US Legacy Ordnance -- Southeast Asia and Pacific Island UXO

Scope: All US-origin ordnance types still encountered as UXO in Laos, Vietnam, Cambodia, and the Pacific Islands.

Why this matters: Over 800,000 tons of UXO remain in Vietnam alone. Laos is the most heavily bombed country per capita in history. These items kill and maim civilians -- predominantly farmers and children -- every single day, more than 50 years after the wars ended.

Casualty totals since cessation of hostilities:

• Vietnam: 40,000+ killed, 60,000+ injured since 1975 (A-1, Vietnamese government data)
• Laos: 50,000+ killed or injured since 1964 (A-2, Legacies of War / UXO Lao)
• Cambodia: 64,000+ killed or injured since 1979 (A-2, CMAA / Landmine Monitor)
• Pacific Islands: 20+ killed per year in Solomon Islands alone; contamination across 9+ island nations (B-2, US State Department)

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PART 1: CLUSTER SUBMUNITIONS (HIGHEST PRIORITY -- PRIMARY KILLER)

Cluster submunitions ("bombies" in Laos) are the single largest category of UXO casualties. Their small size, bright colors, and ball/toy-like shapes make them especially lethal to children.

Historical Dud Rates -- Cluster Submunitions

Claim: Vietnam War-era cluster submunitions had operational dud rates of 10-30%, far exceeding manufacturer claims of 2-5%.

Data: Based on field clearance data from Laos (1996-present), Vietnam (various), and manufacturer test data.

Method: Wilson score confidence intervals applied where sample data is available; most estimates are intelligence-grade analytical assessments based on clearance ratios.

Sources:

Estimate: 270 million cluster submunitions dropped on Laos (1964-1973); ~80 million failed to detonate (~30% dud rate). Vietnam: 800,000+ tons total UXO including cluster munitions. Cambodia: 741 km2 confirmed/suspected cluster munition contamination remaining.

Caveats: Dud rates varied enormously by delivery altitude, airspeed, terrain (soft soil, dense vegetation), and storage/handling conditions. Manufacturer test rates of 2-5% were obtained under ideal range conditions. Operational rates of 10-30% are consistently reported by clearance organizations. The 30% figure for Laos is widely cited but represents an upper-bound estimate.

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BLU-3/B "Pineapple"

Identification

• Designation(s): BLU-3/B, BLU-3A/B
• Type: Anti-personnel fragmentation submunition
• Category: Air-dispensed cluster submunition
• Country of Origin: United States
• Parent Delivery Systems: CBU-2A (360 bomblets), CBU-14A/A (SUU-14A/A dispenser, tube-launched)
• In Service: 1960s-1970s; no longer in production

Physical Characteristics

• Length: 3.75 in (95 mm); 6.7 in (170 mm) with drag vanes extended
• Diameter: ~2.75 in (70 mm)
• Weight: 1.75 lb (0.79 kg)
• Body Material: Aluminum body with steel ball matrix
• Warhead Type: HE fragmentation
• Warhead Weight: 0.35 lb (165 g) Cyclotol (some sources say RDX)
• Fragmentation: 250 embedded steel pellets
• Fuzing: Impact-initiated; drag vanes deploy on release, arm on descent
• Arming Mechanism: Six spring-loaded pop-out drag vanes stabilize the bomblet and arm the fuze during descent. Safety strap holds vanes until release from dispenser.

Dud Rate Assessment

Estimate: 10-30% operational dud rate (field data from Laos/Vietnam clearance operations) Based on: CBU-14 specifically noted for "high percentage of duds" in after-action reports; bomblets frequently found hung in trees undetonated, providing enemy with booby trap material Supporting evidence: HRW cluster munitions reports (B-2), Legacies of War (B-2) Caveats: Exact dud rate data classified or unavailable; range varies by delivery parameters

Quantities Remaining

Estimate:

• Laos: Significant quantities remain in eastern provinces along Ho Chi Minh Trail corridor; exact count unknown but part of the 80 million total UXO submunitions
• Vietnam: Found throughout central provinces, especially Quang Tri, Quang Binh
• Cambodia: Limited quantities; primary cluster contamination from other types Based on: 285 million reportedly dropped on Laos (Legacies of War); proportion that were BLU-3 vs other types unclear Caveats: "285 million" figure sometimes cited may conflate BLU-3 with total submunitions across all types

Common Encounter Scenarios

• Farmers plowing fields at shallow depths (10-30 cm)
• Construction/road building projects disturbing subsurface ordnance
• Children finding partially exposed items after heavy rains/flooding
• Bomblets hung in trees still falling decades later as trees decay
• Scrap metal collectors deliberately handling for recycling

EOD Hazards -- Aged Ordnance

• Cyclotol fill may have undergone partial decomposition; sensitivity changes unpredictable
• Corroded aluminum body may fragment differently than designed
• Drag vane springs may be under tension even in partially armed state
• Impact fuze may be in unknown armed/unarmed state -- treat as armed
• Vegetation growth may conceal and then expose items seasonally

Children/Civilian Risk Factors

• "Pineapple" shape with deployed vanes may appear toy-like or interesting
• Small enough for a child to pick up and handle
• Sometimes found in clusters where dispenser opened, creating concentrated hazard areas

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BLU-24/B "Orange" and BLU-26/B "Guava"

Identification

• Designation(s): BLU-24/B ("Orange"), BLU-26/B ("Guava"), BLU-36/B (variant), BLU-59/B (variant)
• Type: Anti-personnel/anti-materiel fragmentation submunition
• Category: Air-dispensed cluster submunition
• Country of Origin: United States
• Parent Delivery Systems:
  • BLU-26/B: CBU-24 (SUU-30 dispenser, 665 bomblets), CBU-29, CBU-37, CBU-58
  • BLU-24/B: Various CBU dispensers
• In Service: 1960s-1970s; BLU-26 is the MOST COMMON UXO type in Laos

