ad-a238 844

NAVSWC TR 91-102

AD-A238 844

A REEXAMINATION OF THE AIRBLAST ANDDEBRIS PRODUCED BY EXPLOSIONS INSIDEEARTH-COVERED IGLOOS

BY MAICHAEL M. SWISDAK, JR.

RESEARCH AND TECHNOLOGY DEPARTMENT

28 JANUARY 1991

Approved for public release; distribution is unlimited.

NAVAL SURFACE WARFARE CENTERS Dahlgren, Virginia 22448-5000 * Silver Spring, Maryland 20903-5000

DEFENSE TECHNICAL INFORMATION CENTER

9196501 ..,z ..

NAVSWCTR 91-102

A REEXAMINATION OF THE AIRBLAST ANDDEBRIS PRODUCED BY EXPLOSIONS

INSIDE EARTH-COVERED IGLOOS

BY MICHAEL M. SWISDAK, JR

RESEARCH AND TECHNOLOGY DEPARTMENT

28 JANUARY 1991

Approved for public release, distribution is unlimited

NAVAL SURFACE WARFARE CENTERDahlgren. Virginia 22448-5000 a Silver Spring. Maryland 20903-5000

F___

NAVSWC TR 91-102

FOREWORI)

This task was performed for the Department of Defense Explosives SafetyBoard (DDESB), Code KT, under the cognizance of Dr. J. M. Ward.

The mention of proprietary items or company names in this report is fortechnical information purposes only. No endorsement or criticism is intended.

Approved by:

WILLIAM H. BOHLI, HeadEnergetic Materials Division

iiii

NAVSWC TR 91-102

CONTENTS

Chapter Page

1 INTRODUCTION ........................................ 1-1

2 EVENTS CONSIDERED.................................. 2-1

3 DEBRIS/FRAGMENTATION ............................... 3-1DEFINITIONS AND CRITERIA .......................... 3-1ESKIMO I............................................ 3-1HASTINGS IGLOO.................................... 3-2

4 AIRBLAST .... 4-1DEFINITIONS AN D CRITERIA 4-1

5 DISCUSSION OF AIRBLAST RESULTS ...................... 5-1EQUIVALENT 'WEIGHT ................. 5-1GENERALIZED PREDICTIONS FO EKPRESSURE.... 5-2

REFERENCES .......................................... 6-1

DISTRIBUTION................ ......................... (1)

Appendix Page

A FRAGMENTATION/DEBRIS DATA ......................... A-1

B MIRBLAST DATA ....................................... B-1

NAVSWC TR 91-102

ILLUSTRATIONS

Figure Pg

3-1 ESKIMO I: HAZARDOUS FRAGMENT DENSITYVERSUS RANGE (FRONT) ............................... 3-3

3-2 ESKIMO I: HAZARDOUS FRAGMENT DENSITYVERSUS RANGE (SIDE) ................................. 3-3

3-3 ESKIMO I: HAZARDOUS FRAGMENT DENSITYVERSUS RANGE (REAR) ................................ 3-4

3-4 ESKIMO I: HAZARDOUS FRAGMENT DENSITYVERSUS RANGE (FRONT/SIDE DIAGONAL) ............. 3-4

3-5 ESKIMO I: HAZARDOUS FRAGMENT DENSITYVERSUS RANGE (REAR/SIDE DIAGONAL) ............... 3-5

3-6 HASTINGS IGLOO-60-POUND TEST HAZARDOUSFRAGMENT DENSITY VERSUS RANGE ................. 3-6

3-7 HASTINGS IGLOO-80-POUND TEST HAZARDOUSFRAGMENT DENSITY VERSUS RANGE .................. 3-6

3-8 HASTINGS IGLOO-100-POUND TEST HAZARDOUSFRAGMENT DENSITY VERSUS RANGE .................. 3-7

3-9 HASTINGS IGLOO-150-POUND TEST HAZARDOUSFRAGMENT DENSITY VERSUS RANGE ................. 3-7

4-1 NOTS 6: PRESSURE-DISTANCE DATA SCALED TOSEA LEVEL CONDITIONS ............................... 4-3

4-2 NOTS 6: IMPULSE-DISTANCE DATA SCALED TOSEA LEVEL CONDITIONS ............................... 4-3

4-3 ESKIMO I: PRESSURE-DISTANCE DATA SCALED TOSEA LEVEL CONDITIONS ............................... 4-4

4-4 ESKIMO I: IMPULSE-DISTANCE DATA SCALED TOSEA LEVEL CONDITIONS ............................... 4-4

yI St A T. V~A4-5 ~~AJOIL~-13AN -- CAalT'SEA LEVEL CONDITIONS ............................... 4-5

iv

NAVSWC TR 91-102

ILLUSTRATIONS

Figure Pg

4-6 ESKIMO IL: IMPULSE-DISTANCE DATA SCALED TOSEA LEVEL CONDITIONS ............................... 4-5

4-7 ESKIMO VI: PRESSURE-DISTANCE DATA SCALED TOSEA LEVEL CONDITIONS ............................... 4-

4-8 ESKIMO VI: IMPULSE-DISTANCE DATA SCALED TOSEA LEVEL CONDITIONS ............................... 4-6

4-9 BUFFERED STORAGE AND MODULAR IGLOO RESULTSPRESSURE-DISTANCE DATA-FRONT SCALED TOSEA LEVEL CONDITIONS ............................... 4-7

4-10 BUFFERED STORAGE AND MODULAR IGLOO RESULTSPRESSURE-DISTANCE DATA-SIDE SCALED TOSEA LEVEL CONDITIONS ............................... 4-7

5-1 SCALED PRESSURE-DISTANCE OUT FRONT OF IGLOO .... 5-3

5-2 SCALED IMPULSE-DISTANCE OUT FRONT OF IGLOO ...... 5-3

5-3 SCALED PRESSURE-DISTANCE OFF SIDE OF IGLOO ....... 5-4

5-4 SCALED POSITIVE IMPULSE OFF SIDE OF IGLOO .......... 5-4

5-5 SCALED PRESSURE-DISTANCE OUT REAR OF IGLOO ...... 5-5

5-6 SCALED IMPULSE-DISTANCE OUT REAR OF IGLOO ....... 5-5

5-7 SCALED PRESSURE-DISTANCE DATA (FRONT) ............ 5-6

5-8 SCALED PRESSURE-DISTANCE DATA (SIDE) ............... 5-6

5-9 IGLOO EQUIVALENT WEIGHT (FRONT) .................... 5-7

5-10 IGLOO EQUIVALENT WEIGHT (SIDE) ...................... 5-7

5-11 IGLOO EQUIVALENT WEIGHT (REAR) ..................... 5-7

5-12 COMPARISON OF UPPER BOUND ESKIMOPRESSURE-DISTANCE CURVES WITHHEMISPHERICAL STANDARD .......................... 5-8

5-13 COMPARISON OF UPPER BOUND ESKIMOIMPULSE-DISTANCE CURVES WITHHEMISPHERICAL STANDARD .......................... 5-8

5-14 COMPARISON OF UPPER BOUND COMPOSITEPRESSURE-DISTANCE CURVES WITHHEMISPHERICAL STANDARD .......................... 5-9

v

NAVSWC TR 91-102

TABLES

T able Page

2-1 EVENTS CONSIDERED FOR THIS STUDY .................. 2-2

4-1 KINGERY HEMISPHERICAL STANDARD ................... 4-8

4-2 LEAST SQUARES FIT COEFFICIENTS-PRESSURE-DISTANCE .................................. 4-9

4-3 MAGAZINE AIRBLAST DATA COMPARED TO STANDARD .. 4-10

5-1 LEAST SQUARES CURVE FIT COEFFICIENTS .............. 5-10

5-2 IGLOO EQUIVALENT WEIGHTS ............................ 5-11

5-3 UPPER BOUND 90 PERCENT CONFIDENCE INTERVAL ..... 5-12

5-4 COMPARISON OF STANDARD WITH UPPER BOUND OFPREDICTIONS .......................................... 5-13

vi

NAVSWC TR 91-102

CHAPTER 1

INTRODUCTION

At the request of the Department of Defense Explosies Safety Board (DDESB),the Naval Surface Warfare Center (NAVSWC) has conducted a review of theavailable airblast and fragmentation/debris information that was been produced byexplosions within standard earth-covered, explosive storage magazines. The effortbegan during the 1990 fiscal year with the collection and collation of the data.During the current fiscal year (1991), the data have been compared with existingDepartment of Defense (DOD) explosives safety standards. The goals of this effortare to recommend possible changes to the standard (if needed) and to provide the bestavailable prediction tools for both fragmentation/debris and airblast.

According to DOD-6055.9-STD, 1 standard earth-covered magazines areapproved for all quantities of explosives up to 500,000 pounds (227,273 kg) netexplosive weight. The standard defines five basic types of standard magazines:(1) reinforced concrete, arch-type magazines, (2) Navy-type magazines, (3) box-type Amagazines, (4) earth-covered, corrugated steel, arch-type, and (5) earth-covered,circular composite arch. During the past 40 + years of testing, most or all of thesetypes have been tested at one time or another. For the remainder of this report, theauthor will use the generic term "earth-covered igloo" when referring to all of thesetypes. The United States Air Force has conducted many tests in what they havetermed Modular or Hayman Igloos. These are also earth-covered but of a muchsimpler design. The data from these tests will be referred to as from "igloostructures" or from a modular igloo. The "igloo structures" have not been establishedas a standard type of magazine, therefore, they are only approved for storage up to250,000 pounds.

The earliest documented testing of earth-covered igloos occurred shortly afterWorld War 11.2.3 These tests were conducted at the Naval Proving Ground, Arco,Idaho. During the 1960s, tests were conducted at the Naval Ordnance Test Station(NOTS) (now, Naval Weapons Center, China Lake, CA).4 These tests examinedearth-covered, steel arch type magazine construction. Beginning in 1971, theDDESB began a series of tests call ESKIMO (ESKIMO is an acronym for ExplosiveSafety Knowledge IMprovement Operation).5 These tests have continuecFthrough1986 and constitute the source for the bulk of our knowledge regarding the blast andfragmentation/debris produced by explosions within these types of structures.'"' TheAir Force igloo structure and modular igloo data have only recently beenreported.12

1-1

NAVSWC TR 91-102

CHAPTER 2

EVENTS CONSIDERED

Table 2-1 presents a summary of the events considered for this analysis. Manyof them were not suitable for inclusion in the analyses that follow. The reasons forthis range from the type of event (models, external shots, etc.) to the type of datacollected (or not collected).

The ARCO tests3 did not collect or consider fragmentatiordebris data. Theairblast data were collected with paper and foil gauges. As a result, these events areof little primary use to this study. A collateral test series to the ARCO tests used aseries of scale models. 2 Again, the airblast was extremely crude and no debris datawere collected. Because of the small scales involved and the fact that the donorcharge was not scaled, these results are deemed inapplicable to the current study.

The NOTS Test Series4 used a series of scale models to study the behavior ofearth-covered, steel-arch magazines. Again, the scale was small and the donorcharges were not scaled. As can be seen in the data comparison section, these eventsobviously constitute a different data set than the remainder of the igloo tests. One ofthe NOTS tests, NOTS 6, was a full-scale test and these results seem to belong to thesame data set as the remainder of the full-scale igloo tests.

There have been seven ESKIMO tests since the start of that test series in1971.-11 Of the seven, however, only three are applicable to this effort-ESKIMO I,ESKIMO I, and ESKIMO VI. The remainder did not have a donor chargedetonating inside a magazine; rather, they were designed to study other aspects ofigloo construction and safety.

In 1984, the U.S. Army conducted a series of tests to examine the minimumcharge weight that could be contained within standard igloos. 1 7 Because of thenature of the tests, the charge weights and the loading densities were very low. Thecharge weights ranged from 12 to 150 pounds of TNT. In addition, there was a blastshield directly opposite the front door. Only limited low pressure (less than 2 psi)airblast data were recorded. Debris densities as a function of range and azimuth outthe front were also recorded. Because of the nature of these events, the airblast datawill not be considered in the general data base, but will be compared with thepredictive methods derived in this study.

As part of the Air Force Buffered Storage Program, several tesL were conductedinside both simulated and actual earth-covered igloos. The following criteria wereapplied to these tests in selecting which data to include in this study: (1) the NetExplosive Weight (NEW) had to be known; i.e., either the accepLor stack did notdetonate (NEW = donor stack) or the acceptor detonated totally (NEW = donor plusacceptor) and (2) the structure had to have earth cover.

