THIS DOCUMFNT CONSISTS OF_ _ t oL -_PAG - NO _ J Cf SERIES_ L 6 J ___ NAGASAKI AT l' IC BCll E DAMAGE Walter p By Youngs Jr Major C of E AUS CONT E NT S -------- PAGE FOREWARD - Nagasaki Atomic Bomb Damage SYNOPSIS Nagasaki Atomic Bomb Damage • • l - 2 3-4 I General Description of Nagasaki • • • • • • • • • • • • • • • II Description of the Atomic Bomb Explosion • • • • • • • • • • III General Description of Damage IV Damage to Reinforced Concrete Buildings • • • • • v Damage to Structural Steel-Frame Bdiadings • • • • • • • • • • • 33 _ 34 VI Damage to Masonry Buildings • • • • • • • • • • • • • • • • • • • 35 VII Damage to Wooden Buildings • • • • • • • • • • • • • • • • • • • 36 VIII Damage to Reinforced Concrete Riveted Steel Chimneys •• 37 IX Damage to Bridges • • • • • • • • • • • • • • • • • • • • • • • • • 38 x XI • 5 _ 7 - lD • • • • • • • • • • 11 - 21 • 22 - 32 39 Damage to Utilities • • • • • • • • • • • • • • • • • • • • • • • • 40 Damage to Railroads and Roads • • • • • • • • • • • • • • • • • • • • • • • • XII Fires •• • XIII ca sualties Relation to Buil ding Types • • • • • XIV Construction to Resis t Atomic Explosions • • • • • • • • • • • 41 - 4 3 • • • • • • • • l i - -48 • • 49 - 62 DECLASSIFIED Authority By DECLASSIFIED Aut11ority °t I 6 NN O Ff f M Nf A 'J3te l C PANORAW ✓ General view of Nagasaki taken on the road to tfogi from approximately two miles Southeast of the basiness center and about four miles Southea's t of zero point The chirr neys in the oackground are located at the t iitsuolshi Steel and Arms ''Jorks No te t he hills in the right foregroi nd which shielded a large part of the business and residential section from the full effects pf the oomb blast Alan note typical Japanese residential construction consisting of light houses with tile roofs and that the hillsi'des were cultiv'ated and inhabited almost to the tops WOODEtJ HO ES Typical d- ellings with flims r vooden frames and tile rooft1 DECLASSIFIED Authority NND'¥ 0091 WOODEN HCl ES Typical dwellings with fliffisy ·ooden frames and tile roofs • NAGASAKI ATOl IC BOl- B EXPLOSION This is R view of the cloud caused by the e imlosion of the Atomic Bomt The Dicture was taken by thf crew of a B- 29 probably aoout eight miles away The mushroom ex- olcsion cloud at the ton of the picture is estimated to extend to an elevation of about 40 000 feet FIGtTPW • SECR T II DESCRIPTION OF THE AToMI C BOMB EXPLOSION Continued 0 TABLE I Distance from _oinf eet 0 I I I- Hyd static Peak ressure Lbs per Sq Inch 1 1 50 100 2 300 J 5 J -4oo 16 4 0 50 12• 5 4 700 s Dishing of Metal Plate Snappipg of a Telegraph ole Dishing of Concrete Floor Panels Overturning of Memorial Stones Collapse of Oil Drums J - J • 5 12 000 1 4 Venial estimate of damage compared with Macdonal Ranch Trinity 23 000 o 4 5 Fa1l11re of Paper Panels Kamigo Barracks - Method of Determination Ualculiflons xtrapolations Crushing of Tile Urain Pipe 1 50 - 200 8 000 I 11 Zero - Considered the most reliable igure f is a graphical representation of peak pressures showing the sharp decline in intensities with increase in distance from the center or concussion DE us1 FiED ¥ rity H c - 0 BY c li1' 0 1JJlf il a 9I ERIAL VIEW OF NAGASAKI Pre-Strik View •Tnis view was tal en oefore the Atomic bomb was dropped on Nagasaki on 9 August 194 5 Japanese tlme Note how closely buildings are located and the absence of fire breaks Numbererl areas how the important tar iets FIGURE _ • _ _J__ SfeP - DECLASSIFIED AuthorityN ND oOSCI AERIAL VIEW -OF NAGASAKI Pre-Strike View J This aerial view was taken before the Atomic bomb was r dropped on Nagasaki on 9 August 1945 Japanese time The zero point of the explosion center of concussion was just Northeast of the stadi1 llll visible in the upper right portion of the photograph The main targets were the MitsubishiUrakami Ordnance Works Torpedo Works in the upper rightband corner of the picture and the Mitsubishi Steel and Arms Works which is spread out along the East bank of the Urakami River in the central part of the picture Note that this industrial valley is inclosed by steep hills which tended to shield the main business and residential portion of Nagasaki righthand portion of the picture from the full effects of the blast when the bomb mu exploded Also note areas stripped of buildings apparently to serve as fire breaks y • e DECLASSIFIED 4 0SC Authority_b NDicfD _ SECP AERIAL VIE ri OF NAGASAYI Post-Strike View This aerial view was t ken on lJ August 1945 Japanese time four days after the Atomic bomb