Physical Characteristics -- BLU-26/B

• Diameter: 64 mm (2.5 in) -- approximately tennis ball sized
• Weight: 435 g (0.96 lb)
• Body Material: Cast steel with 600 embedded steel fragments
• Warhead Type: HE fragmentation
• Explosive Fill: 85 g (0.19 lb / 3 oz) Cyclotol
• Fragmentation: 600 steel fragments embedded in body; 300 fragments in some variants
• Fuzing: M219 or M219E1 centrifugally armed, impact-fired fuze
• Arming Mechanism: Centrifugal (spin-armed) -- requires spin imparted by dispenser ejection. M219 fuze requires approximately 1,000 ft of air travel to arm.
• Fuzing Options: (1) Instantaneous impact, (2) Airburst 9 m (30 ft) above ground, (3) Selectable fixed time delay after impact

Physical Characteristics -- BLU-24/B

• Type: Drag-stabilized, spin-armed, impact-fuzed HE-frag AP submunition
• Nickname: "Orange" (due to appearance)
• Arming: Spin-armed during flight descent

Dud Rate Assessment

Claim: BLU-26/B had high operational dud rates due to fuze unreliability under variable combat conditions. Data: Field clearance ratios from Laos consistently show 10-30% of delivered submunitions failed to function. Method: Analytical estimate based on total delivered vs. estimated remaining. Result: Operational dud rate estimated 20-30% in Laos conditions. Interpretation: The M219/M219E1 impact fuze proved unreliable when: release altitudes exceeded 500 ft, aircraft speeds exceeded 400 knots, impacts occurred in soft soil or dense vegetation (which prevented proper impact force), or bomblets landed in water/mud. Limitations: Exact operational dud rates are not precisely known; manufacturer claimed ~5% under test conditions.

Quantities Remaining

Estimate:

• Laos: Primary component of the estimated 80 million unexploded submunitions. BLU-26 is the single most commonly encountered UXO type in Laos. All 17 provinces contaminated; 25% of all villages affected.
  • Most affected provinces: Xiengkhuang, Huaphan, Savannakhet, Salavan, Sekong, Khammuane, Champasak, Attapeu, Luang Prabang
• Vietnam: Significant quantities in central provinces (Quang Tri, Quang Binh, Thua Thien Hue, Quang Nam). Part of 800,000+ tons total UXO.
• Cambodia: Found in eastern provinces bordering Laos and Vietnam. 741 km2 total cluster contamination area (confirmed + suspected). Based on: UXO Lao data (A-2), US State Department CWD reports (A-1), CMAA data (A-2) Caveats: Only ~10% of Laos UXO has been cleared to date. At current clearance rates, full clearance will take many more decades.

Common Encounter Scenarios

• Agriculture: Farmers plowing rice paddies or clearing land -- most common scenario
• Construction: Road building, foundation excavation, well digging
• Flooding: Seasonal rains expose previously buried items
• Scrap metal collection: Deliberate handling by scrap collectors (extremely dangerous)
• Children playing: Tennis ball-sized BLU-26 mistaken for a toy ball -- this is a primary risk factor for child casualties

EOD Hazards -- Aged Ordnance

• M219/M219E1 fuze may be in ANY state: unarmed, partially armed, or fully armed
• Corroded steel body increases fragmentation unpredictability
• Cyclotol fill (RDX/TNT) may have undergone exudation -- TNT component can migrate to fuze threads creating contact-sensitive deposits
• Impact fuze striker may be corroded in near-fired position -- minimal additional force could initiate
• Steel fragment matrix embedded in body means the entire item IS the fragmentation envelope
• 50+ years of ground moisture may have penetrated fuze cavity -- unknown chemical interactions

Children and Civilian Risk Factors -- CRITICAL

• Size: Tennis ball-sized -- a child will pick this up
• Shape: Spherical -- looks like a ball, a fruit, or a toy
• Color: Originally olive drab, but decades of weathering may expose bright steel underneath
• Context: Found on surface after rains, in fields, along trails -- exactly where children play
• Lethality: 600 steel fragments at high velocity; lethal within 5 m, casualties to 15+ m
• Recent incident (2025): Five children in Laos seriously injured by wartime UXO; one boy permanently blinded, another lost his right hand
• 31% of UXO casualties in Quang Tri Province, Vietnam are under age 16

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BLU-42/B and BLU-54/B Anti-Personnel Mines

Identification

• Designation(s): BLU-42/B
• Type: Scatterable anti-personnel mine
• Category: Air-dispensed cluster mine
• Country of Origin: United States
• In Service: Vietnam War era

Physical Characteristics

• Weight: Not precisely documented in open sources
• Explosive Fill: 71 g Composition B
• Body Material: Steel/plastic
• Activation: Six spring-loaded tripwires expelled from mine after ground contact
• Special Features: Anti-disturbance feature; self-destruct feature (designed to neutralize after set period -- unreliable in practice)

EOD Hazards

• Anti-disturbance feature makes approach extremely hazardous
• Self-destruct mechanism may have failed -- item should be treated as fully armed
• Tripwires may be concealed by vegetation growth
• Corrosion may have compromised self-destruct timing mechanism

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BLU-43/B and BLU-44/B "Dragontooth" (Butterfly Mine)

Identification

• Designation(s): BLU-43/B, BLU-44/B
• Type: Air-dropped scatterable anti-personnel mine
• Category: Cluster-dispersed land mine
• Country of Origin: United States
• Comparison: Direct predecessor to Soviet PFM-1 "butterfly mine" (reverse-engineered from BLU-43)
• Program: Used in Operation Igloo White (Laos)

Physical Characteristics

• Weight: ~90 g (3.2 oz)
• Dimensions: Wing-shaped plastic body; wings ~120 mm (4.7 in) span (comparable to PFM-1)
• Body Material: Plastic (olive drab, tan, brown, or camouflage)
• Explosive Fill: ~31 g liquid nitromethane/nitroethane
• Fuzing: Hydrostatic fuze mechanism in central aluminum cylindrical body
• Arming Mechanism: Hydraulic activation following aerial dispersal; wing shape causes spiral descent (no parachute needed)
• Activation: Contact/pressure detonated; ~7 kg (15 lb) pressure required
• Variants: BLU-43/B and BLU-44/B differ only in their self-neutralization ("sterilization") mechanism

Dud Rate Assessment

Estimate: Unknown precise rate. Self-neutralization mechanisms were designed to render mines safe after a set period but were notoriously unreliable. Caveats: Many BLU-43/44 mines found in Laos decades later, suggesting sterilization failure rates were significant.

