Nov. 15, 2012
Public Affairs Office
CHAMPAIGN, Ill.--Two undergraduate students employed at ERDC’s Construction Engineering Research Laboratory (CERL) during summer 2012 shared a unique experience when they contributed to a project at Chicago’s electric fish barriers.
The students, Ian McInerney and Ethan Trovillion were fully engaged in the project from concept through planning, design, field work and data crunching – all alongside their dads, Mike McInerney and Jonathan Trovillion.
The Corps Chicago District installed and manages two underwater electric fish barriers in the Chicago Sanitary and Ship Canal near Romeoville, Ill. They are designed to repel Asian carp, an invasive species that could potentially damage or even destroy the Great Lakes’ fragile ecosystem if allowed to enter it.
CERL has been supporting the Chicago District for several years in conducting various measurements of the barriers’ electrical properties. “A 2005 study was done to show how barges, which are massive hunks of metal, affect the electric field as they pass over the barriers,” said Mike McInerney. “In that study, we used only the original demonstration barrier and it had many deficiencies. We wanted the next one to be much better.”
For last summer’s project, CERL instrumented two barges with 117 sensors to measure the electric field as the barges passed over the barriers. The sensors were mounted to steel arrays that were welded to the bottom of the barges. Cables from the sensors were fed through pipes used as feed-throughs from the bottom to the top of the barges. Junction boxes were located at the top of each pipe and additional cables run from the junction boxes to an instrumentation patch panel located in the “hut” on the barges’ topsides.
Ian, a sophomore in electrical engineering at Iowa State University-Ames, was responsible for the electric hardware. “To conduct the tests at the barrier site, we needed to design and fabricate all of the test arrays and then also determine where we would place them on the barges. My main task was to construct and test the wiring harnesses in Champaign to be transported to Chicago for installation on the barges.”
Working under the Student Temporary Employment Program, Ian also designed and constructed two cases to hold the 12 differential probes to be used in the tests. “I consolidated all the probes’ power supplies into one supply per case, reducing the number of AC [alternating current] adapters needed from 12 to two.”
Ethan handled the software programming to optimize data collection and processing. A computer engineering major at the University of Illinois Urbana-Champaign, he worked on the project as a student contractor.
“I set up the MATLAB environment on a laptop to take to the site and hacked up some scripts to emulate functions in toolboxes that I wouldn’t be able to access,” Ethan said. “I also updated some existing code to work with the new data arrangements and came up with new ways to visualize and interpret the extra dimensions we would be collecting data in.”
According to Ian, the experimental setup involved 4,500 feet of wire with 5.2 miles of copper conductor, 45 terminal blocks to connect the two sets of wires, 135 Bayonet Neill-Concelman (BNC) connectors on the patch panel, and 900 ring terminals to connect the wire to the terminal blocks.
“To determine the amount of wire needed for each probe, I created CAD [computer-aided design] models of both styles of barges and placed the probes on the model in their proper positions’” said Ian. “Later I turned the CAD models into sets of drawings that we supplied to the welders at the dry dock so they knew how to configure the barges. I worked with the Contracting Office to procure all of the hardware.”
In addition to being heavily involved in a research project, Ian and Ethan got a taste of working under deadlines in the “real world.” While students often have a lot of control over their schedules, work on the fish barrier was driven by a very specific timeline as coordinated with the U.S. Coast Guard. Because the canal had to be closed for the tests, the team was locked into the scheduled start date and only had two weeks to complete all of the barge preparations and testing. For this reason, everyone on the team worked 12-hour days for 14 days straight.
Even with the long hours and some challenges encountered during the field work, the project offered an insightful experience for the students. “The amount of involvement I had in this project was enormous,” said Ethan. “I sat in on early planning meetings, reviewed drafts of the test plan, helped set up the data acquisition equipment and wired probes. Onsite, I ran cables, wired junction boxes, took test measurements, and of course, crunched data. That depth of interaction, at every step of the way, is what I think sets my experience apart from the norm.”