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TECHNICAL MEMORANDUM U83

SHAPED CHARGE SCALING

BY

OSCAR A. KLAMER

MARCH 1964

SUBMITTED BY APPROVED BY A /

E. SEEGEI Chief, Explosives Application Section

E. H. BUCHANAN Chief, Artillery Ammunition Laboratory

AMMUNITION ENGINEERING DIRECTORATE PICATINNY ARSENAL DOVER, NEW JERSEY

TABLE OF CONTENTS

Section

EXPLOSIVE PROPERTIES

CAVITY LINERS

CHARGE SHAPE AND SIZE

STANDOFF DISTANCE

CONE ANGLE

ALIGNMENT AND CHARGE INACCURACIES

CHARGE ROTATION

IMPACT ANGLE

CHARGE CONFINEMENT

GENERAL SCALING RELATIONS

REFERENCES

ABSTRACT DATA

TABLE OF DISTRIBUTION

Page

2

2

7

9

11

12

14

16

16

17

26

28

2^

U)

FOREWORD T , I

^flrfs memorandum was prepared to provide a brief unclassified presentation of basic concepts, elementary design criteria and scaling techniques for shaped charges. The information is intended for individuals with little or no background in this field of munitions to provide them with sufficient data to understand design require- ments for simple shaped charge items.

Recent literature in this field covers more advanced methods used to maintain or enhance shaped charge performance; however that information is classified and therefore not suitable for inclusion in this report.

Source materials for this memorandum have been obtained from textbooks, articles and various government publications and reports. These are listed on the "References" page.

(Ü)

SHAPED CHARGE SCALING

The design of shaped charge items is governed by two primary considerations -- the required target penetration and the allowable configuration permitted by the delivery technique to be used. The penetration characteristics have been studied extensively to establish the effects of explosive, explosive configuration, size, liner material and shape, orientation relative to the target, spin and symmetry.

The depth of primary penetration, P , depends upon the jet length, L, and the ratio of the jet density, JOJ to the target density, JO . Actually it is described more exactly as:

P'"LJ^- As ~^n be seen from this relationship, the strength of the

target material does not have any appreciable effect on the depth of primary penetration. Since the ultra-high velocity of the impinging jet develops pressures far in excess of target yield strengths, the jet and target act like incompressible fluids, and the target strength can be neglected.

The secondary penetration effect, produced by the lower velocity tail of the jet, does vary with target yield strength. Since the tail velocity will only impart pressures in the range of the yield strength of mild steel, the penetration into homogeneous armor is 10 to 15% less than mild steel.

Basically scaling of a shaped charge depends on the use of the appropriate materials, geometry, and spacing which will result in optimum values for jet length and density to match the target requirements.

Although maximum penetrations in mild steel of up to 12 cone diameters may be feasible, actual penetrations are limited to \ to 2/3 of that depth because optimum conditions are rarely possible under field conditions.

The critical factors, which control the jet properties and formation, will be discussed in terms of their affect on target penetration.

EXPLOSIVE PROPERTIES

The penetration of the jet has been shown to correlate with the explosive detonation pressure. Since the detonation pressure is related to the square of the detonation rate, it can be said t:hat the greatest effect will be produced by the explosive having the highest rate of detonation.

The following table relates the efficiency of four castable explosives:

TABLE (From Reference 8) Relative

Detonation Rate Penetration meters/sec Efficiency

CAVITY LINERS

A variety of liner geometries have been studied to determine the most desirable liner configuration. The investigations have included cones, hemispheres, cylinders, trumpet shapes, and various combinations of these. The effects achieved vary due to the way in which different shaped cavities react. For example, a conical liner collapses from the apex and leaves 70 to 30?« of the liner to follow the jet as a slug. On the other hand, hemispherical liners appear to turn inside out, and most of the liner is projected in the jet; however, rather large standoffs (3 to A cone diameters) are necessary for effective use.

