T h e firew ork s disaster in en sch ede P art 1: O verview an d reconstru ction

A rt ic l e 川川= ‖= 川川‖川

T h e firew ork s disaster in en sch ede P art 1: O verview an d reconstru ction

J.W eerheijm I, A .M .M van W ees *. P. C . A . M .de B ruyn

*,and J .W .K arelBe'*

Saturday afternoon M ay 13,2000 a m ajor firew orks incident occurred At the com pany S .E . F irew orks in the city orE nschede,the N etherlands. T w enty･tw o people w ere killed and m ore than 8eVen hundred w ere injured.W ithin a radius oflm n dred8 0f m eters houses W ere deStrDyed by the blastand debri s generated by the explosions and burntbecause Orthe SCattered Eirew ork8.

T he poBSib)e causes,Safety regtllationS and 88fety controlw ere investigated.B y order ofthe P ublic P r08ccutOr the N etherlands Forensic Science Institute (N F I) and T N O P rin8 M Atlri ts L aboratOry (T N O ･P M L ) perform ed the forensic and tech n ical inve8tigationB in to the reconBtru Ction and the cause of this disaster.

W ithin an hour the incident developed from a m oderate fire and 80m e initiated firew orks in one ofthe buildings into a Seri es ofthree explosions ofincreaSlng vi 01ence.M any peOple wi tnesSed the accident (at distance) and num erous vi deo recordings from different angles w ere m ade.

A fter the di8a8ter an extensive investigation w as Started.T he observed explosion effects,the inventory ofthe dam age in the area and allthe fo ren8ic evidence w ere analysed.T hey form the ba8iS for the reconstruction ofthe diSa8ter.T his wi llbe presented in the first paper.Scenario8 for po88ible cau8e8 0reach ofthe events W ere developed and analysed.T he 8eCOnd paper on the firew ork diSaBter in E nSChede focuses on the chain of event8 And the le880n8 that have tO be learned from this diszIBter,W eerheijm and D e B ruyn7I.

X eyw ords :E xplosion;fire;accident;dam age an alysis;fo ren8ics;rIrew ork8;8arCty regu lations;

bulk storage;dangerou8 goods;transport ClaSSirlCation.

1. lntroduGt ion

S atu rd ay afternoon M A γ 13 . 2 0 0 0 A m aJOr firew orks accident occurred at the com pany S .E . F irew orks in the city ofE nSChede,the N etherlands.

W ithin an hour the incident escalated from a m oderate rlre and 80m e initiAt,ed firew orks in one ofthe buildings into 8 8eri e8 0rthree explosions of increasing violence.T he rlr8tW 88 a relatively Sm all explosion in a container.W ithin a mi nute seven garage boxes (preh b concrete storage facilities) exploded.T his w as follow ed 66 8eCOnd8 later by a

R eceived :M ay 17.2002 A ccepted :July 12,2002

● T N O ･PM L

PO Box 45,2280 A A R ijSW ijk.T he N ctherland8 w eerheijm @ pm 1.tno.nl

● ● N FI

PO Box 3110,2280 G C R ij8W ijk,T he N etherlands P.de.Bru yn@ nfi.mi njuS.nl

further explosion or Storage Cells in the central Storage bu ild in g, w h ereby th e m ost violen t exp losio n occu rred in StOr8ge Cell C 日 . T he resu ltin g blast W ave W a s CO m para ble to A n explosion w ith a m ass betw een 4000 kg T N T and 5 0 0 0 k g T N T . T h e possib le ca u ses. Bafety regul ations and Safety controlw ere investigated.

T he observed explosion eLrects,the inventory of the dam age in the area and allthe fo ren8ic evidence w ere analysed by N F l and T N O .T hey fo rm the basis for the reconstru ction or the disaster.T his paper deSCri be8the observed facts and identification of the m ain , crucial elem en ts in th e ch ain of diSaSt.rOu8 events.

