1 August, 2007: Five Years Later: How the Minneapolis Bridge Disaster changed the way we look at Bridges

I-35W Bridge Memorial. Photo taken in August 2011

It was a day like no other in the summer time: thousands of people leaving their workplaces to get home with others taking their children to a baseball game in the middle of the city. It was a hot summer afternoon and traffic was dense, with tempers flaring from people who are late for a meeting or other commitment. As they head into the city, they cross a gigantic bridge over a mighty river, only to find that the second they got on, they ended up in the water, swimming for their lives and helping others in need. Eyewitnesses videotaping the bridge saw each span falling into the water, one after the other.
The St. Anthony’s Bridge in Minneapolis, Minnesota (USA), a steel deck cantilever truss bridge over the Mississippi River carrying the freeway I-35W was one of the most travelled bridges in the Twin Cities. Built in 1967, it served one of the main arteries and was undergoing some maintenance work, when it collapsed. 13 people died in the tragedy, more than 150 people were injured and that particular artery going through Minneapolis was cut off for over a year and a half while a new bridge was being built.
Five years later, a lot has changed. The disaster served as a wake-up call for the US, with hundreds of billions of dollars being spent on improving the infrastructure, replacing bridges deemed structurally deficient and making the highway system “safe and sound,” the term coined by the Missouri Department of Transportation and the title of its program. Yet we still have a lot of deficiencies that we need to work on in order to ensure that we have a sound infrastructure but not at the expense of historic bridges and the bank.
For instance, the Minneapolis bridge disaster sparked a crusade to eliminate truss and cantilever truss bridges- or at least those with ineffective gusset plates. It started in Minnesota and worked its way to other parts of the country, like Pennsylvania, which has one of the highest numbers of truss and cantilever bridges in the country.  Instead of replacing the ones that desperately needed it, many them were wrongfully replaced when they were in pristine condition, and even if there were some defective gusset plates, these could easily be replaced without having to bring the entire structure down using falsework for support. This includes the two cantilever bridges over the Mississippi River in St. Cloud: the Granite City Bridge (replaced in 2008) and the Sauk Rapids Bridge (replaced that same year as well). This crusade has accelerated the decrease in the number of historic bridges built prior to 1950 nationwide, despite attempts on the part of the state and local agencies and private sectors to save the ones that have the greatest historical significance in terms of design, history and other factors.

Close-up view of a gusset plate on a pony truss bridge in Iowa. Photo taken in August 2011

The collapse also created an enormous backlash on the preservation community and the Preservation Policies, such as Section 106 of the Historic Preservation Laws of 1966, where bridges slated for demolition are to undergo environmental and mitigation surveys to determine the alternatives to demolition and document the structures’ historic significance. Many politicians have touted this policy as a waste of time and money and would like to see it scrapped, while many preservationists and pontists have taken substantial amounts of heat for interfering with progress and being “trouble-makers.” The fortunate part is with the economic crisis in the USA, there has been a change in heart among many who would like to see historic bridges preserved and have embraced some of the preservation practices as a way of saving money and prolonging their lifespan.
Then we have the financial aspect, where many bridges that were structurally deficient but not in danger of collapse are being replaced outright, without consideration of the costs. As a general rule, replacement is more expensive than restoration and rehabilitation, pending on the type of work needed to be done on the bridge let alone the type of bridge. When the I-35W Bridge collapsed, there was a consensus that every bridge that is structurally deficient needs to be replaced. The problem with that draconian approach is that it has been draining the financial resources on both the state and federal levels to a point where many of the bridges that have been deteriorating to a point where repairs are necessary had to be closed off to all traffic and the owners having to wait until funding is available to either fix or replace them. Some that can still carry traffic have weight and height restrictions on them, with some going to extremes by threatening motorists that the bridge would be closed to traffic if the restrictions are ignored.

