Investigation of S-IV all systems vehicle explosion

55 Pages·2.169 MB·English

by  J B Gayle, United States. National Aeronautics and Space Administration

N A S A TECHNICAL NOTE
b
INVESTIGATION OF S-IV ALL SYSTEMS
VEHICLEE XPLOSION
Compiled and edited by J. B. Gayle
George C. Marshall Space Flight Center
Hz.mtsuille, Ala.
NATIONAAL ERONAUTICAS NDS P ACAE DMINISTRATION WASHINGTON, D. C. SEPTEMBER 1964
0 0
TECH LIBRARY KAFB. NM
INVESTIGATION OF
S-IV ALL SYSTEMS VEHICLE EXPLOSION
Compiled and edited by J. B. Gayle
George C. Marshall Space Flight Center
,
Huntsville Ala.
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION

TABLE OCF ONTENTS
Page
...................................................
SUMMARY 1
..............................................
INTRODUCTION 1
.............................................
THE COMMITTEE 2
.....................................
MODE ION FV ESTIGATION 2
..................................................
FINDINGS 3
........................................
Basement Level 4
. ...........................................
Level No 1 5
. ............................
Level No 2 (Firing Level) 5
. ...........................................
Level No 3 5
. ...........................................
Level No 4 5
. ...........................................
Level No 5 6
. ...........................................
Level No 6 6
. .................................
Level No 7 and Above 7
SIGNIFICANCE OF FINDINGS WITH RESPECT TO MAGNITUDE
..............................................
EXO PFL OSION 7
Estimate of ExplosiveW eightB asedo n Damage to TS-1
...................................
ButBleu ri lding 7
Estimate of ExplosiveW eightB asedo n Damage to
.........................
Cover Protective Assembly 8
Estimate of ExplosiveW eightB asedo n Damage to
...........................................
I-Beams 8
Estimate of ExplosiveW eightB asedo n Glass
............................................
Damage 9
Estimate of ExplosiveW eightB asedo nF ragment
........................................
Dispersion 10
................
Summary of ExplosivWe eight Estimates 12
SIGNIFICANCE OF FINDINGS WITH RESPECT TO SIZE AND
......................................
DURATION OF FIREBALL 13
SIGNIFICANCE OFE XPLOSION WITH RESPECT TO PROBABILITY
......................................
FOU FT UINR CEI DENTS 14
.............................................
BLGAA SUTG ES 15
..............................................
CONCLUSIONS 15
...............................................
REFERENCES 48
iii
I
LIST OF TABLES
Table Titie’ . Page
I Propellants and Gases onB oard All
......
Systems Vehicle at Timoe f Explosion 16
Identification of Fragments Showno n
.................................
Figure 3. 17
..............
111 Data foSr elected Fragments. 24
N Calculation of Initial Velocities for
........................
Selected Fragments 30
V Summary of LOX/LH2 Experience with Full-
...............
ScaleF light Weight Tankage 31
iv
LIST OF FIGURES
Figure Page
.................
1 Movement ofV ehicleA fterE xplosion 32
..................
2 View of Test StandA fterE xplosion 33
.........................
3 FragmentD ispersionP attern 34
..............................
4 Glass BreakageP attern 35
.....................
5 Damage toB utlerB uilding. TS-1 36
........
6 Liquid Hydrogena nd Oxygen Sleds( 3rdL evel) 37
........
7 VehicleD ebriso n Top of Engines( 4thL evel) 38
.................
8 BentS tructural Members (5thL evel) 39
...
9 Cable Raceway and Elevator Shed (6th & 7thL evel) 40
...........................
10 Cover Protective Assembly 41
.......................................
11 Damaged I-Beam 42
12 Relation Between Initial Velocity andG round
..........................
Range (Low Velocity’R ange) 43
13 Relation Between Initial Velocity andG round
.........................
Range( H igh Velocity Range) 44
...............................