2. s ituat ion May 13. 2000

M ay 13, 20 0 0 w as a W arm Su nny day.M any people w ere ou tside enJDylng the w eath er an d

‑ 330‑ 火薬学会誌

F ig.1a T he layout Ofら.E .Firew orks (D elta pho t o,adaptionS N F I

F ig.1b T he centralstorage building (E n8Chede )

,adaption8 N F I) attracted to the S.E .Firew ork8

(S E F) area due to th e increasing firew ork effects.

T he SE F firew ork depots W ere 畠 ituated in a residenti

alarea of the city of E nschede.T he location and the

layout Of the S E F ‑depotis given in Fig.1.T he c

om pany S .E . Firew orks perform e

d firew ork displays arid show s , im p orted firew ork s

an d d id som e tra d e in 丘rew orks. T he depotconS

iBted ofa centralstorage building (cells C 2･C 15),seven prefab (garage)boxes and 14 18 0 ･cont8iner8.T he centralbuilding had w ooden doors and w as constructed in cast. rein forced concr

ete w ith a w alland roof thickne88 0f20 cm . C ell2 w as the firew ork叩 reparation and reparation room ,the intern aldim enSion8 0fthe cells C 12,C 1

4 and C 15 w ere 2.5 x 4.0 x 2.8 m

(wi dth x depth x heigh t).T he oth er

,larger Cells had a wi dth of4 m .

T he w alls and roof

Tab Je 1 L icensed BtOr8ge capacities

Location G ro88 m a8S per Cell Th n8pOrt c1888iEicAtio n

C entralbuilding cel18 C 3‑C ll 7000 1.4S or

1.4G C entral building celI C I3

C entralbuilding,sm allcel18 500k

g 1.3G

or 7000 kg I.4S or 1.4G

500k g 1.3G

C 12,C 14,C 16 or 5000

kg 1.4S or 1.4G

M oun ting /preparation room C 2

garage boxee M 1‑M 7 500kg,only during w orking

hour8 1 .4S or l.4G

3500kg 1.4G or l.4S

C ontainer8 E 1‑E

l4 3500kg 1.4G or 1.4S

Tbtal8 158.500kg 1.4S/F or 136.500kg 1,4S/O and 2.000kg 1.3G

(a) (b)

F ig.2a Situation At 15.16 hours And F ig.2b the escalation betw een 15.24 and 15.33 hours

(pictures R .van W illege m ) 3. Sequence of events

D ue to the m any people that w ere attracted to the accident,Severalvideo recDrding8 from var

i ous angles are avai lable.For learnlng and evalua

tion purposes, One m em ber of th e fire brigade w as specially tasked to record fir

e figh ting action8･

E specially his r

ecordings 0f the events have been very helpfulin the reconstru ction of the disa8

ter･

T he global tim e fram e is:

I4:45 F irew ork efrects wi tneBSed 15

:00 F ire reported to fire bri帥de 15:0

8 R econ nai688nCe S E Firew orks terrain 15:

16 Fire in C 2 u nder controL 15.24 S m oke and rlre efre

ct8 from C JI 15:33 S m ok e from con tain er E 2 vi

sib le

(video recording,tim e referenced to sei8m ic re

cordin gs 0f the m AB 8ive explo8ion8)

15:34 S m allexplos

ion,m a88ive den 8grAtion ofcontents

E 2

15:34:40 M 888ive explosion garage Storag e boxe8 M 7･M l

15:35:46 E xplo8ion C ll (Central

building).

A lm oSt Sim ultaneou81y the other cells

An d a num ber ofcontain ers exploded.

