Personnel from each of the services utilize a variety of PPE based on factors such as the operational environment, job description or occupation, and commander discretion. For example, Army and Marine Corps ground combat personnel utilize soft and hard body armor designed to protect against specific small arms, fragmentation, and other unconventional threats, such as improvised explosive devices. Likewise, personnel with aviation based occupations or explosive ordinance disposal responsibilities, and those operating in extreme climates or maritime environments have specific PPE options for their specific assignments. During ground combat operations in Iraq and Afghanistan in the 2000s, Soldiers and Marines typically wore tactical vests or plate carriers with hard armor ballistic inserts, a combat helmet, and other miscellaneous items such as eye protection and gloves. This PPE, added to the other items that personnel typically carry or wear in operational environments (weapon systems, food and water, communications equipment, and other items), cumulatively represent the total load burden on personnel. The total load varies to some degree between the Army and the Marine Corps, and the services use specific load categories for mission-planning purposes. For example, the Army uses three combat loads, fighting (lightest), approach march (mid), and emergency approach march (heaviest), based on a number of factors, including mission duration and purpose, the likelihood of resupply, climate, and other characteristics that affect equipment and supply decisions. Similarly, the Marine Corps uses the following categories for mission and load-planning purposes: fighting (lightest), assault (mid), and sustainment (heaviest). According to Army guidance and Marine Corps documentation, the two services generally use these load parameters as a guide for determining the most appropriate equipment and supply levels required to meet mission objectives. The services each have program offices that develop, acquire, and field PPE and other equipment based on generated and approved operational requirements for Soldiers and Marines. For example, Program Executive Office Soldier develops specifications, and acquires equipment, including PPE, based on capability requirements produced by the Army's Training and Doctrine Command. Similarly, the Marine Corps Systems Command develops, acquires, and fields PPE and other equipment to address operational requirements developed by the Capability Development Directorate of the Deputy Commandant for Combat Development and Integration. The service program offices typically collaborate with each other and partner with industry providers to research, design, and develop PPE and other equipment. The Army and the Marine Corps have developed requirements for PPE to address operational threats but these requirements contribute to the total load burden on ground combat personnel. The services expect ground combat personnel to wear a combination of equipment developed to meet these requirements, including hard armor plates, soft armor plate carrier vests, and combat helmets, as shown in figure 1. According to Army and Marine Corps program managers, these items individually provide specific functions that together form a protective system for personnel. According to Army and Marine Corps documentation, the current system was initially developed and fielded to address specific threats facing personnel operating in Iraq (Operation Iraqi Freedom) in 2003. Officials stated that the two services conducted capability and threat assessments in this theater to determine how best to mitigate threats without hindering mobility or combat effectiveness. The services have documented these assessments and protection requirements in PPE guidance, technical documentation, and acquisition specifications, which include the size, weight, coverage area, protective standards, and other key parameters for each primary PPE component. These documents standardize PPE expectations and operational requirements for Soldiers and Marines. Officials noted that they are able to change PPE requirements or standards to meet evolving needs, incorporate technological advancements, or modify goals. Additionally, they provide industry partners with specifications needed to develop equipment. While the services have produced individual PPE guidance and technical documentation, officials noted that they jointly develop protection requirements and acquire some of the primary PPE components. For example, the Army and Marine Corps jointly acquired modern hard armor plates and have coordinated on the development and acquisition of the enhanced combat helmet. The two services also have similar standards for the soft armor plate carrier vests, but Marine Corps officials noted that because each service has some unique operational requirements, they developed and acquired this item separately. Army and Marine Corps officials we met with stated that the body armor that was fielded to meet current threats provides significant additional protection when compared with previously available equipment. However, they also noted that providing this level of protection adds significant bulk and weight to the total load on Soldiers and Marines, which could impede mobility and have other adverse effects. Both Marine Corps guidance and Army capability requirements indicate that PPE should provide adequate protection levels without hindering mobility or combat effectiveness. The primary PPE (hard armor plates, soft armor vest, and combat helmet) currently used by both Army and Marine Corps personnel averages approximately 27 pounds (for size medium equipment), and adds to the weight of other uniform items and equipment worn or carried by personnel. The cumulative weight of all uniform items and other equipment expected to be carried or worn by personnel in operational environments represents the total load and can vary according to individual position (e.g., squad leader, rifleman, grenadier) and mission characteristics (see figure 2). According to program managers we met with, the typical total load on personnel has increased since about 2003 based on the incorporation of