Because of peretration characteristics, cones have become almost standard with other shapes used occasionally for special applications. Therefore, the remaining discussion will relate primarily to cone shaped liners and the effects of varying cone parameters.

In general the effectiveness of the cone shaped charge will be discussed in terms of the following dimensions:

Confining Cylinder

J d\ Ü2 A

^ . Charge / iL £ Cone, &

Detonator Axis

Figure 1

P - target penetration S - standoff distance L - charge length t - liner thickness

o( - cone apex angle 9 - target orientation angle d,- cone diameter &2~ charge diameter

Liner Mat-.erial

The material from which the liner is fabricated has a very marked effect on target penetration. The physical properties of the liner material, which are considered important, are the density, ductility and melting or boiling point. The liner density directly a££e;ts the jet density,ygj , which should be high for the greatest penetrations. f

It is thought that greater ductility, under high stress, will pro- ide improved performance because more material can be pulled from the base of the liner after collapse. This would result in reinforcing the tail end of the jet, thereby increasing the over-all penetrating power. The British have felt that relatively low boiling metals such as lead, tin, and cadmium would definitely melt and to a certain extent even vaporize during jet formation forming a more continuous jet.

-3-

The following Table 2 will demonstrate the effect of liner material on target penetration, using constant standoff, for cones of 90° apex angle and 1 mm liner thickness:

TABLE 2 (From Reference 8)

Approx. Sp. Gr. Hole Depth Hole Width Metal Group of Liner Metal mm mm

Copper and Copper Alloys 8.5 58 14 Deep driving sheet steel 7.7 55 15 Zinc 7.2 51 17 Sheet iron 7.8 47 16 Aluminum 2.7 29 23 Magnesium alloys 1.7 23 25

Several points should be noted from this data:

The depth of penetration is related to the specific gravity of the liner metal.

There is no appreciable difference in penetration using cones of metal within the same group -- copper and copper alloys.

As the depth of the hole decreased, the width of the cavity increased, so that the hole volume in all cases was practically unchanged.

These results were obtained for a particular set of conditions. The relative effectiveness of different metal con^p might be altered, if the conditions are changed.

Jet penetrations will be increased if the jet can lengthen appreciably before breaking up. This lengthening ability is governed to a great extent by the metallurgical properties of the jet. Aluminum and copper both have such superior characteristics. Therefore, a hign densify liner exhibiting these properties will be most effective for target penetrations. More specific effects of liner material on charge design will be covered under other discussions of parameters.

Liner Thickness

The optimum liner thickness will vary with the cone angle, charge confinement, and liner material as indicated in the following Figure 2 and 3:

-4-

- i

O 4

o z *. w a

OUNCONPINIO CHAHSC. I ■/• 01 AM

A "LICHT" CONFINEMENT. I ■ /•" I I «74* tTEEL

X "HEAVY" CONFINEMENT. I »/•" I t" STEIL

TAKEN MOM «Ef. IT

I I e.ei o.et «ALL TMICRNtSS (CONI DIAN.)

I 0.01

10 to

CONI WEICHT (Cd.)

SO 40

Figure 2. Depth of Penetration vs. Wall Thickness (Reproduced from Figure 5, Reference 3)

Figure 2 points up the possible need for slightly thicker liners as charge confinement is increased.

It has been concluded from various studies that optimum liner thickness for a given metal is proportional to the sine of one-half the cone apex angle; however, the relationship may be somewhat greater for cones more acute than 45°.

In Figure 3 the range of values indicated for each liner metal reflects those in conmon usage.

t * « • to

DENSITY (GNAMS/CC.)

12

Figure 3, Liner thickness versus density of liner Material showing the Range of values in Common usage. (From Figure 1 of Reference 18)

From this liner data, we can conclude that, in general, liner thickness for cones of various materials should be between 0.01 and 0.06 cone diameters. The optimum wall thickness for steel cones with various charge confinements (Figure 2) is also about right for 45° copper cones.