2-1

NAVSWC TR 91-102

TABLE 2-I. EVENTS CONSIDERD FOR THIS STUDY

EVENT NAME DATE DONOR MAGAZINE TYPE CHARGE SIZE/TYPE COMMENTS REFERENE

ARCO i 11/1WO EarfI,-mvered. 930 MK 36 1000-poind bombs~ (1) crude urtol. ASESB To 5

1*11 10t09i onrete arch (500.340 pounds TNT) (2) ro debrisam

ARCO 2 111/8/48 Earth.oovered. 930 MK 36 1 000-pouncl bombs (1) olude seoitreinforced concrete arch (500,340 pounds TNT) (2) ro ders deft

ARCO I 1 &~840 Eaflh-covsrsd. 485 MK 36 1 000-poundl bor-be (1) crude akbinatreiioroad concrete arch (250,110 pounds TNT) (2) no debris da

___________ ______________(3) doub ath c51 oer ______

NOTS 1 1/11712 Eaflh-overed. a AN-m-GA 500-pound bombs (I) model lost WGTS TP SW4steel arch (2.424 pounds TNT equivalent) (2) Ist- debris data

NOTS 2 4/"/2 Earth-cvred. 9 MK 54 350-pound depth bomb (1, model eststeel arch (2.611 pounds TNT equivalet) (2) litl debris did&

NOTSB 12/1183 Earth-oovered. 2106 calsof Composition 1 (1)fll scale_________________steel arch 0 111.039 82unds TNT souslNvJ* f2l litle debri do& __________

ESKIMO 1 12/8/71 Earth-covered, 13.696 155mmiir TNT-oidd projeciles (1) debris data NWC TP 5430________steel sarc, (200,000 pounds TNT) (2) good airfbiit daa

ESKIMOI 11 /622r73 Open revstrent 72 M117 bomrbs (1) Not psicibs NWC TP $567(24,000_pounldsTNT eculvalent) __________ _________

ESKIMO III 6/12f74 Eaflh-covered, 916 M117 bombs (1) srbitaldue NWC TP 5771____________ steel arch (374,406 pounds TNT oufirslsntl 12) no debr ils _________

ESK(IMO IV Sep-75 Oen, hosttpher"oa 4.62S blocks of TNT (1) Not applicable NWC TP 5873wtlei (37,000 pounds TNT)

ESKIMO V Aug-77 Oen, hemispfsrtci 9,376j blocks of TNT (1) Not apkicls NWC TP 5873____________stack (n______00_ pounds_______

ESKIMO VI 7/2&W8 mass propaflaugeomeLry 60 MK It torpeo watsaftad (1) 1/2-scale model ?ICEI TR-889of earth-coversd Tp lID (51.300 pounds TNT equioslert (2) alrtlat data

ESKIMO VII-IIA roof 9/545 FOAMHEST Pttmacord (1) Not appiabe NCEL TM 51 -8-26

ESKIMOVII-118 doors W11,85 Open, hemisphera 1.702 bodra of TNT ;(1) Not applihcabet0i 13.816 punds I

HASTINGS IGLOO 1984 Earth-Wooesd. 8-pound TNT blocks (1) Law Io~ng doerliss ARBRL-0336reinforced conrete arch 12-150 pounds of TNT (2) aitlst doea

_____________ ____________________ (3) debris data

MKI%7-1 2/5/117 Esflfl-owvred 180 MK82 bomrbs (t) No debris MMW-TR-87-C77885AIghObwlret (36,600 pounds TNT equivalent) (2) Ittpulse krcomrac

MK82-2 507/8 7 Earth-oovsred 2701V "12bombs (1) Nodebris MMrW-TR-87-C785AVloo-brarnref (54.890 pounds TNT equivalent) (2) Impule WIWTT5C

MI(82-3 11/4/87 Eanr-oovered 312 MKI2 bombs, (1) Nodebris MMW-TR.87-C7786SAIgloo-bunkr (63,430 pounds TNT equivalent (2) Imlseb Incr~rect

MX82-4 12118/87 Esnfs-ooverod 312 MK92 bombs (t)Nodebris MMW-TR47-C77965Aloloo-bunlrer 183,430 Eounds TNT equlvalent) (21 isqus innWl _ _______

MK84-13 8129/86 Earth-Covered 128 MK64 bombs (1) No debris MMW-TR-87-60102ACreinforced concrete arch (129,430 pounds TNT equfvient( (2) Impulse incorrect

MK84-15 11/14186 Earth-covered 96 MK94 bombs (1) No debris MMW-TF-87-60l02ACigloo bunker (96.620 pounce TNT 9qulveient) (2) Impulse inoorreci

MK84-1 7 6124"7 Earlh-coversd 48 MK84 bombs (1 (No debris MMW-TR-87-501 O2ACigloo bunker (48.535 pounds TNT equtvalent) (2) Impulse Incoffor

MK(84-18 a/12187 Eshth-cWvored 64 MK64bombs (1) No debris MMW TR-B7-501O2ACIgloo bunker (64.714 pounds TNT oquivaisnl) (2) Impulse inoorricl

MKB4-19 9/23/87 Earth-covered 64 MK14 bombs (1) Wo debnt MMW-TR-87-5')102,AC

_________________igloo bunker (64,714 pounds TNT equlva,*nl (21 Impue 9 ncorrd ___________

MODULAR IGLOO 11/18/88 Eaulh-Coyved 450.450 pounds Flake Compoitr, B (1) No debris MMW-TR-7I002ACHayman iIgloo (500.000 pounds TNT epuiair) (12) Inods irrnct

2-2

NAVSWC TR 91-102

CHAPTER3

DEBRIS/FRAGMENTATI ON

Only three events collected debris information that might be considered useful-ESKIMO I, ESKIMO VI, and HASTINGS IGLOO. Of these three, the ESKIMO Ievent collected detailed fragmentation/debris data over a full 3600 azimuth. All thedebris information collected is presented in Appendix A. ESKIMO VI presented onlydescriptive information, so no quantitative detei-,ninations can be drawn from it.

DEFINITIONS AND CRITERI.

The DDESB defines a hazardous fragment density as "A density of hazardousfragments exceeding one per 600 sq ft. (55.7 m2 )."' 1 A hazardous fragment is definedas "one having an impact energy of 58 ft-lb (79 Joules) or greater." Recentinterpretations by the Secretariat of the DDESB h've taken the 600 ft' to bemeasured trajectory-normal as opposed to ground surface pickup. Procedures for thestandardization of the analyses of debris have also been p-oduced.18 Thesestandardized procedures have been used to reexamine the aebris data collected onboth FSKIMO I and the HASTINGS IGLOO tests.

ESKIMO I

Both magnetic and hand pickup were used on this test. Three 5' sectors (off thefront, side, and rear of the structure) were burveyed in and clea ed if vegetation anddebris before the test. These sectors were collected by magnetic pickup. In addition,foot search and hand pickup were conducted in selected 100 ft x 100 ft areas. Theseadditional areas were selected to supplement the data derived from the magneticpickup as well as to extend the collection areas into locations not accessible to thetruck-mounted magnet. For this test, calculations indicated that for a free-fallingfragment or piece of debris to be hazardous, it would have to have a weight of at least0.28 pound.

The data were presented in graphs in terms of debris densities as a function ofrange for various debris weights (_>0.125 pound, _ 0.28 pound, _> 1.0 pound). For thisanalysis, the density-range data were read off the graphs for the ->0.2S poundinformation. These data were then converted to pseudo-trajectory normal de: sitiesand analyzed according to the procedures of Reference 18. Figures 3-1 through 3-5present the results. Reiiiember that the hazardous fragment range is the range atwhich a lez.,. squares exponential fit through the pseudo-trajectory normal datareaches a value of 1. Also shown on each graph is the 90 percent confidence intervalfot the hazardous debris range.

3-1

NAVSWC TR 91-102

Thus, out the front of the igloo on this test the hazardous fragment range N.as3857 feet; off the side it was 2743 feet; o ,the rear it was 2376 feet. These correspondto scaled ranges of 66.0, 46.9, and 40.6 ft/lb 3, i espectively.

HASTINGS IGLOO

Significant debris data were collected on. 3ur of the HASTINGS IGLOO testy,the 69-, 80-, 100-, and 150-pound tests. Fragment density distributions at distancesless than 175 feet (53 meters) were not used due to the masking effect of a blast shieldin front of the structure.

It is probably appropriate to describe the test structures before the results arepresented. Th -_ site was part of an abandoned Navy Ammunition Depot that wasconstructed during World War II. All of the igloos exhibited structural failures in theform of hairline cracks in the sidewalls, arch crest, backwall, and headwall. Erosionof the earth cover was observed ir many cases due to a lack of maintenance. Themagazine headwalls faced an earth-backed concrete blast shield. I ne distancebetween the vet-t.ical he'idwalls and the blast shields varied between 12 feet at thebase and 15 feet at the top.

The debris results are summarized in Figures 3-6 to 3-9. On each test, debriswas collected .n three separa+e zones: 0' to 50, 5' to 100, and 100 to 45' . The hazardoufragment range (i.e., the range at which the hazardous fragment density becomes 1)extended to significant scaled distances out the front. The unscaled ranges are shownon each graph. In addition, the 90 percent confidence interval is shown for each of theranges. These ranges correspond to scaled distances of 112.9, 143.7, 103.0, and150.2 ftllb"r3 . These scaled ranges are much greater that those measured onESKIMO I. They may be affected b, the poor condition of the structures existing atthe time of the test. Moreover, the loading densities (charge weight/internal volumeof structure) used on these tests were quite low; thus, the roof and sides of thestructure did not fail-channeling the debris out the front. The range of hazardousfragme.its is less than 670 feet for less than 100 pounds and the maximum range isless than 700 feet for 150 pounds.

3-2

NAVSWC TR 91-102

1000 -D=415 48 *exp (-0.0015632*R)

< Correlation Coefficient 0.9805

~Lju

-) <Q0 COFDEC INEVL3800-3f

00

ZQLL C

(n FRAGMENT HAZARD RANGE 3a27 feeta. < ~ 90/ CONFIDENCE INTERVAL. 23 t-2895 ft0

0.1

500 1000 1500 2000 2500 3000 3500 40

RANGE, R (feet)

FIGURE 3-2 ESKIMO I: HAZARDOUS FRAGMENT D)ENSITY VERSUS RANGE (SIONE)

1 0 0.. .. ... .. . . . ... .. . .. 3...3

NAVSWC TR 91-102

100 1

AD = 315.90 *exp (-0.0025126-R)Correlation Coefficient: 0.9387

wOL

............. FR A G M EN H A ZA RD R A N GE.. 230... feet............... ..................................

0 Z 10- 920 x -. 0464R

0

o a: FRAGMENT HAZARD RANGE -283 feetW 90% CONFIDENCE INTERVAL: 2750 11-240 ftI

20 000 2500 000 50 300

RANGE, R (feet)

FIGURE 3-. ESKIMO 1: HAZARDOUS FRAGMENT DENSITY VERSUS RANGE ER

(FON/SD DIAGONAL

3-4

NAVSWC TR 91-102

D D1170500 exp (-0.0069142*R)A Correlation Coefficient: 0.9522

0 N

A

FIUR 3-5 ECIOIL-IZROJ FRAGMENT DENITAVESU RANGE=201fe73 < cr (REAROIDE IAGONVAL) 5f-7Il

cc 3-5

NAVSWC TR 91-102

10 0 .. ...............................- ......... ...

............ ; ........................ HA7ARDOUS FRN3MENT RANGES:

<-j 5-10* 406 ft (393It - 418 ft)zl A ........... .... 1OG-45o: 364 ft (349 ft -3W f)

0 1 NOTE: (represents 90% confidence interval

0.1 0 10 0 0 0 0...... .......... ......... ... ... ......... .....A.........E........... .....)..

0 2 ~ ~ IG R 3-........... HASTINGS.... . G......UND S HAZARDOUS............................... ...............FRGETDEST5ERU AG

...... ...........

........ .... ..............0 0.............................. ..............

0 0-5 -y=157e(0.01798x) R= 0.92974

0.1-0-100-200--00-400.500 . 60RANGE... ..........t.......

FIGURE~~~...... 3-..AS.NS.........I ES HZAI)UFRAGMEN y )NST VE88e^.1 45)RU RANGE........ .................

3 -.... .......... ........

NAVSWC TR 91-102

........................HAKZARDOUS FRAGMENT RANGES:0-5: 457 ft (434 ft -479 ft)

Fn 10 . .. ... 5-10': 434 ft (419 ft.-450 ft)

z ........0 ... ...... .......................... :.IIIz......

Z£' ... ........... =.J 449.. ......01 x .. 0..4.... ..