I-35W Bridge Oblique View. Photo taken in August 2011

But the collapse of the I-35W started a renaissance where the public has become more aware of not just the bridges that are structurally deficient and need repairs, but also those that are historically significant and should be restored for reuse. The media has taken a Steven Jobs approach and presented facts and figures that are either sobering to the public, who takes these figures seriously when presenting their opinions about historic bridge preservation vs. replacement or biased to one group or another in order for them to have things their way. What is meant by this is as these facts and  figures are presented and there is a bridge in their vicinity that has weight and/or height restrictions on them, the public usually divides themselves up between those who want the bridge saved and those who want it replaced, thus becoming more involved in the decision-making process. The media has for the most part taken a neutral stance and has indirectly encouraged the public to engage more in these debates.
This public involvement has also spread into the social networks and produced online columns and blogs, where support for historic bridges is being garnered by people from faraway places. While bridge websites, such as James Baughn’s Bridgehunter, Nathan Holth’s HistoricBridges.org or Nic Janberg’s Structurae.net were established prior to the disaster, other online columns, like this one, Tony Dillon’s Indiana Bridges and Kaitlin O’shea-Healy’s Preservation in Pink have taken the stage to address the importance of historic bridges and ways to preserve them, research them to determine their historic significance and bring them and topics involving them to the attention of the public. Even organizations preserving historic bridges, like the Riverside Bridge (in Missouri) and the Waterford Bridge (south of Minneapolis) can be found on social networks, like facebook, and support for these bridges have come not only from within their vicinity, but also from outside as well. This has created an interdependence between the public, the media, and agencies and other organizations where action to preserve or replace a historic bridge has an impact on those who have a connection with them in one way or another. In the case of the Waterford and Riverside Bridges, support for preserving them have skyrocket by up to 200% in the past year, while the media and other historic bridge organizations have reinforced that support through their expertise and knowledge of the subject.
The disaster also fostered the need to exchange information and knowledge on historic bridge preservation. This includes the introduction of welding and other techniques to restoring a historic bridge presented by people, like Vern Mesler, who has held seminars like these in Michigan since 2009. Other steel companies, like BACH Steel, an ally of Julie Bowers and her organization, Workin Bridges in Iowa have engaged in disassembling and restoring metal bridges, while other companies dealing with bridge construction have taken a keen interest in this preservation practice. Many of the bridge companies mandated to replace historic bridges do not fancy destroying them in favor of progress and have become more open to other suggestions, such as relocation or storing them for reuse elsewhere. This was seen with the Upper Bluffton Bridge, where the contractors allowed for some time to see if the owners are willing to take at least part of the two-span truss bridge. The Queenpost truss span was taken in the end, while the Pratt through truss span had to be scrapped, despite the support to save the entire structure.
What has become the most useful of all is having historic bridge seminars and conferences, designed to present these themes- preservation, tourism and the bridges themselves and the stories about the successes- to the attention of the audience. This includes the Historic Bridge weekend, which was started in 2009 by Todd Wilson of Bridgemapper.com and features presentations by bridge experts and tours of bridges in the area of venue. The first two took place in the greater Pittsburgh area, last year’s conference took place in Missouri, while this year’s conference will take place in Indiana, one of the states with the most populous historic bridges in the country. Plans are in the making to host one in Iowa in August 2013. The number of people attending such events have increased since 2009, which is a sign that the interest in historic bridges and preservation is there, and as the news goes around, more people will attend these events to gather information and support for preserving their historic bridges in their communities or their backyard.
There is a reason for the need of such seminars and conferences: tourism. One may never think that historic bridges can be such a tourist attraction, but it is. With rails-to trails programs, many of the historic bridges that used to serve rail traffic are getting a new lease on life as a pedestrian bridge, many historic bridges are being relocated to trails and parks to serve both as an exhibit as well as crossing for cyclists and pedestrians. This includes the Historic Bridge Park in Michigan, the F.W. Kent Park in Iowa, and the Delphi Trail in Indiana, just to name a few. There are even parks where a historic bridge is their centerpiece, and the numbers are increasing. This goes beyond the ones that are in my neck of the woods, like the Freeport Bridge Park outside Decorah and the Moneek Bridge Park in Castalia, both in Winneshiek County, Iowa and the Covered Bridge Park in Zumbrota, Minnesota. These parks have provided tourists with an opportunity to get to know the structure and its role in the development of America’s infrastructure, while at the same time, many communities have cashed in from having these grandiose pieces of artwork, in one way or another.

