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Franklin Applied Physics Inc. (610) 666-6645

July 15, 2013

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Electro Explosive Devices:Functioning, Reliability, Hazards

Franklin Applied Physics, Inc.Oaks, Pennsylvania, U.S.A.


The Fat Lands of Egypt

John James Audubon Introduction• Instructors:

Beth Shimer, Jamie Stuart• Daily Schedule• Week Schedule• Trainees• Franklin Applied Physics, Inc.


July 15, 2013


New Orleans 1830, 100 casualties Test Strength of Materials

Other Government-Funded19th Century Research

• Breakwaters, Telegraph• USS Princeton, 1844

Twentieth Century

• Bombsights• Fuzes• EEDs – test operation, safety, reliability• Symposia• Protection from inadvertent firing• Electrostatic discharge (ESD)• Radio Frequency (RF) hazards


July 15, 2013


Definition of Explosion

Berthelot 1883:“An explosion is the sudden expansion of gases into

a volume much greater than their initial one, accompanied by noise and violent mechanical

effects.”

Marcelin Pierre Eugène Berthelot (1827-1907)

Berthelot TombPhysical Explosions

• Water suddenly vaporized• No chemical reaction• Mechanical bursting• Destructive Effects


July 15, 2013


Praxair, St. Louis, MissouriJune 24, 2005 Nuclear Explosions

• Fission or Fusion• Enormous quantities of heat suddenly

released• Rapid expansion of air• Nearby material vaporized• Radioactive elements not explosive• Explosive trigger

Atomic Demolition Munitions Chemical Explosions


July 15, 2013


Reaction Rate vs. Pressure EXPLOSIVES

• Nuisances• British Definition• Stability• Sensitivity• Safety and Reliability• Effectiveness• Convenience

Electroexplosives:Functioning, Reliability, and Hazards

The Explosive TrainPresented by Franklin Applied Physics, Inc.


July 15, 2013


• Explosion• Explosive• Detonation• Deflagration• High explosive• Low explosive• Propellant• Pyrotechnic• Primary• Secondary• Booster

Basic Terms DDT• Deflagration to Detonation Transition• Heat transfer• Gas products increase pressure• Increased reaction rate• Further increased pressure and heating• Pressure waves build up to shock waves• DDT depends on confinement, particle size, surface

area, packing density, charge diameter and length, heat transfer, thermochemical characteristics of the explosive

SDT• Shock to Detonation Transition• Incident shock wave produces detonation

immediately• Efficient way to function insensitive

secondary high explosives

Elements of a High Explosive Train


July 15, 2013


Common device names

• Igniter• First-fire• Initiator• Fuze• Squib• Primer• ------------• Detonator• Blasting cap

• Detonating cord• Shock tube• Booster• -------------------------• Main charge• Output charge• Secondary charge• Base charge• Bursting charge

Safe & Arm Device• Provision for

interrupting propagation in case of accidental initiation of explosive train

• Interposition• Rotation• Linear motion• Disconnect power

source


July 15, 2013


Point-Impact Base-Detonating (PIBD) Artillery Shell Oil Well Perforating Gun

Shaped Charge Shells M789 ammunition for 30-mm cannon


July 15, 2013


M789 AmmoElectroexplosives:

Functioning, Reliability, and Hazards

EED ConstructionPresented by Franklin Applied Physics, Inc.

Examples of Electroexplosive Devices Complete EED


July 15, 2013


Header Types for Electroexplosive Devices Electroexplosive Transducer Mechanisms

SCB Simplified Sketch


July 15, 2013


Conductive Mix Characteristics of EEDs with Different Transducer Mechanisms

TRANSDUCER MECHANISM

RESISTANCE RANGE (ohms)

SENSITIVITY RANGE (ergs)

FUNCTIONING TIME (micro sec)

Hot Wire 1 to 10 300 to 100,000 5 to 20,000

Conductive Mix 10 to 5,000,000 50 to 50,000 1 to 1,000

Carbon or Graphite

500 to 15,000 50 to 500 1 to 10

Exploding Bridgewire

0.010 to 0.1 250,000 to 1,000,000

5 to 50

Source: Franklin Research Center Note: We normally are opposed to expression of sensitivity in energy units; it is convenient here.

Twin bridge devices Complete EED


July 15, 2013


• Firing modes• pin-to-pin• pins-to-case• bridge-to-bridge• Misfire• Hangfire• Dud

Detonators in Series

Detonators in Series


July 15, 2013


Detonators in Parallel

Electric Match Electronic Detonator with Microprocessor


July 15, 2013


Spark Gap Oilfield Detonators

Fluid Disabled Detonator Transformer in Leadwires


July 15, 2013


Detonators with Toroids Ferrite Filter in Header

Header with Capacitor Electronic Detonator with Microprocessor


July 15, 2013


Apply the All-Fire Stimulus

• Know what it is for your EED• Do not apply a lesser stimulus• Do not exceed the all-fire

stimulus by very much

Explosive ===> Gaseous Products + Heat

Ignition Temperature

Activation Energy


July 15, 2013


Initiator Compositions

• Lead Azide, Silver Azide

• Lead Styphnate

Initiator Compositions

• Lead dinitroresorcinate (LDNR)

• Tetrazene

Primary Explosives

Point-Impact Base-Detonating (PIBD) Artillery Shell


July 15, 2013


EBW Firing Signature Typical Bridge and Firing Characteristics

Energy versus Power

050

100150200250300350400450500

0 1 2 3 4

Time, Milliseconds

Tem

p de

g C

5 A4A3A


July 15, 2013


Deposited Energy,Short Firing Time

tRIERIP

tPE

2

2

RIEt 2

Long Firing Times

050

100150200250300350400450500

0 5 10 15 20 25 30

Milliseconds

Tem

p de

g C

5 A

4A3A0.7A0.3A

Firing Power

RIP 2

AF & NF Current Versus Time

0

0.5

1

1.5

2

2.5

3

0 2 4 6 8 10

Milliseconds

Ampe

res

All FireNo Fire


July 15, 2013


Blasting Machines50-Cap and 30-Cap Size For Claymore Mine

Capacitor DischargeBlasting Machines Wireless Blasting Machine


July 15, 2013


Don’t Use a Battery

• Supplies power without human intervention

• Illegal• May have lost its charge• Not suitable for high-resistance circuit

FIELD PROCEDURE

Field Procedure• Keep shorted.• Measure before connection.• Connect with cap isolated and safe. Then move cap to

charge.• Carry in aluminum foil or ammo can.• Shot line should be tight and twisted.• Don’t patch shot-line through cables close to other lines.• Keep shot lone close to the ground – not over brush.• Keep layout close to ground, with minimum area.• Turn off radio transmitters.• No mobile (vehicle-borne) transmitters in area.• Eight-foot standoff distance for hand-held radio

transmitter. The power limit is 4 to 5 watts.

Firing Many EEDs At Once

• In Parallel• JATO units• Disadvantage: High current• Electronic detonators• In Series• Must be all the same type• Time to function• Time to break bridge wire


July 15, 2013



Devices, Actuators

Presented by Franklin Applied Physics, Inc.

Dimple Actuator

Bellows Actuator Rotary Actuator


July 15, 2013


Piston Actuator Valves

Multiple contact switch Guillotine Cutter


July 15, 2013


Gas generator, pressure cartridgeAutomobile Air Bags

Aircraft Fire Suppression Many uses in space shuttle


July 15, 2013


Pilot Ejection Systems

Explosive Switch


July 15, 2013


Simple AC Circuit Lead FuseBefore and After

Explosive Fuse Commercial Explosive Fuse


July 15, 2013


Pyrotechnic Circuit Breaker Circuit Breaker with Toggle

High-Voltage Circuit Breaker Piston Unlatched


July 15, 2013


Propellant Cartridge Explosive Circuit Breaker

AC Voltage

0 5 10 15 20 25 30 35 40

time (milliseconds)

Volta

ge

Heavy Detonating Charge


July 15, 2013


Corrugated Charge Holder in Vacuum, Before & After

Two Parallel Paths

Burst Heavy Conductor Lower Arcs Clear


July 15, 2013


Upper Path Explosion Final State

Summary Firing System


July 15, 2013


EED Fires Currents in Chassis

Isolation Resistor RInadvertent Ignition

• Improper fire command• Improper use of battery• Compromised isolation• Galvanic cell• Ground current


July 15, 2013


General Rule

• Be sure that any stimulus that may arise naturally, in the environment, is less than the explosive material’s established no-fire level for that kind of stimulus.

