Medical Science Publication No. 4, Volume 1
TUESDAY AFTERNOON SESSION
20 April 1954
MODERATOR
MAJOR CURTIS P. ARTZ,MC
MEDICAL ASPECTS OF BODY ARMOR IN KOREA*
ROBERT H. HOLMES,M. D., WILLIAM F. ENOS, JR.,M. D.,
AND
CAPTAIN JAMES C. BEYER,MC
The results of ballistic surveys of American casualties in Korean fightingwere presented in a previous paper (1) which also stressed the urgentneed for body armor by combat personnel and discussed its probable effectiveness.The first field trial of body armor in Korea (1951) indicated that it couldbe worn without interference to combat performance, that the soldiers unanimouslydesired it, and that an appreciable decrease in casualty rate and alsoin the severity of wounds received could be anticipated. Since that timebody armor has become standard equipment for field forces, both Army andMarine Corps, and has been used by large numbers of troops under combatconditions for a significant period. It is believed that the value of thearmored vest in the total medical effort to conserve the fighting strengthof our field forces has been demonstrated and that this report on it isnot premature.
The causative agents of wounds were carefully evaluated as to relativeincidence, wounding potential, physical characteristics, explosion distances,range, probable velocities and chance factor for wounding. Anatomic regionalfrequency and distribution of wounds were determined under variable tacticalcircumstances, and comparative data compiled for the killed-in-action,the wounded-in-action, and those dying of wounds in hospitals. A largenumber of autopsies upon the killed-in-action were performed in order toobserve significant phenomena of wound production, such as morphologiccharacteristics of entrance and exit wounds, missile passage and adjacenttrauma, and the varied effects of missiles upon skin, soft parts, bone,hollow organs, solid organs, specific lethal wounds and probable casualtysurvival time. Finally, Army missions in 1951 and 1952 determined beyonddoubt that the field soldier could wear, would wear, and desired to wearthe body armor afforded him.
*Presented 20 April 1954, to the Course on Recent Advances in Medicine and Surgery, Army Medical Service Graduate School, Walter Reed Army Medical Center, Washington, D. C. To be published in the Journal of the American Medical Association.
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Classification forbids release of certain date but, in general, thesignificant observations leading to the adoption of body armor were asfollows:
1. The nature and behavior of the wounding agent. It was determinedthat about 75 percent of wounds are caused by shell fragments; not shrapnel,as they are erroneously called. The mean size of these fragments is lessthan 50 grains and about 1 cm. in greatest dimension. Distance from theshell explosion is usually from 1 to 25 meters for the wounded-in-action,and probably much closer for the killed-in-action. This impression hasbeen obtained by examining the relative wound incidence per casualty inthe two groups and by interrogating the wounded.
2. The probable velocity of a significant percentage of the shell fragmentswas determined by deduction from certain wound characteristics and wasfound to fall within a range for which protection could be obtained. Itwas noted that about 70 percent of all missile wounds were of a penetratingtype, that is, having a wound of entrance but no wound of exit, ratherthan a perforating type or "thru and thru wound." This fact allowedfor a fair estimate of the average missile velocity of shell fragmentsupon the battlefield.
3. The anatomic regional incidence of wounds showed that hits on thethorax and abdomen accounted for about 30 percent of the wounds among thewounded-in-action (table 1), 46 percent among those dying of wounds ina hospital, and 45 percent among those killed-in-action (table 2).
Table 1. Regional Distribution of Wounds inWIA
Percent | ||
Without armor | With armor | |
Head | 14. 4 | 14. 2 |
Neck | 3. 0 | 2. 5 |
Thorax | 19. 0}30. 0 | {8. 7} 19. 5 |
Abdomen | 11. 0}30. 0 | {10. 8}19. 5 |
Upper extremities | 25. 0 | 28. 3 |
Lower extremities | 27. 0 | 35. 0 |
Genitalia | 0. 6 | 0. 5 |
|
|
|
Multiple wounds | 53. 0 | 59. 0 |
Small arms missiles | 15. 3 | 15. 4 |
Shell fragments | 84. 7 | 84. 6 |
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Table 2. Regional Frequency of Lethal Wounds(Without Body Armor)
Percent | ||
DOW* | KIA** | |
Head | 25. 5 | 41. 5 |
Neck | 3. 0 | 4. 1 |
Thorax | 24. 0 | 36. 0 |
Abdomen | 22. 0 | 9. 4 |
Extremities | 20. 5 | 6. 0 |
Buttocks | 5. 0 | 3. 0 |
|
|
|
*DOW-died-of-wounds (in a hospital).
**KIA-killed-in-action.
4. Actual field trial in Korea showed that the soldier could carry anadditional 6 to 8 pounds, suspended from the shoulder girdle, without interferenceto combat performance. In addition, he desired this protection and manifestedimprovement in morale and increase in aggressiveness.
Following these observations, body armor was adopted as a standard itemof field equipment and, as quickly as production allowed, was issued tofrontline combat personnel. Subsequent wound ballistics surveys have demonstratedthe value of this armor as shown by the accompanying statistical chart(table 3).