new PPE systems and other equipment that is designed to enhance personnel performance or protection capabilities. According to 2016 Marine Corps data, a typical load is expected to be approximately 90 to 159 pounds, or an average of 117 pounds, depending on the individual function within the squad. Similarly, Army ground personnel are expected to wear and carry approximately 96 to140 pounds, or an average of 119 pounds, depending on individual roles. These can vary based on individual PPE sizes and other equipment variations. However, the expected totals for Army ground combat personnel generally align with actual load totals ranging from 96 to 151 pounds, reported by personnel recently operating in Afghanistan. However, program officials also explained that excessive loads can have negative effects on personnel mobility, lead to earlier fatigue onset, and exacerbate the risk associated with high temperature operational environments. Army Field Manual 21-18, published in 1990, recommends that the fighting load not exceed 48 pounds and that the approach/march load not exceed 72 pounds. According to program managers, the Marine Corps does not have specific load thresholds or maximums, but documentation identifies that loads in excess of 30 percent of body weight for ground combat personnel increase the likelihood of detrimental performance effects. Medical researchers from the services whom we met with agreed that these are some of the risks associated with substantial combat loads, and stated that they have attempted to correlate load burdens with detrimental performance and increased injury risks. For example, the Naval Health Research Center in San Diego, CA, collected injury data from personnel operating in Afghanistan and Iraq between 2011 and 2013 and concluded that excessive loads may have exacerbated the reported injuries. Service officials said that they are studying these potential effects on personnel performance, but also stated that the available load guidelines could be outdated and not reflective of current PPE systems and other capability enhancing equipment. Additionally, they note that these thresholds may not be appropriate for all personnel and that load thresholds or limits could restrict commander flexibility in the field by potentially impairing their ability to properly outfit personnel to meet mission requirements. Nonetheless, officials from both services stated that they continually seek ways to reduce the weight of PPE and reduce or offset the overall loads on personnel while maintaining operational capabilities and protection standards. Army and Marine Corps officials coordinate through formal and informal working groups that seek to develop and improve PPE. For example, two to four times annually the services hold a Cross-Service Warfighter Equipment Board, which allows Army and Marine Corps representatives, along with members of the other military services, to share developments and advancements made to PPE and other individual equipment. The Army and Marine Corps also participate in the Personal Protective Equipment Capabilities Development Integrated Product Team, an interagency forum that shares information, such as injury data, research and development findings, material developments, technologies, and test methodologies, among key stakeholders involved in PPE development. In addition, the Army and Marine Corps work together on the development and procurement of PPE, such as the hard armor plates and the enhanced combat helmet that meet both services' needs. Informally, the Army and Marine Corps regularly communicate on a variety of PPE-related research, technology advancements, and planning efforts. Officials from both Army and Marine Corps program offices explained that coordination is mutually beneficial based on similar equipment needs for ground combat personnel. Officials noted that they have collaborated on the development, management, and procurement of current hard armor plates since their inception in the early 2000s. Additionally, in August 2016 we observed a Marine Corps-sponsored industry event focused on the next iteration of the enhanced combat helmet, where an Army engineer participated and shared with vendors the Army's perspective on weight reduction priorities for the helmet. Army and Marine Corps officials stated that they collaborate with vendors to gather input for the development of PPE. Army and Marine Corps program managers said that when developing or improving PPE and other equipment, they prioritize protection and operational capabilities, and that they have overarching goals of reducing weight, and improving form, fit, and function of equipment. These overarching goals have led to some improvements and reductions in the weight of some PPE. For example, the Army and Marine Corps have made updates and redesigned aspects of their respective soft armor vests, which according to program managers have resulted or will result in weight savings of up to approximately 40 to 50 percent, or about 6 to 7 pounds when compared with previous versions. In addition, according to Marine Corps documentation, the service is incentivizing industry partners to produce lighter equipment and systems by incorporating weight reduction as a part of the source selection process for the enhanced combat helmet. Further, in 2016 the Army began developing a goal and subsequent plan to reduce the weight of hard armor plates by 20 percent, or about 2 pounds, by identifying and eliminating excess ballistic protection parameters and potentially updating testing methodologies. Officials said that protection standards have largely prevented significant reductions to date; however, they believe that the plates may be over- designed and heavier than necessary, based on actual operational threats and PPE performance data collected in Iraq and Afghanistan. According to research officials, updates would allow for weight reductions without increasing the ballistic risk to personnel. According to Army officials, the plan is currently pending approval by senior Army officials. If approved, researchers expect to develop new hard armor plates, with reduced weight, in fiscal year 2019. The Army and Marine