T he fi

gures 2dand 2 ^b illustrate the situation and th e e8C且lation ofthe rl reW Ork reactions in the peri od or 15.16･15.33 hours.T he pictures or F ig.3 8how the rln81explosion (from a diBtanCe Of about 60

0 m )and a tOp vi ew orthe explosion area wi th Searc

h sections taped ou t for the fo renSic inveStigati

on･

T he

F ig.3 Finalexplosion (from a distance of 600 m ) and explosion area after the accident w ith foren白 ic search sections.(P icture explosion a

rea:S FO B ) 3.1 ln it ia l fire in ce ll C2 F rom the

ch ronological accident facts, the param ount ques

tion em erges about the cause of the fire in the w ork

shop,preparation cellC 2 0fthe cen tral Storage building. E xtensive

foren sic investigation w as perform ed to

exam ine th e possibilities 0L1

‑ Sabotage,arson

or im provised explosive devices;

‑ M alfu nctionin

g,defects ofthe electricaland ga8‑

install

ation or other equlpm ent;

‑ F ire cau sed by hum a n

ACtivities at th e S .E . F irew orks terrain;

･ (S e 1 0 ignition offirew ork articles,pyrotechnics or other fuelB Caused by instability or

external efrect,S.

ln spite ofthe extensive

forensiceffortno definite proofw AS found for on

e ofthese scenari os.Itshoul d be noted that the stre

ngth ofthe finalexplosions had a devastating eff

ect and m ost ofthe evidence of the in itial fire w as

destroyed.O ther forensic investigation conce

rned the po88ible trace白0rhigh exploSive8 and am m u n

ition. N o traces of high explosives W ere foun d,th

erefore th e explanations fo r the cause and the devel

opm ent ofthe disaster had to be fo und in the s

tored firew orks and storage conditions.

3.2 Obse

rved exp losion effects T he m aJor explosion eff

ects are the crater , fireba l l,blastand debris･T

he vi deo recordings and the dam age at the expl

osion area show ed that the m ajor three explosions,r

espectively contai ner E 2 , garage boxes and th

e central building, had an

in creasing Strength . C ons

fo rm ed clear evidence fo r th e propagation direction of th e sym pathetic reactions in the cel18 (M 7 tow ards M l ) . In m ost ca8e8 the bl88t Strength of an explosion can be quantified from the building dam age in the 8urrOundingS and especially from the w in dow breakn ge.T he finalexplosion destroyed m ost Ofthis evi dence.A tone vi deo recording ofthe Second explosion.how ever.wi ndow and roof tile dam age i8 Visible.M ore info rm ation abou t the Strength of the explosion i8 Obtained from the 8ei8m ic Slgn818 that w ere recorded of both m aJOr exploSion S. T he ratio of the Bign8ls, the local dam age and the blast dam age to the surrounding area Concluded that the explo8ion lm d a strength of About 800 kg T N T equlValence.T he radiu8 0r the firebal lcorre叩Onds to 17.000 kg propellant.

3.2.3 F ina l exp los ion :

T h e relation betw een the events in E 2. the gEIraFe boxcS And the centralbuilding is descri bed in W eerheijm ELnd de B ru yn O.T he Strength of the explosion in the garage boxes W AS by far suLrlcient to blow the w ooden doorsin to th ecellsOfthe central bu ildin g an d the fireball engulfed the w hole bu ilding.T h e contents of Allcell8 W ere prObAb)y ignited. T h e central bu ilding w as COm pletely destroyed,See Fig.3 and 4.Sym pathetic reactions Occurred bu t the explosion in the central building w as Clearly dom inated by the C l1 reaction .T hi8 cm erges from the facts that:

･ In C ll a crater w as fo rm ed w ith A depth o r I.3 m .T he crater extended to the other cells and w as clearly the resul t of one explosion event;

F ig.4 D Am age Centralbuilding the n oor8 0f the

other cell8 8how no dam age of independent,Severe

explosion reactions,onl y the edges Of th e c

ell floors adjacen t to C ll are Severely dam aged And contri b

ute to the crater (母 ee F ig.4)

the rem alnlng re

inforcem ent 8tub8 0fthe n oor‑

W 811 connections 0r all cells Show den ection directed aw ay from cellC lI

; F ig.5 D ebri8 8t 165 m D ebri8 from th

e centralbuilding caused m any caSu81tieS and seve

re dam age tO buildings.D ebri s w as found up to a d

istance Of580 m eter.(See F ig.

