Since 2000 combat helmet design has made enormous advances. The new helmets have increased protection (often against rifle bullets as employed by snipers) while becoming more comfortable to wear, more accommodating of accessories (especially personal radios and night vision gear) without becoming heavier. Combat helmets were long considered low-tech but that has changed since the 1980s. Creation of new materials plus advances in the design and construction of helmets have been accelerating, especially in the last decade. For example, the American ACH (Advanced Combat Helmet), as popular as it was after appearing in the 1990s, soon underwent tweaks to make it more stable. That was required because more troops were being equipped with a flip down (over one eye) transparent computer screen. The device is close to the eye, so it looks like a laptop computer display to the soldier and can display maps, orders, troop locations, or whatever. If the helmet jumps around too much it's difficult for the solider to make out what's on the display. This can be dangerous in combat.
The first modern combat helmets appeared during World War I (1914-18), with the U.S. adopting the flat, British design steel model and using it for 25 years. This was replaced by the M1 helmet in the early 1940s. This was the “steel pot” and liner system that lasted over four decades. The PASGT (Personnel Armor System for Ground Troops) replaced the M1 in the early 1980s and lasted twenty years. The ACH replaced PASGT by 2007 but by 2012 the ECH (Enhanced Combat Helmet) began appearing as a replacement. ECH, like ACH is built to take lots of accessories and is the version bought by police and emergency service organizations.
It was only in 2005 that the ACH began entering service. The Kevlar PASGT design was a third generation combat helmet, nicknamed the "Fritz" after its resemblance to the German helmets used in both World Wars. That German World War I design, which was based on an analysis of where troops were being hit by fragments and bullets in combat, was the most successful combat helmet in both world wars. This basic design was finally adopted by most other nations after the American PASGT helmet appeared in the 1980s. Most of the second generation helmets, which appeared largely during World War II, were similar to the old American M1 design. The fourth generation helmets, currently in service, use better synthetic materials and more comfortable design.
The ACH, like MICH/FAST are smaller and lighter (they weigh about the same). The ACH was first developed as a special project by the U.S. Army Special Forces and was so successful that the rest of the army began buying them. The current model of ACH weighs 864 gr (1.9 pounds) and is modified to more easily accept accessories like radio earpieces and mikes as well as night-vision gear and add-on armor.
By 2010 the army had started putting microelectronic blast gages in many helmets to measure the impact (and protection provided by the helmet) when troops were hit by roadside bombs or other explosives. The design of ACH was further tweaked by using this data. With many nations now using the ACH design and modifying it, along with civilian firms who make ACH-like helmets for police and firefighters, the technology continues to advance. SOCOM is looking into adding more health monitoring devices and new communications systems. But the first decade of the 21st century will stand as a period of epic advances in combat helmet design and battlefield performance.
ACH was developed from the earlier MICH (Modular Integrated Communications Helmet) which SOCOM (Special Operations Command) pioneered. In 2012 the U.S. Army ordered another 60,000 MICH helmets to make them available for most infantry. Formerly called the Gallet, after the designer, and eventually known as the FAST ballistic helmet, the manufacturer has long been known for designing helmets for fire, police, and rescue personnel. When first issued to troops in 2004 the MICH was 14 percent lighter (at 1.36 kg/3 pounds) and more comfortable than the PASGT. MICH was most appreciated because it can be worn for long periods without becoming uncomfortable. Later models were even more comfortable, with an improved interior that also offered more protection against bumps and explosions.
The older PASGT would, after many hours, literally become a pain in the neck. The MICH helmet offered the same degree of protection and was also less of a hassle when you are in the prone position and wearing a protective vest that is riding a little high (the bottom of the Kevlar helmet tends to collide with the top of the vest in those situations). Initially it was mostly SOCOM and paratroopers who were issued MICH helmets but they could also be bought direct from the manufacturer (which some troops did). The Department of Defense began using them in 2004, with an initial order for 90,000. Even civilian contractors could get them (for about $500).
Inspired by the success of MICH, a version of the helmet was renamed ACH and ordered in large quantities. In 2011 an improved version, ECH showed up. The U.S. Army and Marine Corps found that their new ECH was even more bullet proof than expected. While testing the ECH it was discovered that the machine firing metal fragments at the ECH (to represent shell and bomb fragments) could not fire fragments fast enough to penetrate. The ECH was supposed to be invulnerable to pistol bullets, and it was, but some types of metal fragments were expected to still be dangerous. So ECH was tested to see how well it could resist high-powered rifle bullets. ECH was not 100 percent invulnerable but in most cases it would stop anything fired from a sniper rifle. Overall, it was calculated that the ECH was 40 percent more resistant to projectiles and 70 percent stronger than the previous ACH helmet. Later models were modified to accept additional armor, making the helmet virtually invulnerable to sniper bullets.
The ECH made use of a new thermoplastic material (UHMWP or Ultra-High Molecular Weight Polyethylene), which is also used in the current FAST helmet. UHMWP is lighter and stronger than the Kevlar used in the ACH and earlier PASGT and, it turned out, provided much better protection as well. The ECH began replacing the ACH in 2011 with 200,000 to be purchased. The ECH costs $600 each, twice as much as the ACH. But for troops under fire, the additional cost is well worth the additional protection.