Capt. John W. Hammett poses with one of the Bell H-13 helicopters solopilots used to move patients injured in Korea. Hammett was commander of the 49th Medical Detachment during the Korean conflict. Solopilots were “the helicopter pilots who responded alone to evacuate wounded warriors.” Photo Credit: Howard A. Huntsman via the US Army
Helmet innovation stagnates and combat medicine evolves in Korea and Vietnam
US troops continued to use the World War II-era M1 helmet, albeit with “a few design improvements in the liner and exterior flared edging” through the 50s, 60s, and 70s.
But caring for wounded personnel improved, as did the chances for survival. Troops who were wounded in World War 2 had about a 70% survival rate; odds in Korea increased to 75%, followed by 76% in Vietnam. Another estimate claims that of all who served in the three conflicts, the overall odds of death were roughly:
There were many factors in increasing survival rates, from the weaponry used to the scale, terrain, and tactics in each conflict. But superior medical care played a significant role, including widespread use of antibiotics and the deployment of MASH units, which were coupled with an incredible new tool – the helicopter.
In Korea, helicopters started to be widely assigned to medical duty by October 1950, after General Douglas MacArthur recommended “that helicopters should be in the Tables of Organization and Equipment and should be part of medical equipment – just as an ambulance is.” By the end of the conflict, “medevacs transported more than 20,000 casualties.” A surgeon for the Eight Army “estimated that of the 750 critically wounded soldiers evacuated on Feb. 20, 1951, half would have died if only ground transportation had been used.”
Vietnam: UH-1D helicopters airlift members of a U.S. infantry regiment, 1966. Source: The National Archives
In Vietnam, the use of rotary wing medical evacuation become far more common, and “in most cases a wounded soldier would be in a hospital receiving medical care within 35 minutes of being wounded.”
A 35 to 40 minute standard was common, compared to an “average medical evacuation time in Korea [of] 4-6 hours. Usually the soldiers were well bandaged and/or splinted by the excellent medics in the field and the ‘air ambulance’ was fast, the ride relatively smooth and in some cases a preliminary diagnosis could be radioed ahead. In 1969, the peak year for medical evacuations, over 200,000 casualties were transported by air.”
One estimate states that in Vietnam, the “the mortality rate of wounded soldiers who made it to medical treatment was 2.6 percent as compared to 4.5 percent from World War II.”
About 40% of those killed in Vietnam suffered head and neck wounds. The Vietnam Head Injury Study (VHIS) looked at “1,221 Vietnam veterans who sustained a TBI between 1967 and 1970,” chiefly penetrating (open) wounds rather than closed head injuries. The study had detailed, far-ranging findings, some of which include:
The level of fatigue after traumatic brain injury [TBI] correlated with lesions (areas of damage) in the ventromedial prefrontal cortex, which is an area of the brain that “is implicated in the processing of risk and fear” and “plays a role in the inhibition of emotional responses, and in the process of decision making and self-control.”
Motor disorders: “[P]arietal [at the top of the head] wounds were particularly associated with hemiparesis,” which is weakness of one side of the body. Studying the nature of these wounds helped map losses of motor function to hemispheres of the brain, “suggesting that the left hemisphere has greater neuronal representation for bilateral motor processes.”
Neuropsychological associations: The loss of intelligence sometimes experienced after a TBI was closely associated with the size of any injury (lesion), it’s location, and the patient’s intelligence prior to being injured. Aphasia – problems with speech, writing, and comprehension – was common (experienced in 23.6% of patients studied), though the symptom could improve over time.
Memory disorders “were found to be associated with lesion location,” and further mapped to specific parts of the brain, including the parietal (at the top of the head) and temporal (below the temples) lobes.
The understanding of post-traumatic stress continued to evolve in Vietnam as well. The terms “Vietnam combat reaction” and later “post-Vietnam syndrome” were used to “to describe the 30.9 percent of male and 26.9 percent of female Veterans returning with this affliction. It was used to describe a syndrome which included symptoms of insomnia, recurrent and terrifying nightmares, anorexia, depression, guilt, and severe anxiety.”
Studying returning Vietnam veterans finally led the American Psychiatric Association to officially add the modern diagnosis of post-traumatic stress disorder (PTSD) to The Diagnostic and Statistical Manual of Mental Disorders (DSM-III) in 1980. The wider medical community began to further understand that a “psychiatric” injury was simply another form of head injury – also caused by physical changes to the brain.
“A Marine from the 2nd Marine Expeditionary Force holds an M-60E3 machine gun as he rides in the back of a truck during the ground phase of Operation Desert Storm.” He is wearing a PASGT helmet. Source: The National Archives
Helmet technology starts to catch up with weapons through Grenada and Desert Storm
DuPont’s invention of Kevlar in 1965 paved the way for radical changes in protective gear, including helmets:
In the 1970s, several Army agencies—led by the Army Natick Development Center at the Watertown Arsenal in Massachusetts—began work using layers of tough, puncture-resistant Kevlar 29, a synthetic ballistic fiber bonded with a synthetic polymer resin, to create a helmet capable of stopping most bullets, as well as shrapnel and shell fragments in a skull protecting device that weighed between 3.1 (for the small model) and 4.2 pounds (for the extra-large size).
Because of the malleability and plasticity of Kevlar in the design process, the Army and its agencies were able to make a far more efficient helmet design, creating the PASGT, similar to the one General Schwarzkopf donated to the Smithsonian in 2007. Its design also allowed for coverage of the ears and the back of the skull all the way to the nape of the neck.
This helmet, which was coupled with a Kevlar ballistic vest that together formed the Personnel Armor System for Ground Troops (PASGT), first saw combat in the 1983 invasion of Grenada and was used by the US military through 2003. It was nicknamed the “K-Pot” and later simply a “Kevlar,” which persists as the common word for “helmet” used by US troops today.
The PASGT (“pass-GET”) helmet is rated at Threat Level IIIA protection, which means it can stop various types of shrapnel plus “protects against 9mm full metal jacketed round nose (FJM RN) bullets, with nominal masses of 8.0 g (124 gr), impacting at a minimum velocity of 427 m/s (1400 ft/s) or less, and .44 Magnum jacketed hollow point (JHP) bullets, with nominal masses of 15.6 g (240 gr), impacting at a minimum velocity of 427 m/s (1400 ft/s) or less.”
The PASGT helmet still wasn’t designed to stop a well-aimed, direct hit from the high-velocity 7.62 or 5.56 caliber cartridges fired by common assault rifles at normal distances; but the combination of Kevlar, a greater protection profile, and a relatively light weight meant that it was leaps and bounds better than the standard issue helmets that preceded it.
To Be Continued: The American History of Wartime Head Injuries and Helmets
In the next blog in this series, the United States enters a new kind of war after the attacks on September 11, 2001. Closed head injuries become the “signature wound” of the conflicts in Iraq and Afghanistan – and both combat medicine and US helmets show innovation.
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