Corps are also pursuing other efforts to reduce the weight of PPE. For example, the Army and Marine Corps are promoting PPE scalability as an approach to realize near-term weight reductions. PPE scalability allows Soldiers and Marines to vary the levels of PPE worn, from minimal protection or no PPE to a maximum level whereby Soldiers and Marines utilize all available PPE. The Army and Marine Corps have categorized these protection levels based on configurations of all available PPE, and officials said that potential weight reductions could be realized if commanders were to adjust protection levels (amount of PPE utilized) based on an evaluation of environment, threat, and mission characteristics. However, Marine Corps officials noted that commanders may be reluctant to increase operational risk by reducing PPE protection levels. Finally, Army and Marine Corps researchers are exploring ways to better integrate individual equipment to provide improved functionality and potentially save weight. The Army's Warrior Integration Site and the Marine Corps' Marine Expeditionary Rifle Squad research the integration potential of all individual equipment worn by Soldiers and Marines. According to officials with whom we met, the two services see their analyses potentially resulting in improvements to the weight, form, and function of Soldier and Marine equipment. One analytical method used by both the Army and the Marine Corps entails load effect assessment programs that use instrumented obstacle courses to gather data and evaluate mobility and functions based on various combat loads that personnel experience (see figure 3 and associated video). Officials explained that these data and analyses help them identify specific equipment that could or should be improved. While these efforts may have implications for reducing the load burden of Soldiers and Marines, the main goal for both organizations is to improve personnel performance by providing better integration and function for equipment commonly utilized by Soldiers and Marines. Army and Marine Corps researchers are exploring initiatives--such as improvements to logistics and resupply capabilities, load transfer technologies, lighter ammunition, and reduced battery usage--that may decrease the total load burden on ground combat personnel. Improved Logistics and Resupply Capabilities. Researchers at the Natick Soldier Research Development and Engineering Center said that they are exploring new technologies and systems that could provide improved logistics support for squads in the form of precise and on-demand resupply. Army officials noted that personnel loads are affected by confidence levels in resupply and logistics support. For example, squads that are more confident in resupply may be more willing to carry less ammunition, water, food, and other supplies, thus reducing the total weight carried by personnel. Therefore, developing new aerial delivery systems capable of providing small- and medium-sized payloads with precision could enable Soldiers and Marines to carry not more than the necessary equipment and supplies. The Marine Corps has implemented one of these systems, the Joint Precision Airdrop System, which was developed by the Army's Aerial Delivery Directorate at the Natick Soldier Research Development & Engineering Center. This system is designed to accurately deliver (within 150 meters) up to 700 pounds of supplies to personnel operating in inaccessible environments. A Marine Corps program official stated that the system would likely alter planning and allow personnel to forgo packing excess food, water, ammunition, and other supplies. They also stated that the procurement and sustainment costs for all units of this system totaled approximately $850,000 for fiscal years 2013 through 2016. Load Transfer Technologies: The Army and Marine Corps are evaluating both manned and unmanned load transfer technologies capable of travelling with units or squads (see figure 4). These technologies may allow Soldiers and Marines to offload some items such as food, water, or ammunition. For example, the Marine Corps is currently employing 144 MRZR all-terrain vehicles capable of traveling with squads and transporting up to 1500 pounds of personnel, equipment, and supplies. Marine Corps officials stated that the total acquisition and sustainment costs for all the vehicles are projected to be approximately $15 million between fiscal years 2016 and 2018. Similarly, the Army is in the process of developing an unmanned or optionally-manned squad support vehicle capable of traveling with dismounted personnel and carrying up to 1000 pounds of equipment. The prototypes include both tracked and wheeled variants. Army officials stated that they plan to pursue this as an official program and field the vehicles in fiscal years 2020 and 2021. In addition, the Defense Advanced Research Project Agency supported similar research and development efforts by designing and testing the Legged Squad Support System, which researchers stated had the intended capability to carry up to 1,000 pounds of equipment and travel semi-autonomously with squads and fire teams. While the Army and Marine Corps are not currently pursuing this specific system, they plan to test additional unmanned ground systems with similar load transferring and mobility capabilities. Lighter Ammunition: Army and Marine Corps program managers are developing lightweight technologies and monitoring third-party research related to the development of polymer-case ammunition for commonly used .50 caliber, 7.62 mm, and 5.56 mm rounds. According to program managers, transitioning to polymer based ammunition casing could reduce ammunition weight by as much as 20 to 35 percent based on the weight difference between lighter polymer casing and traditional brass casing. The Marine Corps began testing a polymer-case .50 caliber round in March 2017, which could replace legacy ammunition without modifying the .50 caliber weapon systems currently in use. However, significant weight savings for personnel would require implementing this technology for smaller-caliber rounds with lightweight polymer-case compatible weapon systems, and officials noted