BLU-92/B Anti-Personnel Mine Submunition
1. Overview
The BLU-92/B is an air-delivered, scatterable anti-personnel mine submunition designed to protect anti-tank minefields from dismounted clearance operations. Developed as the companion munition to the BLU-91/B anti-tank mine in the United States GATOR mine system, the BLU-92/B provides a defensive barrier against infantry attempting to manually clear or breach GATOR minefields. The mine features tripwire-activated fuzing with a self-destruct mechanism intended to reduce long-term UXO hazards.
2. Country/Bloc of Origin
- Country: United States of America
- Developer: Honeywell Defense and Marine Systems (later Alliant Techsystems)
- Development Period: Late 1970s to early 1980s
- Service Entry: 1983
- International Users: Primarily US forces; limited export to select NATO allies
The BLU-92/B was developed concurrently with the BLU-91/B to create an integrated area denial system. Cold War doctrine recognized that anti-tank minefields alone were vulnerable to dismounted infantry clearance teams, necessitating anti-personnel mines to protect the anti-tank barrier.
3. Ordnance Class
| Attribute | Classification |
|---|---|
| Type | Submunition / Scatterable Mine |
| Role | Anti-Personnel (AP) |
| Delivery Method | Air-delivered via dispenser (CBU-78/B, CBU-89/B GATOR) |
| Category | Area Denial Munition |
| Mine Type | Tripwire-Activated Fragmentation Mine |
The BLU-92/B is classified as a scatterable anti-personnel mine under international conventions. It is designed to kill or incapacitate dismounted personnel through fragmentation effects when tripwires are disturbed.
4. Ordnance Family / Nomenclature
Primary Designation:
- BLU-92/B (Bomb Live Unit)
Parent Systems:
- CBU-78/B GATOR – Navy/Marine Corps variant containing 45 BLU-91/B and 15 BLU-92/B mines
- CBU-89/B GATOR – Air Force variant containing 72 BLU-91/B and 22 BLU-92/B mines
Related Munitions:
- BLU-91/B – Companion anti-tank mine in the GATOR system
- M74 – Similar ground-delivered anti-personnel scatterable mine (ADAM system)
- PDM (Pursuit Deterrent Munition) – Earlier concept for trip-activated AP mines
NATO Stock Number (NSN): 1345-01-138-8650
Common Names:
- GATOR AP Mine
- Gator Anti-Personnel Submunition
5. Hazards
Primary Hazards
| Hazard Type | Description |
|---|---|
| Fragmentation | Primary kill mechanism; steel fragments projected at high velocity |
| Blast | Secondary effect from explosive detonation |
| Tripwire Entanglement | Multiple tripwires create complex activation hazard |
Sensitivity Factors
- Tripwire Activation: Extremely sensitive; minimal force on any of seven tripwires causes detonation
- Tilt Sensitivity: Anti-disturbance feature activates on movement of main body
- Self-Destruct: Battery-powered timer initiates self-destruct (variable settings)
- Low Battery Hazard: Battery depletion may cause self-destruct failure, creating persistent UXO
Safety Considerations
- Multiple Tripwires: Seven tripwires extend in all directions, creating 360-degree activation zone
- Wire Visibility: Fine tripwires are extremely difficult to see, especially in vegetation
- Overlapping Coverage: Multiple BLU-92/B mines in an area create interlocking tripwire networks
- Arming Delay: Mines have brief arming delay after dispensing
- Anti-Handling: Movement of mine body triggers detonation
Kill/Danger Radius
| Zone | Distance | Effect |
|---|---|---|
| Lethal Radius | ~10 meters (33 feet) | High probability of fatal injuries |
| Casualty Radius | ~20 meters (66 feet) | Significant injury probability |
| Tripwire Range | Up to 6 meters (20 feet) | Each tripwire extends several meters |
| Safety Distance | Minimum 50 meters | For unprotected personnel |
⚠️ WARNING: The BLU-92/B deploys multiple nearly-invisible tripwires that extend several meters from the mine body. The mine will detonate if ANY tripwire is disturbed OR if the mine body is moved. Never approach suspected BLU-92/B munitions without proper EOD training and equipment.
6. Key Identification Features
Physical Characteristics
| Dimension | Measurement |
|---|---|
| Diameter | Approximately 6.4 cm (2.5 inches) |
| Height (body) | Approximately 5 cm (2.0 inches) |
| Weight | Approximately 0.5 kg (1.1 lbs) |
| Tripwire Length | Each wire extends up to 6 meters (20 feet) |
Visual Identification
- Shape: Cylindrical body with domed top
- Color: Olive drab (OD) green body
- Markings: Yellow stenciled text indicating “MINE, AP” with lot numbers and data
- Material: Predominantly plastic casing with metal fragmentation liner
- Distinctive Features:
- Seven tripwire spools visible around circumference
- Small stabilizing ribbon/drogue may be attached or nearby
- Anchor stake at bottom for ground retention
Post-Deployment Appearance
After deployment, the BLU-92/B rests on the ground with its anchor stake penetrating the soil. Seven tripwires automatically deploy outward from spools around the mine body, extending several meters in all directions. The tripwires are fine gauge and extremely difficult to see, especially in grass, brush, or low-light conditions.
