Our recent work for Skana Aluminum Company in Manitowoc, Wisconsin was tons of fun – literally. More than six tons, in fact.
In 2017, A.C.E. Building Service was tasked with a casthouse expansion project for a new 21,500-square-foot facility. The expansion is part of a multi-phase project at Skana Aluminum initiated to replace its 1960s-era melting furnaces. The additional square footage made way for a new, state-of-the-art furnace and expanded raw material storage area. It is designed to accommodate a new furnace as one of the future stages in the overall project. Eventually, a total of three 50,000-pound capacity melt/hold/tilt furnaces and a new casting pit will replace the existing furnaces and casting pit.
A Business and a Building Steeped in Tradition
Skana is in a business — and a building — steeped in tradition.
By the 1890s, aluminum was widely used in jewelry, everyday items, eyeglass frames, and optical instruments. Aluminum tableware was produced by the late 19th century and gradually supplanted copper and cast-iron tableware in the first decades of the 20th century. It wasn’t long before aluminum foil was invented, a mainstay of modern kitchens. Aluminum is soft and light, making an ideal material for a multitude of uses. It was soon discovered, however, that alloying it with other metals could increase its hardness while preserving the low density — a factor which led to even more uses for aluminum.
Skana’s current location formerly housed the Mirro Company. Mirro is widely remembered as an iconic cookware manufacturer and was a major business in Manitowoc from 1909 to 2003. During World War II, Mirro retooled its factories to make aluminum products for the military. At its peak, Mirro was the world's largest manufacturer of aluminum cooking utensils. At one time, it had as many as eight manufacturing plants in three states, with products ranging from pots and pans to small boats and aluminum siding.
Today, the successor occupant of the facility — Skana Aluminum — is unique in the fact that it has melting and casting operations, as well as a rolling mill, all under the same roof. It is both the oldest and largest rolling mill in the state of Wisconsin.
Skana Aluminum is a fully integrated rolling mill, with direct chill (DC) casting, hot and cold rolling, slitting, and tension leveling practices that provide finished coil, sheet, and circle capabilities. Skana is very efficient at casting small quantities of specialized alloys, yet continues to excel servicing those customers who desire higher volume of more common alloys. Its DC casting process and subsequent processing methods allow the company to obtain the extremely small grain structure that is well-suited for deep draw O-temper requirements.
The Best Option: Butler Manufacturing
The A.C.E. project team relied on our partnership with Butler Manufacturing to provide a pre-engineered structure capable of meeting schedule, budget, and design demands that conventional steel could not match. The expansion solution selected was a Butler pre-engineered structure, specifically chosen for its design flexibility, cost effectiveness, and the expeditious schedule Butler offered for getting materials on-site. Todd Gorter was A.C.E. Building Service’s project manager for the Skana Aluminum project. Engineering services were provided by SMI, Inc. in Manitowoc and ZS Architectural Engineering, LLC in Milwaukee.
The Loading Dock Challenge
Skana Aluminum has very active loading docks. As part of this project, three docks were to be affected, which would have significantly impacted its operations. A.C.E. Building Service formulated a plan to split the project into two phases. The first phase included the demolition and reconstruction of two loading docks. A temporary wall was constructed so Phase I could remain weather-tight while Phase II — and the other loading dock — were constructed.
A major challenge was determining how the new casting furnace would interface with the existing building. The A.C.E. team had to structurally modify the existing building where the new furnace is located, in some cases yielding just a few inches of clearance of the 580,000-pound piece of equipment.
Unique Technology to the Rescue
ZS Architectural Engineering, LLC employed BIM modeling software to identify potential interferences which allowed Skana's equipment manufacturer to understand how its furnace would fit inside of the existing building. BIM (Building Information Modeling) is an intelligent 3D model-based process that gives architecture, engineering, and construction professionals the insight and tools to more efficiently plan, design, construct, and manage buildings and infrastructure.
Finally, the foundation for the 290-ton furnace needed to be constructed in the middle of a busy plant floor and in close proximity to existing structural building columns. The excavation required for the footing was approximately 11 feet below grade. Approximately 12,000 cubic feet of material needed to be excavated and removed to allow for the construction of the furnace pit foundation.
“The furnace pit foundation floor is 36 inches thick and is reinforced with more than five and a half tons of rebar - just in the floor!” noted Gorter.
“This project was truly a unique experience to be a part of,” added Gorter. “If you've never seen a piece of equipment that weighs over half a million pounds melt, tilt, and pour molten aluminum, it is quite a neat experience. To be a part of the project that allowed this new technology to be placed in the facility was awesome.”