0*

LL .:::: -510-.- .... 717.99...... e(00 13 x R= .9 5 : .............. ............ ... .. .. . ... ..... .....I- ---- -- .. .. .

.......... .... ...... ...... 17 . 7 A . ........ 8..... Rb . 97538... .. -------- ..................

60 -I

C2 ..................CCA090_ 44.9::::.91~. NOT ()repesen 90%8x R-ic 0.90471

.... ... ... ...--- --- ---......... ...

............... .. ... .. .. ........... .........

1 . £ 05 - y 17495.78 eA(0.0108683x) R 0.953829 ........................o sio- y=361.............0..............5......

0.1 *

0 100 200 300 400 50060 70 80

FIGURE 3-9. HIASTINGS IGLOO-I150-POUND TEST HIAZARDOUSFRAGMENT DENSITY VERSUS RANGE

NAVSWC TR 91-102

CHAPTER 4

AIRBLAST

Airblast information has been collected on almost all of these events.Unfortunately, the coverage has been somewhat spotty. Moreover, the quality of thefar-field data (below 10 psi) has ranged from barely adequate to totally lacking. All ofthe airblast data that has been obtained is presented in tabular form in Appendix B.Only the following events will be analyzed in detail: NOTS 6, ESKIMO I,ESKIMO ITm, and ESKIMO VI.

DEFINITIONS AND CRITERIA

DOD 6055.9-STD' and NATO guidelines define several acceptable exposureswhich might be applied to aboveground magazines. These are:

1. Permissible exposure to airblast overpressure-barricading required: 9W""3

(11.7 psi)

2. Unbarricaded aboveground magazine distance: 11W"3 (8.0 psi)

3. Unbarricaded intraline distance: 18W"3 (3.5 psi)

4. NATO Workshop distance: 20W11 (3.0 psi)

5. Public Traffic Route Distance-W < 100,000 pounds: 24W 13 (2.3 psi)

6. Inhabited Building Distance-Rear of earth covered magazine-W< 100,000 pounds: 25W" ( 2.2 psi)

7. Public Traffic Route Distance-W>250,000 pounds: 30W" 3 (1.7 psi)

8. Inhabited Building Distance-Front and Side of earth covered magazine-

W<100,000 pounds: 35W"3 ( 1.4 psi)

9. NATO Public Traffic Route: 37.5W"3 (1.3 psi)

10. Inhabited Building Distance-W<100,000 pounds: 40W 13 (1.2 psi)

11. Inhabited Building Distance-W>250,000 pounds: 50W"3 (0.9 psi)

12. NATO Inhabited Building Distance: 58.7W"1 3 (0.725 psi or 50 mbar)

13. NATO Twice Inhabited Building Distance: 115W"/3 (0.29 psi or 20 mbar)

4-1

NAVSWC TR 91-102

The scaled distances which these criteria refer to are directly related to peakoverpressure. The relationship is based on the Kingery compilation of surface burst,hemispherical TNT data, 19,20 referred to hereafter as the Kingery TNT standard.Table 4-1 presents an excerpt of the data contained in this standard. This will formthe basis for all the airblast comparisons that will be performed later.

Figures 4-1 through 4-8 present the airblast results measured on the followingevents: NOTS 6, ESKIMO I, ESKIMO III, and ESKIMO VI. The data presented inAppendix B have been scaled to sea level conditions for each event. In addition, thecurve marked standard on each graph is the Kingery hemispherical standard curvefor the TNT weight of the event. Least square curves have been fitted to each of thesedata sets, so that the ranges to various pressure levels can be computed. This curvefit information is presented in Table 4-2.

The Air Force simulated igloo (buffered storage) and modular igloo data arebeing considered separately since they do not represent an, as yet, approvedmagazine design. This data is also presented in Appendix B. There seems to be aproblem with the impulse information. For this reason, none of these data will beanalyzed or discussed further.

Instead of discussing each test within the buffered storage and modular igloodata sets, the Appendix B information has been scaled to sea level conditions and to acharge weight of 1 pound. These results are presented in Figures 4-9 and 4-10 for thefront and side directions. Also shown on each graph is the Kingery hemisphericalstandard. Least square curves have also been fitted to this data set so that the rangesto various pressure levels can be computed. This information is presented inTable 4-2.

Using the information presented in Table 4-2, ranges and pressures can becalculated for each of the potential criteria presented above. This will then allowdirect comparison for each of the standards. These results are presented in Table 4-3.Only the data for ESKIMO VI show any violation of the criteria. In this case, thenumbers are so close to the standard that there is no statistical difference betweenthe least square curve fit value and the standard itself. Thus, based on thisinformation, the standard appears to be safety conservative.

4-2

NAVSWC TR 91-102

............. ................... ...... ----........ . ................ ...... ................. FRONT

3 OSIDE

10 ......... A REAR

U -STANDARD

. . . . .. .. .. . . . . . ... . .. .. .. ... . . .. . . . .. . . . .... .. . . .. . { .. .. .. .

U--A

0.2...............................

20 10

.. 0... ... .... ... & . .. .... .... D.. ... ..

NOTE:~ STANDARDEI BSDON11,3 OUD O N.................. ............ . . . . . ... 0. .... ---- ..

0010014

50........ ........ ... ... ..........-............. R N

4 ~ ~ ~ ~~ w 4 4 0 <

4 ... .. . .. .. . . .. .... .. .. ... . .. . . . .. .. . . .. .. . ......

NOTESTADAR CUVE S BSEDON 11.39TOUNSDOATN

4-A

NAVSWC TR 91-102

50 ! f t I . . .

0OFRONT

. .. ..... ....... ----.. . 4. .4.............. ... ...

o SIDEQ

10.. .:::::::::: A 7 REAR.... . ..... .. .. ...

............. ---- A ... i- ...............i.....

0

LU.. .. .. .. .........:: ......... ............... ... ...... ... .. ... .4.. ...

r. ..... . . ..... . ..................... 4

0 5 ..............- ....... . .....- ----

NOTE: STANDARD CURVE IS BASED ON 200 COO POUNDS OF TNT

...... .. .... ...... . . . . . I ............. ....f.......... ..............

200 1000.14

RANGE (feet)

FIGURE 4-3. ESKIMO 1: PRESSURE-DISTANCE DATA SCALED TO SEA LEVEL CONDITIONS

1000 ! ! !

. . . o FRONT

Q

E~ o. REAR

LU .....- STANDARD

w~ a.._. . . . . . .. . .. . . . . .. . . .. . . .. .. .. . .. . ... . . . -

LU> A: 0

C,,0

100 .. . .

NOESTAND'ARD'CU'RVE'lS *BASED ON 200,000 POUNDS OF TNT.. ... . .. - --...... ......

504200 1000 1

RANGE (feet)

FIGURE 4-4. ESKIMO I: IMPU LSE- DISTANCE DATA SCALED TO SEA LEVEL CONDITIONS

4-4

NAVSWC TR 9 1-102

oSIDE

10 ................. ~ .. ... ................. REAR

LUJ

.......1 ..... .....: ........---........ ......0 5... ..... ..7........ . ............. ..............

NOESADR UV SBSD N3446PUD FTT .

20 100.....0...... ... .. .. .... ........ ....... ..... ... ... ...

1000.... ........::: ..SIDE

...........E .. ...... .............. ..........

-JJ

0010014

RAG (et

FIUR 4-.EKMGl.PESR-ITNEDT CLDT E EE

CODTIN

10 ...... ...... .... . . .. . .. . . ............... ........ 0 S I E.

200............. 1000..'r A G ( ........... *..fe t

FIGURE~~~~~....... ....6... ES7M ...I.LE-ITNEDAASAE T E EELCNiN

7:..... rT 7 47 - 5----* ..... * ...

NAVSWC TR 91-102

50

0SIDE

10Ew.............. ............... ....... .... ... ........... STEANDARD

............ .......... ....... ...... ..... .................... ......... .... ... .... ........ .. ....... ...

wu ............. ........ ...... .... ...... .... ......

NOTE~~~ STDR CUV IS -AE ONNDR ------ -ONSO N

0110 1000................... ..... ..... .. ..... .........

......... RANGE (feet)....FI UR 4-7...... ESKIMO..... .......I...... PR S UR.IS A CE D TA S AL D TO S A .E E

C O N D ITIO NS.... ............................. ....................

........000...... ..... .....

............ o .... ...... O.......N T .......................... S....... ......... ... ....I E .... ...

U)....... ........ ..... ............ ..............

0 a

0.1

1100 1000 5000

RANGE (feet)

FIGURE 4- . ESKIMO VI: PRSSUR-ISTANCE DATA SCALED TO SEA LEVEL NIIIN

CONDIT4O6

NAVSWC TR 91-102

20 -- 0~-u MK84-15 FRONT-COVER

13 MK84-17-FRONT-COVER

10 ..... *... ... .................................... MK84-18-FRONT-COVER

X MK84-19-FRONT-COVER

~ . . £ MK84-13-SIDE-;GLOO

LUT

...... 2............ ......... ....... .*.... MK82-4 FRONT

0 0 * MK812-2 FRONT

1 - £ MK2FRONT

0.7 ----- * ~MODAR GO-R

5 7 10 20 3~050STMAJ.~ ~ ~ ~ ~ S A E R A N GE.. ..... (....f...t..../...... ....................... b................ .. .........&)a - R N

......4... BUFFERED.. STORAGE AND.. MODULAR ........... OO..... RESULTS... PRESSURE-DISTANCE------ .... ----

5l 7 02 05

20 -r- 0 MK 84-15-SIDE -COVER

13 MK417SD -COVE

CL X MK84-193 SIDE -IGOOE

7)i 0 MK82-13 SIDE-CO

LL* MKa2-3 SIDE

o *~ 0 MK82-3 SIDE

1 - --. £ MK82-2 SIDE

07......... ............ ...... - MODULAR IGLOO SIDE

0.5 A

5 7 10 20 30 50

SCALED RANGE (ft/b 1/3

FIGURE 4-10. BUFFERED STORAGE ANDI MOD)ULAR IGLOO RESU LTS PRESSURE-

DISTANCE DATA-SI DE SCALED) TO SEA LEVEL CON I)ITIONS

4-7

NAVSWC TR 91-102

TABLE 4-1. KINGERY HEMISPHERICAL STANDARD

SCALED DISTANCE PEAK PRESSURE POSITIVE IMPULSE(tt/b ^ 1 /3) ( si) -(p.!i-ms)Ib^ 1/3

6.0 27.74 12.737.0 19.78 11.078.0 14.92 9.849.0 11.75 8.8810.0 9.56 8.1011.0 8.00 7.45

12.0 6.83 6.9013.0 5.94 6.4214.0 5.23 6.0115.0 4.67 5.6416.0 4.21 5.3217.0 3.82 5.0318.0 3.50 4.77

19.0 3.22 4.5320.0 2.99 4.3121.0 2.78 4.1222.0 2.60 3.94

23.0 2.44 3.7724.0 2.30 3.6225.0 2.17 3.4826.0 2.06 3.3527.0 1.96 3.2328.0 1.86 3.1229.0 1.78 3.0230.0 1.70 2.9232.5 1.53 2.7035.0 1.39 2.5237.5 1.27 2.3540.0 1.18 2.2142.5 1.09 2.0945.0 1.01 1.9747.5 0.95 1.8750.0 0.89 1.7855.0 0.79 1.6260.0 0.71 1.4965.0 0.63 1.3870.0 0.57 1.2875.0 0.52 1.1980.0 0.48 1.1285.0 0.44 1.0590 0 040 0.99

105c 1 0.35 0.89110.0 0.30 0.81

120.0 0.27 0.74130.0 0.24 1 0 68

REFERENCES:(1) ARBRL-TR-02555

(2) BRL Repor 4344

4-8

NAVSWC TR 91-102

TABLE 4-2. LEAST SQUARES FiT CCEFFICIENTS-PRESSURE- DISTANCE

EVENT DIRECTION A B CORRELATIONCOEFFICIENT

NOTS 6 FRONT 98,21 -1.5264 0.9882SIDE 9,033 -1.2120 0.9643REAR 80,640 -1.5793 0.9996

ESKIMO I FRONT 81,631 -1.4742 0.9970SIDE 10004 -1.1856 0.9985REAR 26,789 -1.3466 0.9917

ESKIMO III FRONT 1,492,300 -1.8279 0.9973SIDE 196,630 -1.5357 0.9947REAR 108,600 -1.5064 0.9822

ESKIMO 6 FRONT 3,402,700 -2.1452 0.9999SIDE 176,840 -1.7317 1.0000REAR 270,610 -1.8330 0.9990

BUFFERED STORAGE/ FRONT* 278.08 -1.5458 0.9874MODULAR IGLOO SIDE* 180.46 -1.3917 0.9885

NOTE: Fit is of the foim : P-A*RangeABScaled to 1 pound

4-9

NAVSWC TR 91-102

ww~~ ~ ~ ~ Tr IN G W W N M

CA0C, C mc wfC v~ mCi ~c y ol 0 Nr-NC' m C0 M m - q Cn to

cC Ic~ CC J~ ' m cv co c'C IV - 04Sf

CO cn V 1%dc NO f -e Ln 0~ cc to n0m w. O ONO CDCos

c; - co_ N-( L o R: 2 6_

(4 L I. 0- - m -C.d Co( Cn C o C

U).

