Flooding update: Eastern Iowa

High water at Anamosa Bridge with broken branch stuck at the railings. Following photos courtesy of Quinn Phelan

River crest much lower than expected; Stone City and Anamosa spared damage, among many river towns; Historic Bridge Weekend on as scheduled

Residents in eastern Iowa are breathing a huge sigh of relief as many communities along major rivers avoided the worst- record flooding. The hardest hit area was along the Wapsipinicon River, where many residents in communities like Independence, Anamosa and others were sandbagging and constructing dikes feverishly to protect their houses and businesses and bracing for the river that was expected to crest at record highs last seen in the Great Flood of five years ago. Yet it never happened. While the river crested in Independence, it caused little to no damage to the community. While the river was expected to set records in Anamosa (which would have been up to a foot higher than the record of 26 feet set in 2008), it only reached 21 feet on Friday. While many roads were closed to traffic and some bridges over small creeks washed out, the region survived what would have been flooding of biblical proportions had the predictions of 27 foot crests come true.

For Anamosa and Stonc City, with its half a dozen historic bridges located within a five mile radius of each other, according to recent reports, they were spared the flooding as they only received minimal damage and will most likely be repaired and reopened very soon. This will be a blessing for many bridge enthusiasts who will be passing through Anamosa for the Historic Bridge Weekend on August 9th and 10th, visiting and photographing the structures along the way.  Because the flood waters did not reach the building, the Stone City General Store and Restaurant was also spared flood damage and is open to the public. The Friday night portion of the Historic Bridge Weekend is on as scheduled. The dedication dinner honoring James Hippen will take place August 9th beginning at 6:30 at the restaurant. Everything else for the 4-day long event August 9-12, 2013 is on as scheduled.

Note: Don’t forget that registration for the 4-day event is due July 15th. Please contact Jason D. Smith at the Chronicles at: flensburg.bridgehunter.av@googlemail.com to obtain a registration form to fill out and return. You can also register through the Chronicles’ facebook page.

Here are some photos of the flooding taken by Quinn Phelan taken as the Wapsipinicon River was dropping at an enormous rate in Anamosa. A couple videos will be posted very soon on the facebook page of the Chronicles:


Flood waters cover the entrance of Wapsipinicon State Park at Anamosa
The Wapsipinicon River at Shaw Road Bridge


Information on the flooding can be found here as well.  Ironically, one of the bridges affected by the flooding, the Hale Bowstring Arch Bridge, was the site of an evening dinner that took place prior to the flooding. More information is found here.

This is the first of three in the series on the flooding situation in the US, Canada and Europe, which has been the central theme this past month. The next installment will focus on the flooding in Germany and parts of Europe and the impact it had on the livelihood of people affected and the bridges involved.

Name that bridge type: The answer to question 1






And now the answer to the question of naming the bridge type. As you will recall, in a posting from last Thursday, there was a post card of a bridge that spanned the Wapsipinicon River near Independence in Buchanan County, located in the northeastern part of Iowa.  While some people may have found the answer through James Baughn’s website, there are some who are not familiar with that, nor the picture, as it was posted most recently and readers have not yet had a look at the picture until now.

I can tell you that I had written about this bridge type a few years ago as part of an essay for a history class at the university here in Germany, and there are some examples of this bridge type that still exist today, even though there are two different types of this truss type that three bridge builders had used during their days.

The answer: The Thacher Truss. In 1881, Edwin Thacher (1840-1920), an engineering graduate of Renesselaer Polytechnic Institute,  invented and patented this unusual truss type. It is a mixture of four truss types: the Warren, Pratt, Whipple and Kellogg. While the Kellogg is a Pratt truss design featuring a subdivided panel supporting the original diagonal beams that connect the vertical beams, the Thacher features two sets of diagonal beams starting at each end of the truss bridge at the upper chord- one creates a panel similar to the Pratt truss, while the other crosses two or three panels before meeting the center panel, which forms an elusive A-frame. The bridge at Independence was the very first bridge that was built using this truss design. It was built in 1881 and was in service for over 40 years. Yet after having the design patented in 1885, Thacher went on to build numerous bridges of this type, most of which were built between 1885 and 1910. He later invented other bridge designs, some of which will be mentioned here later on.