If one chooses the appropriate cone weight, confinement has no net effect upon the penetration. Other conditions being constant, increased liner thickness results in smaller diameter holes.

Non-uniform cone walls can be used to alter jet characteristics somewhat. Figure 4 summarizes some liner designs and the resultant cavity effects.

e.o«o o. Ili

0.IIO

»VEMSE CONE

*••"' O.llt" «ALL THICKNESS TOM UNIFORM 41 CONES OF SAME «El«NT.

0.00»* 0. HO* 0.110* 0.17$

Figure 4. Steel Target Penetration by 4-3/8" Diameter Steel Cones have Tapered Walls. Confinement 1/16"; stand-off, 6". (Reproduced from Figure 4, Reference 3.)

0.119

CHARGE SHAPE AND SIZB

The depth of penetration is a function of both the charge diameter and charge length; however, increasing charge length beyond three to five cone diameters does not significantly increase performance as indicated in Figure 5.

For 1-5/8" Steel Cones (44") at 3" standoff.

X o

< m <i »- - w a X

m k. < O X o X

I 1 * 4 ■ • CM AMI LINCTH . CONI 01A

Figure 5. Depth of Penetration vs. Charge Length (Reproduced from Figure 2, Reference 3)

The translated German documents indicate t! e following relationship for varying cone diameter at constant charge diameter.

100

§

u 4J

s 4! (X,

Cone Dia/Chg Dia 0.2 Cone Dla - mm 10

Figure 6. Depth of Penetration vs. Cone to Charge Diameter Ratio. (Taken from Figure 7 of Reference 16)

Utilization of the maximum cone diameter is apparent from Figure 6; however, for a fixed charged diameter beyond a certain cone size improvement does not continue because a minimum width of explosive layer is necessary, for the charge to function properly.

Another relationship found in the Ger/nan documents is the effect on penetration when varying charge diameter with constant cone diameter.

ion Curve for most favi irable lit 0

1 * C 0

•H 4J

t lickness

«

08 U *J V c <o cu

50

3

w u ij 0)

. 2 c 3

Chg Dia/Cone Dia 1.25 1.5 1.75 2.0 2.25 2.5 Charge Dia-mm 50 60 70 80 90 100

Figure 7. Effect of Charge to Cone Diameter Ratio on Charge Penetration . (From Figure 9 of Reference 16)

It should be noted from Figure 7, that a decrease in penetration effect takes place at constant cone diameter, with increasing charge diameter, despite the larger amount of explosive used. Tnis is explained by the fact that, at the larger charge diameters, the difference in particle velocities of the jet and the jet length decrease.

For reasonable charge designs, if the cone diameter is increased and the other dimensions of the charge and the standoff

8-

changed proportionally, a corresponding increase in target penetration will take place. Because such relationships exist, the various dimensions and the jet effect are usually described in terms of the equivalent number of cone diameters.

Other factois, which influence the cavity effect, are the booster size and external charge snap». The booster must be designed and placed such that the necessary detonation is produced.

The shaping of the charge in the booster region is important, as well as accurate axial symmetry. For example -- a charge type (a) below is capable of producing a jet of greater penetrating power per unit weight of explosive than a cylindrical charge (b) with a length greater than the maximum effective length, L.

«<2 Booster (a)

STANDOFF DISTANCE

Booster 00 2

The standoff distance at the time of functioning, to a large extent determines the effectiveness of the shaped charge. The minimum distance is governed by the space required for formation of the proper jet length before target attack. An excessive standoff distance, conversely, permits breakup of the jet before target penetration and consequently poorer performance. In the following Figure 8, it can be seen that target penetration will increase to a maximum generally between 0 and four cone diameters depending upon the apex angle.

CONC OIMMTIM

T 1114 I 1 »•' 1

0 •

« I M 5 • ■

■ Si m

M »- V «

/ V -^£4 £

•I /

• s X I

m

1 A 1

• > i i I 4 1

IN INC

1 1

Hit

1 •

Figure 8. Standoff vs. Penetration (Reproduced from Figure 6, Reference 3, for steel conical liners of 1-5/8" diameter and various apex angles.)