EOD Hazards -- Aged Ordnance

• Liquid explosive fill may have leaked, creating contamination around the item
• Plastic body degrades but does NOT render the mine safe
• Hydraulic fuze mechanism may be in unknown state
• Extremely low metallic content -- very difficult to detect with metal detectors
• Flat profile can be buried by very thin layer of soil/leaves
• Self-neutralization mechanism should NEVER be relied upon

Children/Civilian Risk Factors

• Wing shape makes it look like a leaf, toy, or interesting object
• Extremely light weight -- a child will pick it up
• 7 kg pressure threshold is within range of a child stepping on it
• Plastic body can be any color -- may blend with ground or attract attention depending on condition

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BLU-49/B

Identification

• Designation(s): BLU-49/B
• Type: Anti-personnel fragmentation submunition
• Category: Air-dispensed cluster submunition
• Country of Origin: United States
• Parent Delivery System: CBU-58 (some sources; CBU-58 also associated with BLU-63)

Physical Characteristics

• Weight: ~1 lb (limited open-source data)
• Construction: Steel fragmentation body with titanium pellets (incendiary capability)
• Fuzing: Impact-initiated

EOD Hazards

• Similar hazards to BLU-26/63 series
• Titanium pellets add incendiary risk even in corroded specimens
• Limited documentation available -- approach with maximum caution

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BLU-61A/B Incendiary Submunition

Identification

• Designation(s): BLU-61A/B
• Type: HE incendiary/anti-materiel fragmentation submunition
• Category: Air-dispensed cluster submunition
• Country of Origin: United States
• Parent Delivery System: CBU-52/B (217 BLU-61A/B submunitions)

Physical Characteristics

• Diameter: 99 mm (3.9 in) -- approximately softball-sized
• Weight: 1.2 kg (2.6 lb)
• Body Material: Two steel fragmentation liner hemispheres with zirconium-tin incendiary liner, encased in urethane plastic shell, joined by stainless steel clamp ring
• Explosive Fill: 277 g (0.61 lb) Octol
• Fuzing: M219E1 all-ways acting (omnidirectional) impact fuze
• Arming Mechanism: Spin-armed during descent

EOD Hazards -- Aged Ordnance

• Zirconium-tin incendiary liner remains pyrophoric indefinitely -- fire hazard even in corroded specimens
• Octol fill is more sensitive than TNT; aging may increase sensitivity
• Urethane plastic shell may have degraded, exposing internal components
• M219E1 omnidirectional fuze means the item can initiate from ANY angle of disturbance
• Stainless steel clamp ring may be only structural element holding hemispheres together -- corrosion of other components may make it fragile

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BLU-63/B Anti-Personnel Fragmentation Submunition

Identification

• Designation(s): BLU-63/B, BLU-63A/B, BLU-86/B (variant), BLU-86A/B (variant)
• Type: Anti-personnel HE fragmentation submunition
• Category: Air-dispensed cluster submunition
• Country of Origin: United States
• Parent Delivery Systems:
  • CBU-58/B (650 BLU-63/B in SUU-30A/B)
  • CBU-75/B (1,800 BLU-63/B in SUU-54A/B)
  • CBU-77/B (790 BLU-63/B in SUU-51B/B)

Physical Characteristics

• Diameter: 76 mm (3 in)
• Weight: 0.45 kg (1 lb)
• Body Material: Scored steel outer casing (two hemispheres held by crimp ring)
• Explosive Fill: 113 g (0.25 lb) Cyclotol
• Fragmentation: 260 fragments from scored steel casing
• Fuzing: Centrifugally armed, impact-fired
• Arming Mechanism: Spin-armed; impact detonation

Dud Rate Assessment

Estimate: CBU-58 with 650 BLU-63/B submunitions at 95% reliability = ~38 unexploded submunitions per dispenser. Based on: Manufacturer reliability specification of 95% (B-2, GlobalSecurity.org) Caveats: 95% is the design specification; operational rates in combat conditions were likely lower (see general 10-30% dud rate discussion above)

EOD Hazards

• Crimp ring holding hemispheres may have corroded -- structural integrity compromised
• Cyclotol fill degradation concerns (see BLU-3 section)
• Small size means items migrate easily in soil and can be found at unexpected depths

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BLU-77/B Incendiary Submunition

Identification

• Designation(s): BLU-77/B
• Type: Incendiary submunition
• Category: Air-dispensed cluster submunition
• Country of Origin: United States
• Note: Limited open-source documentation. Some references indicate CBU-77/B carries BLU-63/B submunitions (790 units), suggesting "BLU-77" as a standalone submunition designation may be confused with the CBU-77 dispenser designation.

Physical Characteristics

• Limited specific data available in open sources
• Incendiary fill -- likely zirconium or thermite-based

EOD Hazards

• Incendiary fill materials remain hazardous indefinitely
• Treat as armed and dangerous; limited reference data increases risk

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BLU-97/B Combined Effects Bomb (CEB)

Identification

• Designation(s): BLU-97/B, BLU-97A/B, BLU-97B/B
• Type: Dual-purpose (anti-armor/anti-personnel/incendiary) combined effects submunition
• Category: Air-dispensed cluster submunition
• Country of Origin: United States
• Manufacturer: Aerojet Ordnance
• Parent Delivery System: CBU-87/B Combined Effects Munition (CEM) -- 202 BLU-97/B per dispenser
• In Service: Still in US inventory; used in Desert Storm, Kosovo, Iraq, Afghanistan

Physical Characteristics

• Length: 20 cm (7.9 in)
• Diameter: 6 cm (2.4 in)
• Shape: Yellow cylinder
• Weight: ~1.5 kg (3.3 lb)
• Body Material: Scored steel fragmentation case
• Explosive Fill: Composition B (exact weight not widely published)
• Triple effect: (1) Shaped charge for armor penetration, (2) Scored steel case for fragmentation, (3) Zirconium ring for incendiary effect
• Fuzing: Impact-initiated; optional FZU-39/B proximity sensor with 10 altitude selections
• Arming Mechanism: Spin-armed; arms at 6 G force threshold; arming takes ~2.6 seconds after release

