Ironhide Green No. 38.
Superior Graphite No.10743.
Minnesota Department of Transportation officials knew the names, identification numbers, and even basic chemical components for the paints their forebears used on the agency's bridges back in 1929, on the eve of the Stillwater Lift Bridge's construction. They were listed -- in black and white -- in the agency's specification books.
Until recently, however, they could only guess at how those colors actually appeared. After nearly eight decades, all traces of the original paints had seemingly been disposed of, sandblasted from bridges to make way for newer colors, or worn away by time and the elements.
Finding traces of the original color is a priority for the agency, as it intends to restore the lift bridge to its original color, as part of a $7 million Historic Stillwater Lift Bridge Management Plan and Repair Project.
The project was negotiated between federal and state agencies and is intended to mitigate impacts to historic properties a new, $715 million St. Croix River Crossing would cause. Construction on the crossing is scheduled to begin in 2013, with lift-bridge restoration likely to begin by 2019.
The lift bridge is listed on the National Historic Register and is one of 24 bridges MnDOT has identified for long-term preservation as part of its 2006 Historic Bridges Management Plan.
Last summer, MnDOT got a break in its search for the bridge's original color. Inside a waste bin for hazardous materials, a maintenance employee stumbled upon a can of dried up paint dating from the 1970s. Upon its label were printed specifications, an identification number, and a name with possibilities: "Highway Green."
"It's not the original paint, but it's as close as we have gotten," said Phil Erickson, MnDOT's metro-area bridge supervisor. "It's the color we had mixed and made to the original specifications back in the 1970s, and as near as we can tell, it's the original color of the lift bridge."
Erickson, who has worked with the agency's bridges since 1972, said the color -- which equates to a deep olive -- is one crews used to paint a handful of older bridges until the 1980s, when the agency adopted new color schemes featuring browns, grays and blues.
The agency's Maplewood materials lab analyzed the old paint's chemical components using a spectrometer, before matching those components to a recipe accompanying the paint's Sherwin-Williams identification number.
To avoid excess cost, officials will likely match that recipe against paints already in use by the federal government, said Bob Frame, a historian with Mead & Hunt, Inc., the agency hired to research the bridge's structural history as part of recently completed management and repair plan.
When the lift bridge is fully restored and converted to a pedestrian and bicycle crossing, possibly by 2019, visitors will see it the way it was conceived, he said.
"It was a wonderful clue," Frame said of the rediscovered paint can. "We had exhausted our possibilities and our available budget when this can of paint showed up."
Last summer, crews had scoured the lift bridge looking for samples of original paint; however, a thorough sandblasting the agency completed during the 1980s seemingly removed all traces. Old monochrome photographs proved little help, other than to indicate the bridge's color was darker than its current slate gray.
"Here we were looking for a green from a MnDOT bridge, and this (sample) looked like something that could be described in one of those old color manuals," Frame said.
An open house on the future of the Stillwater Lift Bridge held last Thursday yielded few changes to plans released nearly a year ago. However, new animations and a scale model of a restored and renovated structure breathed life into plans that had previously been trapped within two dimensions.
The model, painted deep green and built at a cost of $10,000 by Minneapolis-based Feyereisen Studios, showed that the bridge's current automobile lanes would be replaced by bicycle and pedestrian lanes that could be blocked by gates.
A restoration of the bridge's original concourse features, with LED lights installed into fixtures made of metal and plastic, to limit energy costs and replacement costs.
An animation demonstrating the restoration, as well as the management plan that explains it in detail, can be viewed at the Minnesota Department of Transportation lift bridge Web site at www.dot.state.mn.us/metro/projects/liftbridge/.
Under the management plan, the lift bridge structure and surroundings would be extensively rehabilitated within a year of the completion of the interstate bridge. Further, a loop trail would connect the ends of the lift bridge with the new interstate bridge about a mile downriver.
Also included in the management plan:
- damaged concrete piers beneath the lift bridge, steel trusses above it and railings along its deck would all be repaired or replaced.
- counterweight cables, wheels and other parts of the lift mechanism would be restored to allow the bridge deck to continue lifting for river traffic.
- existing blacktop road surface would be removed to reveal the original concrete, and railings and lampposts that are in disrepair would be fixed.
- in addition to the lift bridge being repainted its original deep-green color, its railings would be painted an "aluminum" color similar to one specified in the bridge's original specifications.
Whether the lift bridge project will be completed depends on the outcome of the St. Croix River Crossing project, which remains to be fully funded and is currently being challenged in federal court by the Sierra Club-Northstar Chapter. A verdict is weeks, and possibly months, away.
At the open house, state transportation officials seemed less concerned about the legal challenge and focused more on finances.
Todd Clarkowksi, MnDOT east area engineer, said the Legislature's decision last spring to fund Minnesota's roughly one half of the overall project cost in 2013 greatly increased the chances it will be completed.
Frequently, the federal government pays 80 percent of such interstate projects, while two partner states will split the remaining 20 percent. Although MnDOT anticipates Congress will grant funding for the project in the next federal transportation bill, the agency is prepared to pay for the entire project using state funds if federal funding isn't secured by 2013.
To date, Wisconsin has not committed to providing matching funds for a states-only project. According to Terry Pederson, district planning projects engineer for the Wisconsin Department of Transportation, the project is competing with a handful of other priority projects, mostly in the Milwaukee area.