Thermobaric weapons under fire again
November 22, 2005 War is ugly and inhumane but seemingly inevitable - there are roughly 50 wars being fought somewhere on the planet at any given time and the statistics show that we’re a long way from living peacefully together. One of the problems with warfare, is that it is inevitably conducted in areas where there are non-combatants - civilians are very fragile in a war zone. Which brings us to perhaps the most interesting story of the week. The news was put on the agenda by David Hambling in Defensetech, a military insider news service, and covers a new weapon in use by the US Marines - the SMAW-NE.
Now (Shoulder-Launched Multipurpose Assault Weapons (SMAW) have been in use for two decades, using High Explosive Anti-Armor (HEAA) rockets against tanks and High Explosive, Dual Purpose (HEDP) rockets against bunkers, masonry and concrete walls, and light armor. But it’s the new Novel Explosive (NE) rockets which are causing all the fuss. The Novel Explosive is a thermobaric charge so destructive it can be used to demolish buildings - which makes it very handy for quelling the resistance in a building full of people shooting at you.
The term "thermobaric" is derived from the effects of temperature (the Greek word "therme" means "heat") and pressure (the Greek word "baros" means "pressure") on the target. Thermobarics first disperse a flammable mist of underoxidised fuel which ignites to create a gigantic explosion of immense destructiveness. The explosion of the SMAW-NE is effective in three main ways. Firstly, it is accompanied by a massive fireball which incinerates all in its path. Secondly, it creates a massive pressure wave capable of rupturing the internal organs of all those nearby and so powerful that it can reduce load-bearing walls to rubble and bring down buildings. Finally, the explosion also sucks all the oxygen out of the air, asphyxiating anyone in the immediate vicinity . Basically, if you’re in the building when it hits, it’ll kill you.
Wired magazine wrote about thermobaric devices and the coming of this weapon a few years ago, and it quoted Human Rights Watch arms researcher, Reuben Brigety as saying, "this significantly increases the firepower that can be put in a single person's hands." "I'm not aware of any other conventional munitions used by a single person that can have the same destructive power."
Thermobaric devices are tailor-made for some situations, and there’s a much bigger BLU-118/B Thermobaric Weapon in use, which is very good against Hard and/or Deeply Buried Targets (HDBTs), and no place on Earth has more military targets tunneled in rock than Afghanistan. See these excellent diagrams showing the inventiveness of the Afghani trogolodites from the New York Times and the Washington Post.
The airblast propagation of the BLU-118/B makes it ideal for detonation within such a tunnel system and that’s what it is being used for. The BBC has an excellent diagram explaining how thermobaric bombs work.
The US Military sees thermobaric weapons as very useful and is pressing ahead with the Thermobaric Weapon Advanced Concept Technology Demonstration (ACTD). This leverages existing concepts and efforts in energetic payload technology (explosives), warhead case survivability, guidance, and operational tactics.
The thermobaric weapon integrates, demonstrates and delivers an improved weapon system for the functional defeat of tunnel targets. Functional defeat refers to eliminating a facility's capability to perform its intended function, even though the structure itself may remain largely intact. It relies on denial, disruption, degradation, or destruction of one or more of the critical elements in the tunnel necessary to perform its mission (personnel, equipment, or environmental support). The demonstration will be completed this year.
The ACTD is intended to provide an improved military capability that would require fewer weapons for functional defeat, provide longer duration shutdown, compared to similar conventional attacks, and be less sensitive to intelligence gaps and uncertainties.
As a consequence of the positive results achieved by penetrating weapons against reinforced concrete bunkers during recent conflicts, many nations are moving their most valuable national assets into underground facilities, particularly tunnels. In many cases, the mission critical areas of tunnel facilities are practically invulnerable to physical destruction using current conventional weapons -- requiring a functional defeat of tunnel facilities.
ACTD scientists are addressing these deficiencies by developing a weapon that is capable of generating increased weapon effects to functionally defeat mission areas inside tunnels. The program will design a high-strength warhead case compatible with existing guidance kits and develop an explosive fill with improved air-blast capabilities. Additionally, the program will enhance guidance system and operational tactics to provide the warfighter with an improved capability to defeat tunnel targets.
The Bomb Live Unit (BLU)-118/B is a penetrating warhead filled with an advanced thermobaric explosive that when detonated generates higher sustained blast pressures in confined spaces such as tunnels and underground facilities. The U.S. Air Force fielded 10 of these new warheads compatible with the current Guided Bomb Unit (GBU)-15, GBU-24, and Air-launched Surface-attack Guided Missile (AGM)-130 weapon systems for employment by U.S. Air Force F-15E Strike Eagle aircraft.
The BLU-118/B uses the same penetrator body as the BLU-109 weapon, with the significant difference being the replacement of the high explosive fill with a new thermobaric explosive that provides increased lethality in confined spaces. The Defense Threat Reduction Agency (DTRA) is conducting a three-year Advanced Concept Technology Demonstration for a thermobaric weapon system to defeat hardened underground targets. The Sept. 11, 2001, terrorist attacks motivated changes in program priorities. On Oct. 11, 2001, DTRA organized a quick-response team that included Navy, Air Force, Department of Energy and industry experts to identify, test, integrate and field a rapid solution that would enhance weapons options in countering hardened underground targets.
The explosive experts at the Naval Surface Weapons Center, Indian Head, Md., responded with a developmental explosive that clearly provided enhanced blast effects. The Air Force Precision Strike Program Office at Eglin AFB, Fla., led the team performing the weapon system integration, safety and flight clearances, and produced a modified fuzing system for the new warhead. The Indian Head facility conducted static testing of the fuze to demonstrate reliable initiation of the new explosive. Both static and flight tests were then conducted at full-scale tunnel facilities at the Department of Energy's Nevada Test Site.
The fast-paced program culminated on Dec.14, 2001, with a successful flight test of the GBU-24 laser-guided weapon using the BLU-118B warhead launched by an F-15E. When compared to the standard BLU-109 explosive, results showed the new thermobaric weapon generated a significant improvement in overpressure and pressure-impulse in the tunnel complex.
The Air Force completed verification and validation of the technical data and operational flight clearances needed to deploy the BLU-118B warhead. Ten warheads were immediately made available to the U.S. Air Force for deployment.
The rules of war
Which brings us back to the rules of war and what’s fair. Human Rights organizations were very vocal when the Russians, who have their own version of this weapon, used thermobaric bombs against the Afghanis decades ago (when Osama was a good guy). They more recently used thermobaric weapons against the Chechnyans, and a similar reaction ensued when the Sri Lankan Army procured thermobaric capability for use against the Tamils. For some detail on the devastation caused by the Russian use of fuel air explosives, see this excellent backgrounder.
What’s the answer?
Military effectiveness is reaching new heights thanks to the technological Rennaissance Part 2 going on. Old golf courses are now not big enough to contain the new clubs and balls, racing machines of every type get faster every year and governing bodies continually reframe rules to stop the ever increasing speeds. The same process of searching for ever more effective solutions is ongoing in the military and greater understanding of the laws of the universe is leading to ever-more effective weapons. Technology is rewriting the rules for us and if we fail to recognise this and constantly reframe the rules, civilised behaviour will never prevail. There is a raft of new and ever deadlier weapons under development and consideration by the US military and they aren't going to make war friendlier. War is ugly and it's very difficult to frame rules around just how ugly the weapons might be.
If we can't stop war, we must at least agree on acceptable rules.
Thermobaric weapons are being used in built-up areas where there are known to be civilians and that clearly needs to be stopped. If you're not sure, or are concerned,read this.
BTW - it is not the fault of the soldiers.