Dud Rate Assessment

Estimate: Manufacturer specification: 2.35% dud rate (current production). Operational rates in Kosovo/Afghanistan were higher. Based on: US DoD data (A-2), HRW field assessments (B-2) Caveats: More modern production; better fuze reliability than Vietnam-era submunitions, but still produces significant UXO

Coverage Area

• CBU-87 footprint: 20 x 20 m (low altitude/slow spin) to 120 x 240 m (high altitude/fast spin)

EOD Hazards

• Shaped charge liner (copper) can defeat armor -- extreme penetration hazard
• Zirconium incendiary ring remains pyrophoric
• More recent manufacture means fuze mechanisms may be in better condition than Vietnam-era items
• FZU-39/B proximity sensor (if fitted) adds electronic fuze complexity

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M42/M46 DPICM (Artillery-Delivered)

Identification

• Designation(s): M42, M46 dual-purpose grenades
• Type: Dual-purpose improved conventional munition (DPICM) submunition
• Category: Artillery-dispensed submunition
• Country of Origin: United States
• Parent Delivery System: 155mm M483A1 projectile (64 x M42 + 24 x M46 = 88 per round)

Physical Characteristics

• Diameter: 38 mm (1.5 in) tubular steel body
• Weight: ~213 g (7.5 oz)
• Explosive Fill: 20-50 g high explosive (shaped charge)
• Armor Penetration: Copper shaped charge liner; penetrates 50-100 mm armor
• Fragmentation: Steel body fragments for anti-personnel effect, ~4 m radius
• Fuzing: Impact inertia fuze -- spring-loaded striker with stab-sensitive detonator
• Arming Mechanism: Ribbon stabilizer deploys after dispersal from projectile; spin-armed
• M42 vs M46: M46 has heavier, thicker body with smooth inner wall; M42 has thinner body

Dud Rate Assessment

Estimate: 2-5% dud rate depending on terrain Based on: US DoD data (A-2), field clearance data Caveats: Work was budgeted in 2003 to retrofit M42/M46 with self-destruct fuzes. Soft ground, vegetation, and snow significantly increase dud rates.

EOD Hazards -- Aged Ordnance

• Impact inertia fuze may be in partially armed state -- striker could be corroded near firing position
• Ribbon stabilizer may be tangled but fuze still armed
• Shaped charge copper liner remains functional indefinitely
• Small size makes items difficult to locate; may be found in large concentrations

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M77 DPICM (MLRS-Delivered)

Identification

• Designation(s): M77 dual-purpose grenade
• Type: DPICM submunition
• Category: Rocket-dispensed submunition
• Country of Origin: United States
• Parent Delivery System: M26 MLRS rocket warhead (644 x M77 per rocket; 6 rockets per launcher = 3,864 submunitions per salvo)

Physical Characteristics

• Diameter: 38 mm (1.5 in) tubular steel body
• Weight: 213 g (7.5 oz)
• Explosive Fill: 33 g high explosive
• Armor Penetration: Copper shaped charge; penetrates up to 4 inches (100 mm) of armor
• Fragmentation: Steel case fragments; anti-personnel effect radius 4 m
• Fuzing: Impact inertia fuze (same type as M42/M46)
• Arming Mechanism: Drag-ribbon stabilized; armed during free fall after dispensing

Dud Rate Assessment

Estimate: 2-5% under ideal conditions; higher in soft terrain Based on: US DoD data (A-2) Interpretation: A single MLRS salvo of 6 rockets delivers 3,864 submunitions. At 5% dud rate, that is ~193 UXO items per salvo.

EOD Hazards

• Same concerns as M42/M46 series
• MLRS delivery creates wide area contamination -- submunitions may be scattered over large areas
• Density of submunitions per engagement area can be very high

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PART 2: GENERAL PURPOSE BOMBS

Mk 81 (250 lb GP Bomb)

Identification

• Designation(s): Mk 81, Mk 81 Mod 0/1
• Type: Low-drag general-purpose bomb
• Category: Air-to-ground unguided bomb
• Country of Origin: United States
• Series: Mark 80 series (smallest)

Physical Characteristics

• Length: 74 in (1.88 m)
• Diameter: 9 in (23 cm)
• Weight: 262 lb (119 kg) actual
• Body Material: Forged steel case
• Explosive Fill: 96 lb (44 kg) Composition H6, Minol, or Tritonal
• Fuzing: Nose and/or tail fuze; various options including instantaneous, delayed, and proximity

EOD Hazards -- Aged Ordnance

• Steel casing corrodes but maintains structural integrity for decades
• Tritonal fill is stable long-term but Minol variants (used to offset TNT shortages) may exude in hot/humid conditions
• Fuze mechanisms may be corroded in armed or partially armed states
• Deep burial from impact may make items extremely difficult to locate
• Detonation of even the smallest Mk 80 series bomb produces massive blast and fragmentation

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Mk 82 (500 lb GP Bomb)

Identification

• Designation(s): Mk 82, Mk 82 Mod 0/1; BLU-111 (thermally protected variant)
• Type: Low-drag general-purpose bomb
• Category: Air-to-ground unguided bomb
• Country of Origin: United States
• Note: MOST WIDELY USED bomb in US inventory; dropped in enormous quantities in Vietnam

Physical Characteristics

• Length: 66.15 in (1.68 m)
• Diameter: 10.75 in (27.3 cm)
• Weight: 510-570 lb (230-260 kg) depending on configuration (500 lb nominal)
• Body Material: Streamlined steel casing
• Explosive Fill: 192 lb (87 kg) Tritonal
• Fuzing: Nose and/or tail fuze (Mk 43 TDD, M904/M905 nose/tail, FMU-113 air burst, various others)

Dud Rate Assessment

Estimate: General-purpose bombs have lower dud rates than submunitions (~3-7% for Vietnam-era production) but the enormous quantities dropped mean significant numbers remain as UXO. Caveats: Dud rates increased significantly for bombs dropped in soft terrain (rice paddies, jungle floor) where impact deceleration was insufficient to function fuzes.

