Have you ever considered making drastic improvements to your facility? I’m talking about the kind of improvements that update facility infrastructure, improve efficiency, and provide greater flexibility in order to grow and adapt to the ever-changing economy of your market.
Recently Ford Motor Company's Louisville Assembly Plant started full production on the new Ford Escape. The plant is not only producing a different product after many years of producing the Ford Explorer, but the plant has been revamped to be a flexible and advanced manufacturing facility. The plant reportedly can manufacture up to six different vehicles at one time. Luckett & Farley worked closely with Ford to provide the necessary structural modifications in the opening phase of the renovation. In order to upgrade the facility, changes had to be made not only to the process equipment, but to the plant's shell structure to allow the new adaptable manufacturing process to fit. The total investment by Ford Motor Company in the Louisville Assembly plant was awarded a top 15 ranking of corporate investments in the U.S. for the year of 2011 by Trade & Industry Development magazine. A project that began in-part with Luckett & Farley providing services that included scoping documents for demolition of existing equipment and significant structural modifications.
The Race Against Time
The timing of the project was critical to clear the plant for further renovations. The structural renovation work needed to be completed in a little over a month due to the timing of plant shutdown and the deadline for new equipment installation. In total there were 81 roof trusses that had to be cut with about 40 different design conditions, due to loading and truss cut geometry, to clear the path for a new suspended conveyor. No simple and quick task for design and definitely not for construction. Due to the schedule, the labor time was more critical than the material cost of the modification. Labor hours are always important when considering costs, but total time was just as important as cost to keep the overall renovation on schedule.
How to fit a Square Peg into a Round Hole
The original plant structure consists of 50 ft long structural steel trusses spanning between structural steel girder trusses spanning 45 ft between columns. Conceptually the new manufacturing program required the specific trusses to have 2'-0" cut outat the total depth of the truss. This was significant, especially considering that some of the trusses required the cut along the entire truss length. After reviewing the cut requirements and the truss geometry, the solution Luckett & Farley proposed to Ford was to cut more depth out of the truss than the required 2’-0”, which is not exactly inside the box thinking when it comes to truss design efficiency. In this particular case a cut at about mid-depth of the existing truss would simplify the connection geometry. This was especially true at the center of the span, where a majority of the trusses transitioned from the cut depth to full depth, which creates significant web member forces. Essentially a deeper cut would simplify construction, design, and most importantly save time. The drawback of this solution was higher truss chord forces which meant more steel at the truss chords. The additional steel was insignificant relative to the overall time savings.
Opening Up the Possibilities
The construction phase was one of those project experiences that will always be remembered due to the challenges and the eventual success. The number of welders and iron workers working on this project was incredible when you consider the relative size, but again the schedule required that type of effort. There were approximately 27,000 man hours spent installing over 225 tons of truss reinforcing steel to complete the truss modifications within the one month schedule (information courtesy of Midwest Steel, the installing contractor). In order for the project to be successful it required close and frequent interactions between the structural engineer, the construction manager, steel fabricator, the site superintendents and the inspection and testing agency.
In the end the success of the project was just one piece of the overall renovation of the plant but front and center on the critical path to launching the new Escape.
The Design Solution to cut more helped spend less...time and money. Exactly what companies need to reduce time to market and meet critical deadlines.
When you choose an engineer, look to someone with solutions like these that add value to your company!