Indian Journal of Fibre & Research Vol. 22, December 1997, pp. 348-352

An overview of military

Sabit Adanur & Ashutosh Tewari Department of Textile Engineering, Auburn University, Auburn, Alabama, U.S.A.

Developments in the weapons and surveillance technologies are prompting innovations in individual protection equipments and battle-field related systems and structures. Besides conventional requirements such as durability to prolonged exposure, heavy wear and protection from external environment, the protection is sought from ballistic projectiles, fire, CBN (chemical, biological and nuclear) weapons and surveillance and detection systems. It is a challenge to the "system" designer to satisfy the conflicting requirements within the constraints of physiological requirements, logistics, technological limitations and the cost. This article gives an overview of the requirements, design considerations, developments and innovations related to the textile usage in the military applications. The examples and citations are mostly in the context of the United States Army. Keywords: Ballistic projectile, Biological weapon, Camouflage, Chemical weapon, Nuclear weapon

1 Introduction supporting them, enforcing sanctions, demands The fall of a super power has resulted in laid by the narcotics policy and immigration 2 decreased U.S. defense spending, but it has regulation • certainly not turned this planet into a place of everlasting peace and bliss. The potential remains 2 Role of Textiles in Military for the misunderstandings, security impasses and Textiles are widely used in the military. The internally unstable military powers. The hostile U.S. Defense Department has about 10,000 items states can emerge with little warning. in its inventory made partially or entirely from Although modern wars are being increasingly textiles. About 300 of these items are regarded as fought more or less by remote means as evidenced "combat essential", including uniforms, protective by the recent examples, a combat soldier is still clothing, parachutes, sweaters, socks, gloves, indispensable. Despite hundreds of sorties, U.S. coveralls, sand bags, sheets, blankets and hospital fighter planes with their ultra-modern radars, supplies. The applications of military textiles may sensors and state-of-the-art means of delivery be divided into two categories: (i) personal could not locate the mobile missile launchers of protective clothing and individual equipment Iraq during the Gulf war and not a single one was (battle dress uniforms, ballistic protection vests destroyed from the air. Modern trend in war and helmets, chemical protection suits, belts, fighting needs to have small teams of highly ropes, suspenders and field-packs), and (ii) defense trained, well-equipped combat troops supported by systems and weapons (tents, parachutes, shelters, the state-of-the-art weaponry and communication tarpaulins and textile composites). A detailed list l systems . This requires even more dependable of military textile and apparel items is provided by protection systems as each troop is important due Adanur. to smaller size of the teams.

By the turn of this century, there will be over 20 2.1 The Soldier as a System countries with ballistic missiles, 9 with nuclear The soldier along with his supplies, clothing, weapons, 10 with biological weapons and up to 30 weapons and accoutrements is treated as a system with chemical weapons. Besides direct threat to the (Fig. 1). The soldier system efforts are based Qn national borders, the opportunities to use miIitary the Soldier Modernization Plan of the U.S. army. It force will be provided by the hostage rescues, includes improved individua:l equipment, clothing, punitive action against terrorists and the states weapons and subsistence items to enhance his ADANUR & TEWARI: AN OVERVIEW OF MILITARY TEXTILES 349