5).T he angle of im p

act.the throw distance Ofthe m ajor debri s W as re

lated to the "required" launch velocity. B ecaus

e the lau nch angle i8 u nkn ow n, only an approxim

ate range Of lau nch velocities could be determ ined

.M ost Of the collected debris had a launch veloc

ity in the range 30 ‑ 100 m /ら . M axim u m recon

stru cted velocity w as 150 m /8.

P le88e note that m o

st or the debri s th at could be collected w as m ost

probably not from C ll or the Adjacentcel l s,beca

use the8e W ere broken in Sm all pleCeS due to the high exp

losion pre88ureS in the cells. M o8t evidence fo

r the rlnal explosion Strength w as Obtained fr

om the w indow breAkn ge and the observed dam a

ge in the 8urrOu nding8.W indow b reak age W as

inven toried in th ree d ifferen t directions up to a

di如 nce of850 m .T he distance , position,dim ensi

ons and breakage percentage Of about 700 houses serve

d 88 inputfo r the calcul ation of the sou rc

e stren gth . T he m eth odology to determ ine th e fail

ure probability coupled to the dynami c load is gl

Ven in W eerheijm et 81 ･,200 1･

T he dam age tO t

he hou 8e S , wi thin the radius of 500 m ,w ere categori2

ied to levels A , B ,C b.C a,Or

D .T hese Categori es w e

F ig.6 D am age radii 白 eCOnd W orld w ar ll and are

com m only accepted.

T he 2:OneS are glVen in Fig.6

wi th the radius for dam age level

C a i8 about 230 m . T he final.devastating explos

ion proved to be in th e range of JIO O O･5000 kg T

N T equivalence.T he size of the fireball w as 135

m ,correspon din g to 86.500 k g propellant.It iS evi

dent that th at these eLrectS are not Caused by the co

ntents 0f cell C l1 alone.Sym pathetic reactions 0f

the other cells and also the containers COntribu

ted to the observed effects.O n the video recor

din卵 th e 白 hape of th e fireballshow sClearly som e addit

ional"sub‑sources"

w hich m ay be caused by con

tainer reactions.

4. The exp 一 os ion effects and the s to red f ireyrorks

F or the h w Buit the qut!Stio

n about the reh tion betw een the explosion euects th

atoccurred and the qu an tities and type of in

volved firew orks iS param ount.H itherto,no defi

nite inform ation i8 available of the quantities an

d type of rlreW Orks th atw ere stored in the diq erent

cells.Inform ation

is available from the sal es li如 of S E Firew orks and the heari ng8.T hi8 inform ati

on iS instlfrICient to answ er the question.P lease

note that the local dam age to the noor8,And the v

i sualefrectB On th e videoS glVe u S inform ation

Abou t the firew ork reactions in th e 8peCific cel l s,w hi

le fireba l l,debri s and dam age are caused by the

sum of allfirew ork reactions (a com bination of m i ld and very

白 evere reaetioms). T he license Show s th at On

ly a limi ted am ount of I.3G class articles w ere al lo

w ed (2000 kg) to be stored in som e specific 8tOrage C

ells 0fthe central buildin g,T he bulk ofthe storag

e capacity (136.500 k g) concerned cIAS 8 1.4 G a

rticle8. T h e Safety regul ations are based on th e

prlnCiple that the efrect8 Observed in the U N tran

8pOrt ClaSSi丘cation tests are al so repreSentative fo r t

he potentialeu ects in (bulk) Storage and transpor

t COnditionB.O r in other w ords,the test COnditio

n S Should cover the scal e effect and conrlnem ent in

Storage COnditions.

It is obviou s th at th e effe

cts in the E nSCh ede disaster do not m atch wi t

h th e I.4G and 1.3G transport cIa88ification cri ter

i a.T his m eans th at large am oun ts Of 1.3G ,or eve

n 1.1 articles w ere

Kayaku Gakb ishi. Vol.63, No.6

Fig･7 E m ∋ ct8 during U N 6c test wi th report 8hell8

Stored or the tran叩OrtClassification m ethodology i8 not W ellsuited to cover bul k storage COndition8 and define 8tOr8ge Safety regulations.T he latter 88peCt i8 covered in the second paper 7),here w e w ant tO m ention the cla88iLication te8t8 that W er

e perform ed on various kind of firew ork Articles.