Philips Mill and Crossing in Floyd County. Photo courtesy of the Floyd County Historical Society

While it was unknown how many of these types were actually built between 1881 and 1920, sources have indicated that Iowa may have been the breeding ground for experimenting with this truss type. Apart from the railroad bridge at Independence, the very first structure that was built using the Thacher, as many as four Thacher truss bridges were reported to have been built in the state. Among them include the longest single span truss bridge ever built in the state, the Philips Mill Bridge, spanning the Winnebago River outside Rockford, in Floyd County. Built in 1891, this 250 foot long bridge, dubbed as one of the most unusual truss bridges built in the country, was the successor to a two-span bowstring through arch bridge and served traffic until it was replaced in 1958. Other Thacher truss bridges built included one over the Shell Rock River north of Northwood (in Worth County), the Ellsworth Ranch Bridge over the Des Moines River in Emmet County and the Okoboji Bridge over the Little Sioux River in Dickinson County. Of which only the Ellsworth Ranch and Okoboji Bridges still exist today.

Ellsworth Ranch Bridge in Emmet County. One of many Thacher trusses built in Iowa. Photo taken in August 2011

On a national scale, if one counts the two remaining Iowa bridges, there are five bridges of this kind left, which include the Costilla Bridge in Colorado, Linville Creek Bridge in Virginia, and the Yellow Bank Creek Bridge in Minnesota. Two additional bridges, the Parshallburg Bridge (2009) and the Big Sioux River bridge in Hamlin County (2009) have long since disappeared due to flooding/ice jams and structural instability, respectively.  While the majority of the bridges mentioned here were constructed by the Wrought Iron Bridge Company in Canton, Ohio, the King Bridge Company in Cleveland constructed the Ellsworth Ranch, Yellow Bank and Hamlin County bridges, using a different hybrid of Thacher truss that was modified during James King’s reign as president of the bridge company (1892-1922).  The Clinton Bridge and Iron Company in Clinton, Iowa built the only Thacher pony truss bridge in the Okoboji Bridge, the bridge that is featured in the next article.  While the Ellsworth Ranch Bridge remains closed to traffic and seems to be abandoned, the Yellow Bank Bridge was relocated to Hastings, Minnesota in 2007 to serve as a replica of the Hastings Spiral Bridge at the Little Log Cabin Historic Village.

Okoboji Bridge over the Little Sioux River in Dickinson County- washed out after flooding. Photo taken in August 2011

And that is the answer to the pop quiz, even though for some experts in the field, the answer was obvious. Yet perhaps the next bridge type quiz may be even more challenging than the first one. As for the ones who didn’t know, this one should get you acquainted to the questions that are yet to come that will require some research. So let’s go to the next question, shall we?

Author’s Note: If you know of other Thacher Truss Bridges that existed in Iowa or any part of the US and would like to bring it to his attention (and that of the readers), you know where to reach him: flensburg.bridgehunter.av@googlemail.com or via facebook under The Bridgehunter’s Chronicles. He’ll be happy to add it in any future columns, and for his project on Iowa’s Truss Bridges, it will make an excellent addition.

BHC logo

Guessing Quiz: Name that bridge type

Photo courtesy of Luke Harden


Beginning in April, the Bridgehunter’s Chronicles will start a series on unusual bridge designs- namely bridge designs that were not commonly used for roadways and railroads but were built for experimental purposes.

This bridge is one of them. Before talking about the truss type, take a look at the picture above. This was discovered by fellow pontist Luke Harden and was brought to the author’s attention shortly before Easter. The bridge spanned the Wapsipinicon River in Independence, in northeastern Iowa. It consisted of two truss spans, yet when looking closely at the bridge, it features a rather unusual truss design. It is not necessarily a Warren truss for the diagonal beams form a W-shape. Yet it is not a Whipple, nor a Bollmann, for the diagonal beams slice through three panels before meeting the A-frame panel, which is also sub-divided.






This leads to the Chronicles’ Guessing Quiz, featuring two questions:

1. Name that truss type.

2. When was it built, in your opinion?  As the bridge no longer exists, the other question is when was it removed.

You can leave your answers in the Comment section either here or in the facebook pages bearing the Bridgehunter’s Chronicles’ name.  The answer will be given at this time next week, with some interesting facts about this truss bridge type.  Good luck with the guessing!