In St. Louis, body armor saves the life of a police officer when shots are fired during a bank holdup. In Atlanta, an officer wearing a bullet-resistant vest is shot twice in the chest by two teenagers driving a suspected stolen car. He survives. In New York City, an undercover detective wearing body armor, shot three times during a drug bust in the chest and stomach at point-blank range, lives to tell about it.
Since 1973, there has been no question that body armor is saving the lives of law enforcement personnel. According to statistics compiled by the International Association of Chiefs of Police (IACP)/ DuPont Kevlar Survivors Club(r), soft body armor is credited with saving the lives of more than 2,500 law enforcement officers nationally during the past 27 years.
It is therefore imperative that this history of success continue.
A major factor in the success of ballistic-resistant armor has been the development and evolution of a ballistic-resistant body armor performance standard, first issued by the National Institute of Justice (NIJ) in March 1972 based on research conducted by the Office of Law Enforcement Standards (OLES). This initial standard (0101.00) laid the groundwork for the establishment of a voluntary compliance testing program that to date has resulted in the testing of more than 2,600 different models of armor and the issuing of four revisions to the original standard, the most recent released this fall.
“Since 1987, when the last body armor standard [0101.03] was adopted, there have been many changes in the design, manufacturing, and use of body armor,” says Lance Miller, testing manager for NIJ’'s National Law Enforcement and Corrections Technology Center (NLECTC), which runs the compliance testing program. “The ammunition and weapons threats that police officers face in the year 2000 are different. Plus, most officers today use autoloading pistols as their duty weapon instead of revolvers.”
In addition, Miller says that the design technology used in making the vests has changed significantly, and many new ballistic-resistant materials have been introduced. The revised NIJ Standard-0101.04 reflects the state of the art in threat and design and incorporates and streamlines the administrative changes. Testing under the new ".04" standard began this fall.
According to Miller, the previous standard identified six armor types that are classified by the specific bullets and impact velocities that they will withstand. For example, a Type II armor protects against higher velocity .357 Magnum jacketed soft-point bullets, with nominal masses of 10.2g, at a velocity of 1,400 feet/second, and against 9mm full metal jacketed bullets, with nominal velocities of 1,175 feet/second. A Type III armor protects against a high-powered rifle firing 7.62mm full metal jacketed bullets, with nominal masses of 9.6g, at a velocity of 2,750 feet/second. In each case, the armor also will protect against lower threat levels.
“The 0101.04 revision better reflects the actual threat to law enforcement officers from ammunition and weapons on the street today,” says Steve Lightsey, a consultant to OLES who was involved in the formulation of the standard’'s latest revision. This threat comes in two forms. The first is obvious: bullet penetration. The second is termed blunt trauma injury. Unlike a penetrating wound, in which the skin is broken and the bullet tears through the body, the deformation of armor from a bullet impact results in blunt trauma. This type of nonpenetrating injury can cause severe contusions (bruises) or internal damage and can even result in death.
In formulating the 0101.04 standard, rounds were selected based on a combination of factors that include the type of firearm carried by law enforcement personnel, the type of firearm and ammunition carried by criminals, the type of firearm and ammunition used when an officer is killed, and the capability of various types of ammunition to either penetrate a vest or to cause blunt trauma.
“For example, in the revised standard,” Lightsey says, “the .38 Special was replaced by the .380 ACP for Type I, the .40 S&W replaces the .375 Magnum for Type IIA, and a new .44 Magnum bullet replaced another .44 Magnum bullet that is no longer manufactured for Type IIIA.
“The new 0101.04 standard also continues to ensure consistent, well-documented testing of body armor under NIJ’'s program. The main intent of the revision was to incorporate as many of the lessons learned from the long period of 0101.03 testing experience as possible, particularly in regard to clarification and definition of many of the methods and equipment used to test body armor for compliance.”
In addition to the new threat rounds for testing, Lightsey says other changes reflected in the revision include the “pat down,” or smoothing of the armor panel between shots, and an increase from one to two measurements for the “backface signature.” Lightsey explains that when a ballistic vest is tested, it is attached to clay backing material using elastic straps. Laboratory test technicians shoot the vest in a six-shot sequence that forms a rough triangle and includes a direct impact shot in the center of that triangle. The technicians measure the deformation of the clay backing material from the impact of the first shot at shot locations 2 or 3, called the “backface signature,” to determine the risk of blunt trauma injury.
Lightsey adds that the techniques and equipment for wet conditioning of the test armor, for construction of the backing material fixture, and for firing the test threat ammunition also have been updated and revised. He points out that some ballistic fabrics lose ballistic-resistant efficiency when they are wet.
