Engineers at the Robbins Company designed the first hard-rock tunnel-boring machine. Designing the machine’s cutter head to ensure stability while optimizing the rapid removal of rock, sand and gravel, Robbins’ engineers do their best to manufacture the most efficient tunneling machines.
In fact, the machines have been used to set world excavation records for virtually every tunnel diameter, including, most notably, the Channel Tunnel, otherwise known as the Chunnel, the 50.5-kilometer rail tunnel built in the early 1990s that runs beneath the English Channel linking England and France.
Company engineers use Solid Edge from Siemens to design the boring equipment, and CAD administrator, Melissa Schultz, is responsible for “all the technical questions that come from the team that relate to software,” she said. She also handles the maintenance, training and support for the entire team of engineers, about 80 in total, across three U.S. locations.
In the summer of 2015, Robbins began a proof of principle study on synchronous technology. The goal was to measure the possible improvements on the company’s specific equipment. Schultz guided the modeling portion of the process while a new design was created. Introducing this new technology can be met with resistance from experienced ordered users as they have to change their modeling practices. Schultz intended to prove the measurable benefit and documented the process in her presentation at Solid Edge University 2015.
Synchronous technology allows users to make updates to part or assembly designs without needing to understand how the part itself was originally created, which is vital for Robbins, where engineers design custom machinery but often start from a pre-existing design. The smaller synchronous file sizes also speed changes and redesign, Schultz said.
Robbins designs many custom machines because boring operations are unique.
For instance, the company recently created a prototype machine, the Robbins Remote Controlled Small Boring Unit (SBU-RC), that saw service in April 2015 in Bend, Oregon, where contractor Stadeli Boring & Tunneling had encountered circumstances that could only be addressed by this type of new gravity sewer interceptor.
The contractor needed to install 323 feet of 36-inch steel casing under railroad tracks. Line and grade were crucial and tolerances were close, said Larry Stadeli, president of Stadeli Boring & Tunneling. Oh, and the job was also in solid rock.
The Robbins Company machine was equipped with a smart guidance system by tacs gmbh. The guidance system could show an operator projections of the future bore path so steering corrections could be made before the machine was ever out of line and grade. The feature was critical for the crossing below the railroad tracks, which could not be shut down if problems occurred.
The SBU-RC was lowered into a launch pit 26 feet deep. The machine began boring at 5,000 to 7,000 psi into volcanic basalt rock that was full of fissures, fractures and rubble pockets. While the start-up was rough going, crews quickly began getting rates of 20 feet per day.
“We were able to cut off a couple weeks of our schedule time,” Stadeli said. “When you look down the pipe now after it’s finished, it looks like a rifle barrel. There is no sag, it’s all in one straight line.”
The CAD Behind the Scenes
Prototyping and producing machines like the SBU-RC makes for many CAD questions—enough to keep Schultz on her toes. Schultz is regularly researching and answering engineers’ technical questions about their CAD software.
The Robbins Company holds 112 Solid Edge seats.
Melissa Schultz.
For the past 18 months, Schultz has been a CAD administrator for the Robbins Company, based in Solon, Ohio, a suburb of Cleveland. The original equipment manufacturer makes tunnel-boring machinery as well as small-boring machines, auger-boring machines, cutters and microtunneling machines.
When it comes to an engineer’s technical questions, Schultz calls upon her extensive background designing with Solid Edge. She first began using the 3D design program 15 years ago in her work as a mechanical designer, and her fondness has only grown through years of continual use. Now, Schultz wouldn’t change a thing about her job.
“I never have a boring day because new questions are always coming to me,” she said. “The problem-solving aspect of being a CAD administrator allows me to constantly hone my Solid Edge skillset.”
She also stays on top of upgrades to the software.
“Solid Edge is constantly improving, based on what its customers need,” she added. “Excellent support that goes with the software. My team is able to design our machine equipment with the confidence that it is accurate and will perform to the high standard we have for our machines.”
At Solid Edge University 2015, held in late October in Cincinnati, Schultz led a session titled “Selling Synchronous to Management and Ordered Users.”
During the session, she talked about how to win over engineers currently accustomed to design via traditional history-based software to Solid Edge, which uses synchronous technology and blurs the line between history-based and direct modeling. She also talked about how the synchronous method works on machine design, including file sizes and edit times.
Schultz has put to good use her associate’s degree in mechanical design from Moraine Park Technical College in Fond du Lac, Wisconsin. With that in mind, she’s recently returned to school to pursue a post-degree certificate in information technology programming.
She also plans to maintain knowledge of and fondness for Solid Edge and to use the software long into her own future.
Siemens has sponsored ENGINEERING.com to write this article. It has provided no editorial input. All opinions are mine. —Jean Thilmany
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