-9-

Liner material characteristics will also alter standoff requirements for constant cone dimensions as described in Figure 9.

. 8 I o HI X O 4

>sJ» 0

IS?«*

u * i*_" »TEEL X «° A«.«* IHU«

"-- z

z o

£ > m »- w X w

to 2

41° *lj«C

** _ii-

**•

O

X

•> w e

X

o e i t s t 1 1 7 1 •

ST AND.OFF IN CONI 01 AM.

Figure 9. Standoff vs. Penetration by Material (Reproduced from Figure 8, Reference 3.)

It is obvious from this data that aluminum's physical characteristics permit development of a longer jet, which requires standoffs which are abnormally large for many military applications. Most liner materials will provide maximum penetration at one to three cone diameters for 45° angle cones.

For underwater applications of shaped charges the standoff must be provided as an air space.

Figure 10 describes the relationship between the range in water and the air space for various angle cones of different materials that provide penetration of V mild steel targets.

-10-

X

I

i.o a.i i.o s.f «IH iPACC IM CONE 01AM.

Figure 10. Air Space vs. Range (Reproduced from Figure 9, Reference 3)

CONK ANGLE

The effect of cone angle on liner thickness requirement» has been discussed. Figure 11 describes the results contained in translated German documents. Penetration falls off with increasing cone angle using constant charge diameter, cone diameter and standoff.

200

o 100 ft 4J «a u u 8 at a*

Charge diitensions Charge dT Cone dii. Standoff Liner thifcknes

- 50mm - 40mm - 20mm

s- 2mm

Figure 11,

5

■ 4

■ 3

.. 2

.. 1

i-i 0)

0) c

40* 60* 89* 90* Cone Angle

Effect of Cone Angle on Penetration (From Figure 14 of Reference 16)

11-

In thiti presentation, optimum standoff was not used for the various cone angles tested. A family of curves, each describing penetration at a particular standoff, would be required to describe the effect of cone angle completely.

Available data from NAVORD Report 1248 (Reference 3) indicates similar curves at various standoff values. It should be noted that the curve is altered somewhat when the optimum standoff for each cone angle is used.

<0 40 •° ,0 '•« «10 »40 tli ^o

CONC ANCLE (DEC.)

Figure LI. Cone Angle vs. Penetration by Standoff. (Repro- duced from Figure 7, Reference 3.)

ALIGNMENT AND CHARGE INACCURACIES

Serious impairment of jet formation and subsequent penetration will result from any of the following:

Imperfections such as air bubbles near the base of the liner.

Misalignment of more than 0.5° between the cone and charge axes.

Cone elipticity of only 1.7% (107. drop in penetration).

Foreign objects inadvertently located in explosive caviry.

12-

The following data were obtained by deliberate misalignment of cone and charge axes or displacement of cone and charge axes:

TABLE 3 (Reference 9)

EFFECT OF AXES ALIGNMENT OF

l-5/8"-44* CONES ON PENETRATION

Angle Between Cone and Charge

Axes

0°

0.5°

1.0*

2.0'

4.0*

Penetration Depth Normal to Surface-Inches

6" Standoff

5.1

3.5 5.3

2.3 3.1 2.2 2.3

4.0 3.3 3.3

2.0 3.2 2.3

2" Standoff

4.9

4.5 3.3

13-

TABLE 4 (Reference 9)

EFFECT OF LATERAL CONE DISPLACEMENT ON

PENETRATION

Lateral Displacement

i

Penetration Depth Normal to Target of Cone Axis relative to Charge Axis

Surface-inches 6" Standoff 2" Standoff

0 4.5 3.7 4.2 3.9

1/64 3.4 —

2/64 3.0 3.7 2.9 2.9

5/64 1.9 2.3 i

7/64 1.5

9/64 2.1 2.1

CHARGE ROTATION

Tbi rotation imparted to shaped charges to insure projectile flight stability reduces the depth of jet penetration. The jet is subjected to the same centrifugal forces as the projectile, which results in reducing the density of the normally extremely small diameter jet. The diameter extension at two rotational speeds is shown in Figure 13. Thus the penetration efficiency may drop as much as 507. as seen from Figure 14.