heat-stress, low weight and bulk, moisture-vapor permeability, air-permeability and insulative; and (iv) physical requirements: low weight and bulk, durability, soil-resistance and maintenance. Not only do these requirements overlap, but they also contradict each other at various levels. All of them are important, but the means to fulfill these requirements are not simple and straight­ forward. Improvement in one aspect generally results in the deterioration of the other. For example, protection from environment invariably results in compromises with soldier's comfort, causing heat stress and fatigue. Therefore, it is v.ery important to prioritize the vanous requirements. It is necessary to establish the order in which each requirement needs to be fulfilled. Two important considerations are the frequency and the intensity of exposure and the possibility of Fi g. I-A soldier as a complete system (Photo courtesy of Dupont) integrating solutions. Defense Clothing and Textiles Agency (DCTA) in Essex, U.K. uses overall effectiveness and survivability on the multiple layers of clothing, each one doing a battlefield. Soldie.r system items include several particular function. Integrating different functions related programs that respond to the changing and condensing them to a minimum number of threat requirements and advances in state-of-the­ layers is a tough technological challenge. The art technology. Combat clothing and individual British Army's Combat Soldier 95 system has equipment (CIE) is one of the four main areas in reduced the number to eight. DCT A's goal IS to which the Soldier Enhancement Program (SEP) reduce the number of layers to three in Crusader 21 projects are focused. Some textile related projects clothing system, which is expected to replace the include Enhanced Load Bearing Vest, current outfits in 2005 (ref. 6). The integrated Inconspicuous , Second Generation protection provided by the U.S. Army's battle­ Extended Cold Weather Clothing System dress uniforms is shown in Table I. (ECWCS) and Amlor Crew/Infantry Masks. Mid­ term research and development CIE efforts are 2.3 Textiles for Protection from Nuclear Weapons focused on the li ght weight equipment, ballistic The effects of a nuclear weapon vary depending and laser eye protection and improved chemical on the size, yield and type of weapon and also on protective clothing. Long-term efforts include 21 st the height of burst, nature of terrain, environmental Century Land Warrior (21CLW), which will conditions, etc. Due to brief duration of flash, any identifY less mature technologies to meet longer kind of shelter (leaves, clothing or buildings) is 4 able to protect significantly. Flash bums are not term soldier deficiencies • only confined to the exposed areas of the body but 2.2 Textiles for Personal Protection also affect through vary in g thickness of the For personal protection, the requirements can be clothing. Even a slight mcrease in the thickness or 5 divided into four categories : (i) battle-field: clothing makes a difference between bum and no protection from chemical warfare agents, flames. bum. Skin bums beneath ti ght fittmg clothing but thermal radiation, ballistic impacts and detection is saved in loose cl othing. The first reqUIrement or (camouflage and low-noise clothing); (ii) heat fl ash protecti on is to have a tlame-resistant environmental : water-proof, snow-shedding, wind­ outer, whi ch is able to re ll ect maximum amount or proof, air-permeable and insulative. It should also radi ation back. It should be intact as long as deny entry to in sects; (iii) physiol ogical: minimum possible to give protec tion from in cident radiation 350 INDIAN 1. FIBRE TEXT. RES., DECEMBER 1997

Table I-Integrated protection offered by U. S. army's battle-dress uniform fabrics)

Fabric Characteristics , Nomex®, ®, Cotton, Kevlar®, Nylon, P-140 P-140

Flame resistance No Yes Yes Liquid chemical agent resistance Yes No Yes Electrostatic resistance No Yes Yes Day/ni ght camouflage Yes Yes Yes Durability Yes Yes Yes Weight (o zJyd 2) 1 (g /m2) 7.0 / (237) 5.5 / (186) 6.5 / (220) Cost ($/linear yd) 1 ($ /m) 4.00 / (4 .37) 20.00 / (21 .87) 11.001 (12.3) (estimated) TabJe 2--Characteristics of military ballistic fabrics)

Property Type I Type II Type III (Kevlar® 29) (Kevlar® 29) (Kevlar KM2)

Denier 1000 1500 850 Weave Plain 2x2 basket Plain Fabric count 31x31 35x35 31x31 1 Weight (ozJyd ) 1 (g /m2) 8.3 / (281) 14.0 / (475) 6.8 / (231) Thickness (mil) 1 (mm) 14 / (0 .36) 25 1 (0 .64) 10/ (0 .25)