Firing Signal at Wrong Time

• Examples:• End of shot-line out of sight• Setback closes impact switch• Software error• Solutions

Wabasca-DesmaraisCanada, 2000 Principles of Safety

• Keep the leadwires of your electric igniter short-circuited together, and isolated, until you are ready to fire.

• Make all electrical connections before you arm the system, i.e. before you insert the igniter into the rocket motor.

• Clear all unnecessary people away before you arm the system


July 15, 2013


T23E1 Detonator Rocket Sled AccidentOctober 9, 2008

Rocket in Airplane Proper Test Procedure


July 15, 2013


Accident Set-Up Galvanic Currents

• Dissimilar metals in contact• Conductive material or liquid touching

dissimilar metals• Sea water, urine, etc. in contact with metal• These form an unintended chemical

electric battery, and can fire an EED!• Precaution: always keep EED circuit

isolated from metal objects

Galvanic Cell in Earth Ideal Detonator Array


July 15, 2013


Potential Difference in Ground Leakage Current, Multiple Sources

Grounds for Trouble System Grounds


July 15, 2013


Galvanic Cell Lessons to Learn from this Story

• Keep EED leadwires twisted together, until you connect them to the shot-line.

• Do not ground EED leadwires• Do not ground any part of EED firing

circuit• Do not ground the shot-line• Keep ends of shot-line twisted together,

until you are ready to fire.

Ground Currents

• Faulty electric motor, for example. Short to frame.

• Buried metallic conductors• Exposed pipes• Frame of metal building• Precaution: keep the entire EED circuit

isolated from ground, at all times, whenever possible.


Electrostatic Discharge



July 15, 2013


• rubbing and friction• contact and separation • conduction• induction• spark or corona from another charged

object• particle contact – blowing dust, snow, etc.

Means of Obtaining Static Charge

Nature of personnel ESD sparks• Spark discharge through bridgewire• Spark discharge pins-to-case• Spark from person• Spark from equipment

ESD in EEDs


July 15, 2013


• Grounding• Avoid plastics• Non-static clothing – cotton, linen, leather• Non-static equipment• High humidity• Avoid contact and separation processes• Shielding• Static insensitive EEDs

ESD Safety procedures(some may not be applicable)

Test Circuit

VHV power

supply

ball switch

5 kohm

500pF

DUT

High-voltage probe Ball switch


July 15, 2013


Automated Ball SwitchElectroexplosives:

Functioning, Reliability, and Hazards

Lightning


Thundercloud

• Temperature difference top to bottom up to 100°F (55°C)

• High winds• Small particles ionized• 100 million volts top to bottom

Thundercloud with earth image


July 15, 2013


Sequential Phenomena in the Formation of a Lightning Discharge

Timing of lightning processes

• Stepped leaders form ionized path from cloud to ground -- 20-30 milliseconds

• Return streamer (return stroke) -- large current for ~ 0.1 millisecond

• Process may repeat several times• First stroke is usually largest• May have long-duration continuing current

Radial Electric Field in the Earth Surrounding a Lightning Strike


July 15, 2013



July 15, 2013


Range of Resistivity Values for Several Types of Soils

• Soil Composition

• Sea Water . . . . . . . . . . . .• Marsh . . . . . . . . . . . . . .• Clay . . . . . . . . . . . . . . .• Clay, mixed with Sand and Gravel• Chalk . . . . . . . . . . . . . . .• Shale . . . . . . . . . . . . . . .• Sand . . . . . . . . . . . . . . .• Sand and Gravel . . . . . . . . .• Rock – Normal Crystalline . . . .

• Resistivity (Ohm-cm)

• 100-200• 200-300• 300-16,000• 1,000-135,000• 6,000-40,000• 10,000-50,000• 9,000-80,000• 30,000-500,000• 5,000,000-10,000,000


July 15, 2013


Protection Zone – Probability of Strike < .001Extended Protection Zone with

Grounded Poles and Wire


July 15, 2013


ESD Accidents

ήλεκτρον, “electron”

Greek for amber

T23E1 Detonator

Mounting the T23E1 Self-Propelled Gun


July 15, 2013


Desert Proving GroundSouth Western USA M109 Howitzer with M52 Primer

M52 Primer


July 15, 2013


Gun Mechanism Breech

Slide Safe & Arm Firing Lines Coming Out


July 15, 2013


20 mm Cartridge


July 15, 2013


Phalanx CIWS Friction on Insulating Layer

Spark Voltage on Oscilloscope Separate Ground Connections for Gun and Electric Primer


July 15, 2013


Schematic Diagram Showing Ground Connections Oscilloscope Connection

Solution That Worked 2-Pin Mount for Primer


July 15, 2013


General SolutionA New Safety Rule

• ESD is unavoidable wherever there is motion.

• Don’t ground initiator leadwires.

• Always short-circuit the EED leadwires together, at the same place.

AN UNUSUAL ACCIDENT RE-

CREATED

James G. StuartFranklin Applied Physics, Inc.

In Air & On Ground Chaco Hut


July 15, 2013


Throwing Out Coil of Leadwires This Man’s First Mistake

• He made ballistic connection before electrical connection.

• We should always make electrical connection before ballistic connection.

Accident Causes Considered

• AC power lines• Radio frequency (RF) power• High-pressure air line nearby• Sympathetic detonation from another

blast• Electrostatic discharge (ESD)

ESD Apparatus to Test Detonator


July 15, 2013


Electric Detonator High Explosive Charge with Tape

Thundercloud with Earth Image Charge Separation on Detonator Parts


July 15, 2013


Ignition Tube Ignition Tube Explosion

Recommendations• Make electrical connection before ballistic

connection.• Do not use electric detonators when

thunderclouds are overhead.• Use only electric detonators that are ESD-

insensitive.• Do not throw electric detonator leadwires up into

the air.• Unroll electric detonator leadwires along the

ground.

Lay Out Leadwires on the Ground


July 15, 2013


Demonstrate Explosion

Safely Knotted Leadwires Wrapped Leadwires – Not Recommended!


July 15, 2013


Taped Leadwires –Don't Use Plastic Tape! Plastic Tape

Accident Sudbury, OntarioPlastic Tape with Detonating Cord Friction Tape


July 15, 2013


Don’t Wrap LeadsAround Shock Tube! Lessons Learned

• The pins-to-case firing mode can be particularly sensitive to electrostatic discharge.

• Do not use plastic tape on detonators.• Do not wind the plastic-insulated leads of

detonators around anything.• Any kind of motion can produce

electrostatic charge separation. Use a ground straps.

Perforating Gun ESD Accident Inside Perforating Gun


July 15, 2013


Possible Causes Investigated

Use only detonators that tests have shown to be insensitive to ESD.

Defective Cap, ESD-Sensitive ESD Booster-Cap


July 15, 2013


Factors Affecting RF Safety Output fromPulse-Modulated Transmitter

PT

P

Thermal Stacking Metal Shielding


July 15, 2013


Protecting an EED Resonant Cavity

Quality Factor Q

)()(

PowerLossgyStoredEnerQ

QVS

x Geometrical Factorc

Pineville, Kentucky


July 15, 2013


Pompton Lakes, New Jersey RFID SYSTEMS- ACTIVE TAG

PASSIVE TAG Package with Tag and Detonator


July 15, 2013


Electric Detonator

Radio Band Wavelength125 kHz 2.4 km148 kHz 2.0 km

13.6 MHz 22 m433 MHz 69 cm900 MHz 33 cm2.4 GHz 12 cm

Magnetic Coupling Reader with Loop Antenna


July 15, 2013


Small RFID Transmitting Coil Large RFID Transmitting Coil

Test Pick-Up RF Power PickupTransmitter with zip cord


July 15, 2013


Field Wire is Better EM RadiationMaxwell’s Equations

0

01

144

BtB

cE

tD

cJ

cH

D

Induction & Radiation Fields

• Wavelength c/f• Frequency is f, in sec-1

• Speed of light is c = 3.0 x 1010 cm sec-1

• Induction field predominates for distances less than . Currents and voltages go back and forth.