-14-

18.- i

o ■

'8''

500 HPi

IO 12 14 It It 20 22 2« 26 3t

OISTANCE PROM TOP OF CONC ( CM )

JO 12 :u 16

Figure 13. Calculated profiles of the Jet at 50,«sec after the Detonation wave had passed the base of the liner a^d the equipment was rotating at 150 and 300 rps (From Figure 2 of Reference 19)

2 o-t

! i o.t

■

a *"^o.^

L a.

^^-^1

o —I 1 1—•—1—1—J... 1 1 1 L_^_. to IOO HO »OO ISO

«tVOU/TH,*» HER ttCOMO(RM)

too

Figure 14. Ratio of the depth of Penetration by Rotating Charge/depth of Penetration by unrotating Charges at 7.62 cm standoff distance in mild steel targets as a Function of the Speed of Rotation of the Standard M9A1 Steel Liner in r.ne Standard C.I.T. laboratory charge (From Figure 1 of Reference 19)

15-

This sensitivity to rotation points, up the need for a method of spin compensation or use of non-rotating fin-stabilized projectiles, such as the anti-tank rockets.

IMPACT ANGLE

The impact angle, 9, between the shaped charge axis and the target surface will also alter the penetration normal to the target surface. This can be described by the following relationship:

D = P sin 9

Where D =» effective penetration

P = depth of penetration of jet

9 = angle between target and charge axis

Beyond a certain impact angle the depth of penetration is markedly reduced and non-uniform from round to round. This variability is due primarily to fuze action.

The following ga-ioalizations can be made concerning impact angle:

The critical angle varies for different type of projectiles.

The critical angle is greater for rotating than for non-rotating projectiles.

The critical angle is greater for heavy projectiles than for light projectiles.

CHARCE CONFINEMENT

The effect of charge confinement on liner wall thickness has been described in Figure 2. In addition it can be said that increased confinement does increase the hole dian.eter and hole volume; however, the corresponding problem of shrapnel must be considered also.

In many instances the degree of charge confinement depends upon projectile requirements with some sacrifice of shaped charge performance. Excessive confinement is necessary in aicillery projectile« because of the severe setback and rotational forces encountered during firing. On the contrary, minimal confinement is generally usec in rocket warheads, where excess weight must be eliminated and launching requirements do not demand rugged construction.

-16-

GENERAL SCALING RELATIONS

As mentioned previously a linear relation exists for scaling charges of the same cone shape. Using this concept, penetration can be increased by increasing cone diameter, provided that the apex angle is held constant and the charge diameter, length and confinement; liner thickness, standoff; and booster dimensions are each increased linearly.

Such a homologous family of shaped charges, as indicated in the following Table 5 will produce scaled penetration depths at scaled standoff distances.

TABLE 5 (From Reference 6)

RELATIONSHIP OF CHARGE AND CONE DIMENSIONS FOR

42° COPPER CONES PROVIDING 6 CONE DIAMETERS OF

PENETRATION INTO MILD STEEL

i-

Dimensions Scale Size

2 3 4-4 Change

Standoff of 3 cone dia (in) Penetration & 6 cone dia(in) Cone diameter - inc ^s Cona wail thickne inches Theoretical Altitude Measured cone mass (gms) Charge length-inches Charge diameter-inches Charge casing wall thickness(in]

BooaterF"1*1 P*Uet dia_in* (Tatryl pellet length-in«

5.67 11.34 1.89 0.070 2.4618

82.53 3.271 1.892 0.237 0.683 0.455

8.505 17.010

2.835 0.105 3.6927

278.8 4.894 2.837 0.35''. 1.042 0.683

11.34 22.68 3.78 0.140 4.9236

662.9 6.525 3.782 0.472 1.378 0.912

1 2.835 5.670 0.945 0.035 1.2309

1.627 0.946 0.117

0.223

A number of aids for scaling shaped charges have been evolved based upon the relationships already discussed. These are presented for specific target materials and usually for particular types of cone metal.

