Israeli troops have recently been using a non-lethal crowd dispersal system called Roar (“Sha’aga” in Hebrew) to deal with violent demonstrations at the Gaza border fence. The IDF (Israeli Defense Forces) declared Roar a success but would not provide any details on how it worked. Photos and available descriptions of Roar sound like a similar system first developed in Israel in 2010. This non-lethal weapon was called the Thunder Cannon. Light enough to be mounted in a cart, trailer or hummer type vehicle, it used a new Pulse Detonation Technology that combines LPG (liquefied natural gas) with air to create a sonic boom in a cannon type barrel. Each burst moves forward at 2,000 meters per second and lasts 300 milliseconds. The cannon generates 60 to 100 bursts per second. One 27 pound (12kg) canister of LPG can create 5,000 bursts. A cell phone size control unit does the mixing and detonation. The cannon is effective at hitting people with these sonic bursts, at ranges of up to fifty meters (152 feet), for maximum effect. Even at 100 meters the sonic bursts will cause most crowds to disperse. At ten meters or less, the burst can cause injury, or even be fatal. Anyone hit by the sonic bursts feels it and hears it. It's disorienting, and most people exposed to it flee the area. The effect can be diminished by wearing earplugs or covering your ears with your hands. But that does not make you immune to the impact and when a crowd is the target the crowd tends to break up leaving the more determined folks all alone.
The technology was first developed to chase birds away from crops. It has been very effective at this and is still used that way. The military version can be mounted on vehicles, and fitted with a nozzle that can calibrate the shockwaves for special mission requirements. There is also a multi-barrel version. Bended barrels can also be used to fire it around corners. Not much was heard about Thunder Cannon since 2010 but Roar appears to be an upgraded version or a variation on the basic concept.
As effective as systems like Roar are there is still a problem with the fact that non-lethal weapons are not one hundred percent non-lethal, and not nearly as effective as proponents would have you believe. Nevertheless, people love to call them non-lethal, because such devices are intended to deal with violent individuals without killing them. A classic example of how this works is the Taser. A gun like device that fires two small barbs into an individual, and then zaps the victim with a non-lethal jolt of electricity, the Taser has been popular with police, who can more easily subdue violent, and often armed, individuals. Before Taser, the cops had a choice between dangerous (for everyone) hand-to-hand combat, or just using their firearms and killing the guy. While the Taser has been a major success for non-lethal weapons, for every thousand or so times you use it, the victim will die (either from a fall, another medical condition, use of drugs or whatever). This has been fodder for the media and put Taser users, and non-lethal-weapons developers, on the defensive. Naturally, the manufacturers of these devices want zero deaths, and the users want a device that will bring down the target every time, at a price (for the device) they can afford to pay. There's no way of satisfying all these demands, but it makes great press insisting that someone should make it so.
Another widely used, and somewhat effective, type of non-lethal weapon is the "rubber bullet." This is, literally, a low velocity, rubber-coated bullet (or beanbag fired from a shotgun) that will hurt the victim, but rarely injure or kill. American developers came up with what they believed to be a better version. The FN 303 fires a 17mm plastic round at about 300 feet per second (pistol and rifle bullets travel at speeds of 1,000-3,000 feet per second). The FN 303 is only accurate to about a hundred meters, and the bullet can contain pepper concentrate (that makes the victims skin feel like it's burning), or paint (to mark the guy as someone of note). The FN 303 can be mounted under an M-16 (like the 40mm grenade launcher) or handled as a separate weapon.
About a thousand FN 303s were shipped to Iraq in 2006, mainly for use by military police. Commanders also wanted the infantry to use the FN 303 because more operations are taking place in areas controlled by radical militias. The local civilians threw rocks at American troops and staged rowdy demonstrations to block the movement of U.S. soldiers. The civilians knew that American ROE (Rules of Engagement) prohibited troops from firing into crowds unless someone in the crowd was holding weapons. So it was believed that the FN 303 would allow troops to have some control over these mobs. Two soldiers in each nine-man squad were given an FN 303. The civilians quickly figured out what the FN 303 is (a more powerful paintball gun), and were not very intimidated by it. Many troops wanted shotguns, which can also fire a non-lethal (or much less) round, as well as stuff that will kill or maim, and are more intimidating. In the end, the FN 303 failed in Iraq, although it is still used with some success by civilian police.