Quantities

Estimate: Millions of Mk 82 bombs were dropped during the Vietnam War. The US dropped more than 7.5 million tons of bombs during the entire conflict. Mk 82 was the workhorse. Based on: USAF historical data (A-1)

Common Encounter Scenarios

• Deep-buried bombs (3-10+ meters) encountered during construction, well-digging, road building
• Partially exposed by river erosion or flooding
• Farmers striking buried bombs with plows (usually fatal)
• Bombs in former target areas that were never fully surveyed

EOD Hazards -- Aged Ordnance

• 192 lb of high explosive -- massive blast radius
• Fuze may have armed during delivery but failed to initiate on impact
• Fuze components corroded -- unknown sensitivity state
• Deep burial means extraction is extremely hazardous
• Tritonal is relatively stable but 50+ years of ground moisture creates uncertainty
• Nose fuze (if present) is the primary initiation point -- approach from side/rear when possible
• Some bombs fitted with anti-disturbance fuzes or long-delay fuzes -- TREAT ALL AS HAZARDOUS

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Mk 83 (1,000 lb GP Bomb)

Identification

• Designation(s): Mk 83, BLU-110 (thermally insensitive variant with PBXN-109)
• Type: Low-drag general-purpose bomb
• Country of Origin: United States

Physical Characteristics

• Length: 9 ft 10 in (3.0 m)
• Diameter: 14 in (36 cm)
• Weight: 985-1,030 lb (447-470 kg) depending on configuration
• Explosive Fill: 445 lb (202 kg) Tritonal

EOD Hazards

• Same concerns as Mk 82 but with more than double the explosive content
• Blast and fragmentation effects significantly larger

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Mk 84 (2,000 lb GP Bomb)

Identification

• Designation(s): Mk 84
• Type: Low-drag general-purpose bomb (largest in Mk 80 series)
• Country of Origin: United States

Physical Characteristics

• Length: 10 ft 9 in (3.28 m)
• Diameter: 18 in (46 cm)
• Weight: 1,972-2,083 lb (894-945 kg) depending on configuration
• Explosive Fill: 945 lb (429 kg) Tritonal, Minol, or Composition H6

EOD Hazards

• Nearly 1,000 lb of explosive -- catastrophic blast radius
• Deep penetration on impact (can bury 10+ meters in soft soil)
• Recovery/disposal requires significant standoff distances
• Any UXO Mk 84 is an immediate evacuation-level hazard

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M117 (750 lb GP Bomb)

Identification

• Designation(s): M117, M117R (retarded), M117A1, M117A1E2
• Type: General-purpose demolition bomb
• Category: Air-to-ground unguided bomb
• Country of Origin: United States
• Primary Platform: B-52 Stratofortress (primary delivery in Vietnam)

Physical Characteristics

• Weight: 750 lb (340 kg) nominal; ~820 lb (372 kg) actual with fuze/retardation
• Body Material: Steel casing
• Explosive Fill: 386 lb (175 kg) Tritonal (M117/M117A1) or 377 lb (171 kg) Minol II (M117A1E2)
• Fuzing: Configurable -- nose, tail, proximity, or magnetic influence
• Variants: M117R has retardation system (pop-out air brake fins) for low-altitude delivery

CRITICAL WARNING -- Minol II Variant

The M117A1E2 used Minol II filler to offset TNT shortages. Minol II was known to expand and ooze/extrude through bomb joints in hot, tropical conditions during storage. This means:

• UXO M117 bombs in Southeast Asia may have compromised body seals
• Explosive filler may have partially extruded from joints
• External explosive contamination around the bomb body is possible
• Extruded explosive material may be more sensitive to impact/friction than confined fill

EOD Hazards -- Aged Ordnance

• Minol II extrusion issue makes M117 particularly hazardous as aged UXO
• 386 lb explosive fill -- large blast and frag radius
• B-52 carpet bombing created dense patterns of bomb impacts -- UXO from these patterns may be found in clusters
• Deep burial in soft terrain common

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BLU-82/B "Daisy Cutter" / Commando Vault

Identification

• Designation(s): BLU-82/B
• Type: Conventional blast bomb (surface burst)
• Category: Air-to-ground special purpose bomb
• Country of Origin: United States
• Program: Commando Vault (Vietnam); later used in Afghanistan
• Delivery: MC-130 cargo aircraft (rolled out rear ramp with parachute retardation)

Physical Characteristics

• Weight: 15,000 lb (6,800 kg)
• Explosive Fill: 12,600 lb (5,700 kg) GSX slurry (DBA-22M) -- ammonium nitrate, aluminum powder, polystyrene
• Fuzing: 38-inch fuze extender for above-ground detonation
• Design: Optimized for blast effect (no crater); designed to clear helicopter landing zones in jungle

Performance

• Overpressure: 1,000 psi (6,900 kPa) near ground zero
• Designed to flatten forest in approximately 200-foot radius

EOD Hazards

• GSX slurry is an ammonium nitrate-based explosive -- may absorb moisture over time
• 12,600 lb of explosive -- any UXO BLU-82 is an extreme hazard requiring very large evacuation radius
• Parachute delivery system means dud items are found on or near the surface
• Extremely rare as UXO -- limited quantities used

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PART 3: CLUSTER BOMB UNITS (DISPENSERS)

The dispensers themselves are generally less hazardous than their submunition payloads, but may contain residual submunitions that failed to eject.