Moneek Bridge at the park in Castalia. Photo taken in August 2011

Still despite all this, we are still lacking the educational aspect of preservation versus replacement, let alone learning to design a structure that is appealing to the public. That means that on the one hand, there is a lack of sufficient knowledge on how to preserve and maintain bridges with historic value because of the lack people with experience, combined with the lack of will to engage in preservation practices and the dollars and sense to preserve these structures. The mentality has been to fast-track as many bridge projects as possible so that they have the new structure in place as soon as possible, regardless of its appearance. Most of the bridges built today are bland and tasteless, and have a lifespan that is much shorter than the structures of yesterday (at least 70 years ago). Even the cable-stayed bridges, the norm for bridge construction, is not the permanent solution, as like beam, girder and slab bridges, their wear and tear can be seen more quickly because of weather extremities combined with traffic loads that are 10 times more than what we were used to 20 years ago. We need to veer away from the mentality that we need a bridge that lasts for 100 years and does not require maintenance and embrace in education on how to preserve historic bridges, how to maintain bridges, and how to design bridges that are appealing to the drivers but have no design flaws and are meant to last for more than 20 years. We also need to encourage more rail and public transport services to wean motorists away from the car and alleviate the load on our aging structures. We also need to enforce sanctions on people who violate the weight restrictions and destroy a bridge as a result. And most of all, politicians should take a backseat with regards to bridge preservation vs. replacement. We have capable bridge engineers, preservationists and bridge technicians who have the capabilities to determine which bridge needs repair work or replacement and which ones deserve to be restored for reuse. It is the job of the politicians not to interfere with these issues but foster them. We live in an interdependent society where the action of one affects all, and this holds true for historic bridges in the United States, which are decreasing by the dozens as each year passes.
To finish up on this piece, we have to say that we have learned a great deal from the disaster of five years ago. We know what the main causes of the disaster were. We know that we can never afford to repeat this again. Yet we know that there is a right and a wrong way of treating this issue- bridge design, bridge construction, bridge maintenance, and bridge preservation. We know that the public has a very keen interest in this subject. And as we cross the new I-35W Bridge in Minneapolis, looking at the neighboring 10th Avenue Bridge, a concrete arch bridge built in the 1920s, we know how to get it done. It is just a matter of listening and learning from others and taking the right course of action to ensure the all will be happy with the results.

10th Avenue Bridge, located right next to I-35W Bridge. Photo taken in August 2011

There are a lot of reactions to the five-year anniversary of the I-35W Bridge Disaster, but some examples are posted in the next article.

From Bridges to Borders: How Carelessness is destroying our (Historic) Bridges


Taken by Bradley Widding; used with permission

It is a scene that drives everyone up the wall: a driver turns off the main highway onto a gravel road in an overweight truck carrying a trailer with oversized equipment. The total weight is 9 tons with the maximum height of 14 feet. He approaches a through truss bridge, whose vertical clearance is 13 feet and has a weight limit of 3 tons. The driver has taken his truck across the structure many times as it serves as a shortcut to his destination, plus the Pratt structure built in 1890 represents a picturesque view of the river valley. While he sees a weight restriction sign, he disregards it and goes across it, only to find that the whole structure swayed side-to-side and as he managed to get off the bridge, the whole structure fell into the river! He gets out of the truck and surveys the damage only to react with the words “……!”  (I’ll let the reader fill in the blanks).

This happened to the Fryer’s Ford Bridge in Conway County, Arkansas this past Monday, as the driver of an H20 Transfer Service truck carrying a trailer with a hose track dropped the truss bridge into the water as he was getting off. Although he claimed that he had crossed the bridge many times before, this time was definitely his last; especially because of the fact that he was later ticketed for driving an oversized vehicle on the bridge and is expected to face more legal action in the coming days. While the bridge may be rebuilt as it sustained minimal damage from the photos taken at the scene, the Wrought Iron Bridge Company structure will be reduced to recreational use only as it will never be able to serve vehicular traffic ever again. And it will be unfortunate as it was the oldest bridge of its kind still in operation in Arkansas before the accident took place.

