The potential utility of thermobaric artillery rounds is an interesting topic, but there are specific reasons why conventional high-explosive (HE) shells remain the preferred choice for most artillery applications. Here’s a breakdown of the factors that limit the practicality of thermobaric rounds in artillery and how they compare to traditional HE shells:
What Are Thermobaric Weapons?
Thermobaric, or fuel-air explosive (FAE) weapons, use a two-stage process. First, they release a cloud of fuel into the air, which then ignites, creating a powerful blast wave and vacuum effect that lasts longer than a conventional explosion. This makes them especially devastating in enclosed spaces, such as bunkers or buildings, where the fuel cloud can penetrate before detonating. Thermobaric weapons are particularly effective at:
- Clearing fortifications: The overpressure and fireball can penetrate small openings, making them effective against personnel in trenches, bunkers, or caves.
- Producing high overpressure: The resulting blast can be more devastating to personnel than a standard HE round due to the intense heat and pressure.
Why Thermobaric Rounds Are Rarely Used in Artillery
1. Design and Structural Constraints:
- Shell Casing Strength: Artillery shells need to survive the extreme acceleration and pressure when fired from a cannon. As a result, their casings are heavy and reinforced. This limits the internal volume available for the thermobaric explosive mixture.
- Insensitive to Artillery Applications: Thermobaric effects rely on dispersing a fuel cloud before ignition, which is easier to achieve with rockets that have gentler launch conditions, like those from multiple launch rocket systems (MLRS). Artillery shells, subjected to higher launch stresses, face difficulties in achieving the precise dispersal needed for an optimal fuel-air mixture.
2. Conventional HE Rounds Are More Versatile:
- Fragmentation Effects: Conventional HE shells are designed to produce a combination of blast and fragmentation. When they detonate, the shell casing fragments into high-speed shrapnel, which is highly effective at causing casualties over a wide area. This is critical in open-field combat where spreading damage across a broader range is more beneficial.
- Modular Fusing Options: Modern artillery shells can be equipped with various fuses, such as proximity, delay, or point-detonating fuses, allowing them to adapt to different target types—whether that’s infantry in the open, light vehicles, or reinforced structures. This versatility makes HE shells a more practical choice for a wide range of targets.
3. Effective Range and Weather Sensitivity:
- Range Limitations: Thermobaric munitions need a specific atmospheric density for optimal fuel-air dispersal, making them more sensitive to weather conditions like wind and humidity. This sensitivity can reduce their effectiveness in varying field conditions, particularly when compared to the more straightforward mechanics of an HE round.
- Reduced Blast Radius: The effects of a thermobaric explosion, such as intense overpressure and heat, are more localized compared to the blast and fragmentation pattern of a conventional HE round. While devastating in enclosed spaces, the open nature of many battlefield environments in conflicts like Ukraine means that an HE round’s wider fragmentation pattern is often more effective.
4. Ammunition Logistics and Production:
- Standardization Benefits: Using standard HE shells simplifies logistics, ammunition production, and resupply chains. In a high-intensity conflict, maintaining a streamlined supply chain is crucial, and introducing a different type of round with specific applications adds complexity.
- Economics of Mass Production: HE shells are already widely produced and stockpiled by most militaries, making them more readily available. Producing and distributing a specialized thermobaric shell would require new production lines and logistics, adding costs that might not be justified by the limited tactical advantage.
Situational Use Cases for Thermobaric Rounds
While thermobaric artillery rounds are not common, there are some scenarios where their use could be more effective than standard HE rounds:
- Urban Combat and Clearing Enclosed Structures: In urban warfare, where troops may encounter enemy forces in buildings, bunkers, or underground tunnels, the overpressure and vacuum effect of thermobaric rounds could provide a significant advantage.
- Enemy Trenches or Caves: Forcing air-fuel mixtures into trenches or caves could allow a thermobaric round to create a more lethal overpressure effect than an HE round in these specific settings.
In such cases, the more common solution is to use thermobaric rockets or shoulder-fired systems like the Russian TOS-1 or the American SMAW-NE for clearing structures, as these systems are better suited for deploying thermobaric effects.
Conclusion: Why HE Rounds Remain Dominant
Ultimately, while thermobaric artillery rounds could theoretically offer certain advantages in specific situations, the drawbacks outweigh these benefits in most conventional artillery engagements:
- Conventional HE rounds provide broader damage through fragmentation and blast.
- They are versatile and can be adapted to different mission profiles through fusing options.
- The logistics and standardization of HE shells make them more practical for sustained operations.
In modern conflicts like the war in Ukraine, where artillery is used extensively against a range of targets, from infantry positions to vehicles and reinforced structures, the all-around capabilities of HE shells make them the preferred choice for most militaries. Thermobarics, despite their niche effectiveness, remain specialized tools rather than a mainstay of artillery tactics.