“It’'s not only rain that causes this loss of protection,” he says. “Heavy perspiration could also affect performance.” Laboratory tests conducted by the U.S. Army Soldier Systems Center in Natick, Massachusetts, verified that vests will absorb perspiration in amounts comparable to a vest that has been allowed to drain following immersion in water. Consequently, all versions of the NIJ body armor standard, including this latest one, require that a vest provide the same level of protection when wet as it does when dry.
Also, as part of the standard’'s revision, OLES has developed a performance assurance program to determine the ongoing performance of body armor currently in service or of a new production unit of a previously tested and approved model. Called the Baseline Ballistic Limit Test, this procedure will establish a benchmark of penetration performance. According to Lightsey, it is a more reliable and consistent way to retest NIJ-compliant armor.
“It is essential to understand that the ballistic limit test does not have a pass or fail performance requirement,” he says. “The Baseline Ballistic Limit Test exists only to provide additional information about the ballistic performance of a given armor model. This ballistic limit testing is done after the armor model has successfully passed the traditional penetration and backface signature testing. The performance assurance program is based on a modified form of ballistic limit testing commonly known as V50.”
Traditional V50, or ballistic limit testing, is a statistical test developed by the U.S. Department of Defense and often used as a design tool by manufacturers as they develop and assess new body armor designs. V50 testing identifies the theoretical velocity at which a specific projectile has a 50-percent chance of either penetrating or being stopped by the armor. To compute that velocity, testers shoot enough bullets at various velocities to obtain equal groups of nonpenetrating and penetrating impacts within a velocity range of no more than 150 feet/second. The V50 ballistic limit is calculated as the average velocity of the 10 bullets. “All ballistic-resistant materials can ultimately be overmatched,” says Lightsey, “whether by bigger or faster bullets or simply by firing the same bullet fast enough to eventually overcome the ability of the given material to stop it.”
The V50 ballistic limit, within statistical reason, identifies the velocity at which the armor material stops the bullet at least half the time. “Knowing that the ballistic limit of a particular body armor model is well in excess of the NIJ reference velocity-at which no penetration is expected or allowed for in compliance testing-provides additional assurance of the overall ballistic performance of the armor,” says Lightsey, “even in instances where the encountered threat may be beyond the expected norm.”
Also stemming from the .04 revision will be a single computer-based reporting format and comprehensive database archival system that will standardize reports, thus making testing data more manageable and accessible to users.
Initial efforts to update the 0101.03 standard began at OLES in 1996 and were continued in 1997, when NLECTC-Rocky Mountain began preliminary testing to determine whether the standard was still valid, given the existence of different present-day threats posed by newer combinations of weapons and ammunition. As part of that analysis, NLECTC- Rocky Mountain assessed existing threat rounds and potential replacement ammunition by performing comparison tests on body armor to confirm its recommendations for changes to the threat rounds.
The revisions were developed with the active participation of the body armor industry, which includes fiber producers, weavers, and manufacturers; the law enforcement community; and NIJ, NLECTC, and OLES. The final draft of NIJ Standard-0101.04 was circulated for review among the membership of the Law Enforcement and Corrections Technology Advisory Council and the National Armor Advisory Board (NAAB). NAAB is composed of law enforcement officers and body armor industry representatives, including fiber and fabric manufacturers, weavers, and armor manufacturers.
For a copy of NIJ Standard-0101.04, Ballistic Resistance of Personal Body Armor, contact the National Law Enforcement and Corrections Technology Center, 800-248-2742, or access the NLECTC system’'s World Wide Web site, JUSTNET, at www.nlectc.org.
[Editor’'s Note: Also available through JUSTNET is the Body Armor Testing Program Database, an up-to-date, searchable database of body armor models that have been found to comply with the standard. In addition, departments looking to purchase or replace body armor should obtain a copy of the Selection and Application Guide to Police Body Armor. This publication, which also can be downloaded from JUSTNET, not only details body armor selection, training, and maintenance and care, it also gives indepth background on the history of body armor, the NIJ standards and testing program, and body armor construction.
In addition, a video is being developed about body armor. Surviving a Shooting: Your Guide to Personal Body Armor, presents the facts on personal body armor: what it is, what it can and cannot protect against, how to select it, and how to wear and care for it properly. The video depicts how NIJ tests and validates body armor. Also discussed is the .04 standard and how performance levels are developed by OLES.]
Copywrite 2001 - The Justice Technology Information Network (JUSTNET) is a service of the National Law Enforcement and Corrections Technology Center (NLECTC). NLECTC is a program of the National Institute of Justice Office of Science and Technology.