0Z - n q-.. Q Ln 0 coc I- a)0-r -

22CM 4 n nt - m m Lo 0, RU

co tn~w -e u-4 C\n M %n ,

CD m N~- Do

0 Lo0 w0

5 4 I- a- Un r w 0 C ~ iCi

0) U)t U) Go C14

0m o ) N ) 0 O a) N -Ln1: wqC

E; V r 0 w w 0 074o-10 U

NAVSWC TR 91-102

CHAPTER 5

DISCUSSION OF AIRBLAST RESULTS

It would be extremely useful if the airblast data presented in the previouschapter could be collapsed into a set of curves representing the three directions (front,side, and rear) for all types of igloos. A basic approach would be to use cube-root orHopkinson-Cranz scaling. A basic assumption here, however, is that the amount ofearth cover and the type of construction are of secondary importance to thephenomena being considered (pressure and debris throw).

The information presented in the last chapter (both the igloo data and thebuffered storage/modular igloo) has been scaled by the cube root of the equivalentTNT charge weight. The results are presented in Figures 5-1 to 5-6 for theigloo/Eskimo data. When the buffered storage/modular igloo data are included, theresults are shown in Figures 5-7 and 5-8. Bad or erroneous data points have beeneliminated. Both sets of data (Eskimo and Buffered Storage/Modular Igloo) appear tobe from the same family. Least squares curves have been fit to each set of data,separately, as well as to the combined data. Shown on the figures are the results of apower law fit of the form:

F = A*XB

where:

F = either peak pressure (P) in psi or scaled positive impulse (I/W1"'3)in psi-ms/lb" 3

X = scaled distance (R/W 13 ) in ftllb"3

R = distance (feet)W = equivalent TNT charge weight (pounds)A,B,C = fitting coefficients.

A power law fit represents a straight line to the logarithms of the data. In addition tothis fit, a second order polynomial was also fit to the logarithms of the pressure-distance data. The form of this fit is shown below:

F = A*(B+ C * In())

The improvement in the correlation coefficient was, at best, marginal. Table 5-1presents a summary of all of the curve fitting coefficients.

EQUIVALENT WEIGHT

The definition of equivalent weight is the weight of a standard explosiverequired to produce a selected shock wave parameter of equal magnitude to thatproduced by a unit weight of the explosive in question. The standard which is used is

5-1

NAVSWC TR 91-102

the Kingery hemispherical TNT standard. 19 The selected shock wave parameters arepeak pressure and positive impulse.

Using the second order polynomial curve fit to the logarithms of the pressure-distance data and a power law fit to the impulse-distance data (Table 5-1),Figures 5-9 to 5-11 were generated. These are the equivalent weight versus pressurecurves for the three directions. The curves for the pressure and impulse outside adetonating earth-covered magazine are not parallel to the Kingery standard.Because of this, the equivalent weight varies with the range (pressure level). It isstill useful, however, to talk about an average equivalent weight. These arepresented in Table 5-2.

GENERALIZED PREDICTIONS FOR PEAK PRESSURE

The least squares curve fits presented in Table 5-1 can be used to makegeneralized predictions. However, because of the nature of the data and because thedata are coming from such varied sources, the upper bound of the 90 percentconfidence interval for a power law fit will be used. The equations of these upperbound curves are presented in Table 5-3. Figure 5-12 compares the 90 percent upperbound composite of the Eskimo pressure-distance data with the Kingery hemi-spherical standard. Figure 5-13 presents similar comparisons for positive impulse.Figure 5-14 presents comparisons based on a composite of the igloo and bufferedstorage/modular igloo data.

To be safety conservative, the upper bound of the 90 percent confidence intervalshould not exceed the values prescribed in the DOD standards and guidelines. Thiscomparison is presented in Table 5-4. As can be seen, only one of the values exceedthe standard-out the side at the 0.9 psi level for the Eskimo data. Because of thelimited amount of data out the side and rear, definitive conclusions cannot bereached. However, it appears that the standard is not met in the side direction at thelower pressure levels.

The limited amount of airblast data recorded on the HASTINGS IGLOO testsindicate pressures occurring at much shorter ranges than those given by thestandards-scaled distances between 11 and 31 ft/lWI, white the standard wouldindicate distances on the order of 40 or greater for the measured pressure levelsk1.2 psi).

5-2

NAVSWC TR 91-102

20i1.-y = 347.39 _(1 .6488) R= 0.98111

.) 5 ...... ..... . .. . ... . . . ....... .. . . . . . . . . . . .. ..........------- .........7 ...... ................ .......... * ... ......- . ......... ...

D 0

LLI A NOTS 6A

(L 1 . .. .SK.M..

.. 0 E S K IM O 31. ..................... ......... -- .....: -

..................... ........... .............. ........ A0.3 .....

A A A I . . ........ .. ... ... . . . . .. 1 * ...

0. 6 5 7 89 10 20 30 4050 60 80

SCALED RANGE (ft/lb"13)

FIGURE 5-1. SCALED PRESSURE-DISTANCE OUT FRONT OF IGLOO

10-y 58.166 xA(..0.95223) R= 0.99075

.7 ... .. ........ ... ... ..... ......... ... .... ............. ...... .......

7 ......................... .....

-- - - - ... ... ..... . .

Lii

> ~ 2 .. .........

a_ 0 SIM:

0...... -. .

W 1 *ESKIMO61

CL) combined .. .................. ...

0.7 4

0.5. 5 6 7 8 910 20 30 40 50 60 80

SCALED RANGE (ft/Ib" 3)

FIGURE 5-2. SCALED IMPULSE-DISTANCE OUT FRONT OF IGLOO

5-3

NAVSWC TR 91-102

10 ' -i --

.................. ..... +.....9 .242 6 R= 0.98916

3...................... .. .. ..

a:£ NOTS 6

< ~ ~ ESKIMO 10

0 ESKIMO3 0

1.. .................. ........ .......... .... ....

... ESKIM O 6 .. ............ . . .................... ... ...........

0.7 .... .........OM............E....

055 6 7 8 9 10 20 30 40 90 60 80

SCALED RANGE (ft/lb"3)

FIGURE 5-3. SCALED PRESSURE-DISTANCE OFF SIDE OF IGLOO

10 - : : : : ; T 7

........ ..................... .....- Y = 53.202 XA (-1 .004) R= 0.97316

........ ..... .... ..... ...........

A NOTS 6

Lu 2> ESKIMO 1 0:

I- A

0 ESKIMO 3 0

W* ESKIMO6 ...................

CD 0.7 - CO M BINED ...................... ......... a...... .......

0.51~* t-5 6 7 8 9 10 20 30 40 50 80

SCALED RANGE (ft/ib")

FIGURE 5-4. SCALED POSITIVE IMPULSE OFF SIDE OF IGLOO

5-4

NAVSWC TR 91-102

20 - - v--y 249.35 x(1.6901) R= 0.98825

7. .....L .. ... .. ............. ..L ........... ....... .....1 05. .... ........ .. .. ... .................. .............. .....

.. .... .... ............... .... .. ........ --- .....7LU...... ..... ......... .... .. ...................

L3~ 0 5 ....... L...... ..... ... ........ ........ .... ..... .. ....... .... .. .

.2 ...... -. c m n d *....... .................. -.... ........ .....

0.1 A ___________ 6 t

-. .. . . . . - .... 20.........69 A~. 75 )R=09

a- 1 ...... E-SI O 1 ......... ... ....... ....

L~ ....L .... ..... . -.. ...... .................1

_L ..... * ESKIMOl AtoL 2. ...... ...... .. ......

*ESKIMO 6

0.

5 6 7 8 910 20 30 40 50

SCALED RANGE (ft/1b "')

FIGURE 5-. SCALED IPRSUSE- DISTANCE OUT REAR OF IGLOO

0-

NAVSWC TR 91-102

20 Y T-y 271.62 xl(-1 .5434) R= 0.98078

10 c e. ............. ......---...-.---.-.-.4 .

7- - ----- -- .......... ---------.. ., . I. .. ....

U)A. 5. .

c)

2 . . ..L --- ---- .....,... ....

.. .0 .... ......... ...

COMBINED 0-------- 0- . . . . . .. . . .. . .

0 .7............. .. .

0 5 o ESKIMO/IGLOO DATA............ ................

SBUFFERED STORAGE/MODULAR IGLOO .............---------- ...

0.31 d I

5 7 10 20 30 50 70

SCALED DISTANCE (ft/1bl/ 3)

FIGURE 5-7. SCALED PRESSURE- DISTANCE DATA (FRONT)

20 --

. .... ........ ----- - Y 153.46 *XA(-1 .3467) R= 0.97291 ....7. ........................ ......... ........ ....

. .ESKMO/GLO DATA .........

0.3.. .... .

E 7 ....... 20. 30... 50...70

IUR 5-8 SCL. .RES..ED....C DATA.......E.

5 -6 ............ ......... .....

NAVSWO TR 9 1-102

U uii L

uii

- C,

. . .. . . . . .cn >

........ .............-----.

..... .... .... ..

................. ............... 0....

~L. -

wU <

4u

~ C" Q,~ Pw~E1SA3DN4O~eL1P) 1H~M131VAflD

cr 0

... .... Er ....... ....

LL -.. .... .... ... ....

aL ..... ....

... ... '0 ... ..... ..... .... .0L LJ 0 0--- 0--- ............0..

0 0.. 0 .. .0. . ,. .. .

...pe3 ......... ..... ........) ....... ...... ...........

i5-

NAVSWC TR 91-102

20-

-FRONT

: ~~~~~~~~.................................... ... ID7 ..... ..... .... . ..--- ............... ............. --- --R EA R..... ... 5. ...... ... ..... .................

" .- STANDARD...

C/') 2 ..... ... ...

Co)cc

(L 0 .2 ......I.... ............. ...7. ...........1 0. ................2 0. ........... .....3 0 ..... ..

0.5 ~ ~ ~~ CA E D.....:.................I A C .(f.............. .......... ..... ....

20 7 020 3

20

10 . ..... 0. .... ....................... ........ ...

....-.. ........................................ S DL N .Front Side,................... and.Rear.curves .are.the .upper.bound.ofoI he O c fi ecinte..............r.............. ..a......l........

CURVES.. WITH.. HEMIPHE ICA STANDARD........... .,z.....ST N A D ..

U ) 3 ...... ..... ... ... ... ... ...... ..........%... ...... ...... ......... ....... ...........8...

NAVSWC TR 91-102

20 -I

-STANDARD

....... ........ 10 ...... .............................. .. . CO M BINED-FRO NT ................. •".........i ... ...... N ...!', .................................... .. .........,• ...

7 ........... ....---- -_--COMBINED SIDEi i i i . ", m -

C 5...... ....... :. . .... : .......... ........ ;7 ............. ..--i --:'- . -- ............ ......... ------- .... ....... ... ...... ----

w........ ..; ........ ":....... .. .... .. .... .................... ..... .......... ........... ............... .................. i............. ..-; ......... -........ ? ...

S 3 ......t----- .... :.... .......................................... . . . ................... ... .... ... ..... ....wcc, 2 ....... .: ..-....... ----:. ... .......................... .... .. .. .......... .............. .. ..... ... .

...... .... .......... ........

1 NOTE: Front and Side curves are the upper bound of...........

the 90% confidence interval......... .........0.70 .7 ................... ......... .. ... ...... ....... ...... .