This scene has been played out many times over again throughout the country as the infrastructure in the US is crumbling to a point where the country is on the same level as a third world country, such as Uganda, Sudan, or even Libya. The latest report card issued by the American Society of Civil Engineers has graded the infrastructural system in the country as a whole a D, with the bridges being graded a C. However, when it comes to awareness of historic structures and ways to preserve them, let alone inform the public about the restrictions historic bridges have- especially with regards to weight limits- the grade for that one is D- at best; ironic given the fact that the literacy rate in the US is 99%, and one can obtain information everywhere at any time. Why is this the case?

There are two arguments that play a role in the problem with historic bridges and awareness. The first is with regards to the lack of maintenance. Normally for structures, like the Fryer’s Ford Bridge or any bridge to be exact, one has to find ways of maintaining the structures as they are. This means that they must be inspected regularily, repairs must be done when and where needed, and in case the bridge may approach the end of its useful life, one must try and prolong it as long as possible, which includes rehabilitating it at a fraction of the cost of replacing it with another bridge- at least a quarter of the cost to be exact. That means for a historic bridge, the cost for rehabilitating a structure like the one in Arkansas could range from $20,000 to $120,000 pending on what needs to be done with it, which could include new flooring, strengthening the beams and other connections and painting it so that it is rust resistant. By replacing the bridge outright with a concrete span, the cost could go up to $500,000, which in the end, tax payers will be footed the bill. Should restrictions be needed, they should be posted accordingly, and fines should be imposed on drivers caught disregarding the restrictions. Unfortunately though, most of the time this happens when it is too late.

Putting historic bridges aside, there have been many bridge failures due to the lack of maintenance and the lack of information on the structures and their capabilities to handle traffic. A couple of regional examples coming to mind include the partial collapse of a bridge carrying a county highway south of Brewster, Minnesota on the Nobles and Jackson County borders on 19 October, 2010, as a milling machine was on the bridge during the construction of the county road. One half fell through leaving the other one open to one way traffic only. That bridge is scheduled to be replaced this year. The other example is the collapse of a Kingpost pony truss bridge in western Winneshiek County in Iowa in 1995, after a county maintenance vehicle crossed it. And then there is the infamous I-35W Bridge in Minneapolis in 2007, a cantilever deck truss bridge that failed because of too much equipment on the structure. This disaster in particular served as a wake-up call to look at the American infrastructure and its dire state.

Transversal view of the county bridge near Brewster. Photo taken by Brian Korthals of the Worthington Daily Globe, used with permission
The Milling Machine being removed from the wreckage. Photo taken by Brian Korthals of the Worthington Daily Globe, used with permission

While wreckages involving historic bridges through accident caused by lack of maintenance may be annoying, what drives many people to the boiling point is when accidents can happen due to a combination of ignorance, carelessness, and in many cases, downright stupidity. Many times drivers with overweight or oversized vehicles ignore the weight restrictions signs and proceed to cross the bridge haphazardly, risking the damage or destruction to the structure itself, let alone to the property of the driver himself. Sometimes excuses are brought up to justify the actions, although much of them have been questioned by local authorities, let alone the preservationists. The primary excuse used for justifying the actions of crossing the bridge is that “It has been done before.” Those who read about the collapse of the Fryer’s Ford Bridge have countered that claim saying that it was no excuse, and that “….everytime the person crossed the bridge (with too much weight) was damage inflicted on the structure, weakening it significantly.” Another excuse used in justifying the crossing was that the bridge was a shortcut and that taking a detour costs money and time. This was used with the Frenchmans Bluff Bridge in Lincoln County, Missouri in 2006, when an oversize delivery truck brought down the 1886 iron Pratt through truss  structure built by the King Bridge Company.  But not all bridge mishaps have to do with overweight vehicles. Carelessness in general, resulting from reckless driving, can also produce dire consequences, as was happened with the Blood Run Creek Bridge in Livermore in Humboldt County, Iowa in 2003, as a pick-up driver lost control and slammed into the Pratt through truss bridge, taking the 1901 structure down in the process. The bridge was one of the last built by the Marshalltown Bridge and Iron Works in Iowa.