• Radiation field predominates for greater distances. Energy goes out to infinity.

Plane Wave Solutions

00

12

02

01

),(

),(

EBk

k

eBtxB

eEtxEtixki

tixki

377

/1041

/100.31

/13

4

mturnamperex

mVxoersted

cmstatvoltHE


July 15, 2013


Maximum Allowed Levels

Unrestricted UnrestrictedElectric Magnetic

Frequency Field Field Range Intensity rms Amp-turnMHz V/m rms per square meter

0.01 to 2 70 0.192 to 30 200 0.53

30 to 150 90 0.24150 to 225 90 0.24

etc.

Radiation from Isotropic Source

24 rPS

Radiation from Anisotropic Source

24 rPGS

RF Pickup in EEDAbsorbed Power-Safety Margin

Pr SAr

ASPNF


July 15, 2013


RF Power Pickup

P PG G

Rrt r

2

2 216

P PGR

Art

r4 2

24 RAGPP T

Half Wave Dipole and Aperture

= 4

Safe DistanceFundamental Expression

24 rAGPP ett

r

et

r

t AGPPr

4

RF Effects


July 15, 2013


Plane Reflectors

Absorbed Power (Gaussian)

rr

rr

AEcP

ASP2

08

Absorbed Power, MKS

rr

rr

AREP

ASP2

Transmitting Tower near EED


July 15, 2013


Direct and Reflected Waves Reflection Coefficient

11

1

EE

EEE

TOT

REFLTOT

Incorporate Reflection (Gaussian)

A Ac E A

c E A

FS

o

o FS

1

8

8 1

2

2

2 2

P

P

r

r

Incorporate Reflection (mks)

FS

FS

ARE

ARE

AA

22

r

2

r

2

1P

P

1


July 15, 2013


Earth’s Surface

Refraction at Earth’s Surface

Refraction at Interface

sinsin

'

'

sin

sin

E E E

E ETOT

TOT 1

Far-Distance Approximation

for r hhr

E Ehr

Ahr

A

TOT

fs

2 1

2

,


July 15, 2013


Loss Resistance

Wire Dimensions and Resistance

ALR

Metal Conductivity

Skin Depth


July 15, 2013


Gaussian mks

c

2 2

Copper Ironc 3.00E+10 3.00E+10 cm/sec 1 1f 5.40E+05 5.40E+05 1/sec 3.39E+06 3.39E+06 1/sec 5.20E+17 8.80E+16 1/sec 9.01E-03 2.19E-02 cm 3.5E-03 8.6E-03 inch

Skin Depth in Various Metals

Loss Resistance in Round Wire(Gaussian Units)

f

rcL

rcL

rL

ALRL

22

2

Loss Resistance in Round Wire(mks units)

f

rcL

rL

rL

ALRL

222


July 15, 2013


Reduced Aperture

fsL

e ARR

RA

Matching Section

Loss in Matching Section(Gaussian units)

fse

fsL

e

L

A

frR

RA

ARR

RA

frR

L

0

0

21

212

Loss in Matching Section(mks units)

fse

fsL

e

L

A

frcR

RA

ARR

RA

frcR

L

42

42

2

0

0


July 15, 2013


Mechanical Aperture

Antenna Types• EED as Dipole• Monopole• Vertical Antenna• Short Dipole• Half-Wave Dipole• EED Pins• Long Straight Wire• Small Loop• Geometrical Pattern• Multiple Sources

Dipole Antenna Equivalent Antennas


July 15, 2013


Vertical Whip Antenna Half-Wave Dipole Works Best

2

cf

f c 2

Half-Wave Dipole Formulae

G = 1.65

A

2

4 G

A 165 2.

Incorporate Other Effects

22

0

2

2

222

11

214

65.1

114

frR

RfcA

RRRGA

e

Le


July 15, 2013


Gain & Radiation Resistanceof Short Dipole

GM ( / )3 2

3

22

20

220

6

21

12

cfd

R

RIP

cdkI

P

EED Pins –Circular Aperture, or

Worst Case Half Wave Dipole

Current Zones in Long Dipole Gain & Effective Apertureof Small Loop

GM ( / )3 2

AA

cR

R Re

L

442

2

2 2


July 15, 2013


Longer Wires

Maximum Gain of Wire Antennas

Maximum Gain forGiven Wire Length

20775.01322.05.1 G

22

2

0775.01322.05.141

4

fc

fcA

fc

GA

Multiple RF Sources

21

22

21

2

2211

21

21

sinsin

PPP

RIRIP

RIP

tItII


July 15, 2013


Aperture of Short Dipole

423

4

)2/3(

2

2

A

GA

G

M

Mr

M

Le

L

Re

RcdA

RR

A

16

423

2

2

Effective Aperture ofHalf-Wave Dipole

2

2

4 65.1fcA

Small Loop withSkin-Effect Loss

2

0

2

22

0

22

22

44

44

fcr

R

Rc

AA

fcr

R

RRR

cAA

e

L

Le

Small Loop with Skin-DepthLoss and Reflection

2

0

2

22 441

f

crR

Rc

AAe


July 15, 2013


Blasting Wire at Low Frequencies Shielded Firing Cable

Cable Faults Wireline with Faults


July 15, 2013


RF Safe Distance

Model EED System Aperture:

• Short dipole• Half-wave dipole• Long straight wire• Wire longer than wavelength, not straight• Small loop• Mechanical aperture

Aperture of EED Alone• Model as short dipole of length d• Use maximum dimension of EED as d

RcdA16

2

Safe DistanceFundamental Expression

24 rAGPP ett

r

et

r

t AGPPr

4


July 15, 2013


Use Known No-Fire Level-

In “Safe Distance” equation, insert EED’s PNF

value for received power Pr

EXAMPLE CALCULATION• Electric detonator• One ohm bridgewire• 0.2 ampere no-fire current level• Copper leadwires• Extended leadwires and shot-line (worst case)• Leadwires are twisted together at end• Nearby AM radio broadcasting station• How close can we get?

Further Assumptions• AM radio band is 0.54 to 1.6 MHz. As a worst

case, we say frequency is 1.6 MHz. Thus, wavelength is about 188 meters.

• AM radio transmitters are often very directional. As a worst case, we say Gt =10.

• Transmitter power 50,000 watts – legal max• As a worst case, we assume someone has

picked up one of the EED wires, leaving the other on the ground, making a triangular loop.

PICKUP LOOP


July 15, 2013


Particulars of Pickup Loop• Loop is much smaller than a wavelength

• Therefore, we will use our aperture formula for a small loop

• Loop area 2.3 m2

• Perimeter Length 7.3 m

Safe Distance Formula

et

r

t AGPPr

4

2

0

12

fcr

R

RcP

PGc

fArr

t

Safe Distance from AM Transmitter

Recommended Distances from Commercial AM Broadcast

T ransmitting Antennas 0.54 to 1.6 MHz

0100200300400500600700800900

0 10000 20000 30000 40000 50000 60000

Transmitter Power Watts

Saf

e D

ista

nce

Met

ers


July 15, 2013


References• Safety Guide for the Prevention of Radio Frequency

Radiation Hazards in the Use of Commercial Electric Detonators (Blasting Caps). Safety Library Publication No. 20. Institute of Makers of Explosives (IME), 1120 Nineteenth St. NW, Suite 310, Washington, DC 20036-3605, U.S.A.

• IEEE Recommended Practice for Determining Safe Distances from Radio Frequency Transmitting Antennas When Using Electric Blasting Caps During Explosive Operations. ISBN 0-7381-3422-8; IEEE Product No. SH95045-TBR;IEEE Standard No. C95.4-2002

Electroexplosives:Functioning, Reliability and Hazards

Testing for SafetyPresented by Franklin Applied Physics, Inc.

Instrumented EEDs Factors Affecting RF Safety


July 15, 2013


Anechoic Chamber Band 1H B P run 34476

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

19:55.2 20:38.4 21:21.6 22:04.8 22:48.0 23:31.2 24:14.4 24:57.6

time (minutes:seconds)100 88.3 77.6 68.2 60.0 52.7 46.2 40.8 35.6 31.6 27.7 24.2 21.6

frequency (MHz)

rela

tive

volts

FprtnRFpassLFdvr1dvr2PRTpcLpassRsideLSYNCH


July 15, 2013


Functioning, Reliability, and Hazards:

Non-destructiv

e TestsPresented by Franklin Applied

Physics, Inc.