-17-

The German documents established a form for scaling up a 40° angle conical shaped charge. By choosing a desired penetration, the standoff, charge diameter, cone diameter and liner thickness are specified.

100

50 100 150 200 Penetration Depth - mm

250

Figure 15. Design Graph for Scaling of 40° Conical Shaped Charges (From Figure 6 of Reference 16)

For example, if it is desired to penetrate 200mm with a 40° conical charge, the following cone dimensions should be used:

Charge diameter - 75mm

Cone diameter - 60mm

Liner Thickness - 3mm

Standoff 30mm

Another German scaling law for 30° cones was drawn up using the cone diameter for some relationships.

•18-

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-19-

A design nomograph for perforation of homogeneous armor has been developed from performance records of actual weapons. Included in this presentation are provisions for adjustment of penetration effects due to rotation and charge to target inclination.

I nti« Plea» tor Of liner At let«

•".in

-A. a

Thickness Perforated By

*••

■«■Oft IK «lit krnor

l.O- •

\ -».•

Con« Angle «, ttfrtti

m n IPJ»

-I.« I

I

■4.»

1.0

\ \

\

I.»

1.5

1.0

Mild Steal i *

1.0

-0.0

4.0

-•».0

7.0

4.0

i.O

ESTIMATED Accmucr t 2«

Thick neSS r>rfnr«tcd »r

t. I-

Hoaogenecuj ! Mi Id trmo' Steel

10.n.

'.0 dotation factor:

uit either

* V or Murjle Velocity

I «. fll t»c for rIf Iing with twist of I In I in 30: 32:^

o-r o —o^-

o « 4

»otetionel Speed, It. rit/lll , t laoa liaaar IMeawUr,

1- .o -p to.o .. r ••• }— 1.0 L. 7.0

l_ i.O

9

a.o 7.0

1.0

1.0'

K0-7 lib — 1100 joo^-noo— Jioo •f« --J000—»w

if cona a» • «alias in angle 6 with perpen- dicular to put«, atiltiply final thieknes« by tft« following factor:

^9 l»3 20 30° 1 »0° s°1 «(-co« e) 0.90 0.9". 0.87 | 0.77 O.SU

k.0

- ♦,«

' «.•

-I.o

X-L0 ■

— 1.1

».«."j-to.o M.I

ElAetUE: it nor««l Incidence, an NEAT lOJaa M67 having a «Mil« velocity of 9S0 jtli-.t and a twist of I in 20 »ill per- forat* about i ta of araor. «a ahoan by th« indei I in««. At 30«, the performance »ill 0« about S ■ 0.87 " «.3 in.

•UratMRCE OF •AITICUIM WAfO«:

•»•«•ft

•MO-

Thickness of Arawr m rVfe» «tad, («

faeraai laetdeace NEAT M6A3(8ciooka) 5.3 6renait« MUI 1.0 NEAT S7w T-20 E-2 5 MEAT 7OM Ml I.I HCAT lOfcea MA 7 «.1 •IAT l.i NEAT 1.7-lit i IIJM S.O fenierfeust (10. «0 A 100) 1.0 •anierichreck (Gar. latooks) I.I A.T. Conical Hand

S'anad« 2.1 i.t. ilfl« 6r«n«d« 1

Th« noaograa jives thickness of homogeneous araor perforated by Mgn roe /ete from con«-«nd hollow charge projected »eapont.The underlying «apincal eque tIcxt. deduced fro* performance record» on actual »«apons la