The U.S. Department of Defense also tried to apply high tech when developing non-lethal weapons. This resulted in two notable devices, the LRAD (sonic cannon) and the microwave ADS (Active Defense system). The ADS began development in the 1990s and was scheduled for use in Iraq many times but never made it. This was mostly because of bad image ("death ray"), and fear of the bad press they would get if the ADS were used, whether people died or not. There were also persistent reliability problems.
The ADS is a non-lethal weapon that looks like a radar dish. The ADS "radar dish" projects a "burn ray" that is about 110cm (four feet) in diameter. It is effective in fog, smoke and rain. When pointed at people and turned on, it creates a burning sensation on the skin of its victims, causing them to want to leave the area, or at least greatly distracts them. The microwave weapon has a range of about 500 meters. ADS is carried on a hummer or Stryker, along with a machine-gun and other non-lethal weapons. The proposed ROE (Rules of Engagement) for ADS are that anyone who keeps coming after getting hit with painful microwaves is assumed to have evil intent, and will be killed. The microwave is believed to be particularly useful for terrorists who hide in crowds of women and children, using the human shields to get close enough to make an attack. This has been encountered in Somalia and Iraq.
Later a new, smaller, version of ADS, called Silent Guardian, with a range of about 250 meters, was developed for use in defending vital targets (like nuclear power plants) against terrorists. The manufacturer also pitched Silent Guardian to the navy (for ship protection), the State Department (for embassy protection) and organizations like the border patrol, or anyone looking for a non-lethal way to quickly disperse crowds.
Deployment of ADS has been delayed for years because of concerns about how non-lethal it really is. ADS has been fired, in tests, over 3,000 times. Many of these firings were against human volunteers, and the device performed as predicted, without any permanent damage. But generations of exposure to lurid science fiction descriptions of "death rays" has made the defense bureaucrats anxious over the negative public relations potential if something like ADS was actually used. From a publicity perspective, using more lethal "non-lethal-weapons" is preferable to deploying something safer, but that could be described, however incorrectly, as a "death ray." ADS is undergoing endless evaluation prior to being sent into action.
Somewhat more successful, sort of, has been LRAD (Long Range Acoustic Device). This is basically a focused beam of sound. Originally, it was designed to emit a very loud sound. Anyone whose head was touched by this beam heard a painfully loud sound. Anyone standing next to them heard nothing. But those hit by the beam promptly fled, or fell to the ground in pain. Permanent hearing loss is possible if the beam is kept on a person for several seconds, but given the effect the sound usually has on people (they move, quickly), it is unlikely to happen. LRAD works. Some U.S. Navy ships also carry it, but not just to repel attacking suicide bombers, or whatever. No, the system was sold to the navy for a much gentler application. LRAD can also broadcast speech for up to 300 meters. The navy eventually used LRAD to warn ships to get out of the way. This was needed in places like the crowded coastal waters of the northern Persian Gulf, where the navy patrols. Many small fishing and cargo boats ply these waters, and it's often hard to get the attention of the crews. With LRAD, you just aim it at a member of the crew and have an interpreter "speak" to the sailor. It was noted that the guy on the receiving end was sometimes terrified, even after he realized it was that large American destroyer that was talking to him. This apparently gave the army guys some ideas, for there were soon rumors in Iraq of a devilish American weapon that makes people believe they are hearing voices in their heads. In 2009, off Somalia, LRAD was used by a tanker crew to try and defeat a pirate attack. But the pirates simply took the pain, kept on coming, and got aboard the chemical tanker.
Israel has long used a number of non-lethal weapons, usually for dealing with crowds of angry (and often rock throwing) Palestinians. The Israelis overcome the uncertain effectiveness of non-lethal weapons by always having guys with guns standing by. Roar is the latest example of that.