14 Sequenceo fE xplosion 45
15 FireballD iametersf orV ariousW eightsa ndT ypes
......................................
of Propellants 46
16 FireballD urationf orV ariousW eightsa ndT ypes
.....................................
ofP ropellants 47
V
TECHNICAL NOTE D-
INVESTIGATION OF
S-IV ALL SYSTEMS VEHICLE EXPLOSION
SUMMARY
Investigation of the S-IV A l l SystemsV ehiclee xplosioni ndicated
thef ollowing:h ighe xplosivee quivalent, 1 percent;f ireballd iameter,
380 feet;f ireballd uration, 11 seconds; maximum fragmentr adius, 1500
feet. The relatively low yield was due tos ubstantiallyi nstantaneous
ignition of the spilled propellants which probablyr esulted from the
extremef lammabilityo fh ydrogen. Ift hist rendp ersistsi nt hes cale
model test programs now inp rogress, some reductioni nt he 60 percent
highe xplosivee quivalentc urrentlyu sedf ors itingo f LOX/LH2 vehicles
may be possible.
INTRODUCTION
On January2 4, 1964, the S-IV A l l SystemsV ehiclee xploded and
burnedd uringt het erminals tageso ft he countdown for its initial
testf iring. The incidentw hicho ccurred at Test Stand 1 oft he
DouglasA ircraft Company( D AC), Sacramento test facility was the
second known failurei nvolvings ignificantq uantitieso ft hep ropellant
Combination, LOX/LH2. Inasmuch as thep reviousf ailurei nvolvingt hese
propellantso ccurredd uringt heb oosterp haseo ft hef irstC entaur
launch,t he S-IV All SystemsV ehiclee xplosion was the first for which
a detailed examination of the resulting damage was possible.
A number of small scale studiesc urrently are beingc onductedt o
assess theh azardsa ssociatedw itht heu seo f LOX/LH2 and otherp ro-
pellantc ombinations;h owever,e xtrapolationo ft her esultso ft hese
studies to obtain siting criteria introduces a considerabled egreeo f
uncertainty whichc an bestb ee liminatedo rm inimizedb y tests in-
volvingf ull-scalet ankageo ff lightw eightc onstruction.A lthough
such tests are contemplated,t hey are note xpectedt ob ea ccomplished
before FY-66. Therefore, it was consideredm andatoryt hat a compre-
hensive investigation be made oft he S-IV A l l SystemsV ehiclee xplosion
and thatt hei nformation b.e analyzedw ithr espectt ot hec urrently
accepted siting criteria for LOX/LH2.
THE. COMMITTEE-
The chairmano ft hei nvestigatingc ommittee was Dr. W. R. Lucas,
Chief of the Materials Division,P ropulsiona ndV ehicleE ngineering
Laboratory,M arshallS paceF lightC enter (MSFC). The alternatec hair-
man was Dr. J. B. Gayle,C hiefo ft heP hysicalC hemistryS ection,
ChemistryB ranch,M aterialsD ivision, MSFC. Other members from MSFC
Mr. Mr.
were: H. C. Dyer, Test Laboratory; L. L. Roberts,S afety
Mr.
Office;a nd 0. S . Tyson, MSFC residente ngineer at DAC Sacramento.
Members fromo ther NASA organizationsw ere: Dr. F. E. Belles, Lewis
Mr. Mr.
ResearchC enter; P. V. King, Cape Kennedya; nd G. D. McCauley,
Mr.
NASA Headquarters. Members from Air Forcei nstallations were: .
C. R. CookeE, dwards Air ForceB ase,a nd Mr. L. J. Ullian,P atrick
Air ForceB ase. Dr. P. A. Longwell,C aliforniaI nstitute oTf echnology,
serveda s a member representing DAC. Consultantst ot hec ommittee were
Mr.
Mr. A. J. Hoffman, BallisticR esearchL aboratories (BRL), and W. M.
Smalley,A erospaceC orporation.
MODE OF INVESTIGATION
The committeem et a t 9:00 a.,m. a t DAC, Sacramento on February 5,
1964. Dr. Lucas was unablet oa ttendb ecause of a longstanding
previous commitment so thea lternatec hairman, Dr. Gayle,p resided.