CBU-2A/A

• Submunition: 360 x BLU-3/B "Pineapple"
• Dispenser: Clamshell-type
• Era: Early Vietnam War

CBU-14A/A

• Submunition: BLU-3/B "Pineapple"
• Dispenser: SUU-14A/A -- six metal tubes strapped together; submunitions ejected from rear of tubes
• Note: High dud rate reported; bomblets frequently found hanging in trees, used by enemy for booby traps

CBU-24/B

• Submunition: 665 x BLU-26/B "Guava"
• Dispenser: SUU-30
• Note: Primary delivery system for the most common UXO in Laos

CBU-29/B

• Submunition: BLU-26/B series
• Dispenser: Variant of SUU-30 system

CBU-37/B

• Submunition: BLU-26/B series
• Note: Limited open-source documentation on this specific designation

CBU-52/B

• Submunition: 217 x BLU-61A/B (incendiary/fragmentation)
• Dispenser: SUU-30
• Weight: 785 lb total loaded
• Fuzing: Various proximity fuzes or mechanical MK-339 timed fuze

CBU-58/B

• Submunition: 650 x BLU-63/B (fragmentation with titanium incendiary pellets)
• Dispenser: SUU-30A/B
• Note: At 95% submunition reliability, one CBU-58 could produce ~38 UXO items

CBU-71/B

• Submunition: 650 x BLU-86/B (some sources say BLU-68/B) incendiary submunitions with titanium pellets
• Dispenser: SUU-30
• Special feature: Random time-delay fuzes -- submunitions detonate at varying times after impact (area denial)
• EOD HAZARD: Time-delay fuze means items may still be "waiting" to function decades later

CBU-87/B Combined Effects Munition (CEM)

• Submunition: 202 x BLU-97/B CEB
• Dispenser: SUU-65/B
• Weight: 950 lb total
• Length: 92 in
• Diameter: 15.6 in
• Still in US inventory

Dispenser EOD Hazards

• Empty dispensers (SUU-30, SUU-65, etc.) may contain retained submunitions that failed to eject
• Dispenser fuzing (FMU-140/B or similar) may still function
• Do not assume an open/empty dispenser is safe -- inspect for retained submunitions

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PART 4: ROCKETS

2.75" (70mm) Folding-Fin Aerial Rocket (FFAR) -- Mk 4 / Mk 40

Identification

• Designation(s): Mk 4 FFAR, Mk 40 FFAR (improved motor); later evolved into Hydra 70
• Type: Unguided air-to-ground rocket
• Country of Origin: United States
• Caliber: 2.75 in (70 mm)

Physical Characteristics

• Length: ~4 ft (1.2 m)
• Weight: 18.5 lb (8.4 kg) with HE warhead
• Warhead: ~6 lb (2.7 kg) HE; multiple warhead options (HE, HEAT, flechette, smoke, WP, illumination)
• Motor: Solid propellant rocket motor
• Stabilization: Four folding fins deploy on launch; spin-stabilized
• Range: ~3,700 yards (3,400 m) maximum effective

Delivery

• Fired from pods of 7 or 19 rockets
• Launched from fixed-wing aircraft and helicopters

Dud Rate Assessment

Estimate: Rocket motors and warheads both contribute to dud rates. Warhead fuze failure and motor failure both produce UXO. Caveats: Thousands of these rockets were fired in Vietnam; rocket motor casings and warhead components are common finds.

EOD Hazards -- Aged Ordnance

• Warhead may be armed but unfired (motor failure) or fired but unfuzed (fuze failure)
• Solid propellant rocket motor may still contain propellant -- fire/explosion hazard
• Warhead fuze may be in armed state
• Rockets that impacted at low angles may have skipped/ricocheted and be found far from target areas
• WP (white phosphorus) warhead variants are extremely hazardous -- WP ignites on contact with air

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5" Zuni FFAR

Identification

• Designation(s): Zuni 5-inch FFAR, Mk 32 (rocket motor designation)
• Type: Unguided air-to-ground rocket
• Country of Origin: United States
• Manufacturer: Hunter Douglas Division of Bridgeport Brass Company
• Caliber: 5.0 in (127 mm)

Physical Characteristics

• Length: ~110 in (2.79 m) -- varies by warhead
• Weight: ~107 lb (48.5 kg) -- varies by warhead
• Warhead Options: GP-HE, shaped charge (HEAT), various fuze options (point-detonation, delayed-action, proximity)
• Delivery: 4-round LAU-10 pod

Historical Note

Zuni rocket mishandling caused the catastrophic 1967 USS Forrestal fire (134 killed). This underscores the hazard of aged/corroded rocket munitions.

EOD Hazards

• Larger than 2.75" FFAR -- significantly more explosive
• Rocket motor propellant remains hazardous
• Multiple warhead types means unknown threat until identified
• Shaped charge variants can defeat armor

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PART 5: MINES

M14 Anti-Personnel Mine ("Toe Popper")

Identification

• Designation(s): M14
• Type: Blast anti-personnel mine
• Country of Origin: United States (in service since ~1955)

Physical Characteristics

• Diameter: 56 mm (2.2 in)
• Height: ~40 mm
• Weight: 100 g (3.5 oz)
• Body Material: Plastic (minimum metal content -- extremely difficult to detect)
• Explosive Fill: 29 g (1 oz) Tetryl
• Activation Pressure: 20-35 lb (9-16 kg) foot pressure
• Design Intent: Maiming, not killing -- designed to wound foot/lower leg

Countries Where Found as UXO

Angola, Cambodia, Chad, Chile, El Salvador, Eritrea, Ethiopia, Cyprus, Iran, Iraq, Jordan, Laos, Lebanon, Malawi, Mozambique, Somalia, Vietnam, Zambia

EOD Hazards -- Aged Ordnance

• Minimum metal mine -- EXTREMELY difficult to locate with metal detectors
• Plastic body may have degraded but does not make mine safe
• Tetryl explosive becomes more sensitive with age (crystal growth)
• Very small size -- can be completely buried by minimal soil accumulation
• Pressure plate mechanism may be in any state of readiness

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M16 Bounding Anti-Personnel Mine

Identification

• Designation(s): M16, M16A1, M16A2
• Type: Bounding fragmentation anti-personnel mine
• Country of Origin: United States (based on German S-mine/Bouncing Betty)

Physical Characteristics

• Weight: 3.5 kg (7.7 lb)
• Explosive Fill: 450 g (1 lb) TNT
• Bounding Charge: 4.5 g black powder (launches mine body into air)
• Body: Steel outer sleeve (remains in ground); inner iron body bounds upward
• Fragmentation: Cast iron body fragments; lethal
• Casualty Radius: 27 m (M16/M16A1); 30 m (M16A2)
• Activation: Pressure (on prongs) or tripwire

