Project SummaryWhen Perkins Specialized Transportation Contracting learned that a utility needed to transport a 400-ton generator from California to Utah, the company’s President and Chief Executive Officer Neil Perkins immediately grasped the stakes. “It was a lot like a moon launch,” he explains. “There were no rehearsals and the risk was high. If the transporter trailer had a structural failure on the freeway or crashed down a mountain, the resulting costs would be unimaginable.”

Perkins Specialized Transportation was uniquely prepared to tackle the daunting project. Not only did the Minnesota-based company have decades of success hauling super loads, it had the resources required to design, plan, and execute the mega-transporter project flawlessly. Using Autodesk® Inventor® Professional and Autodesk® Simulation Mechanical software, the company digitally designed and simulated the transporter trailer and its route before welding a single part. “Planning was absolutely critical on a project of this size,” says Perkins. “We simulated and tested everything in engineering and operations for three years.”

With help from Autodesk software, Perkins Specialized Transportation:

• Integratedsimulationearlyintheproductdevelopment process, helping to optimize the design

• Metstringentstateregulationsforaxleweightand gross vehicle weight

• Negotiatedchallengingintersectionsandhighwayentrances and egresses as planned

• Delivereditspayloadwithinhoursofascheduleset 18 months earlier

The ChallengeTo get permits to traverse California, Nevada, and Utah, the transporter designed by Perkins Specialized Transportation needed to meet axle weight and gross vehicle weight requirements set by those states. In addition, it had to overcome a host of operational challenges. Perkins explains, “The transporter had to negotiate 8 to 10 percent grades, back up two miles, and reach a maximum speed of 30 mph—twice as fast as any existing heavy-load transporters. To cross highway structures, it needed to expand from 20 feet to 34 feet wide. And because the route included severe cross slopes—which impact center of gravity—the transporter had to be able to keep its load properly balanced and level.

Perkins Specialized Transportation also needed to conduct extensive planning and testing to ensure the transporter would operate as designed along the route. “You don’t want to get halfway through a turn with a 400-foot-long transporter and realize you’ve got a problem,” says Perkins. “Any mistake in planning would’ve been devastating to our customer and everyone involved.”

The SolutionBefore Perkins Specialized Transportation started designing, it took to the streets—literally—to document the route. “Our route survey helped us identify the most challenging intersections,” says Jim Meehan, the design manager on the project. “As we iterated the design, we superimposed 3Dmodelsofthe transporter onto Google Earth™ satellite images and performed turn studies. It was really slick—and gave us confidence throughout the design process that our equipment would work on the road.”

Super transporter goes nuclear.

With help from Autodesk software, Perkins moves massive nuclear plant steam generator without a hitch.

Perkins Specialized Transportation ContractingCustomer Success Story

Autodesk® Inventor® ProfessionalAutodesk® Simulation Mechanical

We executed this ambitious project without staffing up in large part because we used Autodesk software … Within a month of completion, we’d already had several inquiries for similar projects from other plant operators. —Neil Perkins President and Chief Executive Officer Perkins Specialized Transportation

Creating a Serpentine Design with Inventor Following the more stringent California requirements, Perkins Specialized Transportation determined that 9-foot 1-inch axle spacing would allow the heaviest load at 26,000 lbs. per axle. Then, using Autodesk Inventor Professional, the company defined the dimensional characteristics of the load, tires, and axle spacing to develop potential shapes for the transporter—resulting in a transporter trailer longer than a football field and with 48 axle dollies capable of moving independently. “We designed it for serpentine operation,” says Perkins. “Each dolly beneath the transporter could articulate in any direction. By alternating the dollies, we even made it possible for the transporter to expand in width.”

Using motion simulation functionality in Autodesk Inventor Professional, Perkins Specialized Transportation put each assembly through its full range of motion. “Our models were so sophisticated that when we ‘turned’ the tow bar on the digital prototype, we could see all the affected linkages moving and turning the axles and tires,” says Meehan.