0.55 7 10 30 50 70

SCALED DISTANCE (Mb 13)

FIGURE 5-14. COMPARISON OF UPPER BOUND COMPOSITE PRESSURE-DISTANCECURVES WITH HEMISPHERICAL STANDARD

5-9

NAVSWC TR 91-102

TABLE 5-1. LEAST SQUARES CURVE FIT COEFFICIENTS

EVENT PRESSURE

DIRECTION A B C Correlation CoefficientESKIMO FRONT 347.39 -1.6488 0.9811

839.44 -2.3355 0.1283 0.9887

SIDE 96.824 -1.2296 0.9892223.91 -1.7021 0.0668 0.9780

REAR 249.35 -1.6901 0.9883246.40 -1.8865 0.0845 0.9899

COMBINED: ESKIMO/ FRONT 271.62 -1.5434 0.9808BUFFERED STORAGE/ 674.16 -2.1628 0.1025 0.9841

MODULAR IGLOOSIDE 153.46 -1.3467 0.9729

213.27 -1.5718 0.0374 0.9866

REAR 249.35 -1.6901 0.9883246.40 -1.8865 0.0845 0.9899

IMPULSEESKIMO FRONT 58.166 -0.9522 0.9908

SIDE 53.202 -1.0040 0.9732REAR 20.695 -0.7658 0.9334

NOTES:(1) Fit is of the form: F=A*ZA(B+C*In(Z))(2) Z is scaled distance (ft/lbAl/3)(3) The impulse data for buffered storage/modular igloo were not used

5-10

NAVSWC TR 91-102

TABLE 5-2. IGLOO EQUIVALENT WEIGHTS

DIRECTION EW-P EW-I OVERALLFRONT 0.63 0.70 0.66SIDE 0.61 0.49 0.55REAR 0.32 0.31 U.31

EW-P is equivalent weight based on peak pressureEW-I is equivalent weight based on positive impulse

NOTE: Standard is Kingery hemispherical TNT standard

5-11

NAVSWC TR 91-102

a 0z z f

< < CL<

C~CD> LO 04 CO P liC \J (D09 m - CO cf -- m C-

hClf 1 LOCU)rc >Cf -vO0OC o CM c O C ) CD V -- '@CO CD C C0) 0 OC)0-00 0 0V-t m ( nc

z - U, O Lf V '0 -0 -L LU 0

E- ~L 0) oCz CV)Lf -

o U ON- m-L

zU ___ U)*

U) ~ ~ .< (0 O - Mioc -'< I. <<~ Na) D 0a. i

LU 04 CV U,0 o Oz m

0.U. coa

0 I -0 CL ~Lu a:U ZLUJ CC ZUC

<~~ #%~< L) o ~< 'a~ oC- 0 LU '-' LUIu cc - LU CV 0

LL L

E-- 80 8> 0 L f)

LU _i0! LU

5-1

NAVSWC TR 91-102

z

All

'0 n a r o

co~

U)~

Q o

~ A Y

LU %D W, CY

C4 q

(U R

0 0

5-13

NAVSWC TR 91-102

REFERENCES

1. Ammunition and Explosives Safety Standards, DOD 6055.9-STD, change 2,28 Oct 1988.

2. Scale Model Igloo Magazine Tests, ASESB Technical Paper No. 4, Aug 1946,

AD 223 342.

3. Igloo and Revetment Tests, ASESB Technical Paper No. 5, Oct 1946.

4. Sound, A. R., Summary Report of Earth Covered, Steel-Arch Magazine Tests,NOTS TP 3843, Jul 1965, AD 619 241.

5. Weals, F. H., ESKIMO I Magazine Separation Test, NWC TP 5430, Apr 1973.

6. Weals, F. H., ESKIMO II Magazine Separation Test, NWC TP 5557, Sep 1974,AD 000 089.

7. Weals, F. H., ESKIMO III Magazine Separation Test, NWC TP 5771, Feb 1976.

8. Weals, F. H. and Wilson, C. H., ESKIMO IV Magazine Separation Test, NWCTP 5873, Mar 1977, AD A039 343.

9. Weals, F. H. and Finder, B., ESKIMO V Magazine Separation Test, NWCTP 6076, Feb 1979, AD A070 918.

10. Tafoya, P. E., ESKIMO VI Test Results, NCEL TR R889, Nov 1981,AD B064 461.

11. Murtha, R. N. and Beyer, M. E., ESKIMO VII: Test Data Report,NCEL TM 51-86-26, Dec 1986.

12. Lewis, M. J., Friesenhahn, G. J., and Nash, P. T., MK 82 Buffered Storage TestSeries: Part I-Technical Report, MMW-TR-87-C77865A, Dec 1988.

13. Lewis, M. J., Friesenhahn, G. J., and Nash, P. T., MK 82 Buffered Storage TestSeries: Part II-Data Report, MMW-TR-87-C77865A, Dec 1988.

14. Lewis, M. J., Friesenhahn, G. J., and Nash, P. T., MK 84 Buffered Storage TestSeries: Part I-Technical Report, MMW-TR-87-50102AC, Dec 1988.

15. Lewis, M. J., Friesenhahn, G. J., and Nash, P. T., MK 84 Buffered Storage TestSerLes.- Part II-Data Report, MMW-TR-87-50102AC, Dec 1988.

6-1

NAVSWC TR 91-102

REFERENCES (Cont.)

16. Lewis, M. J., Friesenhahn, G. J., and Nash, P. T., Modular Igloo Test: DataReport, MMW-TR-88-71002 AC, Dec 1988.

17. Reeves, H. and Robinson, W., Hastings Igloo Hazards Tests For Small ExplosiveCharges, ARBRL-MR-03356, May 1984.

18. Swisdak, M. M., "Procedures For the Analysis of the Debris Produced ByExplosion Events," Minutes of the 24th Department of Defense Explosives SafetySeminar, St. Louis, MO, Aug 1990.

19. Kingery, C. N. and Bulmash, G., Airblast Parameters From TNT Spherical AirBurst and Hemispherical Surface Burst, ARBRL-TR-02555, Apr 1984.

20. Kingery, C. N., Air Blast Parameters Versus Distance For Hemispherical TNTSurface Bursts, BRL Report No. 1344, Sep 1966.

6-2

NAVSWC TR 91-102

APPENDIX A

FRAGMENTATION[DEBRIS DATA

NOTS TEST 5

Donor: Three complete missiles-total weight of energetic material = 1,275 pounds

Date: 4 April 1963

A-I/A-2

NAVSWC TR 91-102

FRAGMENT DISTRIBUTION, TEST NO. 5

FragmentID No. Description

1 Large piece corrugated steel arch, #1.2 Four large pieces corrugated steel arch (in immediate vicinity

of crater and near acceptor igloo C), #2.3 Concrete fragment with reinforcing rods (11" x 14" x 17"), #3.4 Bottom right side of donor door frame and pilaster, #4.5 Motor entrance nozzle, #5.6 Top piece of south door of donor (45" x 42"), #6.7 Bottom piece of south door of donor (51" x 56"), #7.8 Piece of north door of donor (44" x 38"), #8.9 Piece of corrugated steel arch (45" x 38").

10 Small (about 5 Ib) concrete fragment (6" x 7" x 8").11 Large concrete fragment with reinforcing rods (40" x 29" x 17").12 Large concrete fragment with reinforcing rods (39" x 26" x 16").13 Motor exit nozzle.14 Piece of motor (about 8 Ib).15 Piece of motor (about 10 Ib).16 Piece of motor (about 5 Ib).17 Limitation of debris.18 Large piece of concrete with reinforcing rods. Part of donor

door frame and pilaster (est. 6' x 20" x 18").19 Piece of door frame.20 Motor entrance and exit nozzles (attached).21 Motor exit nozzle.22 Large piece metal door frame.23 Concrete fragment (about 50 Ib).24 Piece of donor door (24" x 24").25 Plow-shaped piece of donor metal door frame.26 Piece of metal donor door frame.27 Part of donor door hinge-strap.28 Small part of internal door framing.

A-3

NAVSWC TR 91-102

0

0

C0

.0

14

0

aI,

1.

b.

0

/

A-4

NAVSWC TR 91-102

'D C

CL mmu C 2 0

~o E C)o' ,:' o ,, C

Cl ~ td-tCE LO

00 -S2~~ ~3~LL -ar

.0U &) oE wS Lo -n w

ccw M O Cc ) 0

co w a: iiia: :, Ec 0 rC< a: > - 2E =) z LLC

I --0 < wW 0 w 0acn 0 ac oC r -0 yE

in CD

ccU

C6 6 , C) m CD

~ cnLU _ _ _ _ _ _ _ _ _ _ _ _ _ _ 0

0~~ 9D

0-0

U)) Cu U

U-U- Cu

C U ) CO t C Cu

InU ' U ) 0 1 )C

.00

E CD0g *It ) WO * u co) v C') N cul2 CYD

2u( a) 1001 0 CoCD'MOD.

CY c CD

0 0 .0 .0 W .CUL cD c C')- 'V c CC)

Cu

(D LC) Ln C3 C) q q in CCCCD C C:)c, CD CD aC.CD C CDC (C) D CD 0Q

N: CD) m Cu. C) ~

A-5

NAVSWC TR 91-102

Appendix E

ESKIMO VI DEBRIS STUDY

Figure E-1 summarizes the results of a debris study conductedfollowing the ESKIMO VI test. The objective of the study was to quan-tify the amount and size of fragments generated by the test. Thesedata will be used to estimate initial velocities of the particles and willbe entered into the NCEL data base for explosion-generated fragmenta-tion. Only large items were listed (tabulated in Table E-l) out to arange of about 2,000 feet. Special attention was paid to the wingwalltrajectories (items 21 and 22) since they were the largest projectilesgenerated by the test. In general, most fragments were generated bythe roof breakup.

Figure E-2 illustrates the soil distribution following the test.e19 0

2000" 20

* *16

QUADRANT 4 17&18 14&15 10 QUADRANT 11500' 013 21

012 0

/

e23 1000' 7 /11

22

'• H 500' H

60*

1500" 1000' 600' GZI I I ;

.29 500' 1000" 1500'

30 .425

'500'24

QUADRANT 3 I 24 QUADRANT 2* :-1000'

3

*28-1500'

027

26

2000'

Figure E-I. ESKIMO VI debris collection.

A-6

NAVSWC TR 91-102

Table E-1. ESKIMO VI Debris Collection

Distance

Item From WeightNo. Ground Quadrant (lb)D

Zero(ft)

1 810 3 80 7-ft 6 -in. I-beam2 760 3 122 6 x 2-ft plate3 1,010 3 102 5 x 2-ft plate4 493 2 245 4 x 6-ft plate5 635 1 46 1-1/2 x 3-ft plate6 583 1 184 3 x 6-ft plate7 920 1 204 4 x 5-ft plate8 1,218 1 56 7-ft channel9 850 1 81 4 x 2-ft plate10 1,622 1 81 2 x 4-ft plate11 900 1 326 4 x 8-ft plate12 1,345 1 242 3 x 8-ft plate13 1,499 1 60 4-ft 6 -in. channel14 1,690 1 20 2-ft 4-in. channel15 1,690 1 81 2 x 4-ft plate16 1,768 1 92 12-ft 4-in. I-beam17 2,036 4 39 5-ft 4-in. I-beam18 2,036 4 54 7-ft 4 -in. I-beam19 2,367 4 85 5-ft 8-in. I-beam20 2,224 1 85 5-ft 8-in. I-beam21 1,641 1 1,913 47-ft 2 1-in. plate21-H 837 1 -- First impact of #2122 1,082 4 1,913 47-ft2 1-in. plate22-H 897 4 -- First impact oi #2223 1,912 4 122 3 x 4-ft plate24 1,003 2 142 2 x 7-ft plate25 686 2 245 4 x 6-ft plate26 1,811 3 270 5-ft 10-in. I-beam27 1,791 3 54 7-ft 4 -in. I-beam28 1,952 3 82 4 x 2-ft plate29 639 3 300 12 x 3-ft plate30 825 3 180 6 x 3-ft plate

A-7

NAVSWC TR 91-102

-6W

Figure E-2. Aerial view of the ESKIMO V I site' final soil distribution.