• The firing of an electroexplosive device is irreversible, non-repeatable, and not fully predictable in advance. A number of indirect methods have been developed that can determine whether a given EED might be defective, without actually firing it. Joseph McLain

Bridgewire Resistance Test• Special ohmmeter to limit current• < 1 milliampere for hot-wire device• < 10 microamps for carbon bridge• Check every item• - on production line• - before and after test exposure• - system check• RF Impedance

Thermal Transient Response TestRosenthal Equation

• C is heat capacity of the system• T is temperature above ambient• t is time• a is heat loss coefficient of the system• b is thermal coefficient of resistance of

bridgewire material• Ro is initial resistance of the EED

)1()( 2 bTRItPaTC odtdT


July 15, 2013


Solutions for constant current

If t<<C/a i.e. very short time

• If t is very large i.e. equilibrium situation

tC

bRIabRIa

RIT o

o

o2

2

2

exp1

tyHeatCapaciEnergyt

CRIT o

2

powerbRIa

RITo

o

2

2

Increasing “a” decreases equilibrium temperature

Increasing C increases time to equilibrium Increasing Ro increases equilibrium temperature


July 15, 2013



July 15, 2013


Leak Test

• Keep out moisture• Hermetically sealed• Seals between different materials –• metal, glass or ceramic, plastics, etc.• Helium• Krypton-85• Red dye

X-rays of EEDs

Testing EEDs• Random sample from large lot of EEDs• Sampling by attributes• MIL-DTL-23659D• Don’t re-use test samples

Turn-On Time

• Bridgewire posts

• Current Heating

• Conduction Cooling

RIkdtdT 2

0TT

dtdT


July 15, 2013


• Current rise rate

• Combine effects

tI

022 TT

RtkdtdT

Alternative Explanations

• Current overshoot

• Dudding

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

0 1 2 3 4

Milliseconds

Am

pere

s

Electrical Test Stimuli for EEDs

• All-fire – Short Time• No Fire – Long Time• ESD• Constant Current or Voltage• Constant Power• Capacitor Discharge• RF Power

ESD Tester


July 15, 2013


Photo of ESD Tester Simulator Set Up-Leads should be short!

HV Lead in Conduit-Not Recommended! ESD Pin-to-Pin Test


July 15, 2013


Current,Instantaneous Power

( ) = = ( )

EnergyBridge Wire Temperature= 2 = 2 + + 2 +

= 2 +

Constant-Current Tester

1

121

1

2121

RVI

RR

RVI

RRRR

VI

Constant-Voltage Tester


July 15, 2013


Constant-Power Test

• Semiconductor bridge (SCB) initiators

• Conductive mix initiators• Ratio of voltage to current

(apparent resistance) depends on temperature

Power as Function of Constant Voltage or Current• =

• =

Constant Power Tester Sample Data


July 15, 2013


Capacitor-Discharge Tester

Capacitor-Discharge Test

DISCHARGE TIME < THERMAL TIME CONSTANT

RF Voltage and Current RF Voltage and Power

tVV cos0

dtIVT

PTt

t

0

1


July 15, 2013


RF Period

2T

RF Voltage and Current out of Phase

tIItVV

coscos

0

0

cos21

coscos1

1

00

00

0

0

IVP

dtttIVT

P

dtIVT

P

Tt

t

Tt

t

Measure Voltage, Current, and Phase Angle. V2= Phase Difference


July 15, 2013


Phase Angle and Measured Average RF Power

Dd 2

DdVVP

IVP

2cos2

cos21

21

00

Lead Length for EED RF Tests

EEDLEAD RR

Allowable Lead Length

f

crR

rR

LEAD

LEAD

2

22

rx

Rf

cm

rx

Rf

MHzohm

EED

EED

10 7 10

12 10

1832

4

. sec

.

Output Tests on EEDs• Squibs - hot gas – closed bomb

• Detonators – shock wave – witness


July 15, 2013


Card Gap Test Data From Card Gap Test

Timing Light Output AfterCapacitor Discharge


July 15, 2013


Light from 2 EEDsFired in Parallel Light Sensor Module

Light Sensor System Firing Chamber Safety Factor


July 15, 2013


Sealed Tube Ultimate Tensile Strength

=

Thin-Walled Metal Tube Upper Half of Tube

= 2 ℓ= sin ℓ = 2 ℓ


July 15, 2013


Barlow’s Formula for Burst Pressure

= = 2 Tube Calculation

Pressure from 3 grams HE

→ 3 + 3 + 3 3 = 0.0135 → 0.12 =

Safety Factor for Tube(Greater for Test Chamber)

= = 194


July 15, 2013


One-Level TestUniformityFew DefectivesPoisson DistributionTest Lots with Defectives

EEDs with Varying Resistance

• Divide test units into two lots by resistance• Perform all-fire test on low-resistance lot• Perform no-fire test on high-resistance lot

RIP 2

Assumption: Few Defectives

• Large population with few defectives• Fraction of defectives • Value of is small• Sample size n• We find number of defectives x• Sample size n >> x• Product n is small (less than 25)

What We Need to Know

• What value of x, i.e., how many defectives, can we reasonably expect to find?

• If we obtain a certain number of defectives x, what can we say about the value of ?

• How many items n do we need in our test lot?


July 15, 2013


Poisson Distribution

!)|(

xexp

nx

Probability ofZero Defectives

eep!0

)|0(0

Probability ofOne Defective

eep!1

)|1(1

Probability of One or Fewer Defectives:

eepp )|0()|1(

Zero Defectives, Lot Size 10

0.065 0.273

0.130 0.204

0.195 0.163

0.260 0.135

0.325 0.112

0.390 0.094

0.455 0.079

0.520 0.065

0.585 0.054

0.650 0.043

0.715 0.034

0.780 0.025

0.845 0.017

0.910 0.009

eep!0

)|0(0

0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.000 0.500 1.000

Alpha

Thet

a

Reliability & Confidence230.0100.0 for

230.0100.0 for230.0100.0 thatyprobabilit

230.0900.0 thatyprobabilit770.0)1(900.0 thatyprobabilit

%77%90 yreliabilitthatconfidence


July 15, 2013


Probability ofc or fewer defectives

c

x

x

xe

n

0 !

Confidence and Reliability• If we draw a sample of size n from a population

with a defective fraction , then the probability that we will find c or fewer defective items is .

• If we test n items, from a population with a defective fraction less than or equal to , then the probability that we will obtain c or fewer defectives is (1- ).

• If we draw a sample of size n, and we find c or fewer defective items, then the probability is that the population has defective fraction ≥

Another Way of Putting It

• If we draw a sample of size n, and we find c or fewer defective items, then we have 100(1- confidence that the population has defective fraction ≤

• If we draw a sample of size n, and we find c or fewer defective items, then we have 100(1- confidence that the population has reliability ≥ 100(1-

Confidence and Reliability

Confidence ↔ Confidence = 100(1 - )%

Reliability ↔ Reliability = 100(1 - )%


July 15, 2013


Two or Fewer Defectives

2

2

eee

n

Expose 500 to AF, all but 2 fired: Reliability w/ 90% confidence?

9894.01

010644.0500322.5

322.52

110.0

!

210.0%90)%1(100

2

2

0

n

n

eee

xe

c

x

x

One or Fewer Defectives

een

Zero Defectives

en


July 15, 2013


Examples of ValuesNot in Tables

• Find lot size• Find Confidence Level• Find Reliability• Increase Lot size

Find Lot Size• AF=3.5A, 97.5% Reliability, 92%Confidence• Equation for Zero Defectives

en

Find Confidence• Test 30 squibs (n=30). None fires.• No-fire level (95% reliability) is 0.400 A• What confidence that squibs meet spec?• Probability for zero defectives

en

Find Reliability

• What is reliability of firing unit?• 22 caps; all of them fire• Use formula for zero defectives

en


July 15, 2013


Increase Lot Size

• Specify DC no-fire current 0.150 ampere• Specify 90% reliability, 90% confidence• “Zero Defectives” table: 24 squibs• Expose 24, the last one fires• Expose more – how many?• “One or Fewer Defectives” table: 39• We must obtain & expose 15 more• If no more fire, specification is met.

