilton side over the old dike road. Most of you would remember it as the covered bridge on the old Illinois approach to the bridge, It was destroyed in a 1969 act of arson.
Shortly after the turn of the 20th Century, the growing popularity of the automobile began to cause grumblings of dissatisfaction with the old bridge & its safety.
After the lock & dam was completed here in 1913, several of the Keokuk & Hamilton businessmen proposed running the railroad traffic across the top of the Dam to separate the traffic for safer conditions. They formed the Inter-City Bridge Company after appeals to Andrew Carnegie to rehab the current bridge were rebuffed, and took their cause to Washington D.C. where they gained approval to run the rails over the dam In 1914.
Seeing no other choice, Carnegie, still controlling the major shares of the Keokuk-Hamilton Mississippi Bridge Company, relented & agreed to rebuild the old bridge.
This process was begun in 1915 & the new double deck bridge opened to traffic on August 17, 1916.