He statedt hatt hep urpose of thec ommittee was toi nvestigatet he
n a m e andm agnitudeo ft hee xplosion,i nsofar as possible,f rom a
post-morteme xamination,b ut was nott oc onsidert hec ause of the
failuree xcept as it relatedt ot he magnitudeo ft hee xplosion.
Informationp reparedi na dvance was distributed.T hisi ncluded
air andg round-basedp hotographs of the test stand and maps of the
area showingf ragmentd ispersiona ndg lassb reakage. A briefing OR
thee ventsl eadingt ot hee xplosion and thet hen-currentt heoriesr e-
gardingt hep robablec auseo ft hee xplosion were given by Mr. Ted
GordonC, hiefE ngineerW, C,SacramentoF. ourc olorf ilms of the
explosion were shown:o nef rome ach of theu pstreama ndd ownstream
camerasl ocatedr oughly 300 feet fromt hes tand, ando nef rome acho f
two enginea rea cameras locateda pproximately 10 feet fromt hev ehicle
on the level just below that at whicht hee xplosiona ppearedt oo ccur.
Afterd etailedi nspection oft hesef ilms,t heg roupv isitedt he
explosion site for a quickl ook and thenr econvenedf ori nitial
discussions.B ecause it was evidentt hat a systematice xamination was
essential,t hec ommittee was dividedi ntot hreeg roups. One group was
responsiblef ors urveyingt hee ntirea reat oo btaind etailedi nformation
onf ragmentd ispersion. A second-group was responsiblef orn otingt he
damage suffered by small, nearbys tructuress ucha sB utlerb uildings
and trailers.T his groupa lso examined several damaged beams located
ont het ests tandi nt hei mmediatev icinityo ft hee xplosion. The
last groupe xamined the test standi na s much detail as timep ermitted.
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Afterc ompletiono ft hesea ssignments,t hec ommitteer eassembled
forf urtherd iscussion.B ecause it 'appearedi mpracticalt oa ttempt
ano n-the-spota ssessmento ft hef indings,s pecific i.tems of data were
assignedt ov ariousi ndividualsf orc onsideration and evaluation
followingt hem eeting.A fterr eceivingt hesea ssignments,m osto f
thesei ndividualss pentt hes econdd ayo ft hem eetingo btaininga d-
ditionalp hotographs,m easurements,a ndo therp ertinenti nformation on
theira ssignedp ortionso ft hei nvestigation.A rrangements were made
too btain similar dataf or LOX/RP-1 explosionsf orc omparison,a nd
liaisonw itht hec ommitteei nvestigatingt hec auseo ft hee xplosion was
established. The test standt hen was releasedt o Mr. 0. S. Tysona, nd
them eeting was adjourned.
FINDINGS
Weightsa nd conditions ofo n-board propellants and pressurization
gases at the time oft hee xplosiona reg iveni nT able I. The indicated
weights of LOX and LH2 were,r espectively, 84,244 and 16,954 pounds for
a combined propellantw eighto f1 01,198p ounds.
A detailedd iscussion oft hee ventsp recedingt hee xplosion and
thep robableu nderlyingc auseso ft hei ncidenta rec ontainedi nt he
classifiedr eporto ft hec ommitteer esponsiblef ori nvestigatingt his
aspect of thei ncident( Ref. 1). The immediatec auseo ft hef ailure
was theo verpressurizationo ft he LOX container.E xtrapolation of
test recordsi ndicatedt hatf ailureo ccurred at a LOX pressure of
approximately1 00p siao r well abovet hed esign l i m i t fort hev ehicle.
Frame-by-framei nspec,tiono ft hev ariousf ilmss uggestedt hati nitial
ruptureo ccurreda roundt hep eripheryo ft he common bulkheada ndt hat
ignitiono ccurredi mmediately upon rupture.T hus,t here was no visual
oro there videncet oi ndicates pillage of the LOX beforei gnition.T his
couldi ndicatet hatr upture of thee xternals kino ft he LOX tank was
followedb ys imilarr uptureo ft he LH2 tank within a few milliseconds.