Drawbacks• Many useful conclusions from the kind of

test where we expose explosive devices to a single stimulus level.

• This kind of test does not tell us what might happen at a different level of stimulus.

• Large number of explosive items required, particularly when we test high levels of reliability, at high levels of confidence

Testing at Many Stimulus

LevelsHow to determine

all-fire and no-fire levels for EEDs

Cumulative Firing Probability

0

10

20

30

40

50

60

70

80

90

100

0 10 20 30 40 50 60 70 80 90 100

Stimulus Value, Arbitrary Units

Perc

ent F

iring

Pro

babi

lity


July 15, 2013


Fitting Data

0

10

20

30

40

50

60

70

80

90

100

0 10 20 30 40 50 60 70 80 90 100

Stimulus Value, Arbitrary Units

Perc

ent F

iring

Pro

babi

lity

All-Fire & No-Fire• Bayes Principle• Notion of Accuracy Does Not Apply• Percentage Points of Normal Distribution (ALL-

FIRE)

Measurement Protocols

Bruceton Protocol

• Bruceton, Pennsylvania, U.S.A.• Up-and-down test• Pencil-and-paper calculations• Determine mean and standard deviation• Determine all-fire & no-fire levels• Introduction to Statistical Analysis. Dixon,

W.J. and Massey, F.V., Jr. McGraw-Hill Book Co., Toronto, 1969.


July 15, 2013


(n+1) evenly spaced levelsy0, y1, …, yn

= + STIMULUS VALUES

• Not the same thing as evenly-spaced levels

• h0, h1, …, hn

• Stimulus values need not be evenly-spaced

Linear Transformation

= ℎℎ = 1

Logarithmic Transformation

= β ln ℎℎ =


July 15, 2013


Common Logarithmic Transformation= 1ln 10= ℎℎ = 10

Example of Common Logarithmic Transformation

Stimulus Value,

amperes Level5.37 0.734.27 0.633.39 0.532.69 0.432.14 0.331.70 0.23

Example Continued

• Protocol predicts no-fire level -0.05

• No-fire stimulus value is 10-0.05

• No-fire stimulus value is 0.89 ampere

LINEAR TEST DATA

DUT 1 2 3 4 5 6 7 8 9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

Level

30 X25 O X X X X20 X O X O X O O X X15 X O O O O O X X10 O O


July 15, 2013


ALL-FIRE STIMULUSCALCULATION FROM DATA

ConfidenceProbability

All-Fire

Percent Perce

nt k lStimul

us

95 0.95 99.9 0.999 3.090 1.645 51.335

90 0.9 99.9 0.999 3.090 1.282 48.383

95 0.95 99 0.990 2.326 1.645 43.565

90 0.9 99 0.990 2.326 1.282 41.303

Langlie Protocol

• Differently spaced levels• Requires a computer• Langlie, H.J. 1962. A Reliability Test

Method for “One-Shot” Items. Aeronutronic division of Ford Motor Company, Publication No. U-1792. Work performed under U.S. Army Contract DA-04-495-ORD-1835.

Langlie Parameters

it

i

i

i

i

ii

t

ii

dttgG

Gu

Guh

etg

st

)(

11

21)( 2

2

Langlie Sums

0)(

0)(

1)

1)

i

N

iii

i

N

ii

htgt

htg


July 15, 2013


Langlie Test Data Limits: Lower Upper

199.8 20.39 100 350

Trial s u t g h gh tgh1 225 0 1.2359 0.1859 -1.1214 -0.2084 -0.25762 163 1 -1.8048 0.0783 1.0369 0.0812 -0.14653 194 0 -0.2845 0.3831 -2.5771 -0.9874 0.28094 178 1 -1.0692 0.2253 1.1662 0.2627 -0.28095 186 1 -0.6768 0.3173 1.3320 0.4226 -0.28606 268 0 3.3448 0.0015 -1.0004 -0.0015 -0.00507 227 0 1.3340 0.1639 -1.1002 -0.1803 -0.24058 203 1 0.1569 0.3941 2.2850 0.9004 0.14139 215 1 0.7455 0.3022 4.3860 1.3253 0.988010 241 0 2.0206 0.0518 -1.0221 -0.0529 -0.107011 228 0 1.3830 0.1533 -1.0909 -0.1672 -0.231312 216 0 0.7945 0.2910 -1.2714 -0.3699 -0.293913 158 1 -2.0500 0.0488 1.0206 0.0498 -0.102114 187 0 -0.6278 0.3276 -3.7724 -1.2358 0.775815 172 1 -1.3634 0.1575 1.0945 0.1724 -0.2350

TOTALS 0.0108 0.0002

Sum of Squares 0.00012Step Size

0.1 Ctrl-A to increase, Ctrl-S to decrease 0.01 Ctrl-N to increase, Ctrl-M to decrease

Other Protocols

• Probit• Robbins-Monro• Neyer• Einbinder (OSTR)• Equivalence• Which is better? – the class decides

Minimum ContradictorinessStimulus T Functioned Did not

function

5.0 4 04.8 2 04.6 2 24.4 2 24.2 1 24.0 1 23.8 0 13.6 0 1

Incremental Functioning Probability


July 15, 2013


Incremental Non-Functioning Probability

Incremental Probability for Contradictory Result

Normal Distribution of Incremental Probability

= 12 ( )Joint ProbabilitySum of Squares

= 12 = 12 ∑ = ∑ −


July 15, 2013


Excel SpreadsheetD6 is =+IF(A6>$B$1,C6,B6). Column A B C D E

Row 1 Trial 4.3723 Stimulus T Did

FunctionDid notfunction

Contra-dictory

Contri-bution

4 5.0 4 0 0 05 4.8 2 0 0 06 4.6 2 2 2 0.10587 4.4 2 2 2 0.00188 4.2 1 2 1 0.02899 4.0 1 2 1 0.136910 3.8 0 1 0 011 3.6 0 1 0 01213 Q() 0.2734

Uses of No-Fire & All-Fire Levels

• For safety, ensure no extraneous signal reaching the EED exceeds the no-fire level.

• For reliability, design your firing circuit so that its output exceeds the all-fire level.

Optimal Firing Circuit

2

2VCE

Safety Margin


July 15, 2013


Input (Sensitivity) Tests

• Quantal Response• Important to know exactly how

sensitive• Tests on EEDs

Continuous Statistics

• Sample of EEDs• On each one, turn up the power until it

fires• Record final (firing) power level• Sample (x1, x2, …, xn)• Assume sample from normal distribution

N( ).

Normal Distribution Estimate Population Parameters

• Values represent entire population

2

1

21

n

jj xxsn

n

iix

nx

1

1


July 15, 2013


Standard Normal Distribution

Percentage Points ofNormal Distribution

( ) ,

( ) ( )

z e z

P z z z dz

z

z

12

22

Sample Comparison Test

Sensitivity same?Contamination?

Possibility : 2 Bruceton tests

References• Quantitative Effect of Gritty Contaminants on the

Sensitiveness of High Explosives to Initiation by Impact. Henry J. Scullion, Journal of Applied Chemistry and Biotechnology, 1975, v. 25, pp. 503-508.

• Manual of Tests and Criteria. Recommendations on the Transport of Dangerous Goods. ST/SG/AC.10/11/Rev.3. United Nations, New York and Geneva, 1999. Appendix 2, “Bruceton and Sample Comparison Methods.”


July 15, 2013


Example Bruceton Test on #1

Samples of #1 and of #2

Underline Differing Results

One Bruceton Test

• If ignition, decrease stimulus• If no ignition, increase stimulus• Subject sample of 2nd explosive to same

stimulus as sample of 1st explosive• Use only pairs of results with different

responses• Pairs n, explosive A has fewer ignitions• Have x cases where A ignited, B did not


July 15, 2013


Distribution of ResultsExample: BBBBABBBBB

)( xnx

Probability

• Probability that first one will be B is ½• Probability that second one will be A is ½• Probability first two will be BA is (½) * (½) • Probability of any given sequence of n As

and Bs is (1/2)n

Number of CombinationsProbability of x A’s in n Trials

)!(!!

xnxn

!!!

21)(

xnxnxp n

Probability of x, given n=10

0

5

10

15

20

25

30

0 2 4 6 8 10 12

x (number of A's)

Prob

abili

ty p

erce

nt


July 15, 2013


Cumulative Probability“x or fewer” - Example for n=10

xi

i n ininfewerorxp

0 !!!