Condition Indicators
- Armed: Mine body on ground, tripwires extended in multiple directions
- Partially Deployed: Some tripwires extended, others still spooled
- Dud/UXO: May appear intact but failed to deploy wires properly; still extremely dangerous
Tripwire Characteristics
- Material: Fine steel or nylon monofilament
- Color: Dark or natural color, difficult to see
- Deployment: Automatic spring-loaded spool release upon landing
- Tension: Minimal force required to activate (less than 1 kg pull)
7. Fuzing Mechanisms
Primary Fuze System
The BLU-92/B employs a tripwire-activated mechanical/electronic fuze system:
| Component | Function |
|---|---|
| Tripwire Sensors | Seven wires connected to mechanical triggers |
| Pull Sensors | Detect tension on any tripwire |
| Firing Circuit | Electronic initiation of detonator |
Arming Sequence
- Dispensing: Mine ejected from dispenser canister
- Stabilization: Drogue/ribbon orients mine during descent
- Landing: Impact triggers anchor stake deployment and tripwire release
- Wire Extension: Seven tripwires automatically deploy from spring-loaded spools
- Arming Delay: Electronic timer counts down arming delay period
- Armed State: Mine becomes sensitive to tripwire disturbance and body movement
Safety Mechanisms
- Arming Delay: Prevents detonation during and immediately after dispensing
- Setback Safety: Requires acceleration of dispensing to initiate arming sequence
- Sequential Arming: Tripwires must deploy before mine arms
Self-Destruct System
The BLU-92/B incorporates a battery-powered self-destruct mechanism:
- Timer Options: Multiple self-destruct time settings (hours to days)
- Function: After preset time expires, mine self-destructs
- Reliability Issue: Battery depletion before timer expiration can cause self-destruct failure
- Self-Deactivation: Backup feature intended to render mine inert if self-destruct fails
Anti-Handling Features
- Tilt Sensor: Mine detonates if body is significantly disturbed or moved
- Tripwire Redundancy: Seven independent tripwires provide multiple activation paths
- Purpose: Prevents manual clearance; any approach likely to contact tripwire
8. History of Development and Use
Development Background
The BLU-92/B was developed as an integral component of the GATOR area denial system. Military doctrine recognized that anti-tank minefields required protection from dismounted infantry attempting manual clearance. The addition of anti-personnel mines mixed with anti-tank mines created a more robust barrier that required combined arms breaching operations to defeat.
Development Timeline
| Year | Event |
|---|---|
| Late 1970s | Development initiated alongside BLU-91/B |
| Early 1980s | Testing and evaluation completed |
| 1983 | Entered service with US Air Force and Navy |
| 1991 | Combat debut in Operation Desert Storm |
| 1997 | Ottawa Treaty signed (US did not sign) |
| 2000s | Continued service despite international pressure |
Tactical Concept
The mixed minefield concept of GATOR serves multiple purposes:
- Delay: Slows enemy advance while defenses are prepared
- Channelization: Forces enemy into predetermined kill zones
- Attrition: Causes vehicle and personnel casualties
- Protection: AP mines protect AT mines from clearance attempts
Combat Employment
Operation Desert Storm (1991): GATOR systems were employed extensively during the Gulf War to interdict Iraqi lines of communication and potential avenues of approach. The mixed AT/AP minefields created significant obstacles for Iraqi forces.
Kosovo (1999): Limited use during NATO air operations.
International Controversy
The BLU-92/B has been subject to significant international opposition:
- Ottawa Treaty (1997): Banned anti-personnel mines for signatory nations (US did not sign)
- 2008 Convention on Cluster Munitions: Additional restrictions on cluster munitions
- Humanitarian Concerns: Tripwire AP mines cause disproportionate civilian casualties post-conflict
- US Policy: Subject to various policy restrictions and reviews
Current Status
The BLU-92/B remains in US inventory but faces significant policy restrictions on use. International pressure and evolving US policy have limited deployment scenarios. The system remains controversial due to both anti-personnel mine and cluster munition concerns.
9. Technical Specifications
Explosive Content
| Specification | Detail |
|---|---|
| Main Charge Type | Composition A5 or similar |
| Charge Weight | Approximately 0.1 kg (0.22 lbs) |
| Fragmentation Liner | Steel fragments for anti-personnel effect |
Performance Characteristics
| Specification | Detail |
|---|---|
| Lethal Radius | Approximately 10 meters |
| Casualty Radius | Approximately 20 meters |
| Tripwire Length | Up to 6 meters each (7 wires) |
| Activation Force | Less than 1 kg (2.2 lbs) tension |
| Operating Temperature | -40°C to +52°C (-40°F to +126°F) |
| Self-Destruct Time | Variable (typically 4 hours to 15 days) |
Dispenser Configuration
| System | BLU-91/B Quantity | BLU-92/B Quantity | AT:AP Ratio |
|---|---|---|---|
| CBU-78/B | 45 | 15 | 3:1 |
| CBU-89/B | 72 | 22 | ~3.3:1 |
Battery and Electronics
- Power Source: Lithium battery
- Battery Life: Limited; determines maximum self-destruct time reliability
- Environmental Sealing: Waterproof design
Fragmentation Data
| Parameter | Value |
|---|---|
| Fragment Material | Steel |
| Fragment Count | Hundreds of fragments |
| Fragment Velocity | High velocity (supersonic) |
| Fragment Pattern | Omnidirectional from ground level |
10. Frequently Asked Questions
Q: Why does the BLU-92/B have seven tripwires instead of just one or two? A: The seven-tripwire design creates a 360-degree activation zone around the mine, making it extremely difficult to approach from any direction without triggering detonation. The multiple wires overlap in area coverage and provide redundancy—even if some wires fail to deploy properly or are defeated, others remain active. This design maximizes the probability of intercepting anyone attempting to approach or traverse the mined area, particularly personnel trying to locate and clear the companion BLU-91/B anti-tank mines.
