DETROIT ARSENAL – U.S. Army DEVCOM Ground Vehicle Systems Center engineers are in the final phase of testing for electrical connectors that, once in use, will deliver a safer alternative to legacy equipment and improve long-term sustainment.
According to GVSC Environmental, Coatings, and Corrosion Branch Chief Michelle Davis, the tests stem from a broader Army effort to eliminate use of the known human carcinogens cadmium and hexavalent chromium, or hex chrome. She said for decades many military connectors have relied on finishes containing cadmium and hex chrome due to their corrosion resistance. However, as the health risks associated with these materials became better understood, GVSC began searching for solutions.
“Across the Army, we’ve been trying to get rid of hex chrome and reduce exposure for our Soldiers for 20 years,” Davis said. “Other items have been replaced, but electrical connectors were one thing where we still needed to find a proven solution.”
Davis said much of the equipment in the Army’s inventory currently contains electrical connectors with these carcinogens. After identifying potential cadmium- and hex chrome-free replacements in the marketplace, Davis and her team—in coordination with the Detroit Arsenal Prototype Integration Facility—developed a testing plan to demonstrate the new connectors could effectively be incorporated into vehicle electrical systems.
“The goal is to show that we can take the new ones and integrate them into existing equipment without performance loss,” Davis said.
With the plan in place, GVSC engineer Sarah Carman coordinated with multiple Army organizations to acquire funding for the critical testing of the new connectors.
The testing was mainly funded by the Safer Alternatives for Readiness Program (SAFR), which is a DEVCOM level funding effort that looks for alternatives to current products with known safety concerns in the field. Specifically, this was funded under the Toxic Metal Reduction Program, Carman said.
In addition to the collaboration within the Army to fund testing, Carman said the project couldn’t have moved forward without the involvement of industry partner Battelle and the Infantry Squad Vehicle—Utility (ISV-U) team.
Working alongside partners such as Battelle, the GVSC helps identify and mature innovative technologies that can successfully transition into military applications. By actively removing barriers for industry to access government, GVSC creates a faster, more transparent on-ramp to Army problems.
“We need to leverage all the partnerships we have,” Carman said. “If we’re making sure we’re using all the resources available, even if they’re not necessarily the traditional ones we’ve used in the past, we’ll be able to deliver new, safer capabilities to our Soldiers as fast as possible.”
The connector testing first began four years ago.
“The first phase was the laboratory tests,” Carman said. “Battelle set up a corrosion chamber and took all the different types of connectors we were considering and paired them both with themselves and with our legacy cadmium and hex chrome connectors so we could evaluate the differences.”
In the chamber, Carman said the connectors were exposed to various environmental conditions that would accelerate the corrosion process, including salt, water, and temperature changes. Following the successful completion of the lab testing, she said Battelle then subjected the connectors to an even harsher environment.
“They set up our samples on their beachfront location in Florida,” Carman said. “The samples were outside for two years, which is typical for corrosion testing, and energized the whole time. The results of lab and outdoor exposure tests showed there weren’t any electrical performance issues.”
Carman said historically, performance loss has always been the main concern when combining connecters made from dissimilar metals. Despite seeing success in both the lab and outdoor testing, she said one final test was vital to provide programs confidence to use the connectors on their platforms.
“We had to identify a way that we could demonstrate satisfactory performance in a representative environment—on a vehicle,” Carman said. “That would provide evidence the new connectors will perform well in the field.”
According to Carman, GVSC worked hard to then find a project partner for the final phase of testing, and to determine how to conduct the test without impacting program-funded test results. She said once they identified the methodology, ISV-U volunteered and accepted the team’s request to leverage their planned test.
“We’re not directly integrated into the system’s electronics other than a small power draw,” Carman said. “Our test assets are riding along on the ISV connected to an independent monitoring system that sends out test voltages and reads them back to verify electrical performance.”
The ISV-U test is set to take place this month. Carman said it will be the culmination of years of research transitioning to operational testing.
“We wouldn’t have been able to do the testing without these partnerships,” Carman said, “and without test results, we can’t build the trust in the products. Collaboration is vital in directly improving Soldier readiness.”
Carman said moving forward, GVSC will work with acquisition programs to transition to cadmium- and hex chrome-free electrical connectors for ground equipment. With this testing, though, she said GVSC has accelerated the delivery of safer options without needing to replace current equipment altogether.
“Eventually we’re going to see legacy connectors become less available and more expensive,” Carman said. “We’re getting ahead of that issue with these alternatives, which are better for the health of our Soldiers and maintainers, and ensure the modernization of our systems at a lower cost.”
The electrical connector testing process demonstrates how GVSC continues to solve Army problems and technology gaps through effective collaboration and leveraging industry-funded innovation, and how science and engineering enhance Soldier safety.