21)(

0

20

40

60

80

100

120

0 2 4 6 8 10 12

x (number of A's) or fewer

Prob

abili

ty P

erce

nt

Confidence that Coin is not “Fair”

xi

i n ininK

0 !!!

211100

References• Quantitative Effect of Gritty Contaminants on the

Sensitiveness of High Explosives to Initiation by Impact. Henry J. Scullion, Journal of Applied Chemistry and Biotechnology, 1975, v. 25, pp. 503-508.

• Manual of Tests and Criteria. Recommendations on the Transport of Dangerous Goods. ST/SG/AC.10/11/Rev.3. United Nations, New York and Geneva, 1999. Appendix 2, “Bruceton and Sample Comparison Methods.”

Conductive Floor Hazard


July 15, 2013


Movie: High Power Worker

Bird on Wire Not Shocked Person Shocked


July 15, 2013


Grounding Necessary Electric Current →Bodily Harm

RVI

Electric Current Hazard Guidelines

Safe Practices

• Zero energy state• Lockout/tag out• Check with voltmeter• Initial contact with the back of hand• Keep other hand in pocket• Remove ground strap• Special wrist-to-wrist strap• Ground fault interrupters


July 15, 2013


Care for Electric Shock Victim

–

Safe Circuit Design

Grounding An Electrical Circuit Example Appliance


July 15, 2013


Meter Safety


July 15, 2013


Measuring Resistance Measuring Current

Function Classification

• High explosives detonate to:– Create shock waves– Burst– Shatter– Penetrate– Lift and heave– Create air blast– Create underwater bubble pulses


• Propellants burn to:– Propel projectiles and rockets– Start I.C. engines and pressurize other piston

devices– Rotate turbines and gyroscopes


July 15, 2013



• Pyrotechnics burn to:– Ignite propellants– Produce delays– Produce heat, smoke, light and/or noise

Sensitivity Classification• A primary high explosive can detonate easily.• A secondary high explosive can detonate, but

less easily.• We do not require a propellant explosive to

detonate at all.• It is probably true that all primary explosives are

capable of detonation. We do not require this. We require only deflagration.

Hershey Bypass IOC 3.8 MT 01 Oct 1991


July 15, 2013


IOC 5.0 MT 21 Dec 2005 Exploding Whale


Chemistry



July 15, 2013


Molecular Energy Levels Burning (oxidation)

• 2H2 + O2 → 2H2O

• C3H8 + 5O2 → 4H2O + 3CO2

• (propane)

• Exothermic reactions

Molecular Energy Levels Explosive and pyrotechnic mixtures

• Black powder

• ANFO

• Emulsions

• Thermite

• Safety matches


July 15, 2013


Some explosive molecules

• RDX C3H6N6O6

• PETN C5H8N4O12

• Lead styphnate C6H3N3O9Pb

• Mercury fulminate C2N2O2Hg

“Green” explosives

• Many primaries have heavy metals• DBX-1• Substitute for lead azide• Similar properties• Less reactive with other substances

(copper, some secondary explosives)

TNT - Trinitrotoluene 2C7H5N3O6 3N2 + 5H2O + 7CO + 7C

• Other products include:• H2• NH2• NH3• HCN• NO• NOx• CO2

• CH4• CH3OH• C2H2• C2H4• C2H6• CH2O• CH2O2• C2H5OH

Oxygen Balance

• Ω (%) = 100 AWO [ NO – 2NC -½NH ]• MWexpl

AWO = 16.000 MWexpl = 12.01NC + 1.008 NH + 14.008NN + 16.000 NO


July 15, 2013


• Ω = 0 maximum energy output

• Ω < 0 underoxidized, fuel rich

• Ω > 0 overoxidized, fuel lean

• Nitroglycol C2H4O6N2 Ω = 0

• TNT Ω < 0

• Nitroglycerin C3H5O9N3 Ω > 0

TNT - Trinitrotoluene 2C7H5N3O6 3N2 + 5H2O + 7CO + 7C

• Afterburn:

• 2CO + O2 2CO2

• C + O2 CO2

First Law of Thermodynamics

• Energy cannot be created or destroyed, it can only be transformed from one form of energy into another

• The total energy of a closed system remains constant

• (conservation of energy)


July 15, 2013


• Heat of formation = internal energy of final state minus sum of internal energies of initial components

• (a negative quantity)

Molecular Energy Levels

• Heat of reaction = [Σ heat of formation of products] – [Σ heat of formation of reactants]

• Negative for exothermic reaction• Often labeled Q or ΔH

Molecular Energy Levels


July 15, 2013


• Heat of explosion• Heat of detonation• not constant, depend on conditions during

explosion

Temperature of explosion

• Texpl – Tambient = Q • Σcmean

• Molar heat capacities ( c ) are smaller for smaller molecules

• 2500 – 5000 oC

Volume of gas from explosion

• 1 mole of gas at STP has volume 22,400 cm3

• RDX C3H6N6O6 → 3N2 + 3H2O + 3CO

• 9 moles from 1 mole (222 gm)

• 9x22,400 cm3 ~ 1000 cm3 / gm at STP• 222 gm

Pressure of explosion

• P ~ ¼ ρD2

• RDX: ρ=1.767gm/cm3 D=8.79km/s• P=34.1 GPa ~ 300,000 atm


July 15, 2013


Chemical Reactions in Just a Few Molecules

• Decomposition• Thermal runaway


Physical EffectsPresented by Franklin Applied Physics, Inc.

Comparison of Energy Storing Devices


July 15, 2013


Why use explosives?

• Powerful• Fast• Compact • Self-contained• Cost effective

• Adequately accurate

• Simple• Sturdy• Reliable• Versatile

• Usable once

Comparison of energy releasing processes

MATERIAL PRESSURE(atmospheres)

RATE (g/sec)

POWER DENSITY (watt/cc)

AcetyleneFlame

1 1 100

Propellant inGun

2,000 1,000 1,000,000

DetonatingHigh Explosive

400,000 1,000,000 10,000,000,000

From W.C. Davis

Comparison of Power and Energy for Various Fuels and Storage Means


July 15, 2013



July 15, 2013


DETONATIONBurning and Detonation


July 15, 2013


Detonating Explosive DETONATION

• Initiating Detonation

• Burning to Detonation (Milliseconds to Minutes)

• Shock to Detonation (Microseconds)

Partition of Energy

• Propellants

• Detonation in Air

• Confined Detonations

• Measuring the Partition of Energy

Detonation Velocity & Pressure

• Effect of Density of Loading ( )

• Effect of Confinement (charge diameter)

• Effect of Detonator Strength

211415

21 105.3 scmgDD


July 15, 2013


Detonation Velocity ofCommercial Explosives

Detonation Parameters ofMilitary Explosives

Chapman-Jouguet Condition

wCD

D’Autriche Apparatus


July 15, 2013


VOD Measurement –Resistance Method Voltage vs. Time

, = 2 − 1 , = 4 − 3

Four and More Resistors Detonation Pressure

1227105.2 gscmbarD


July 15, 2013


SHAPED CHARGESHOCK WAVE SHAPING

Damage Capacity - 2 Effects

Shock Wave inCylindrical Charge

• Cooling prevents plane wave• Constant convex

Internal Shaping: Plane Interface


July 15, 2013


Internal Shaping atCurved Interface –

Explosive Lens

High-to-Low orLow-to-High Transition

To Produce Planar Wave

Implosion DeviceNuclear Fission Bomb

Explosive-Metal Wave ShaperAir Lens


July 15, 2013


CORED CHARGEAPPROXIMATELY PLANAR

SurfaceWave

Shaping

Detonation Wave fromCylindrical Charge

Shock Wave fromPlane-Ended Charge


July 15, 2013


Shock Wave fromHemispherical End, Wedge SHAPED

CHARGE

Hollow Charge Liner Acceleration


July 15, 2013


Uses for Shaped Charge Slow-Motion Shaped Charge

PENETRATION

• Proportional to

• M is mass of jet• v is speed of jet, very great• A is cross-sectional area of jet, very small

Variables Affecting Shaped Charge Use

• Detonation parameters of the explosive• Ratio of charge length to cone diameter CD• Ratio of stand-off to CD• Ratio of liner thickness to CD• Liner geometry• Symmetry• Liner material• Fuzing mechanism (for a missile)• Effect of spin (for a gun projectile)• Cost effectiveness


July 15, 2013


Depleted Uranium Liner

• Non radioactive• Byproduct of enrichment• Heavy, 1.7 times density of lead, more like

gold & tungsten; heaviness enhances kinetic energy

• Low melting point, 1132 deg C, half that of tungsten; facilitates jet control

• Pyrophoric – burns in air – hot!