Q: How do the BLU-91/B and BLU-92/B work together tactically? A: The GATOR system deploys both mine types simultaneously in approximately a 3:1 ratio (AT to AP). The anti-tank BLU-91/B mines create the primary barrier against armored vehicles, while the anti-personnel BLU-92/B mines protect this barrier from dismounted engineers or infantry attempting manual clearance. An enemy force cannot simply send dismounted teams ahead to clear the AT mines because they will encounter the AP mines. This forces the enemy to employ more complex and time-consuming breaching operations, achieving the delay and disruption objectives of the minefield.
Q: Why are tripwire-activated mines considered particularly dangerous to civilians? A: Tripwire-activated mines like the BLU-92/B pose severe risks to civilians for several reasons: the tripwires are nearly invisible and can be triggered by any person or large animal that contacts them; they do not distinguish between military personnel and civilians; children are particularly vulnerable due to their smaller size and tendency to explore areas; post-conflict, civilians returning to homes or farms may unknowingly enter mined areas; and the wires can persist and remain functional even after the mine’s intended operational period if self-destruct fails. These factors contribute to ongoing civilian casualties long after conflicts end.
Q: What makes detecting BLU-92/B mines especially challenging? A: Several factors complicate detection: the predominantly plastic construction reduces magnetic and metal detector signatures; the fine tripwires are extremely difficult to see visually, especially in vegetation, poor lighting, or when buried under debris; the low profile of the mine body can be concealed by grass or leaves; environmental factors like rain, wind-blown debris, or vegetation growth can obscure both mines and tripwires; and the wide dispersal pattern from air delivery means mines may be in unexpected locations over a large area.
Q: Can the tripwires be safely cut to neutralize the mine? A: No. Attempting to cut tripwires is extremely dangerous and should never be attempted by anyone other than qualified EOD personnel using proper procedures and equipment. The pull sensors may activate from the cutting motion itself, the mine body may be disturbed during the attempt, the anti-handling tilt fuze may activate, and there may be hidden or secondary wires not visible. Additionally, even if tripwires could theoretically be cut, the tilt-sensitive anti-handling feature means the mine cannot be safely moved afterward. EOD personnel use specialized remote or standoff techniques to neutralize these mines.
Q: What happens when a BLU-92/B’s self-destruct timer expires? A: When functioning properly, the self-destruct timer triggers an electrical signal to the detonator after the preset time, causing the mine to explode and destroy itself. This is intended to limit the mine’s persistence and reduce post-conflict UXO hazards. However, if the battery has depleted before the timer expires, or if there is a malfunction, self-destruct may fail. A backup self-deactivation feature is supposed to render the mine inert as the battery dies, but this is not completely reliable, and failed self-destruct BLU-92/B mines may remain armed and dangerous indefinitely.
Q: Are there visual differences between a functioning BLU-92/B and a dud? A: From a safe distance, it is often impossible to distinguish a functioning BLU-92/B from a dud or partially functioning mine. A dud may have failed to deploy some or all tripwires, but the mine body may still be armed. Conversely, a mine with deployed tripwires may have a malfunctioning fuze. Some visual indicators of potential problems include: tripwires that haven’t fully extended, obvious damage to the mine body, exposure of internal components, or unusual positioning. However, these indicators are not reliable for safety assessment. Every BLU-92/B must be treated as fully armed and functional until rendered safe by EOD personnel.
Q: Why is the BLU-92/B banned under international law while the US continues to retain it? A: The 1997 Ottawa Treaty (Mine Ban Treaty) prohibits the use, stockpiling, production, and transfer of anti-personnel mines for states that have ratified it. The United States has not signed or ratified this treaty, citing national security concerns, particularly regarding the defense of South Korea where minefields are part of established defensive plans. Additionally, the US argued that scatterable mines with self-destruct features like the BLU-92/B present less humanitarian risk than traditional persistent mines. However, human rights organizations and many nations dispute this position, noting that self-destruct mechanisms are not 100% reliable and that the mines still cause civilian casualties.
This document is for educational and training purposes only. All ordnance should be treated as dangerous until rendered safe by qualified EOD personnel. Never attempt to handle, move, or disturb any suspected explosive ordnance.