Blood Run Bridge in Livermore. Photo taken by Jason D. Smith in 1999

So what do we do with this compound problem? This is a question which everyone is asking themselves even as this column is being read. Most of the time when mishaps involving bridges take place, those who caused the accident are usually the ones getting away with a small fine and a slap on the wrist. The sad part about this aspect is the fact that it also applies to historic bridges, like the Fryer’s Ford Bridge; especially given the fact that it was listed on the National Register of Historic Places. And many historic bridges destroyed by carelessness caused by lack of maintenance combined with recklessness on the part of the drivers are either eligible for listing on the National Register or are listed already. But even with the bridge near Brewster, which is not considered historically significant, one has to maintain the structures to cut costs for replacing them outright and to prolong their structural lives, while at the same time, apply strict rules to protect them from damage caused by reckless driving or even vandalism. There’s no such thing as a bridge that is built to last 100 years and needs no maintenance, as was stated by the Pennsylvania Department of Transportation at one time, last year. Bridges have to be maintained for the purpose of safety, cutting costs and (in the case of historic bridges) structural integrity. State of the art technology is being introduced to determine the stability of the structure and ways to make more precise repairs to them, regardless of the bridge types (truss, arch, beam, etc.) It is more of a question of investing the time, money and effort in doing that, which is possible, even in light of the current economic crisis.

There is however the upgrading of sanctions against drivers who willingly ignore restrictions on bridges and cause accidents by crossing them intentionally. It does not necessarily have to deal with very strict guidelines like the laws in Singapore, which fine people hundreds of dollars for even spitting on the sidewalk. Nor should it be as detailed as the Flensburg Point System, where persons could receive 7 points on his driving record, be forced to take driving classes and be paid thousands of dollars in fines had such an incident occurred in Germany (please refer to the sister column’s article on the Flensburg Point System).  But it should hold drivers accountable for any damage caused to the bridge, no matter how severe nor does it matter the circumstances. They can range from the driver paying for repairs to the bridge, let alone for a new one, to having the driver’s license revoked, to even taking compulsory classes on driving safety.  This is especially important for historically significant bridges, like the Fryer’s Ford Bridge, as stricter laws will serve the purpose of providing a lesson in respecting pieces of American History which are becoming rare by the year, as well as in driving safely in areas most sensitive to traffic and the changing driving habits, which have become more erratic over the last 15 years.

While the future of the Fryer’s Ford Bridge still remains in doubt after the accident, this mishap will serve as a reminder of how precious historic bridges like these really are. The questions that all of us should ask ourselves are the following: 1. Is it worth cutting funding for improving our infrastructure or should we find other sources where cuts would be needed (like defense spending, for example), 2. Is it worth spending more money on a new bridge when we could maintain and even rehabilitate the old one to prolong its life a bit more at less cost, 3. Is it worth taking the shortcut to a bridge that is unable to carry the weight of your own vehicle just to save on gas and time, or is it worth making that extra three mile detour, and finally 4. Is it worth being ignorant or should we be aware of what we have and what we can do to better things? After all, one can make do with what little is available at his disposal without having to spend extra at the cost of others….

Fryer's Road Bridge: Future in limbo after accident. Photo taken by Bradley Widding, used with permission.

The author would like to thank Bradley Widding, Kari Lucin and Brian Korthals for the usage of the photos and the contribution to this column.

Links:

Fryer’s Road Bridge:

http://www.bridgehunter.com/ar/conway/fry/

http://www.todaysthv.com/news/article/153099/2/Truck-collapses-historic-Conway-Co-bridge

Frenchmans Bluff Bridge:

http://www.bridgehunter.com/mo/lincoln/frenchmans-bluff/

Blood Run Creek Bridge:

http://www.humboldtnews.com/main.asp?Search=1&ArticleID=501&SectionID=12&SubSectionID=12&S=41

http://www.bridgehunter.com/ia/humboldt/blood-run/

Brewster Bridge:

http://www.dglobe.com/event/videos/tag/bridge%20collapse/

http://www.dglobe.com/event/article/id/42002/publisher_ID/24/

American Society of Civil Engineer’s Report Card for 2009:

http://www.infrastructurereportcard.org/

The Flensburg Files Column on the Flensburg Point System:

http://flensburgerfiles.areavoices.com/2011/04/04/flensburg_points_system_60/