Shaped Charge

Perforating Gun Underwater Shaped Charge


July 15, 2013


Linear Cutting Charge Shaped Charge andExplosively Formed Projectile

Fragmentation Munitions

• Antipersonnel: small• Anti-vehicle: 5-10 grams• Ratio charge weight/case weight• Increase velocity, thin cloud of fragments• Need more than 1000 m/s to penetrate 10

mm steel

Scabbing (Spalling)


July 15, 2013


EMP Warhead

Explosive-driven, magnetic-flux compression

generator

Flux Compression

Energy Storage Flux Generation


July 15, 2013


Coil with Copper Tube Details of Tube

Explosive Compression Peak B-Field


July 15, 2013


Rock Blasting Avalanche Control

• Explode charge in snow (cannon) –water

• Explode on surface (flying saucer) –crater

• Explode above surface – shock wave spreads out over large area

• Gondola story

Steel Cable (Wire Rope)and Closed Spelter Socket Swaging Process


July 15, 2013


Swaging with Det Cord Explosively SwagedCross Sections

High Energy Rate Forming(HERF) has advantages over… Spelter Method

• Unlay cable strands and wires• Insert into spelter socket• Pour in molten metal• Fills & bonds• Zinc, 850 degrees Fahrenheit• No heavy equipment. Quick.• Heat hazardous, awkward• Zinc is a hazard


July 15, 2013


PropellantsBurningGunsGun PropellantsRocket Propellants

BURNING

• All explosives burn• Burning can occur when confined• Burning at or just above the surface• Surface itself recedes layer by layer

(Piobert’s Law, 1839)• Traité d'artillerie Théorique et Pratique by

Guillaume Piobert (1845)

BURNING

• Heat radiated from reaction zone

• Heat conducted from reaction zone

• Heat from decomposition

Rate of Regression

• Burning Rate Index • Mass Rate of Burning• A Surface Phenomenon

Pr


July 15, 2013


GUNS• Interior Ballistics, 3rd Edition. James M.

Ingalls. John Wiley & Sons, New York. 1912.

• Elements of Ordnance. Thomas J. Hayes. John Wiley & Sons, New York. 1938.

• The Machine Gun. Design Analysis of Automatic Firing Mechanisms and Related Components. George M. Chinn. Volume IV, Parts X and XI. Bureau of Ordnance, Department of the Navy. 1955.

French 75

Long Recoil System Spring-Loaded Magazine Positions Cartridge in Front of Bolt


July 15, 2013


Typical Gun PropellantGrain Geometry Properties Required in a Propellant

• An acceptable high energy/bulk ratio.• A predictable burning rate over a wide range of

pressures.• An acceptably low flame temperature.• A capability of being easily and rapidly ignited.• An acceptably low sensitiveness to all other possible

causes of initiation.• A capability of cheap, easy and rapid manufacture and

blending.• A long shelf life under all environmental conditions.• A minimum tendency to produce flash or smoke.• A minimum tendency to produce toxic fumes.

Rate of BurningGuillaume Piobert (1839) Vieille’s Burning Rate Law (1893)

• Rate of burning (mm s-1) is r.• Burning rate coefficient is .• Pressure is P• Pressure index is .

Pr


July 15, 2013


Paul Vieille (1854-1934) Solid Form –Spheres, Plates, Cylinders

• Decrease in surface area during burning

• Degressive burning• Decrease in dm/dt with time

(at a theoretical constant pressure)

Single-Perforated Form

• Inner surface area increases• Outer surface area decreases• Burning area approximately constant• Neutral burning characteristic• Constant dm/dt (at theoretical constant P)

Effect of Grain Geometry on Pressure/Time Curve


July 15, 2013


Performance in Gun Chemical Nature of Propellants

• All contain nitrocellulose• Single-base - nitrocellulose• Double-base – nitrocellulose,

nitroglycerine (NG) – higher energy• Triple-base – nitrocellulose,

nitroguanadine (picrite) – intermediate energy – suppress flash

• Energized Propellants – RDX, NG

Other Ingredients

• Stabilizer• Plasticizer• Coolant• Surface moderant (deterrent)• Surface lubricant• Decoppering agent• Anti-wear additive

Recent Developmentsin Gun Propellants

• Caseless Ammunition – small arms

• Liquid Propellant - gunsRegenerative Traveling Charge


July 15, 2013


Heckler and KochCaseless Ammunition Regenerative Injection

Traveling Charge Injection Rocket Propellants

• Liquid monopropellante.g. hydrazine N 2 H 4

• Liquid bipropellantFuel and oxidizer

• SolidCase bondedInhibited


July 15, 2013


Rocket Propellant Grains Javelin

All Burnt On Launch - ABOL “Materials capable of combustion when correctly

initiated to producea special effect”

• Burn, not detonate• Importance of initiation• Special effects distinguish pyrotechnics

from other explosive types


July 15, 2013


Pyrotechnic Special Effects

Basic Components

Pyrotechnic Fuels & Oxidizers

Binders for Pyrotechnics


July 15, 2013


Binders

• Increase cohesion between particles• Aid consolidation• Coat (protect) reactive components• Modify burning rate• Reduce sensitivity of friction• Enhance performance

Material Properties

• Degradation• Salts• Impurities• Chemical Reactions• Sensitivity

Devices Requirements for First Fire• Ignite readily from initiator• Generate large amount of heat• Not too rapid or violent• Advantageous to leave a hot slag• Chemically compatible• Not too sensitive• Output matches initiation requirements of

base charge


July 15, 2013


Pyrotechnic Delays Pyrotechnic Delay Rings in M54 Fuze

DELAYS Henry Shrapnel


July 15, 2013


Time-Delay Grenades Pyrotechnics

Heat Produced

FRH and MRE


July 15, 2013


Example of Thermite Reaction

2 Al + Fe2 O 3 → Al2 O 3 + 2 Fe

Pipe Recovery

Thermite Initiator Thermite Cutting Tool


July 15, 2013


AN-M14 TH3Incendiary Grenade

Hans Goldschmidt

Disadvantages of Thermite Reactions

• Difficult to Start (magnesium, glycerin/potassium permanganate)

• Must Be White Hot• Extremely High Temperatures• Keep Flammables Away!• Boiling Metals

Thermal Battery


July 15, 2013


Pyrotechnic Whistle Entschede – May 2000

Testing Explosives

Output TestsInput (Sensitivity) Tests

Ballistic Pendulum


July 15, 2013


Input (Sensitivity) Tests

• Quantal Response• Important to know exactly how

sensitive• Powder tests (mfg and filling)• Charge Tests

Ball Drop Apparatus

Bureau of MinesBall-Drop Apparatus Die Cup


July 15, 2013


Drop Tester for Powder Friction Test Apparatus

Sliding Block Friction Apparatus Diagram ofFriction Pendulum Apparatus


July 15, 2013


BAM Friction Tester High Voltage Spark Tester

Large Scale ESD TesterSTANAG 4490, Mil-Std-1751A

SMALL SCALE ESD TESTERSTANAG 4490, MIL-STD-1751A


July 15, 2013


Nylon Washer Dimensions

Sample Preparation

Bullet Impact Test

Electroexplosives:Functioning, Reliability and Hazards

Accident PreventionPresented by Franklin Applied Physics, Inc.


July 15, 2013


• All commercial explosive materials are designed to detonate when supplied with a sufficient amount of initiating energy. Unfortunately, the explosive material cannot differentiate between inintiating energy purposely supplied and that accidaentally supplied. It is the responsibility of all persons who handle explosive materials to know and to follow all approved safety procedures.