“When you put three years of planning into a project with very close tolerances, you don’t want to realize there are interferences when you begin to actually build the transporter,” adds Perkins.

Autodesk Inventor Professional also helped Perkins Specialized Transportation effectively plan how to load the steam generator parts in a manner that met permit criteria and reduced the payload’s width and height. “Inventor helped us simulate how to place the payload on the flatbeds—like a jigsaw puzzle,” says Meehan.

Predicting Performance with Autodesk Simulation Mechanical While Autodesk Inventor Professional provided Perkins Specialized Transportation with the motion simulation it needed to check for interferences, the

company relied on Autodesk Simulation Mechanical software to perform sophisticated stress simulations that would ensure the transporter trailer could withstand the massive loads. The company had switched to the software after a disappointing experience with ANSYS®DesignSpace®. “ANSYS involved so many arcane things to master and memorize,” recalls Meehan. “I was confident that Autodesk would provide the mechanical simulation tools we needed in a more logical, natural workflow.”

Engineers modeled parts and assemblies in Autodesk Inventor Professional, and then brought them into Autodesk Simulation Mechanical for stress simulations to optimize strength and weight. “We applied loads acting in different directions on the primary support beams to make sure they’d hold up,” says Meehan. “For example, there was one huge nozzle with a yoke-like beam around it that we tested three to four times in Autodesk Simulation Mechanical. It would buckle in certain regions, so we’d go back to Autodesk Inventor and add a rib for reinforcement. Then, we’d rerun the simulation.”

By incorporating simulation into the design workflow at the very earliest stages, Perkins Specialized Transportation reached an optimal design that met design goals faster. In fact, Meehan says Autodesk Simulation Mechanical helped get the weight for the design within 700 lbs. of the weight they’d predicted. “That level of variation can be taken up by welds alone,” he says.

The ResultOn August 1, 2011, 80 project stakeholders and support staff members gathered to witness the transporter begin its 850-mile journey. Eighteen days later, the transporter and its payload arrived in Utah within hours of the delivery time set 18 months earlier. “From an on-time standpoint, the project was perfect,” says Perkins. “Everything went according to plan—there were no surprises.”

Simulating the transporter throughout the design phase helped meet stringent regulatory and operational criteria.

Images courtesy of Perkins Specialized Transportation Contracting

Autodesk, Autodesk Inventor, and Inventor are registered trademarks or trademarks of Autodesk, Inc., and/or its subsidiaries and/or affiliates in the USA and/or other countries. All other brand names, product names, or trademarks belong to their respective holders. Autodesk reserves the right to alter product and services offerings, and specifications and pricing at any time without notice, and is not responsible for typographical or graphical errors that may appear in this document. © 2012 Autodesk, Inc. All rights reserved.

The company credits Autodesk software with making the feat possible. “We basically did this project entirely digitally—with no physical prototyping or rework of components,” says Meehan. “We drastically reduced the risk factor by knowing what we were getting into, and how we were going to do it.”

Autodesk software also made the project more cost-effective, as Perkins explains: “We executed this ambitious project without staffing up in large part because we used Autodesk software. We efficiently transferred models between Autodesk Inventor and Autodesk Simulation Mechanical to check for interferences and conduct stress simulations, saving countless engineering hours.”

The project also primed Perkins Specialized Transportation to take on even more ambitious super-load projects. “The entire industry watched this project,” says Perkins. “Within a month of completion, we’d already had several inquiries for similar projects from other plant operators.”

Learn More To find out how Autodesk software can help you design, visualize, and simulate products rapidly and cost-effectively, visit www.autodesk.com/digitalprototyping.

MasterGraphics, an Autodesk Gold Partner, helped Perkins Specialized Transportation get up to speed on Autodesk Simulation Mechanical, providing training and support on the feature-rich product. “MasterGraphics provides incredible support,” says Jim Meehan, design manager, Perkins Specialized Transportation. “It’s reassuring to know their help is only a phone call away—they’re indispensable to us.”