while the portion already absorbed is transferred to Development in the production of high-strength the inner layers. polymers has been at a phenomenal rate. Presently, ballistic protection is offered by , high For nuclear protection in the U.S. army, 65/35 molecular weight polyethylene and liquid-crystal /cotton blended fabric is used which has based ; the most common of these being advantages of better durability to de-contamination Kevlar®, ®, Technora® () and process. The new fabrics usually have I % carbon Spectra®, Dyneema® (polyethylene)3. Different content and the rest is nylon. Nylon/polyester characteristics of the main ballistic fabrics used by blends are also used in some cases3. New the U. S. army are shown in Table 2. "intumescent" substances are being investigated, A Personal Armor System for Ground Troop which swell and char to form a thick protective (PASGT) vest is made from 13 layers of Type-Ii layer. Even a few additional milimetres of Kevlar® 29 [14 oz/yd2 (475 g/m2)] ballistic fabric thickness can add up to 30 s of protection. covered by 8 oz/yd2 (271 g/m2) of camouflage ballistic nylon fabric. Kevlar® also provides 2.4 Textiles for Ballistic Protection Soldiers need to be protected from bullets and excellent flame and heat protection. Ballistic other projectiles like sharpnels, metal fragments helmets are composites made from Kevlar® 29 and flying penetrating debris of various sizes, (nineteen layers) and polyphenyl butyryl and shapes and velocity. Underlying principle is of phenol-formaldehyde resins. They are extremely using up the kinetic energy of the projectile by effective and provide as good a protection as. dissipating it through stretching and breaking the conventional steel helmet but at 15% less weight. Research is continuing to further reduce weight-to­ yams of the protective vests. strength ratio of ballistic protective materials. Plain or 212 basket weave performs the best. Loose weaves or fabrics with low yam-to-yam 2.5 Textiles for Camouflage friction perform badly due to the yam slippage at Earlier camouflage requirements encompassed the impact point. Balanced weaves perform better only the visible and the near infrared regions of the 5 than the unbalanced weaves • Ballistic protection spectrum. Visual cam04flage is obtained by of the eyes requires light weight transparent printing patterns of colors in various shades materials that resist ballistic penetration and are depending on the background in which it is also scratch resistant. intended for use. Detection devices now span ADANUR & TEWARI: AN OVERVIEW OF MILITARY TEXTILES 351 ultraviolet, near and far infrared, radar and seismic hydrostatic resistance and chemical and biological sectors in an integrated multi-sensor system protection. U.S. army's air crew battlefield uniform through visual, black and white, color, false color, for chemical and biological protection uses a foliage penetrating radars, side-ways looking microporous semi-permeable membrane in radar, remote ground sensors, etc. Protection from combination with active carbon impregnated foam. such a wide range of possible detectors is almost The ultimate solution will consist of integration of impossible to attain in a single solution based on current protective systems with selective the current state-of-the-art. permeable materials which will provide extensive The material now being used as a camouflage environmental protection in addition to chemical structure is a spun bonded to one and biological protection. surface of which a number of randomly oriented In an infested environment there is no better metal fibrils are attached. This fabric is then coated protection other than complete encapsulation, but with PVC on both sides. PVC can be impregnated it has its down-sides in that it cannot be worn for with specific pigments to obtain desired more than a couple of hours due to the problems of camouflage. heat stress. It requires bulky and expensive The background may not remain the same 3 microclimate cooling systems • Microclimate throughout an attack. Mission Research cooling vests have been developed to be used by Corporation, in Santa Barbara, California, is the tank crews. A . modified cooling system was designing an automatic camouflage system using used by allied forces in the Gulf war in which a hollow fibers. filled with a mixture of liquid dye centralized cooler had multiple extended vents to and a solid pigment. The solid pigment responds to dispense the coolant. Soldier plugs into the system the changing electric fields generated by a and the coolant is released inside their special vests computerized camera, effecting an overall change to cool them down. in color of the mixture, resulting in a camouflage system that adapts to the soldier's current Protective gloves are usually made from butyl environmene. rubber, natural rubber, neoprene and PV A or PVc. The U. S. army is developing camouflage fabric, Different thickness (7, 14 and 25 mils) / (0.18, called "town and country" for urban backgrounds. 0.36, 0.64 mm) provide varying degrees of Another camouflage pattern which mimics the grid: protection. These gloves do not provide flame of a night-vision scope has been tested by retardance or POL (petroleum, oil and lubricants) Pentagon. resistance.