Table 3. Effectiveness of Body Armor AgainstMissile Hits
Total | Shell fragment | Small arms | Unknown | |
Vests hit by missiles: Number | 254 | 184 | 63 | 7 |
Percent | 100. 0 | 72. 4 | 24. 8 | 2. 8 |
Missiles hitting vests: Number | 874 | 725 | 123 | 26 |
Percent | 100. 0 | 82. 9 | 14. 1 | 3. 0 |
Defeated by vest | 593 | 549 | 30 | 14 |
Perforating vest | 281 | 176 | 93 | 12 |
Percent defeated* | 67. 8 | 75. 7 | 24. 4 | 53. 8 |
Percent perforating* | 32. 2 | 24. 3 | 75. 6 | 46. 2 |
Average number of missiles per vest hit | 3. 4 | 3. 9 | 2. 0 | 3. 7 |
*Percentage of missiles hitting vests.
Nylon and Doron, a compressed fiber glass, are the materials presentlyutilized in the various prototyes of body armor. The first
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armored vests used in Korea (1951) were a combination of nylon and Doron,the shoulder girdle being tailored with nylon. This allowed for comfortand mobility. The protective properties of the two materials are essentiallythe same. Recent vests in use by the Army have been made entirely of nylon.They weigh about 8 pounds and provide a high degree of protection againstshell fragments and some degree of protection against small arms fire,depending upon the angle of incidence of the bullet and the range. Bulletshitting at acute angles and/or reduced velocities occurring at the terminusof flights are frequently defeated by the vests. In other instances, theseverity of wounds is significantly reduced even though the vest may beperforated.
Because of the widespread use of this armor a relative increase hadbecome apparent in the percentage of head wounds, neck wounds and severewounds of the extremities. For example, those who have suffered multiplemissile wounds, some or one of which could have been lethal if in the thoraxor abdomen, survive to reach a hospital with a head wound or severe mutilationsand amputations of the extremities. Combat surgeons have also noted thatthe severity of abdominal wounds has decreased and fewer extensive bowelresections are performed. This increase in survival time actually leadsto an additional reduction in killed-in-action because of advanced technicsin battlefield recovery and helicopter evacuation. Once a casualty reachesa hospital, modern medicine and surgical care assure him of a 98 percentprobability of survival. In addition to the prevention of wounds and reductionin severity of wounds to the thorax and abdomen, a valuable psychologicaladjunct has accrued in terms of improved soldier morale, for greater confidencein personal safety increases aggressiveness in combat.
Classification forbids detailed discussion, but it can be stated thatin a statistically significant number of instances 68 percent of all missilehits on armored vests worn in actual combat were defeated. In other words,two out of every three of all missiles hitting the vests failed to producea wound. Because of the probability of multiple wounds, this does not necessarilymean that a casualty or a fatality was prevented, but it does mean an absolutereduction in the number of wounds any one of which conceivably could havebeen fatal or disabling. Since about one-third of all who sustain thoracicand abdominal wounds are wounded in these anatomic regions alone, it followsthat there is also an actual reduction in total casualty incidence. Itis possible, and now appears to be true, that this reduction in casualtyincidence is of approximately the same magnitude for both killed-in-actionand wounded-in-action; therefore, a significant change in the KIA-WIA
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ratio due to body armor need not be expected. This ratio will remainconstant or fluctuate, determined by the relative change in the two magnitudes.The true effectiveness of the vest is a simple expression of the percentageof missiles of all types on the battlefield which hit the vests and aredefeated. The determination of the ballistic qualities of present bodyarmor is dependent upon carefully controlled laboratory experiments, andits value on the battlefield is specifically related to the number of missileswhich it defeats. This has been shown to be 68 percent.
The body armor in current use has been designed primarily for the reductionof battlefield killed-in-action. Any reduction of wounded-in-action isa gratuitous and natural expectancy. The use of such armor is, and alwayswill be, a compromise between the maximum protection desired and the weightload that can be carried without lowering combat efficiency. Vital anatomicregions-head, thorax and abdomen-must therefore assume unquestioned priorityin protection. Improvement of design and search for new materials providingmaximum protection with minimum weight are continuous.
It is also cogent to consider the application of similar protectivedevice in the civilian defense program. The battlefield is no longer confinedand the spectre of atom-bomb and H-bomb blast upon homeland cities is anaccepted prospect. Injury from flying debris, such as masonry, metal andglass, is of great importance following such blast (2), and conceivablythe use of body armor could lessen appreciably the staggering morbidityand mortality anticipated in such a mass civilian disaster.
Summary
Medical care upon the battlefield is one of the greatest challengespresently before us and it is being met vigorously by prevention of woundsas well as by treatment of wounds. The concept of prevention is of potentialvalue also in meeting the tremendous problem of civilian medical care inthe event of all-out war.
References
1. Holmes, R. H.: Wound Ballistics and Body Armor. J.A. M. A. 150: 73-78, 1952.
2. Liebow, A. A., Warren, S., and DeCoursey, E.: Pathologyof Atomic Bomb Casualties. Am. J. Path. 25: 853-1027, 1949.