• --from IME Do’s and Don’ts

Some causes of unintended initiation

• Fire • High temperature• Thunderstorms• Electromagnetic fields• Sparks• Static electricity• Current and voltage sources• Impact• HUMAN ERROR

Fire prevention• Good housekeeping• Avoid storing combustibles (paper, rags)• Avoid storing fuels• No smoking or open flames (heaters, burners, lighters)• Maintain electrical equipment and cords• Care with sources of heat• Fire extinguishers readily available (only to prevent

spread to area near explosives)

Thunderstorms

• Monitor weather conditions• Storm monitoring equipment or AM radio • 5 miles approach• Shut down operations and evacuate• Use single ground point for EED systems


July 15, 2013


Electromagnetic fields

• Twist and coil leadwires (small aperture)• Stay away from transmitters (even small

ones like cell phones)• Use RF protected devices (with ferrites,

coils, capacitors) – not all frequencies• Perform worst-case analysis and field

tests before use

Spark Prevention

• Use non-sparking tools (wood, bronze, lead, "K" Monel)

• Avoid metal work surfaces, floors, etc.• Well-maintained equipment• Some electric motors produce sparks• No flash bulbs or electronic flash• Prevent static electric sparks

Static electricity prevention

• Ground everything (and check frequently)• Avoid plastics• Avoid contact and separation processes• High humidity – above 55%• Non-static equipment & environment• Proper clothing• Use verified static-insensitive EEDs


July 15, 2013


Current sources

• Use only approved meters to measure resistance (less than 1 mA, or 10μA for carbon bridge)

• Consider all modes of initiation• AC sources• Batteries• Ground currents• Galvanic current

Human Error• Educate all workers• Always follow standard operating procedures exactly• Do not take shortcuts• Do not improvise• Know characteristics of what you are working with• Don’t assume one type of device can be handled the

same as another type• Know what to do in an emergency

Reckless Way to Open a Powder Keg

Miner with Torch on HatPouring Black Powder


July 15, 2013


Hazard Avoidance

• Mechanical shock• Heat

Electric WeldingHazards to EEDs

• Fire• Electromagnetic Radiation• Magnetic Field Coupling• Ground Currents

Circuit with Grounds Electric Welding Near Well


July 15, 2013


Recommendation

• Maintain 50-foot (15 meter) standoff distance.

AC Overhead Power Line

• Hazard to power line

• Hazard to blaster from electric shock

Non-Hazards

• Electromagnetic effects from AC power line

• EMP• Radioactivity

Non-Hazards

• Modern digital camera with automatic focus and built-in flash (but be careful of batteries)


July 15, 2013


Storage and Shipment•Receiving•Storage•Use•Shipment•Disposal

US Naval Ammunition DepotEast Camden, Arkansas

PEOPLE WHO CAN RECEIVE AND SHIP EXPLOSIVES

• “Responsible Person” –on license application

• “Employee Possessor” –separate application

Receiving Paperwork

• Log book• Unpack, saving

materials (photo)• Count• Box tag• Transaction log• Receiving report

• Waybill• EX letter• MSDS• Box card


July 15, 2013


Storage Paperwork

• Daily transaction summary• Update box card• Check locks weekly

Use Paperwork

• Magazine transaction log

Shipping Paperwork

• Log book• Shipping report• EX letter• Waybill• Labeling

Magazine Requirements• Separate magazines• Bullet-proofing• Security• Quantity-Distance• Recordkeeping• Housekeeping• License Display• Warning Sign – “Explosives: Keep Away”


July 15, 2013


Shipping Classification

Shipment• CFR 49• Proper Shipping Name, UN Number• Hazard Classification, Orange Label• 24-hour telephone number• Competent Authority, EX number• Certification – be careful what you sign!• Training every 3 years• Packaging• Vehicle Requirements – placard, inspection• Cost

IME SLP Titles


July 15, 2013


Shipping Papers•Proper Shipping Name, Hazard Class, UNxxxx, Packing Group

(Cartridges, power device, 1.3C, UN0276, Pkg Gp II

•n.o.s (not otherwise specified)

(Substances, explosive. n.o.s., 1.1D, UN0475, Pkg Gp II,

6573.3 propellant, 5808.17 propellant, mix)

•“EX” number for explosives

•24 hr phone (3E Company 1-800-451-8346)

•Quantity

•Package type

•Certification and signature

DOT-SP 8451 Shipping Container

DOT SP-8451 Labeling Related Reading

• Recommendations on the Transport of Dangerous Goods – Manual of Tests and Criteria. 1999. United Nations. ST/SG/AC.10/11/Rev.3.

• Institute of Makers of Explosives (IME). 1120 Nineteenth Street N.W., Suite 310, Washington, DC 20036-3605.


July 15, 2013


Disposal of life expired stocks – UK policy to return to UK everything except not safe

to move

Novobogdanovka, Ukraine, 2004

Chubs for Use in Disposal Munition with Chubs


July 15, 2013


Containment

HISTORY

694

Greek Fire

695

Congreve Rocket

696


July 15, 2013


History and Development ofMilitary Pyrotechnics

• Faber, Henry B. Military Pyrotechnics. Volume 1.Ordance Department, U.S. Army. Washington, DC, U.S.A. Government Printing Office (1919)

• “The first preparation for the work of the future is a knowledge of what has already been accomplished in the past. Pyrotechny is the art of fire, and its history began long ago.”

697

East London, 1917

698

Halifax, 1917

699

Picatinny Arsenal ExplosionSaturday, July 10, 1926

Cause: lightning1500 tons of explosive

700


July 15, 2013


1500 Feet from Blast

701

2200 Feet from Blast

702

Oppau, 1920, 4000 t fertilizer

703

Oppau

704


July 15, 2013


Bombay 1944

705

RAF Faulds, 1944, 3500 t

706

Blausee-Mithols, 1947, 3000 t

707

Texas City, 1947

708


July 15, 2013


Roseburg, Oregon

709

Roseburg, Oregon, U.S.A.1959

710

Finland, July 1999

711

Ejection-Seat Cook-offat China Lake

712


July 15, 2013


Nagoya, August 21, 2000

713

AZF Factory, Toulouse, 2001

714

Enschede, NetherlandsFireworks Explosion, May

200122 dead, 947 injured

(movie)

715

Saint Barbara –Sigfrido Martín Begué, 2003

716


July 15, 2013


Martyrdom of St. Barbara

717

RESOURCESSources of Information

InspirationEncouragement

Technical ReportsTests & Analyses

• Franklin Applied Physics, Inc. (1960 to present), www.franklinphysics.com

• National Technical Information Service (NTIS), www.ntis.gov

Newsletters, Journals


July 15, 2013


I.S.E.E. SYMPOSIAName Sponsor When

CAD/PAD TEW

NSWC Indian Head MayEven years

FreeMaryland

Disposal Conference

Swedish Combustion Institute

NovemberOdd years

In a castle

DoDESB U.S. Government Every August In a hot placeEnergetic Materials

Fraunhofer ICT Every June Karlsruhe, Germany

Explosives, Blasting

I.S.E.E. EveryFebruary

USA

HEMCE India NovemberOdd years

India

Int’l Pyro Seminar

Int’l Pyrotechnic Society Every June Location alternates

NTREM Univ. Pardubice Every April Czech Rep.

Proceedings, Printed, CD-ROM ENCYCLOPEDIA


July 15, 2013


AMC HANDBOOKS AMC-R 385-100 Safety Manual

DOD 4145 . 26 - M DOE M 440.1 - 1


July 15, 2013


DoD 6055.9 - STD

Engineering Standards BOOKS


July 15, 2013


G. S. Biasutti, History of Accidents in the Explosives Industry

CATALOGS, WEB SITES


July 15, 2013


FORENSIC INVESTIGATION

Reference:

• “Forensic Investigation of Explosions,” edited by Alexander Beveridge

• Taylor & Francis Ltd., London (1998).

• ISBN 0-7484-0565-8.


July 15, 2013


Chapters by Many Experts

• Military research establishments• National police forces• EOD (explosive ordnance disposal) units• Government aviation experts• Medical departments• Legal systems• Explosives manufacturers• Et cetera

Outline

• Basics of energetic materials – propellants and explosives

• Explosion process in detail – blast waves and their effects

• Detection of hidden explosives• How to gather evidence at the scene of an

explosion – aircraft – gas in buildings• Detailed laboratory methods to analyze

chemical & mechanical evidence

Outline -- Continued

• Medical pathology of human victims of an explosion -photographs, x-rays

• How to give evidence in a court of law

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