B ased on the sales listofS E F irew orks A Selection w as m ade orarticle8 that could be ofa class I.3G or h igher. C om parable,Sim ilar articles (display and sound eLrects) w ere purch88ed and tested fo

r transport C1888ification.T he selection covered cAkeboxe8,rom an Candles,colour and reportShells a8 W ell aS fou ntains And rockets.E BpeCially the ti

tanium report8hell8 and the larger Bhell8 Show ed S

evere reactions.Som e ofthe articles teSted w ere cla

88irled as 1. 1.Figure 7 illuStrate8 One Of the 6c te

8t8 W ith report Shells.T he test 8ericS are glVen in Jong and D irkBe 〇･･ l'･T he tests learned that the Selected item s W ere Ofcl8S S 1,3g or 1. 1.B ecAu8e no derlnite info rm ation is avai lable ofthe am o

unts a n d ty pes Of Stored firew ork s, it can not be concluded that the disaster W as Caused due to th

e kind of stored firew orks only. Scale effect

and con rlnem ent COnditions m ay have been of m aJOr im portance.T his aspecti8 discu88ed in m ore detai

l in the Second paper w ith the chain orevents

and the potentialeffects.

5. Con￠lud ing rem a r ks

･ T he explo8ion8 at S ･E ･F irew orks in E nschede on M ay 13. 2000 caused 22 1ethalities･ 947

‑ 336 ‑ lnJu rie 8 , a COm plete residen ti

a l area W as d estroy ed . 5 0 0 h ou ses W ere COm p le

tely dem olished and 1350 hou8e8 W ere d8m 8ged.

T he m ai n cause Ofthe dam age in the neigh bourho

od w as the m assive connagrAtion ofth e old ho wi th w ooden moors caused by the throw out of uses firew orks. In th is first p a p e r W e focu sed o n th e ob8erVAtion8 and fact与 .B e8ides the initial fire in the centralbuilding,three cru cialevent8 a

re identified that dom inate the escah t,ion of the accident.T hese are the Severe rl reW Ork reactio

ns in container E 2,follow ed by the explo

8ion8 in th e garage boxes a n d fin ally th e m 8B8ive explosion in the Storage Cell C ll of the cent

ral building and the Sym pathetic reA

ction8 0r the other Storage Cells and containers.

In Spite of the extensive forensic inve8tigation no definite evidence for the initialcau

se Of the ch ain or even ts w a s fou n d. T h ere

w as n O in d ication of sabotage. N o traces 0f hi

gh explo8iveS W ere detected;a

ll traces indicated firew orks related Subs

tances.

W indow breakage, StruCtural dam age, Crater dim ensions, debris and the SeiSm ic Si

gnals enabled the quantirICation of the tw o m a

jor explo8ion8･T he explosion in the gara

ge boxes had 8 Strength of th e order of 800 k

g T N T

equivalence w hile th e 8trength of th e Fi

explosio nal

･ P robably the classes of Stored rlreW Ork articles, qu antitieS and Storage conditions caused the initial fire to esca late in to th e diSa8trOu S exploSionS.T he second paper AddreSSe8 m ore in detAilthe Safety analysi阜Of80m e Of the cri tical A8peCt8 and events duri ng th e escalation of the rlreS and explosions and the le8BOn8 tO be learned ror th e b u lk Stora ge a n d tra n sp ort or pyrotechnics.