A-8

NAVSWC TR 91-102

HASTINGS IGLOO-60 POUND TEST

DISTANCE HAZARDOUS FRAGMENT DENSIT~ number /600 ftA 2)

(OT 050 5-100 10-450100 6.3 4.7 9125 24.3 21.9 26.8150 19.9 10 7.1175 40.4 25 23.2200 19.4 12.7 6.3225 18 9.7 4.7250 20.7 13.3 3.1275 10.4 6.3 1.8300 2 1.5 0.3325 1.8 2.2 1.1350 1.6 0.8 0.6375 1.5 0.8 0.2400 0 0 0.8425 1.4 0.7 0.1450475500525550575600625650675700725

A-9

NAVSWC TR 91-102


DISTANCE HAZARDOUS FRAGMENT DENS[TY(number /600 ftA 2)(O) -50 5-100 1 0-450

100 0 0 2.8125 0 0.6 2.1150 10 10.5 3.8175 28.6 16.8 4.6200 20.4 13.2 4.2225 15.5 10.7 7250 18.4 10.9 2.9275 4.1 3.1 1.2300 11.4 6.6 2.4325 0.9 1.3 1.9350 2.4 1.6 3.2375 3 1.5 0.8400 5.6 3.2 1.5425 0.7 0.7 0.1450 1.3 0.8 0.3475 1.2 0.6 0.2500 2.8 1.7 0.7525 1.1 0.5 0.1550575600625650675700725

A-10

NAVSWC TR 91-102

HASTINGS IGLOO--100 POUND TEST

DISTANCE HAZARDOUS FRAGMENT DENSITY(number /600 ftA2)

(FT) 0-50 5-100 10-450100 0 0 3.5125 0 2.4 3.1150 23.8 18.8 9.3175 16.8 15.8 8.5200 3 8 6.9225 0 5.8 1.4250 20.8 15 4.1275 2 4.1 2.1300 3.8 3.6 1.1325 3.6 3.1 0.9350 0.4 0.7375 1.1 2.5400 0.7 0.6425 0.7 1.2450475500525550575600625650675700725

A-11

NAVSWC TR 91-102


DISTANCE HAZARDOUS FRAGMENT DENSIT?(number /600 ftA2)(Fr) 0-50 5-100 10-450100 3.1 2.4 3.8125 0 3 6.1150 21.9 12.5 9.5175 10.2 5.9 1.2200 1S.1 12.5 6.4225 3.9 3.8 2.6250 1.2 1.2 1.1275 7.2 6.2 1.6300 5.8 4.8 1.8325 4.5 2.9 0.8350 4.8 4.6 k.3375 9.9 5.5 1.3400 4.2 3 1425 4.7 ?.7 0.7450 3.2 1.8 0.6475 2.4 2 0.4500 2.3 1.7 1.1525 3.2 2 0.8550 5 2.6 0.7575 0 0.1 0.2600 1 0.7 0.7625 2.2 1.3 0.7650 2.2 1.4 0.3675 0.4 0.3 0.4700 0.4 0.2 0.1725 0.2

A-12

NAVSWC TR 91-102

APPENDIX B

AIRBLAST DATA

B-1/B-2

NAVSWC TR 91-102

ARCO TEST 1

RANGE PRESSURE (Ps(ft) FRONT SIDE REAR

275 28.1 28.1330 18.5 18.5 CHARGE WEIGHT: 500,340 pounds TNT385 14.8 18.5440 12 14.8 CASE WEIGHT: 429,660 pounds500 9.7 9.7 8.2 STRUCTURE WEIGHT: 341,250 pounds500 8.2 COVER WEIGHT: 4,500,000 pounds565 8.2 8.2565 9.7 7.9 8.2 DATE: 1 October 1946640 8.2 8.2 Barometric Pressure: 25' (12.28 psi)640 7.9 7.9 8.2 Temperature: 620F725 8.2 8.2725 6.4 6.4 5.6 GAUGE TYPE: paper & toil820 5.6 8.2820 5.2 6.4 5.6 DONOR: 930 MK36 1000-pound TNT-loaded bombs930 5.6930 5.2 5.2 5.6 REFERENCE: ASESB Technical Paper No. 510551055 5.6 3.3 3.31190 2.3 3.3 3.31350 3.3 2.3 3.31530 2.3 3.3 2.31730 1.5 3.3 1.51960 1.5 1.5 0.942220 1.5 0.94 1.52515 0.94 0.94 0.942845 0.6 0.94 0.63220 0.6 0.6 0.63645 0.38 0.38 0.38

NOTE: not scaled to sea level condibons

B-3

NAVSWC TR 91-102

ARCO TEST 2

RANGE PRESSURE (psi(ft) FRONT SIDE REAR

275 34.3 22.8330 34.3 14.8 CHARGE WEIGHT: 500,340 pounds TNT385 18.5 12440 14.8 12 CASE WEIGHT: 429,660 pounds500 12 8.2 STRUCTURE WEIGHT: 341,250 pounds500 8.2 COVER WEIGHT: 6,300,000 pounds565 12 9.7565 13.8 8.2 8.2 DATE: 8 October 1948640 14.8 7.9 Barometric Pressure: 25.19" ( 12.37 psi)640 8.2 8.2 8.2 Temperature: 45OF725 9.7 6.4725 5.6 8.2 5.6 GAUGE TYPE: paper & foil820 7.9 6.4820 5.6 5.6 5.6 DONOR: 930 MK36 1000-pound TNT-loaded bombs930 6.4 5.2930 5.6 5.6 5.6 REFERENCE: ASESB Technical Paper No. 510551055 3.3 3.3 3.31190 3.3 5.6 2.31350 3.3 2.3 2.31530 0.94 2.3 2.31730 1.5 1.5 1.51960 0.6 2.3 0.942220 0.6 0.6 0.62515 0.6 0.38 0.62845 0.25 0.38 0.63220 0.38 0.38 0.383645 0.6 0.38 0.38

NOTE: not scaled to sea level conditions

B-4

NAVSWC TR 91-102

NOTS TEST 1

RANGE PRESSURE (psi(ft) FRONT SIDE REAR/rear quarter

50 34.8759 3.4965 4.14 3.07 CHARGE WEIGHT: 2,424 pounds TNT equivalent65 3.3965 4.34 CASE WEIGHT: 1,816 pounds

130 13.01 STRUCTURE WEIGHT: 3,000 pounds130 2.07 COVER WEIGHT: 478,000 pounds280 3.64590 0.99 DATE: 17 January 1962590 0.33 Barometric Pressure: 941.9 mbar ( 13.66 psi)590 0.35 Temperature: 48°F1180 0.441180 0.15 GAUGETYPE: BRL Self-Recording1180 0.19

DONOR: 8 AN-M-64A1 500-pound Comp B-loaded bombs

REFERENCE: NOTS TP 3843NOTE: not scaled to sea level conditions

RANGE IMPULSE (psi-ms

!L.) FRONT SIDE REAR/rear quarter

50 44.159 32.965 49 37.465 133.365 60.4130 155.8130 24.7280 24.4590 23.1590590 9.11180 9.91180 4.61180 4.2


B-5

NAVSWC TR 91-102

NOTS TEST 2

RANGE _____ RESSURE (psi ______

01) FRONT SIDE REAR/rear quarter

59 5.32130 10.08130 9.63 CHARGE WEIGHT: 2,611 pounds TNT equIvalent130 2.56290 4.14 CASE WEIGHT: 918 pounds290 1.09 STRUCTURE WEIGHT: 3,000 pounds388 2.38 COVER WEIGHT: 478,000 pounds590 1.09590 0.4 DATE: 6 Apil 19621180 0.35 Barometric Pressure: 948.7mbar ( 13.76 psi)1180 0.25 Temperature: 48OF

GAUGE TYPE: BRL Self-Recording

DONOR: 9 MK54-1 350-pound HBX-1 loaded depth bombs

REFERENCE: NOTS TP 3843NOTE: niot scaled to sea level conditions

RANGE IPULSE s-i)011)... FRONT SIDE REAR/rear quarter

59 49.08130 122.8130 105.97130 28.19290 50.07290 18.85366 37.26590 10.87590 9.02

1180 10.731180 4.96

NOTE: niot scaled to sea level conditions

B-6

NAVSWC TR 91-102

NOTS TEST 6

RANGE PRESSURE (psi

Mft) FRONT SIDE REAR/rear quarter

300 20.98300 10.2300 7.74 CHARGE WEIGHT: 111,039 pounds TNT equivalent500 8.87500 6.57 CASE WEIGHT: 21,060 pounds500 4.69 STRUCTURE WEIGHT: 5,000 pounds500 5.49 COVER WEIGHT: 3,600,000 pounds500 5.65750 3.67 DATE: 18 December 1963750 2.48 Barometric Pressure: 935.0 mbar( 13.56 psi)750 3.73 Temperature: 57.60F1000 2.51000 1.79 GAUGE TYPE: BRL Self-Recording1000 2.241855 1.22 DONOR: 2,106 cans of Comp B1855 0.551855 0.91 REFERENCE: NOTS TP 38433630 0.4


RANGE IMPULSE (psi-ms)(ft) FRONT SIDE REAR/rear quarter

300300 219.7300500 284.14500 188.81500 136.98500 239.96500 243.99750 173.28750 106.31750 138.941000 151.821000 91.310001855 92.0718551855 69.833630 39.45


B-7

NAVSWC TR 91-102

ESKIMO I

RANGE PRESSURE (psi(ft) FRONT SIDE REAR/rear quarter

410 12410 7.45526 7.86 CHARGE WEIGHT: 200,000 pounds TNT526 5.71526 6.05 CASE WEIGHT: 1,159,000 pounds703 4.08 STRUCTURE WEIGHT: 5,000 pounds703 4.54 COVER WEIGHT: 4,890,000 pounds880 3.02880 2.6 DATE: 8 December 1971880 3.31 Barometic Pressure: 936.0 mbar ( 13.58 psi)1580 1.47 Temperature: 55OF15802690 0.75 GAUGE TYPE: BRL Self-Recording2690 0.89

DONOR: 13,696 155-mm TNT-loaded projectiles

NOTE: not scaled to sea level condilions REFERENCE: NWC TP 5430


4;C 530410 248526 418526 252526 292703 194703 250880 216880 154880 2291580 15215802690 1072690 78


B-8

NAVSWC TR 91-102

ESKIMO III

RANGE PRESSURE (psift) FRONT SIDE REAR/rear quarter

660.00 10.80660.00 10.40660.00 8.06 CHARGE WEIGHT: 374,406 pounds TNT equivalent660.00 8.35660.00 6.34 CASE WEIGHT: 337,100 pounds660.00 5.50 STRUCTURE WEIGHT: 5,000 pounds1320.00 2.20 COVER WEIGHT: 6,550,000 pounds1320.00 2.881320.00 3.30 DATE: 12 June 19741320.00 3.60 Barometric Pressure: 936.0 mbar ( 13.58 psi) (est)1320.00 2.40 Temperature: 85OF (est)1320.00 1.802115.00 1.28 GAUGE TYPE: BRL Self-Recording2115.00 1.482115.00 1-60 DONOR: 916 M1l17 TRITONAL-loaded bombs2115.00 1.212630.00 0.752630.00 0.80 REFERENCE: NWC TP 57712630.00 1.272630.00 1.153526.00 0.883526.00 0.41



660.00 515.93660.00 529.68660.00 428.65660.00 435.30660.00660.001320.00 -

1320.00 223.681320.001320.001320.00 187.741320.002115.00 136.332115.00 172.102115.002115.00 112.032630.00 55.702630.002630.00 149.322630.00 80.963526.00 20 353526.00

NOTE, not scaled to sea level conditions

B-9

NAVSWC TR 91-102

ESKIMO VI

RANGE PRESSURE (psi)(fJ) FRONT SIDE REAR/rear quarter

210.00 36.00210.00 17.80210.00 14.20 CHARGE WEIGHT: 51,300 pounds TNT equivalent530.00 5.30530.00 3.75 CASE WEIGHT: 31,200 pounds530.00 3.10 STRUCTURE WEIGHT: 2,000 pounds880.00 2.20 COVER WEIGHT: 1,015,000 pounds880.00880.00 1.60 DATE: 23 July 19801760.00 0.35 Barometric Pressure: 936.0 mbar ( 13.58 psi) (est)1760.00 0.45 Temperature: 85°F (est)1760.00 0.26

GAUGE TYPE: BRL Self-Recording & piezoresisive

DONOR: 60 MK 16 HBX-3-oaded torpedoesNOTE: not scaled to sea level conditions

RANGE IMPULSE (psi-ms) REFERENCE: NCELTR 889(ft) FRONT SIDE REAR/rear quarter

210.00 613.00210.00 300.00210.00 270.00530.00 185.00530.00 121.00530.00 115.00880.00 25.50880.00880n) .

