The Orphan Bridge that Cobban Adopted: How It Was Lost

The year is 1912, the Titanic had sunk and some visionaries changed the Chippewa Valley forever. Logs were no longer flowing down rivers to the sawmills with the end of the Wisconsin logging industry. When the power company realized more electricity was needed, they decided to build an additional dam which would create Lake Wissota.

Fig.1 The Cobban Bridge.JPG

Moving the Orphan Cobban Bridge

This water wonderland, combined with Yellowstone Trail improvements which also began in 1912, brought tourists (and their money) in new horseless carriages to North Central Wisconsin. All great news for nearby Cobban except a new, nearly-500-feet-long pin-connected overhead truss bridge had just been placed over the Chippewa River. The bridge, deem too short for its new location, was scheduled for demolition.

But there was hope!

The community of Cobban realized a free bridge could replace their ferry over the same Chippewa River. During the winter, farmers disassembled the giant erector set of the truss bridge and moved each member 17 miles north, one-by-one via horse and sleigh. The structure was reassembled on both shores and pulled into position by a horse and cable across the river the following winter. The Cobban Bridge is now the last of this type still standing in Wisconsin.

Rehabilitation and Relocation

Over time road salt deteriorated components of the Cobban Bridge significantly. In 1996, it was closed and underwent major rehabilitation. In 2017 it was again closed to all traffic, vehicles and pedestrians. After the 2016 general election, information flowed down to the states regarding infrastructure improvements, the state adopted a new policy known as “Replace-In-Kind” in 2017.

While the total spending on bridge projects increased, this policy set spending limits on each, which channeled a way to maximize the number of bridges to be replaced. This same year, the Chippewa County Board authorized the replacement of the Cobban Bridge. The shortest and cheapest distance across the Chippewa River is where this historic bridge stands today.

Historic Registration Considerations

The Cobban Bridge is eligible for inclusion on the National Register of Historic Places, but because it is not currently listed, the National Historic Preservation Act (NHPA), Section 106 process was invoked. Consultation meetings were intended to solicit public mitigation ideas from stakeholders and the public in general. At the very first meeting, the preservation consultant suggested two commonly used mitigations:

  1. Sending high quality photographs to the Library of Congress

  2. Expanding the historical marker

The Federal Highway Administration (FHWA) was in attendance and indicated that there was precedence for allocating demolition funds to relocation. The Cobban Bridge Preservation, Inc (CBPI) concluded that the estimated demolition engineering cost would be sufficient for the project with reimbursement occurring after contractor bids validated the estimates.

By this time, CBPI had been formed with five team members: (1) the owner of a civil drafting and engineering firm , (2) the owner of a metal fabrication and welding firm, (3) a retired WisDOT bridge inspector, ((4) a retired educator as secretary and treasurer, and (5) the history-concerned founder/president.

At this first consultation meeting, we suggested relocating one span across the adjacent highway onto donated farmland to become a roadside park, as shown below.

Suggested re-location: Roadside park from donated farmland, along the adjacent highway

Suggested re-location: Roadside park from donated farmland, along the adjacent highway

Relocation Procedures

Following this first meeting, dozens of bridge repurposing sites were visited in Wisconsin, Minnesota, Iowa and Illinois. CBPI further concluded the same relocation procedures from a hundred years ago could be used again today and research and experimentation ensued (video above).

Railroad track would replace multiple wood cribbing columns on the ice. And across the adjacent highway, a tow truck would replace a horse. A house moving company would move the span 1/8 mile south to its ultimate destination on the donated property. An engineering firm was engaged to evaluate and it was determined the process was technically feasible given additional strengthening.

Simultaneously, WisDOT and SHPO were preparing the Memorandum of Understanding. The final mitigations approved were only the two original ones provided by the consultant in the beginning plus making the bridge available for ownership transfer with conditions. No other stakeholders were contacted to pursue mitigation ideas.

 Diverted Flow: Running into Challenges

The ownership transfer solicitation announcement contained a new long list of insurmountable requirements. CBPI chose to propose their relocation based on the requirements as publicized from the beginning. WisDOT ultimately decided that CBPI was not qualified, did not have the expertise or experience nor sufficient independent funding. The reimbursement had changed from the new bridge’s contract award time to after its completion. The proposal was denied. WisDOT engineers concluded that the only viable relocation process was to “pick” the spans using massive cranes on land and river barges.

 In retrospect, two tragic strategic errors were made. First, there was a lack of communications among CBPI and various agencies. All other repurposed bridge projects were either a public or  public/private partnership, where there were formal arm’s-length communications among the agencies. In fact, it was a competitive proposal process that prevented CBPI from learning that a township to the north had expressed an interest in the other span.

The second strategic error was not involving media or press from the very beginning. The intention was to maintain a low profile and good relationships. In hindsight however, both decisions contributed to the ultimate project failure.

 Digitally Preserving the Bridge

With the bridge heading for demolition, a jewel in the sand arose in the form of an article in the Merrill Foto News covering the imminent demotion of the T.B. Scott Mansion. The structure had been laser-scanned for documentation. CBPI contacted Matt Jarosz, the Executive Director of the Wisconsin Trust for Historic Preservation. His immediate and overwhelmingly-optimistic response resulted in three of his staff members spending an entire day at the Cobban Bridge, documenting the structure with tripods and drone scanners. This work generated three dimensional computer model for public viewing.

Fig.3 model .jpg

Even though the historic Cobban Bridge could not be physically preserved, the hi-res, detailed authentic rendition of what was lost due to a short-sighted vision of history can be viewed forever by generations to come.