I • Js_ case find)

n»ll/j|

«riere tint) ■ 1.0, 0.69, 0.5 7, o.*8, for ia • 0, JOO.600.900 '■ *■'. < respect Iv«1/. Hit notation on ««•/'••• '

Factora auch «a thickness and tutorial of llrsjr, type and density of eiplo- a|y«, conflnoMnt of charge, stand-off distance, etc. are not Included in th« relation, although cnangat in these quantities «re reaponslble fo' soaw variation In observed results. Kith the empirical relation used, scatter In th« data precludes aaklng a distinction between dtps* «/ p«««trol m In mes- »iv« plat« end IIKIIIII of plate »Worai.d. Thus the present relation»ill bo useful In estimating performance of any »aapon deslgneo according torea- «otabla prsctlc«, but should b« considered a rough guide to b« us*d only In tf« absence of «iMriaantal data.

'laelc data «reaelnl/for projectiles having ateel liners end filled Cycle» tol or »entolite. Eiplosives combining high power »ith high rate of detona- tion glv« greatest target damage. Aa thv aquation above shows, rotated pro- J«etll«e generally for« shallower craters; however, these are likely to be »Ider than th« erster» du« to atatlc detonation.

Figure 17. Penetration of Homogeneous Armor by Weapons with Cone-End Charges (Reproduced from Figure 15 of Reference 3)

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For information and comparison with the data given for steel, some additional graphs follow, which present the penetrations into

concrete and permafrost.

«• DEPTH OF PENETRATION..«»«.

•O «0 TO #0 »0 WO «r « WEIGHT Of EXPLOSIVE ,»ww>.i

The graph shows dep t h of penetration produced in concrete by t cone-en« charge »laced Kith mi per- pendicular to the slab face. fhe «can line mi dtttrained by a leatt squares reduction; shaded band include* valuet 20% above and below aean.

lecauie of »cabbitg on r«ar face (*«• in»*t sketches) perforation often reaulti even when slab thick- nei» it great«' than the penetration depth that would result in aassive concrete.

TTPC OF E CPLOSIVt. Effect» ar* not greatly dependent on eiploiive type provide« charge is thoroughly

coapect and adequately priaed. »EST - TUT/ROI Plastic N.E. GOOD - Pentolite Nobel 80» POO« - 60/»0 Aattol

TpT/PfTN Cycloto! TPT Picric Acid P. A. «. THT/CC P.£. Lyddite Tetrytol

Dependence on ■«•«rial and thick'ie»« i» not great. »1ST - Pressed itoel. Forai It'ge «lug which aay itick in hole, etpecially if cone

angle i» lea» than about 70°; »ay thu» iopair insertion of draolition charge. GOOD - Clan. Hole toaewhat shsllower b-4 of larger voluae than .»ith steel, (.ass

debris is left in hole. Cast bras» and cast aanganess broni« also good. Various thicknesses used, £«periaents indicate opt lava valuaof about 0.1 inch (steel) >or a charge of »-inch diaaeter, and weighing appro«ioateIy 10 lbs.

CODE ANCLE: «ol eitreaely critical, but «0° te 10° usually adopted.

LEMeTN-eiAMCTE« «ATI 0: »slues »f »/» (»tt skotcho») between J and I are rteoaaondt*.

JTAND-OfF PI STANCE: The eptlaua itmf-.H, i. tpptan t. be between about i and li disasters.

In ggntral, slightly larger but »•« dttper holts reeelt In softer ccncrtto.

C0"( LIKING: Materials:

Thicknots :

CONCMTt STIEN8TN: PILLtOI TESTS: Tr i.l. indi cat. «hat a 7S- It. char«. .HI d.f.st a S-f t. thick pi II be ..I I and throw

teak capable o» Itth.l «r lattpteitat in» effect« on any occupants.

•am »»*• onmmn m »t latmtia MM* •»» tr »WTIM mmntn •#> »SPPP».»

Figure 18. Penetration of Concrete by Detonation of Cone- End Charges (Reproduced from Page 20 of Reference 3)

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