1760.00 23.591760.00 30.5f1760.00 15.24


B-10

NAVSWC TR 91-102

HASTINGS IGLOO AIRBLAST

CHARGE WEIGHT CHARGE POSITION* GAUGE POSITION" PEAK PRESSURE POSITIVE IMPULSE(pounds) (feet) (feet) (si psi-ms)

24 13 80F 0.590F 0.460S 0.76 3.7590S 0.55 2.59

100 40 60F 1 9.85

90F 0.7 7.7850S 1.2 8.5590S 0.74 4.11

150 40 6OF 1.41 13.4690F 1.23 9.9450S 1.53 8.8390S 1.07 7.21

12 13 60F 0.4 4.6912 13 60F 0.62 4.83

90F 0.46 3.2750S 0.67 5.52

90S 0.34 3.0612 67 60F 0.16 0.53

90F 0.25 1.7350S 0.39 1.91

90S 0.23 1.1012 67 60F 0.36 2.87

90F 0.33 1.0550S 0.69 2.3790S 0.27 1.05

16 13 60F 0.49 4.03

90F 0.34 2.5050S 0.51 3.2490S 0.35 2.36

*Distance measured from headwall to charge location inside igloo-Distance measured from center of headwall to where gauge located

F = in front of headwallS = to side of headwall

CHARGE WEIGHT: see table

CASE WEIGHT: 0STRUCTURE WEIGHT: unknownCOVER WEIGHT: unknown

DATE: 1984Barometnc Pressure: unknown (sea level assumed)Temperature: unknown (standard assumed)

GAUGE TYPE: piezoelectric

DONOR: TNT blocks

REFERENCE: ARBRL-MR-03356

B-11

NAVSWC TR 91-102

MK 82 BUFFERED STORAGE I

RANGE PRESSURE (psi_(feet) FRONT SIDE REAR

550 2.14 3.54900 1.56 CHARGE WEIGHT: 36,600 pounds TNT1200 1.151500 0.62 0.931600 0.64 0.81 DATE: 2/5/87

Barometric Pressure: 25.87" HgTemperature: 460F

NOTE: not scaled to sea level conditions DONOR: 180 MK82 bombs-TRITONAL loaded34,560 pounds TRITONAL

RANGE POSITIVE IMPULSE (psi-ms) STRUCTURE: IGLOO BUNKER(feet) FRONT SIDE REAR

550 36.79 96.909001200 36.961500 38.99 43.491600 24.33 36.01


B-12

NAVSWC TR 91-102

MK 82 BUFFERED STORAGE 2

RANGE PRESSURE (psi(feet) FRONT SIDE REAR

550 3.62 4.51900 1.56900 1.56 2.351200 1.12 1.361200 1.16 1.35 CHARGE WEIGHT: 54,890 pounds TNT1650 1.02 0.931650 0.83 0.91

DATE: 5/7/87Barometric Pressure: 25.86' HgTemperature: 80 0F

NOTE: not scaled to sea level conditions DONOR: 270 MK 82 bombs-TRITONAL loaded51,840 pounds TRITONAL

RANGE POSITIVE IMPULSE (psi-ms)(feet) FRONT SIDE REAR STRUCTURE: IGLOO BUNKER

550 187.63 180.05900 104.59900 102.95 122.541200 82.43 78.091200 83.65 83.731650 85.79 62.951650 61.62 47.76


B-13

NAVSWC TR 91-102


RANGE PRESSURE (ps!(feet) FRONT SIDE REAR

200 11.73 8.83200 10.67400 7.19 4.93400 5.75550 3.38550 3.50 CHARGE WEIGHT: 63,430 pounds TNT900 1.95 2.15900 1.70 1.641200 1.06 DATE: 11/4/871200 1.09 1.29 Barometric Pressure: 25.96" Hg

Temperature: 520F


RANGE POSITIVE IMPULSE (psi-ms)(feet) FRONT SIDE REAR STRUCTURE: IGLOO BUNKER

200 333.16 401.59200 229.68400 341.45 160.72400550 130.86550 242.14900 92.49900 95.75 83.761200 68.251200 77.02 64.40


B-14

NA VSWC TR 91-102



200 21.4 18.1200 19.9400 8.21 4.67400 4.96550 4.57 4.51550 4.f3 4.32 CHARGE WEIGHT: 63,430 pz,,inds TNT900 2.06 2.06900 3.26 1.731200 1.38 DATE: 12/16/871200 1.31 1.64 Barometric Pressure: 22.24' Hg

Tempr..ure: 27°F

NOTE: not scaled to sea level conditions DONOR: 312 MK 82 b.) nbs-TRITONAL loaded69,904 pounds TRITONAL

RANGE POSITIVE IMPULSE (psi-ms)(feet) '-RONT SIDE REAR STRUCTURE: IGLOO 2UNKF

200 135.90 233.70200 165.20400 153.40 155.30400 168.30550 108.00 90.80550 150.80 114.20900 184.00 90.20900 144.60 77.301200 75.501200 75.80 135.90


B-15

I I Im

NAVSWC TR 91-102

MK 84 TEST 13


431 14.13 11.25431 14.5 10.94707 4.7707 5.94 4.91178 2.18 2.151178 2.16 1.91570 1.381570 0.96 1.401963 0.88 0.98 CHARGE WEIGHT: 129,430 pounds TNT1963 0.35 1.102198 0.74 0.862198 0.74 0.88 DATE: 8/29/86

Barometric Pressure: 25.1" HgTemperature: 84°F

NOTE: not scaled to sea level conditions DON'OR: 128 MK 84 bombs-TRITONAL loaded120,960 pounds TR. .ONAL

RANGE POSITIVE IMPULSE (psi-ms)(feet) FRONT SIDE REAR STRUCTURE: EARTH COVERED CONCRETE

ARCH IGLOO431 613.00 413.00431 662.00 420.00707 259.00707 288.00 256.001178 164.00 148.001178 145.00 119.00

1570 114.001570 78.00 118.001963 88.00 88.501963 32.50 99.50

2198 80.00 81.302198 80.00 83.80

NOTE: not scaled to iG ;,dvel conditions

B-16

NAVSWC TR 91-102

MK 84 TEST 15


550 4.47 5.01900 2.12900 2.5 3.11200 1.12 1.391200 1.26 1.661500 1.07 1.331500 1.13 1.211650 0.97 1.151650 1.11 CHARGE WEIGHT: 96,620 pounds TNT

DATE: 11/14/86Barometric Pressure: 25.15" HgTemperature: 580F

NOTE: not scaled to sea level conditions DONOR: 96 MK 84 bombs-TRITONAL loaded90.720 pounds TRITONAL

RANGE POSIfIVE IMPULSE (psi-ms)(feet) FRONT SIDE REAR STRUCTURE: SIMULATED EARTH COVERED

IGLOO550 179.20 197.60900900 164.401200 86.501200 83.02 91.571500 82.30 104.801500 97.70 89.101650 89.67 90.901650 83.72


B-17

NAVSWC TR 91-102

MK 84 TEST 17


550 4.05 3.9550 4.17 3.6900 1.95 1.7900 1.9 1.831200 1.45 1.321200 1.27 1.341650 0.78 0.71650 0.90 0.72

CHARGE WEIGHT: 48,535 pounds TNT

DATE: 6/24/87Barometric Pressure: 25.20' HgTemperature: 760F


RANGE POSITIVE IMPULSE (psi-ms)(feet) FRONT SIDE REAR STRUCTURE: SIMULATED EARTH COVERED

IGLOO550 157.00 146.00550 168.00 142.80900 90.49 84.48900 94.11 85.001200 79.00 69.001200 49.00 72.121650 50.23 48.681650 49.68 44.00


B-18

NAVSWC TR 91-102

MK 84 TEST 18


200 23.4 17.1200 19400 8.35 6.65400 7.26550 5.34 4.69550 5.16 4.6900 2.35 1.96900 1.891200 1.98 1.43 CHARGE WEIGHT: 64,714 pounds TNT1200 1.77 1.59

DATE: 8/12/87Barometric Pressure: 25.68" HgTemperature: 71°F


RANGE POSITIVE IMPULSE ( si-ms)(feet) FRONT SIDE REAR STRUCTURE: SIMULATED EARTH COVERED

IGLOO200200

400 262.00 206.90400 227.60550 197.20 172.50550 267.30 170.00900 128.50 139.10900 143.701200 96.23 89.271200 111.50 87.89


B-19

NAVSWC TR 91-102

MK 84 TEST 19

RANGE _PfESSURE (psi(feet) FRONT SIDE REAR

200 22.26 14.52200 25.02 14.32400 8.27 7.13400 6.9 5.92550 4.61 3.99550 4.14 3.77900 2.28 1.53900 2.08 2.001200 1.46 1.67 CHARGE WEIGHT: 64,714 pounds TNT1200 1.45 1.02

DATE: 9/23/87Barometric Pressure: 25.90' HgTemperature: 65°F


RANGE POSITIVE IMPULSE (psi-ms)(feet) FRONT SIDE REAR STRUCTURE: SIMULATED EARTH COVERED

IGLOO200 463.40200 366.50 268.60400 276.50 224.00400 197.50550 167.00 150.00550 140.00 134.20900 100.40 38.20900 39.50 106.401200 75.10 88.401200 83.10 40.30


B-20

NAVSWC TR 91-102

MODULAR IGLOO

RANGE PRESSURE (psi)(feet) FRONT SIDE REAR

476 13.70 14.40 8.42873 4.60 8.80 4.00 CHARGE WEIGHT: 500,000 pounds TNT1429 3.10 3.122381 1.08 0.99 1.063969 0.61 0.71 0.56 DATE: 11/18/884445 0.28 0.36 0.49 Barometric Pressure: 873.9 mbar

Temperature: 2.9 °C

NOTE: not scaled to sea level conditions DONOR: 450,450 pounds flake COMPOSITION B

RANGE POSITIVE IMPULSE ( si-ms) STRUCTURE: MODULAR IGLOO(feet) FRONT SIDE REAR

476 281.00 344.00873 156.70 322.001429 109.30 111.002381 46.20 39.80 45.003969 34.60 33.00 23.804445 19.60 16.70 22.70


B-21

NAVSWC TR 91-102

DISTRIBUTION

Copies Copies

Defense Technical Information Chief of Naval ResearchCenter Attn: ONR-410 1

Cameron Station ONR-430 1Alexandria, VA 22304-6145 12 800 N. Quincy Street

Arlington, VA 22217ChairmanDepartment of Defense Explosives Office of Naval Technology

Safety Board 800 N. Quincy StreetAttn: DDESB-KT 50 Arlington, VA 22217 1

DDESB-KT1 (Ward) 12461 Eisenhower Avenue Chief of Naval OperationsAlexandria, VA 22331-0600 Attn: OP-411F 1

Department of the NavyOffice of the Secretary of Defense Washington, DC 20350ODDRE (R & AT/ET)Attn: R. Menz 1 CommanderWashington, DC 20301-3080 Naval Sea Systems Command

Attn: SEA-0333 1Office of the Secretary of Defense SEA-665 3OUSDRE (OM) SEA-66511 1Washington, DC 20301-3080 1 SEA-662 1

SEA-99612 1Defense Logistics Agency Naval Sea Systems CommandAttn: K. Siler 1 Headquarters805 Walker Street Washington, DC 20362-5101Marietta, GA 20050

CommanderCommander Naval Air Systems CommandMilitary Traffic Management Attn: AIR-516C 1

Command Library 1Attn: MT-SS 1 Washington, DC 203615611 Columbia PikeFalls Church, VA 22041-5050 Commanding Officer

Naval Facilities EngineeringDirector CommandDefense Nuclear Agency Attn: Code 03 1Attn: Code LEEE (J. Eddy) 1 Code 032E 16801 Telegraph Road Code 04A4 1Alexandria, VA 23310-3398 Code 04T5 1

200 Stovall StreetAlexandria, VA 22332

(1)

NAVSWC TR 91-102

DISTRIBUTION (Cont.)