Referen￠es

1) B ru yn,P.C .A .M de;K arelBe a.W .(2000)

T h e fo ren8ic investigation F irew ork D iS88ter E n8Chede

T h e N eth erlands F oren8ic ln 8titu te, report 2000.05.17.0 18

2) C om m i88ie P rev en tie v a n R a m p en d oor G evaarlijke 8tOEfen (2000)

"M ethods for the determ ination of possible dam age to people and objects resu ltin g from relea8e Ofd8ngem uS m ateri 818".S du P ublishers ,

C P R ･16E .Second edition ,T he H ague.

3) Jong, E .D .de and D irk ee,M .W .L .(200 1) C la88ification investigation on display firew orks

of S E F irew orks

P art 2:C 1aBSirICation experi m ents T N O report 200 1･C 29

4) D irk 8 e,M .W .L and Jong E .G .de,(200 1) T he explosion at S .E .F irew ork 8,

P art 2:T ran8pOrtCla88ification judgem ent for confiscated firew ork

T N O report P M L 2000･C 12 1,vS 2.0 5) M erri field,A .and M ya t t,S .G .(200 1)

T he eWect8 0fE xternal F ire on Firew orks Stored in SteelISO containers,

Journalof P yrotech nics,2001

6) W eerh eijm ,a .;W ees,van A .M .M .; D oorm aal , van a.C .A ,M .;R hijnsburger,M .P.M .(200I).T he exp losion 8 a t S .E . F irew ork s; T N O P rin S M auri ts L aboratory,P M L 2000･C 120 and C 122.

P art 1: T h e explosion stren gth s b ased on observ ed dam age

P art 3:T he reconstruction ofth e chai n ofevents 7)W eerheijm ,a.;B ru yn ,P.C .A .M .de (2002)

T h e rLreW Ork S disaster in E n8Chede, P art 2:

S afety & P yrotechnics ,

IS E M 2002,M ay 2002,Japan

Kayaku G 8kkaishL 〉ol 63. N 0.6. 2002 ‑ 33 7‑

60 Sci.and Tech.Energotic N ateriaJs.Vol.64.No.1.2003

訂 正 と お 詫 び

火 薬 学 会 誌 3 2 8 号 V o l . 6 3 , N o . 6

} P L次 上 よ り 4 布 目の飴 文題名

(演)The Fireworks d isaster in enschede ‑ (正 )The fireworks d isaster in Enschede

■ 日次 上 よ り 5 布 目の論 文題 名

(洪)The Fireworks d isaster in enschede ‑ (正 )The rireworks d isaster in Enschede

■ 目次 上 よ り 7 番 目の給 文 頁数 ( 釈)36 2 ‑ (正)354

■p 3 3 0 胎文髄名

( 畝)The rirevorks d isaster in enschede ‑ (正 )The fireworks d isaster in I:nschede J p 3 3 8 独文儲名

( 訊)The fireworks { 総 目次 v i ペー ジ,

( 畝)The fireworks

●総 目次 v i ペー ジ, ( a )The fireworks

■総 目次 v i ペー ジ,

d isaster in enschede

･ (正)The rirevorks disaster in Enschede 上 1 行 目

d isaster in enschede I. (正 )The fireworks disaster in Enschede 上 3 行 目

d isaster in enschede l ‑ (正)The rirevorks disaster in Enschede 上 8 行 目

(釈)36 2 ‑ (正)3 54

以 上 . 絡 ん でお 花 び 申 し上 げ ます .

Science and Technology of EnergetiG Materials

第 64 巻 第 1 冊 通巻 329 号

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発 行 所 社 団 法 人 火 薬 学

会 長 Lfl 村 昌 三

〒 10 4 ‑ 0 0 2 8 炎東都 (rl央区八重洲 2 ‑ 7 ‑ 7 八鹿 洲 旭 ビル 6 F 日本 火 薬 工 業 会 内

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寵話 /FA X o93 (884) 3 3 1 9

編典兼発行人 田 村 肖 三

編 集 部 東京大学大学院 二 Ⅰ 二 学系研究科 化学 システム工学専攻

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E‑m ail:jes･edit唾● explosion.chem .t.u･lokyo.ac.jp

印 刷 所 (育)デジタル･プレス･ワークショップ結城

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