EOD Hazards -- Aged Ordnance

• Bounding mechanism may function unpredictably when disturbed
• Tripwire may be concealed by vegetation or corroded but still functional
• Pressure prongs may be corroded in near-activation position
• When mine bounds, it detonates at approximately waist height -- devastating fragmentation pattern
• 27-30 m casualty radius -- significant standoff required

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M18A1 Claymore Directional Mine

Identification

• Designation(s): M18A1 Claymore
• Type: Directional fragmentation anti-personnel mine
• Country of Origin: United States (adopted 1960; first used Vietnam 1966)

Physical Characteristics

• Length: 8.5 in (216 mm)
• Width: 1.375 in (35 mm)
• Height: 3.25 in (83 mm)
• Weight: 3.5 lb (1.6 kg)
• Body Material: Fiberglass-filled polystyrene (curved, convex)
• Explosive Fill: 1.5 lb (680 g) Composition C-4
• Fragmentation: ~700 steel spheres (1/8" diameter / 3 mm), 10.5 grains each, embedded in epoxy resin
• Fragment Velocity: 3,900 ft/s (1,200 m/s)
• Initiation: Command-detonated (M57 electrical firing device / "clacker") or tripwire-activated

EOD Hazards -- Aged Ordnance

• C-4 explosive is very stable -- remains effective for decades
• Blasting cap/detonator in the mine body is the primary initiation hazard
• Electrical firing wire may be corroded but still conductive
• Tripwire-configured Claymores are especially hazardous -- wire may be invisible
• "FRONT TOWARD ENEMY" marking may be illegible on aged specimens
• Enemy forces in Vietnam frequently turned Claymores around to face friendly forces -- orientation cannot be assumed

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Mk 36 Destructor (Sea Mine Converted from Mk 82)

Identification

• Designation(s): Mk 36 DST (Destructor)
• Type: Aircraft-laid bottom influence mine
• Country of Origin: United States
• Base Item: Mk 82 500-lb GP bomb body and explosive charge

Physical Characteristics

• Weight: 500 lb (227 kg) -- same as Mk 82
• Maximum Depth: 299 ft (91 m)
• Conversion: Standard Mk 82 bomb converted to mine by installing modular kit components:
  • Nose cavity: Arming device and explosive booster
  • Tail cavity: Magnetic-influence firing mechanism with battery
• Explosive Fill: Same as Mk 82 (192 lb Tritonal)
• Detection: Magnetic influence -- detects change in earth's magnetic field from passing vessel

EOD Hazards -- Aged Ordnance

• Combined bomb AND mine hazards
• Magnetic influence fuze may be active -- ferrous metal in proximity could trigger
• Battery may have degraded but some battery chemistries can remain viable for decades
• Bottom mine sitting on seafloor/river bottom for 50+ years -- extreme corrosion
• Used to mine Haiphong harbor and inland waterways -- still potential hazard in Vietnamese waters
• Modular fuze kit configurations varied -- exact fuze type unknown without inspection

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PART 6: GRENADES AND SMALL MUNITIONS

M26 Series Hand Grenades

Identification

• Designation(s): M26, M26A1, M61 (variants)
• Type: Fragmentation hand grenade
• Country of Origin: United States

Physical Characteristics

• Weight: ~1 lb (454 g)
• Body: Sheet metal body with fragmentation coil
• Explosive Fill: 5.5 oz (160 g) Composition B
• Fuze: M204A1/M204A2 pyrotechnic delay (4-5 sec), or M217 (impact detonation)
• Safety Features: "Jungle clip" safety wire added in mid-1960s for Vietnam use

EOD Hazards

• Composition B fill stable but corroded fuze train is unpredictable
• Spoon (safety lever) may be missing or corroded -- grenade may be in armed state
• Pull pin may have corroded away -- only spoon pressure prevents initiation

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M67 Hand Grenade

Identification

• Designation(s): M67
• Type: Fragmentation hand grenade (replacement for M26 series)
• Country of Origin: United States

Physical Characteristics

• Weight: 14 oz (400 g)
• Shape: Spheroidal steel body
• Explosive Fill: 6.5 oz (180 g) Composition B
• Fuze: M213 pyrotechnic delay (4-5 sec)
• Kill Radius: 5 m; casualty radius: 15 m; fragments can travel 230+ m

EOD Hazards

• Same as M26 series
• Used for booby traps in Vietnam -- may be found rigged with tripwires
• Steel body maintains structural integrity for decades

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40mm Grenade Rounds (M79/M203)

Identification

• Designation(s): M406 HE, M433 HEDP, and numerous other 40x46mm low-velocity variants
• Type: Low-velocity grenade cartridge
• Country of Origin: United States
• Launchers: M79, M203

Physical Characteristics -- M406 HE

• Caliber: 40mm
• Weight: ~0.50 lb (230 g)
• Explosive Fill: Small quantity of Composition B (exact weight varies; sufficient for 300+ fragments)
• Fuzing: Spin-armed, impact-initiated
• Arming Distance: 14-27 m (46-89 ft)
• Kill Radius: 5 m; casualty radius: 130 m (from fragments)
• Fragment Count: 300+

Dud Rate Assessment

Data: Testing of 576 rounds of M406 resulted in 4.34% dud rate. Interpretation: Failed rounds included 8 unarmed fuzes, 7 partially armed, 2 defective firing pins, 7 with detonator indentations (near-fired). Source: DTIC investigation report (A-2) Caveats: Historical test data; operational conditions would vary.