Copies Copies

Commander CommanderNaval Civil Engineering Laboratory Naval Safety CenterAttn: Code L51 1 Attn: Code 43

Code L51 (Tancreto) 1 Naval Air StationPort Hueneme, CA 93043 Norfolk, VA 23511

Commanding Officer HeadquartersNaval Research Laboratory Department of the ArmyAttn: Technical Information Attn: DALO-SMA

Section 1 Room 1D567, PentagonWashington, DC 20375 Washington, DC 20310-0541

Commanding Officer HeadquartersNaval Weapons Center Department of the ArmyAttn: Code 38 1 Attn: DACS-SF (R. Fatz) 1

Code 62 1 Room 2C717, PentagonCode 3208 1 Washington, DC 20310 05A1Code 3212 1Code 3260 1 CommanderCode 32601 1 Armament Research, Development andCode 3269 1 Engineering CenterCode 3276 1 U.S. Army Armament, MunitionsCode 6212A 1 and Chemical CommandLibrary 1 Attn: AMCPM-AL (D. Scarborough) 1

China Lake, CA 93555 SMCAR-AEE-BR (W. Seals) 1SMCAR-AES (S. Kaplowitz) 1

Commander Picatinny Arsenal, NJ 07806-5000David Taylor Research CenterAttn: Code 1740 1 Commander

Library 1 U.S. Army Materiel CommandBethesda, MD 20084 Attn: AMCAM-LCP (G. Bottjer) 1

AMC-SF-E (R. Vaselitch) 1Commanding Officer 5001 Eisenhower AvenueNaval Explosive Ordnance Disposal Alexandria, VA 22333-0001

Technology CenterAttn: Technical Library 1 CommanderIndian Head, MD 20640-5000 USA Safety Center

Attn: CSSCI-PRCommanding Officer Ft. Rucker, AL 36362-5363Naval Ordnance StationAttn: Code 04 (M. Hudson) 1 Director

Technical Library 1 AMC Field Safety ActivityIndian Head, MD 20640 Attn: AMXOS-SE

Charlestown, IN 47111-9669Commanding Off icerNaval Weapons Support CenterAttn: Code 50 1Crane, IN 47522-5083

(2)

NAVSWC TR 91-102


Copies Copies

Director CommanderU.S. Army Technical Center for USA Construction Engineering

Explosives Safety Research LaboratoryAttn: SMCAC-ES 1 P.O. Box 4005

SMCAC-ESL 1 Champaign, IL 61820 1Savanna, IL 61074-9639

Commanding GeneralDirector U.S. Army Missile CommandU.S. Army Defense Ammunition Attn: AMSMI-RD-PR-T (Thorn) 1

Center and School Redstone Arsenal, AL 35898Attn: J. ByrdSavanna, IL 61074-9639 AFISC/SEWV

Attn: P. Price 1Executive Director for Explosives LTCOL J. Humphrey 1

Safety W. Blount 1Attn: AMCDRM 1 E. Smith 15001 Eisenhower Avenue Norton AFB, CA 92049-7001Alexandria, VA 22333-0001

AFSG/IGFWDirector Attn: W. Hammer 1U.S. Army Engineer Waterways Andrews AFB

Experiment Station Washington, DC 20334Attn: K. Davis 1

C. Joachim 1 AFLC/IGFWCEWES (J. Ingram) 1 Attn: W. Rieder

P.O. Box 631 Wright Patterson AFB, OHVicksburg, MS 39180 45433-5001

Commander OO-ALC/MMWEU.S. Army Ballistics Research Attn: MAJ C. Dougherty 1

Laboratory G. Stratman 1Attn: SLCBR-TB-B 1 Hill AFB, UT 84056

SLCBR-TB-EE 1AMXBR-TBD 1 Air Force Armament Laboratory

Aberdeen Proving Ground, MD Attn: MSD/XRS (J. Jenus) 121005-5066 MSD/XRS (K. Gravois) 1

MSD/SE (Collins) 1Commander MNE (Parsons) 1U.S. Army Toxic & Hazardous MSD/SES (F. West) 1

Materials Agency Eglin ''iFB, FL 32542-5434Attn: DRXTH-TE 1Aberdeen Proving Ground, MD Commander21010 Air Force Weapons Laboratory

Attp" NTE 1Commanding General NTESS 1U.S. Army Natic Research and Kirtland Air Force Base

Development Command Albuquerque, NM 8'I i !7-6008Attn: LibraryNatick, MA 01782

(3)

NAVSWC TR 91-102


copies Copies

Air Force Astronautics Laboratory Morton ThiokolAttn: R. Weiss 1 Attn: W. Thomas

C. Merrill 1 P.O. Box 400006F. Roberto 1 Huntsville, AL 35815-1506

Edwards AFB, CA 93523Wilfred Baker Engineering

Department of Energy 8700 Crown Hill, Suite 310Quality Verification Division P.O. Box 6477Attn: Code EH-321 (E. Patagalia) 1 San Antonio, TX 78209Washington, DC 20545

Southwest Research InstituteLos Alamos National Laboratory Attn: W. Herrera 1Attn: L. Hantel 1 P. Bowles 1

Technical Library 1 Technical Library 1P.O. Box 1663 P.O. Box 28510Los Alamos, NM 87545 6220 Culebra Road

San Antonio, TX 78284Lawrence Livermore National

Laboratory TERAAttn: M. Finger 1 New Mexico Institute of Mining

E. Lee 1 and TechnologyTechnical Library 1 Attn: T. Joyner

Livermore, CA 94550 Socorro, NM 87801

Mason & Hanger CETRAttn: A. G. Papp 1 New Mexico Institute of MiningP.O. Box 30020 and TechnologyAmarillo, TX 79177 Attn: P. A. Persson

Socorro, NM 87801Department of the InteriorBureau of Mines ]IT Research InstitutePittsburgh Research Center Attn: Technical LibraryAttn: R. Watson 1 10 West 35th StreetCochrans Mill Road Chicago, IL 60616Pittsburgh, PA 15236-0070

Napadensky Engineers, IncDepartment of Transportation Attn: Ms. Ilyla NapadenskyAttn: DHM-21 (C. Shultz) 1 650 Judson Avenue400 7th Street SW Evanston, IL 60202-2551Washington, DC 20590

Advanced Technology, IncInstitute of Makers of Explosives Attn: W. Smith 11120 19th Street NW, #310 L. Wilson 1Washington, DC 20036-3605 1 2121 Crystal Drive

Arlington, VA 22202NSACSSAttn: G74(TA) 1Ft. George G. Meade, MD20755-6000

(4)

NAVSWC TR 91-102


Copies Copies

Kilkeary, Scott & Associates, Inc Aerojet Solid PropulsionAttn: F. McCleskey 1 P.O. Box 15699C

G. Clatterbuck 1 Sacramento, CA 95852-1699 12009 N. 14th Street, Suite 408Arlington, VA 22201 Integrated Systems Analysts, Inc.

Attn: K. Shopher 1Applied Ordnance Technology 740 Bay BlvdAttn: R. Beauregard 1 Chula Vista, CA 92010

E. Daugherty 12001 Jefferson Davis Highway, Integrated Systems Analysts, Inc.

Suite 909 Attn: E. Jacobs 1Arlington, VA 22209 7 Buckingham Way

Shalimar, FL 32579Applied Ordnance TechnologyAttn: Pilot NIMIC 1 Internal Distribution:1000 Century Plaza, Box 24, E231 2

Suite 212 E232 310630 Little Patuxent Parkway R 1Columbia, MD 21044 1 R04 1

R10 1Vitro R11 1Attn: W. Price 1 R12 1400 Virginia Ave SW, Suite 825 R13 1Washington, DC 20024 R14 1

R15 1JHU-APL/CPIA R10B 1Attn: T. Christian 1 R101 1Johns Hopkins Road R15 (M. Swisdak) 10Laurel, MD 20707 R15 (P. Montanaro) 1

R15 (V. Moore) 1Atlantic Research Corporation R15 (J. Connor) 1Attn- K. Graham 1 R15 (J. Powell) 1Bldg 2335945 Wellington RoadGainesville, VA 22055-1699

Library of CongressAttn: Gift and Exchange Division 4Washington, DC 20540

(5)

Form ApprovedREPORT DOCUMENTATION PAGE OMB No. 0704-0188

Public reporting buroien for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searhing eistiig datasources, gathering and maintaining the data needed, and completing and reviwew,- the collection of information Send comments regarding this burden estimate or any otheraspect of this collection of information, including suggestions for reducing this burden, to Washengton Headquarters Services, Directorate for Information Operations andReports, 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and Budget. Paperwork Reduction Prolect (0704-0188),Washington. DC 20503

1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE 3. REPORT TYPE AND DATES COVERED

28 January 1991

4. TITLE AND SUBTITLE 5. FUNDING NUMBERS

A Reexamination of the Airblast and Debris Produced by ExplosionsInside Earth-Covered Igloos

6. AUTHOR(S)

Michael M. Swisdak, Jr.

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATIONREPORT NUMBER

Naval Surface Warfare Center (Code RI 5)10901 New Hampshire AvenueSilver Spring, Maryland 20903-5000

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSORING/MONITORINGAGENCY REPORT NUMBER

Department of Defense Explosives Safety Board2461 Eisenhower AvenueAlexandria, VA 22331-0600

11. SUPPLEMENTARY NOTES

12a. DISTRIBUTION/AVAILABIUTY STATEMENT 12b. DISTRIBUTION CODE

Approved for public release; distribution is unlimited.

13. ABSTRACT (Maximum 200 words)

The airblast and fragmentation produced by explosions inside earth-covered explosive storagestructures (IGLOOS or bunkers) have been reexamined and assembled into one document. The data wereexamined with the following questions in mind: (1) How do they compare with current Department ofDefense Standards? (2) Can the data be scaled to produce general empirically-derived predictionequations? (3) I)o the structures tested during the Air Force Buffered Storage Test Program come fromthe same data family? These goals were met. Generalized prediction equations (with confidence limits)are provided for airblast. It was discovered that there is a major deficiency in the data relating to thedebris/fragmentation produced by explosions in such structures.

14. SUBJECTTERMS 5. NUMBER OF PAGES

ESKI MO TESTS IG1OO Explosive Safety 81

Earth-covered Magazines Safety Standards Airblast 16. PRICE CODEFragmentation Debris17. SECURITY CLASSIFICATION 18. SECURITY CLASSIFICATION 19. SECURITY CLASSIFICATION 20. UMITATION OF

OF REPORT OF THIS PAGE OF ABSTRACT ABSTRACT

UNCLASSIFIE) UNCLASSIFIE) UNCLASSIFI"'I) SARNN 7540-01-280-5500 Standard Form 298 (Rev 2-89)

Presribed by ANI Std Z39 I8298 102

GENERAL INSTRUCTIONS FOR COMPLETING SF 298

The Report Documentation Page (RDP) is used in announcing and cataloging reports- It is important thatthis information be consistent with the rest of the report, particulary the cover and its title page.Instructions for filling in each block of the form follow- It is important to stay within the lines to meetoptical scanning requirements.

Block 1. Agency Use Only (Leave blank). Block 12a. Distribution/Availability Statement.Denotes public availability or limitations. Cite any

Block 2. Report Date. Full publication date including availability to the public. Enter additionalday, month, and year, if available (e.g. 1 Jan 88). limitations or special markings in all capitals (e g.Must cite at least the year. NOFORN, REL, ITAR).

Block 3. Type of Report and Dates Covered. Statewhether report is interim, final, etc. If applicable, DOD - See DoDD 5230.24, "Distributionenter inclusive report dates (e.g. 10 Jun 87 - Statements on Technical Documents."30 Jun 88). DOE - See authorities.

Block 4. Title and Subtitle. A title is taken from the NASA - See Handbook NHB 2200-2

part of the report that provides the most meaningful NTIS - Leave blank.and complete information. When a report is pre-pared in more than one volume, repeat the primarytitle, add volume number, and include subtitle for Block 12b. Distribution Code.the specific volume. On classified documents enterthe title classification in parentheses. DOD - Leave blank.

DOE - Enter DOE distribution categoriesBlock 5. Funding Numbers. To include contract and from the Standard Distribution forgrant numbers; may include program element Unclassified Scientific and Technicalnumber(s), project number(s), task number(s), and Reports.work unit number(s). Use the following labels: NASA - Leave blank

NTIS - Leave blank.C - Contract PR - ProjectG - Grant TA - Task Block 13. Abstract. Include a brief (Maximum 200PE Program WU - Work Unit words) factual summary of the most significant

Element Accession No. information contained in the report.

BLOCK 6. Author(s). Name(s) of person(s)responsible for writing the report, performing the Block 14. Subiect Terms. Keywords or phrasesresearch, or credited with the content of the report. identifying major subjects in the report.If editor or compiler, this should follow the name(s).

Block 15. Number of Pages Enter the otalBlock 7. Performing Organization Name(s) and number of pagesAddress(es). Self-explanatory.

Block 16. Price Code Enter appropriate price codeBlock 8. Performing Organization Report Number. (NTIS only)

Enter the unique alphanumeric report number(s)

assigned by the organization performing the report. Blocks 17.-19. Security Classifications Self-

Block 9. SponsorinQ/Moni.toring Agency Name(s) explanatory Enter U.S Security Classification in

and Address(es). Self-explanatory accordance with U.S Security Regulations (i.e,UNCLASSIFIED) If form contains classified

Block 10. Sponsoring/Monitoring Agency Report information, stamp classification on the top andNumber (If Known) bottom of the page

Block 11. Supplementary Notes. Enter information Block 20. Limitation of Abstract This block mustnot included elsewhere such as: Prepared in coop- be completed to assign a limitation to the abstracteration with...; Trans of...; To be published in... Enter either UL (unlimited) or SAR (same as report)When a report is revised, include a statement An entry in this block is necessary if the abstract iswhether the new report supersedes or supplements to be limited If blank, the abstract is assumed tothe older report, be unlimited

Standard forrn 298 Back (Rev 2 89)