Anotherf ailure mode whichc annotb ee xcluded is thei nitial.r upture
oft he common bulkhead,p robablyw iths imultaneousi gnitiono ft he
propellants, ands ubsequentr uptureo ft hee xternals kino ft hev ehicle.
Still other modes are possible;h owever,r egardlesso ft hea ctual mode
of failure, all availablee videncei ndicatest hatt here was little or
no time form ixingo ft hep ropellantsb eforei gnition.I nspection of
thef ilmss uggestedt hatt he.explosiono riginatedn eart hec enterl ine
oft he test stand rand neart hed ecko f level No. 5. Inspection of
damage tot he test standi ndicatedt hatt hec enter oft hee xplosion
couldb ea pproximatelyl ocated at a point, in the vertical direction,
midway betweent hej unctureo ft he common bulkheada ndt hes ide wall
andt heu ppermostp ortiono ft hec urvedb ulkhead.
3
It also appeared to be five feet to the west of the vertical center line
of thet ank.T hus,t hea pparentc enter of detonation was at a height
of 55 feeta bovet heh ards urfaceda prono nw hicht hes tand was located
and five feet west of the north-south center line.
Inspectiono fp hotographsp repared by enlargingi ndividualf rames
fromo neo ft hee ngine area camerasi ndicatedt hatt hei nitialm otion
of the vehicle caused by thee xplosionh ad a definite westerly vector.
This was determined by locating readily definable parts of the vehicle
withr eferencet ot he test stands tructuref romp hotographst aken
immediatelyb eforea nda ftert he start oft hee xplosion. The results
are shown in FIG 1. The movement from left to right shown in this
figurer epresents movement in a north-westd irection.S incet his
analysisi ndicatest hatt hei nitial movement of theu pperp art of the
vehicle was Poward rathert han away fromt hea pparentc entero ft he
explosion, it appearst hatt hebrincipale xplosion may haveb eenp re-
cededb y a smaller onel ocatedn eart hep eripheryo ft hev ehicle.
The areas urroundingt he test stand was ropedo ffi mmediately
aftert hee xplosion, anda ccess was rigidlyc ontrolledt hereafter.
Thisg reatlyf acilitatedt he worko f thec ommitteea nd,i np articular,
insuredt hev alidityo fs urveyso fs hrapneld ispersiona nd test stand
.
d ama ge
Figure 2 shows the test standa ndv icinitya ftert hee xplosion.
Inspection of thisf igurei ndicatest hatt heo verheadc rane and
supporting structures were virtually undamaged and that the effects
oft hee xplosion were largelyc onfinedt ot he test standp roper.
Figure 3 is a map showing thel ocationo fd ebrisw hich was
disperseda ss hrapnel.T able I1 givest hei dentification oft he
fragments shown on FIG 3. Table I11 is a tabulation of thea pproximate
sizes,w eights, and locations( ind istancef romt hec enter of thee x-
plosion)o ff ragmentss electedf orp ossibled etailedi nvestigation.
Glassb reakageo ccurred at distances up toa pproximately 1,100
feet fromt hec entero ft hee xplosion, as shown in FIG 4. Most
significant to this study were windows brokeni ng uards hacks,h ouse
trailers, and Butlerb uildings.
The ButlerB uildiQgd esignated TS-1 sufferedw hat we considered
relativelyl ight damage (FIG 5). One endo f thisb uilding was, positioned
facing the blast, with the nearest surface at a distance of 210 feet
from a pointo nt heg roundd irectly below the assumed center oft he
explosion. Damage tot he test stand is described by individuall evels.
BasementL evel
The doorso ft heb asements witcha ndg enerator room were blown in-
warda nd were offt heirh inges. These were metal doors,e ach 4 ft. 2 in.
by 8 ft. 6 in. However, no damage was done insidet he room.
4