that these investments would likely hinder near-term implementation. Reduced Battery Usage: The Army and Marine Corps are researching potential hardware and software changes that could reduce the energy demand for some commonly carried electronics and thus reduce energy usage and weight associated with batteries. For example, Army researchers stated that they are evaluating systems that harvest energy from Soldiers' movements and solar technology that could be used to power communications systems and other battery-driven equipment. Additionally, officials noted that they are monitoring private-sector technology developments that could reduce the weight of batteries by 20 percent while providing the same amount of energy as those batteries currently used. Marine Corps program officials explained that they are also developing a single radio with the same capability as is provided by two separate radios currently used by Marines. Officials stated that this new radio may reduce the need to carry excess batteries. However, Army and Marine Corps officials noted that battery demand and its associated weight continue to pose a significant challenge. For example, Army program managers said that squad leaders currently carry approximately 8 pounds of batteries to power a variety of optics, communications systems, and other equipment. DOD provided technical comments on a draft of this report, which we incorporated as appropriate. We are sending copies of this report to the appropriate congressional committees and to the Secretary of Defense, the Secretaries of the Army and the Navy, and the Commandant of the Marine Corps. In addition, the report will be available at no charge on the GAO website at http://www.gao.gov. If you or your staff have any questions about this report, please contact me at (202) 512-5431 or russellc@gao.gov. Contact points for our Offices of Congressional Relations and Public Affairs may be found on the last page of this report. GAO staff who made key contributions to this report are listed in appendix II. In addition to the contact named above, Alissa Czyz (Assistant Director), Larry Junek (Assistant Director), Alexandra Gonzalez, Amie Lesser, Sean Manzano, Michael Shaughnessy, Michael Silver, Grant Sutton, and Cheryl Weissman made key contributions to the report.

Summary:
Army and Marine Corps ground combat personnel have long worn a variety of PPE such as vests, armor, and helmets to help protect them from operational risks. The two services have documented the advanced protection capabilities of current PPE systems, but identified that the armor contributes to the total load burden--or cumulative weight of items typically worn or carried. In addition to PPE, personnel typically carry food, water, ammunition, communications equipment, and other items. House Report 114-537, accompanying a bill for the National Defense Authorization Act for Fiscal Year 2017, included a provision for GAO to review Army and Marine Corps efforts to reduce the weight of PPE and other equipment worn or carried in combat. This report describes (1) the current operational requirements associated with PPE, and how those requirements contribute to the total load burden on Soldiers and Marines in combat environments; and (2) the coordination between the Army and the Marine Corps regarding efforts to reduce the weight of PPE and the total load burden on personnel. GAO reviewed Army and Marine Corps documentation related to PPE, total load burden on combat personnel, and weight reduction initiatives; and interviewed service researchers and program officials. The Army and Marine Corps have developed requirements for personal protective equipment (PPE) to address operational threats in ground combat environments, but this PPE has increased in weight over time and has added to the total load burden on personnel. PPE primarily consists of hard armor plates, soft armor plate carrier vests, and combat helmets. Army and Marine Corps officials stated that the PPE provides significant additional protection when compared with equipment used prior to operations in Iraq in the 2000s. However, they also noted that providing this level of protection adds significant bulk and weight to the total load on Soldiers and Marines, which could impede mobility and hinder combat effectiveness. According to service-provided data, the typical total load in 2016 for Army and Marine Corps ground combat personnel averaged about 119 and 117 pounds, respectively, of which the primary PPE represented about 27 pounds based on equipment sizes (see figure). Officials stated that these totals have increased over time based on the incorporation of new PPE and other equipment. Recognizing that the weight of PPE and other equipment could have negative effects on personnel performance, the Army and the Marine Corps have coordinated and developed goals for PPE-related weight reductions and are pursuing some efforts to reduce overall load burdens on personnel. The two services coordinate through formal working groups and informal methods to develop and improve PPE. Army and Marine Corps officials stated that while they prioritize protection and operational capabilities when developing PPE, they have overarching goals of reducing weight, in addition to improving the form, fit, and function of equipment. These goals have led to reductions in the weight of some PPE. The Army is also developing a goal and plan to reduce the weight of hard armor plates by 20 percent by identifying and eliminating excess ballistic protection. In addition, the Army and Marine Corps are pursuing other efforts to reduce the weight of PPE, such as by giving commanders the option to employ varying levels of PPE at their discretion and studying the effects of integrating PPE with overall combat loads. Finally, the Army and Marine Corps are exploring research initiatives that may reduce the total load on ground combat personnel, such as improvements to logistics and aerial delivery capabilities, load transferring systems, and other enhancements to equipment. GAO is not making recommendations in this report. DOD provided technical comments on a draft of this report, which GAO incorporated as appropriate.