Monday, April 21, 2008

Washburn Grain Elevator Complex Reuse Study: A Case of Extreme Preservation?


Perhaps a sign that historic preservation is raising its building-saving success level, a 215-foot-high complex of concrete cylinders supporting a nearly inaccessible five story concrete structure, are now being studied to find reuse possibilities that can keep the complex a productive component of the Minneapolis Historic Riverfront. Now that rehabilitation of brick warehouses has become a routine activity, the preservation movement may be readying itself for what could be called “extreme preservation.”

The Washburn Grain Elevator Complex Reuse Study was conducted by Thomas R. Zahn & Associates and Miller Dunwiddie Architects, and was prepared for the Minnesota Historical Society and the Mill City Museum.

No. 1 Elevator was built in 1906-1908, consisting of 15 cylindrical reinforced concrete shafts 120 feet high with a 750,000 bushel capacity, topped with a steel and concrete 95-foot-high head house. Within the head house, incoming grain was machine-cleaned, then
transported by a sizeable horizontal conveyor to the nearby A mill for processing into flour. Saint Anthony Falls Rediscovered, a 1980 publication by the Minneapolis Riverfront Development Coordination Board, notes the reinforced concrete cylinders were built with a slip-form method that facilitated the construction. A smaller elevator with 15 storage shafts were built in 1928, between #1 Elevator and the A Mill.

The Washburn Grain Elevator Complex design became a true application of “Form follows function,” the cardinal architectural dictum promulgated by the Early Modern Movement a decade or so later. Here the milling process determined the shape and structural configuration of the complex, an innovative change from design and construction of the grain processing facilities that preceded this project.

The Washburn Grain Elevator Complex, once part of one of the largest industrial areas in the world, experienced over seven decades as grain storage for nearby flour milling facilities. The elevators became empty in the early 1980s after their grain storage use was halted, and now used now as a habitat for some stray pigeons and raccoons. The unusual architecture of this empty site evokes an eerie feeling for the few people who enter this place that is no longer intended for human presence As John Crippen, director of Mill City Museum with oversight of this study, remarked, “There seems to be an illicit sense about the place.”

As if seeking to make the reuse study as difficult as possible, the team mandated a high level of preservation principles. No window openings would be cut into the unbroken curved surfaces of the bin shafts, and no entrances providing access would penetrate public view sides facing West River Parkway and the Chicago Avenue plaza. The exterior shell is to be kept as near original as possible.

The study encountered several formidable challenges. On one hand, the volume of space is very large, yet the 30 round concrete cylinders built as closed containers with diameters of 13’-9” and 18’-0” clustered together repel the typical historic building reuses such as living units, office spaces or other functions needing relatively large flat floor plates with convenient access to corridors and exits. As if not attempting to pound a square peg in a round hole, team
members’ study of the bin shafts placed minimal work on uses requiring floors and instead investigated storage type uses. No specific uses for the bin shafts were identified that could be readily applicable for these cylinders, but several in-the-future potential ideas were examined, such as coolant water stored for district air conditioning. But can “nothing” be a possibility – that is, emptiness itself have a function? A highly unusual possibility for this nothingness factor, already in operation elsewhere in the nation, would be a series of aural chambers in which avant garde music could be enhanced by empty space giving sonic reverberation to sounds induced into the shafts. Storage of what could be called archival materials is another possibility.

The building component called the head house, the tall rectangular form, five stories stepping down to three stories, that looks like a typical building situated on top of the cylinder cluster, does have typical floors and series of windows. In Crippen’s words, “This is the part of the complex that has a human scale.” The total head house floor area totals 1,750 square feet, enough for multiple functions, augmented by ceiling heights ranging from 17 to 20 feet. The long and narrow profile of this structure situated high above the adjacent mill district structures, presents panoramic views of the river on one side and downtown Minneapolis on the other. Possible uses such as condominiums, prestige office spaces, events facilities and other uses seemed feasible given the height and floor areas. A shortcoming of head house reuse is access – elevators and exit stairways would present more difficulty than retrofit in typical multi-story buildings, but the team located a means of constructing them that was workable and within an area where the grain elevator complex abuts the adjacent Mill Museum building. Another shortcoming is the lack of on site parking, but two city ramps are within short walking distance.

What may be an important re-use in general terms is for expansion of Mill City Museum that is out-growing its present facility, as more museum storage and ancillary spaces is being considered. Perhaps more significant, Mill City could use the complex in an as-is condition as an interpretive center, with guides leading tour groups through this unusual outlay of spaces and volumes that still contains much of the original operating machinery. Several mining towns and industrial sites have turned to visitor interpretive use, keeping their facilities untouched, with rust and dust all around, to present the raw original workings of the site for guided tours.

In the meantime, Mill City Museum is planning to embark on a necessary first step — to develop a stabilization plan to repair exterior concrete surfaces. Otherwise, in terms of current maintenance, the sheer simplicity of these large volumes requires no repair.

The Washburn Grain Elevator Complex Reuse Study provides Mill City Museum with the task of making the reuse recommendations set in place. Right now, the mill building complex exists as an anomaly – a towering but mute presence in the center of an important and most vibrant surrounding neighborhood.

(For more information on Bob Roscoe, go to Design for Preservation)

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