EOD Hazards -- Aged Ordnance

• Small size -- easily overlooked or mistaken for debris
• Spin-armed fuze may be in any state of arming
• Partially armed fuze (7 of 25 duds in test) is particularly dangerous -- near initiation threshold
• Aluminum cartridge case may have corroded, exposing explosive train
• Commonly found in former patrol areas, firebase perimeters, ambush sites

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White Phosphorus (WP) Munitions

Identification

• Designation(s): M15 WP grenade, M34 WP grenade; WP-filled artillery projectiles and rocket warheads
• Type: Incendiary/smoke
• Country of Origin: United States

Physical Characteristics

• M15: 31 oz (879 g) total; 15 oz (425 g) WP filler
• M34: 27 oz (765 g) total; 15 oz (425 g) WP filler; M206A2 fuze; prescored cylindrical steel body
• M34 replaced M15 in service

EOD Hazards -- CRITICAL

• White phosphorus ignites spontaneously on contact with air
• WP remains active indefinitely -- does not degrade with age
• Corroded body may have exposed WP to soil moisture, creating phosphine gas (toxic)
• ANY breach of the body will cause WP to ignite -- burns at ~1,500 degF (815 degC)
• WP burns CANNOT be extinguished by water (only smothered by excluding air)
• Fragments of WP can re-ignite when disturbed even after initial burning
• Artillery WP rounds contain much larger WP fills and are proportionally more hazardous
• WP munitions were used extensively in Vietnam for marking, screening, and antipersonnel purposes

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PART 7: AGED ORDNANCE HAZARDS -- CROSS-CUTTING CONCERNS

This section applies to ALL items in this database.

Explosive Sensitivity Changes Over Time

TNT-based fills (Tritonal, Comp B, Cyclotol):

• TNT component can undergo exudation -- crystals form on external surfaces, particularly at fuze threads and body joints
• Exuded TNT can be more friction-sensitive than confined fill
• Composition B (RDX/TNT mixture) shows aging behavior similar to aged TNT -- reduced friction resistance over time
• In contrast, RDX/wax compositions (Comp A-3) show minimal measurable sensitivity changes

Cyclotol (RDX/TNT):

• Present in BLU-3, BLU-26, BLU-63, and other submunitions
• TNT component ages as described above; RDX component more stable
• Crystal growth at grain boundaries may create internal stress points

Ammonium nitrate-based fills (GSX/DBA-22M in BLU-82):

• Hygroscopic -- absorbs moisture from environment
• Long-term moisture absorption may reduce explosive performance but creates unpredictable sensitivity

Fuze Degradation

• Mechanical fuzes (impact, inertia): Springs corrode, strikers may be near-fired position, detents may have weakened
• Centrifugal fuzes (M219 series): Spinning mass components may have corroded in armed or near-armed position
• Pyrotechnic delay trains: Delay compositions may have degraded -- timing unpredictable
• Electrical fuzes/batteries: Batteries may have leaked, creating corrosive internal environment; some batteries retain charge for decades
• Proximity fuzes: Electronic components degrade but may still function intermittently

Corrosion Effects

• Steel casings: Surface corrosion reduces structural integrity; fragmentation pattern may differ from design
• Aluminum components: Oxidation; may create galvanic corrosion where aluminum meets steel
• Copper components (shaped charge liners): Green patina but copper maintains structural integrity -- shaped charges remain functional
• Plastic components: UV degradation, embrittlement, but does NOT render explosive content safe

Environmental Factors in Southeast Asia

• Hot/humid tropical climate accelerates all corrosion and degradation processes
• Monsoon flooding cycles alternately expose and re-bury ordnance
• Dense vegetation conceals items and makes survey difficult
• Acidic soil in jungle areas increases corrosion rates
• Rice paddy water immersion followed by dry season creates extreme corrosion cycling
• Termite mounds and ant hills can build over/around ordnance

The Fundamental Rule

ALL aged ordnance should be treated as MORE dangerous than new ordnance, never less. Degraded safety mechanisms, corroded components, and aged explosives create unpredictable hazards that may exceed the original design threat.

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PART 8: QUANTITIES REMAINING BY COUNTRY

Laos

Estimate: 80 million unexploded cluster submunitions; total UXO including bombs, rockets, etc. significantly higher Based on: 270 million submunitions dropped (1964-1973); ~30% dud rate = ~80 million UXO Supporting evidence:

• Legacies of War (B-2)
• UXO Lao government data (A-2)
• US State Department CWD program reports (A-1) Contamination:
• All 17 provinces affected
• 25% of all villages contaminated
• Most heavily affected: Xiengkhuang, Huaphan, Savannakhet, Salavan, Sekong, Khammuane
• UXO Lao operates in 9 most affected provinces with 210 clearance teams (2024) Clearance status: Only ~10% cleared; at current rates, full clearance will take decades Caveats: "80 million" is an analytical estimate. True number could be higher or lower. Deep-buried items and items in inaccessible terrain are not captured in survey data.

Vietnam

Estimate: 800,000+ tons of UXO remaining; 5.6 million hectares contaminated (~17.7% of national territory) Based on: Vietnamese government survey data and US bombing records Supporting evidence: Vietnamese government data (A-2), US Embassy Hanoi fact sheets (A-1) Most affected provinces: Quang Tri (most contaminated -- frontline of DMZ), Quang Binh, Thua Thien Hue, Quang Nam Quang Tri detail: 51,000 hectares confirmed hazardous areas; 8,540+ casualties since 1975 (3,432 deaths); 31% of casualties under age 16 Clearance status: At current operational tempo, Quang Tri alone requires ~12.5 more years; national clearance timeline much longer

Cambodia

Estimate: 741 km2 total cluster munition contamination (154 km2 confirmed hazardous, 587 km2 suspected) Based on: CMAA reporting through 2022 (A-2), Landmine Monitor (B-2) Most affected areas: Northeastern provinces bordering Laos and Vietnam Casualty data: 39 casualties in 2025 (20% decrease from 2024); 64,000+ total since 1979 Clearance status: Missed December 2025 clearance deadline; requested extension to 2030 Caveats: Full extent of contamination not known; new areas still being discovered

Pacific Islands

Estimate: Significant but less quantified than Southeast Asia; 9+ island nations affected Items: Primarily WWII-era US and Japanese ordnance (bombs, artillery shells, mortar rounds, naval munitions) Most affected:

• Palau (Peleliu Island): 10,844 ERW found since 2016 survey began
• Solomon Islands (Guadalcanal): 20+ casualties per year; extensive contamination
• Marshall Islands (Mili Atoll, Maloelap Atoll): Clearance ongoing
• Also: Guam, Federated States of Micronesia, Papua New Guinea, Kiribati, Nauru Clearance: US has committed $5.4M+ for Palau; $6.8M+ for Solomon Islands since 2009

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SOURCES