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Blast and ballistic improvement in helmets earn Carderock engineer another patent

By By Benjamin McKnight III, NSWCCD Public Affairs | NSWC Carderock | March 21, 2019

WEST BETHESDA, Md. —

The United States Armed Forces have seen a great amount of advancement in the technology behind protective gear through the years. With each conflict, a newer challenge was presented for more sufficient equipment. Philip Dudt, an engineer in the Hull Response and Protection Branch of Naval Surface Warfare Center, Carderock Division, was recognized for his effort to the cause in 2018 when an invention he contributed to was awarded a patent.

In Dudt’s 50 years at Carderock, he has been a part of multiple teams of inventors to receive patents on various products. His most recent work went to U.S. Patent No. 9,869,533, Blast and Ballistic Improvement in Helmets. Working with four other engineers, Dudt’s challenge was to create a material for helmets that would adequately protect its wearers against explosive blast, in addition to bullets. Blast exposure has been associated with traumatic brain injuries.

According to Dudt, helmets have traditionally prioritized stopping bullets. The years of recent conflicts in the Middle East introduced warfighters to increased threats of roadside bombs and IEDs, likewise creating the need to focus on protecting service members from the blast. As of the first quarter of 2018, the Department of Defense reported over 380,000 traumatic brain injury diagnoses since it began keeping record in 2000, per the Defense and Veterans Brain Injury Center website.

The root of this effort started when Dudt and his peers were looking for ways to improve blast protection on ships. He cited the attack on USS Cole (DDG 67) in October 2000, which killed 17 U.S. Sailors, as one of the inspirations behind their original research. Work focused on special coatings that have the ability to increase strength and stiffness under shock and blast loads. As they saw successes in their experiments, a collective epiphany surfaced.

“We said, ‘What if we just try coating a combat helmet? Could it affect the level of damage that the brain could experience?’” Dudt said. 

The keys to this assessment were efforts by Carderock’s Dynamic Instrumentation Group, where engineer Bill Lewis designed a full-scale instrumented head-neck manikin, and the Non-metallic Materials Research and Evaluation Branch’s polymer facility, which was used to apply the coatings. Dudt said, “When we put the coating on the helmet, it did help quite a bit.”

Intracranial accelerations and impulses were significantly reduced. Their major drawback: the considerable increase in helmet weight. “You put the coating on the helmet and it’s seven pounds instead of almost five,” he said.

Dudt said that DuPont USA, a major helmet designer, proposed working with his team by making thinner helmet shells with stronger materials to negate the increased weight disadvantage. An even lighter overall weight helmet compared to the conventional design was a final result.

Blast testing was done on the Navy side of the project using the Carderock test pit and against full-scale IEDs at the Navy’s explosive ordnance disposal facility in Indian Head, Maryland, while DuPont took care of ballistic testing to ensure that the change didn’t compromise the helmet’s original intent of defeating bullets.  

As the collaborative efforts increased, both parties decided it was worth filing a patent together, so DuPont and the Navy filed the patent in April 2015. In addition to Dudt, there were four other engineers who contributed to the invention: Bryce VanArsdalen (DuPont), Roshdy Barsoum (Office of Naval Research), Alyssa Littlestone (Naval Sea Systems Command, formerly at Carderock) and Charles Roland (Naval Research Lab).

There is not a full agreement in the medical community on the causes of traumatic brain injury to date. Within the patent, the invention description identified numerous possible causes linking blasts to traumatic brain injuries. These factors included skull flexure, blast-induced cerebral spinal fluid cavitation, brain axonal stretching and direct pressure pulse transition into the brain. “Everyone can agree that it is important to lower the brain’s exposure level to the injury causing parameters the coating mitigates,” Dudt said.

The research for this invention looked at brain injuries as a whole, but other investigations were started to focus on specific structures and regions of the brain.

“Regardless of the underlying mechanism, it is agreed by all that it is important to limit the level of blast exposure to the brain,” the patent reads.

For the time being, Dudt’s work on the blast-protection concept is complete. On the idea that there could be a chance that blast and ballistic improvement can reach other forms of protective equipment, Dudt said, “I think the testing just hasn’t been done yet.” And while the patent hasn’t turned into a mass production of new helmets for service members, the technology implemented in this patent process indicates that it is a possibility for the future.