2.6 Textiles for Chemical and Biological Protection 2.7 A Comfortable Soldier U. S. army uses permeable, semi-permeable and The load carried by a soldier is in the range of impermeable material systems to protect from 39-57 kg during combat conditions. This is much chemical and biological warfare agents. The more than the physiologically desirable maximum permeable system uses active carbon liners. These of around 18.5 kg. Excessive weight impedes the materials provide moisture vapor escape and. mobility of a soldier and reduces his effectiveness. adequate chemical agent protection. It is a nylon Everything possible is done to keep the load tricot base fabric coated with polyurethane foam carried by the soldier to minimum possible. In this impregnated with activated charcoal which light even the battle dress is a candidate for weight provides adsorbing surface for the chemical vapor reduction. Most NATO countries use a 305 g/m2 100% cotton fabric. In the USA, a 50/50 agents. Additionally, surface finishes can be 2 2 applied to protect from liquid penetration. Semi­ cotton/nylon blend [7 ozJyd (237 g/m ) ] is permeable systems, in the form of coatings and llsed for the battle-dress uniform. 67/33 and 65/35 films, can be engineered with various levels of polyester/cotton blends are also used in 245 and 5 porosity. Microporous and ultraporous materials 195 g/m2 constructions . offer the most desirable balance of properties like Low weight and bulk conflict with the high moisture vapor transmission rate, high requirements of ballistic protection, thermal 352 INDIAN J. FIBRE TEXT. RES., DECEMBER 1997 insulation; tlame-resistance (application of finishes 3 Remarks add~ weight) and protection from high intensity Obviously, a lot needs to be done to develop thermal radiations. better protective fabrics for the military personnel. Not only in terms of performance of individual 2.8 Textiles Prote~t from Harsh Environment aspects of protection but also integration of A garment can be water-proofed by coating it solutions into a protective system, which is with polymers such as !1.lbber, PVC, neoprene and economical, stress-free and perfonns optimally. acrylics or polyurethanes; These solutions furnish Science fiction has always found a way to become very low permeability values (200 g/m2/24h) reality. Some of the threats challenging. both the against the requirement of 2000-2500 g/m2/24h. soldiers and the designers and scientists are as Water repellent finishes are good for light showers follows: but not adequate for prolonged_ exposure to heavy • Surveillance devices of enhanced accuracy, downpours which is not uncommon in a soldier's range and deployment methodology. life. The most efficient solution is to laminate a • Nuclear, chemical and biological weapons with nylon base fabric with a layer of microporous increased lethality. PTPE film, also known as Gore-tex membraneS. • Laser weaponry. The U.S. Army Natick Research, Development • Particle-beam anti-personnel weapons. and Engineering Center has developed an • Liquid propellent guns. Extended Cold Weather Clothing System to • Electromagnetic guns. protect soldiers from extremely cold weather. It • Powerful adhesives and super lubricants for consists of polypropylene underwear, cold weather temporary immobilization. trousers, field jacket and trouser made with a semi- • Less than lethal weapons. permeable film laminated fabric. This system Work is continuing towards new solutions and performs well up to -25°P (-31. rC). This range elimina~ion of incompatibihties of requirements can be extended to -60oP (-51.1 0C) by adding a and new technologies and inventions will have a polyester shirt and bib oVeJ"alls. lot to offer in the future. Smooth surface, achieved by using 100% man­ made filament constructions of the garment is References convenient for snow-shedding. Coating of silicon I Sullivan G R, Changes, constants in land warfare, The Futurist, 28 (2) (1994) 57. improves snow-shedding but has negative effects 2 Lake A, Entering the 21 st century: Challenges confronting on flame-retardancy. The smooth constructions America's military (Department of State Dispatch, USA). and finishes make the fabrics rustle when they are Vol. 7 No. 25 (1996) 318. moved. Acoustic camouflage is very important 3 Adanur S, Wellington sears handbook of industrial textiles since a slight noise can cost lives by attracting (Technomic Publishing Co. Inc, Lancaster, PA), 1996. 4 http://www.dtic.milldefenselinkipubslarmyfact/soldter. attention. html. DCTA, U.K. is developing an "intelligent" 5 Morris J V, Protective clothing for defense purposes, insulation system. It is a 3-D textile in which two paper presented at the 61 st annual conference of The conventional layers are separated by a special Textile Institute, 1977. 6 Mullins J, Dressed to kill, New Scientist, 20 July (1996) , which linearly expands or contracts with fall 24. and rise of external temperature, resulting in 7 Invisible soldiers: military technology, The Economist, 4 6 regulated insulation • June (1994) 87.