explosion This nicture shows very clearly that the great industrial valle r of Nagasaki was almost cnmoletely wioed out The large I i teubishi-U ra kami Ordnance orks and the Mi teubishi Steel and Arms Ylo rks the main targets fere ver' severely damaged i'his vi·ew shnws that nor- tione of the ma in buslnl' s and residential centere were also seriously da aged F'rr URE_ DECLASSIFIED Authority _ NND'¥J oosef 1- _ A RIAL VIEW OF' NAGASAKI Post Strike View - Section I This view indicates zero point and the two principal targets Concentric circles show distances from the blast center Note that the only structures left standing were the reinforced concrete buildings and some of the steel frames of the 1 1 1 tsubishi factories Buildings surviving the blast were damaged significantly FIGUREJ i _ C 14 DECLASSIFIED Authority osq ND D- VI OF NAGASAKI Post Strike View - Section II This view shows the extent of damAge at distances greater than L-1 2 miles South of zero point Note portion of main business section on the East bank of the river 1-3 4 to 1 4 miles from the olast center severely damaged by blast and fire Buildings of the shipyard dock and engine works as far as 2 6 miles from zero point est bank were stripped of part of their roofs and siding FIGURE DECLASSIFIED N ND11oosef Authority Cff5 ' ' ' t ZERO POINT View of wr ckage and rubble immediately beneath center of tomic Bomb concu sion The man is Private Joseph Calev Signal Corps Photo- grapher who took most of the pi ctu res sho n in this reoort 'FI GURF DECLASSIFIED- Authority Nf'J I 0_ 1 ft ZERO POINI' Close-up view at zero point showing debris and large amount of combustible material which did not burn • • w' r--oECLASSlFlED QSq 'llil ' - -- - Authorityb NDiq o • OENERAL DAMAGE View of rubble and wreckage very close to zero point FIGURE--4 - 'L_ DECLASSIFIED Authorityj'J ND1'10091 - DECLASSIFIED AuthorityNND Oc#J J ITSUBISHI ST EL AND ARMS 'NOR KS From 0 • 3 to 1 2 Hles South of Zero Point This aerisl view looking North toward zero Point shows about the middle three-fourths of ·the above plant with the damage caused by the Atomic bomb etriopen of roof an l siding Note damaged steel frame work The long buildings in the South between reinforced concrete offices are concrete arch-roof structures that collapsed The buildings on the West bank of the river a re the remainfl of the Mi tsubiahi Steel Casting PlAnt Note logs ready for orocessinp into lumber at Mi tsubishi Wood Working Plant further South 1 DECLASSlFlEU AuthorityNND'¥l0091 · PANORA A View of devastation by blast and fire looking South Building and chimneys in background are remains of l ' i tsubishi Steel and Arms lforks The road is of reinforced concrete approximately l 8-feet wide It was undamaged but is still- partially covered with debri • - --AutborityNNDf1 JtJ91 DECLASSTFIED - DECLASSlFIED Authority NND oOS9 ----- ---- --- J j PANORAUA View from Prigon looking South toward Kitsubishi Steel and Arms Works showing- blast and fire damage FTGlmE q •• L I DECLASSTFIED fVl'Jf 'J ltJIJ 91 Authority U El LASSIFIIW Authority Ni D'ff oOSC j PANORAMA Aerial view North of zero no nt lookinp Jouth showing devastation along East side of Urakami River tions in foreground are rerrairts of the Prison V-shaped foundaBuildings in left backgro md are those of Nagasaki li edical School and P ospital reinforced concrete frames Note steel frames of r i tsu- bishi Steel and Arm8 7orks along oack of the river also note bridge destroyed by the blast AJ l of this area was thickly covered with factories and dwellings FIGURE q2- o - • DECLASSIFIED Authority tJ I D'¥ DOSCf PRISON AporoximRtely 1 4 I ile Uortheast of Zero Point View showing wreck d concrete walls IJj oi cUSSTF t o9f A utborH y OECLASSlFIEO Authority j l - OSl ND'¥ D - --- -r7' --- PANOIW A Aerial view showing damage South of zero point and itest of Uraklimi River Lar e building in center is a nublic school reinforced concrete approximately J 4 of a mile Southwest of zero point F Gt IBE o- - - • '1 ' 1 '· 1A · -- - 1Ji-•- r ¼ '7t- • • U 'l LA ll' u v A uthority asq NNDitJ0 PANORAMA View looking 'es t to Chinsei t idrlle School approximately O J 1 iles Southwest of zero point showing blast and fire damage Note large amount of com bus ti ble material r emaining I P'IGUR c 2 _J • L '091 - DECLASSIFIED Authod1yj JN 7'1 DECLASSIFIED Authority Ni D'¥ 0 Ptt NORA vJ Aerial vie 7 showing devastation North of zero poin ann 'West of the Urakami River Note that not only all of the heavily o iilt- up areas were completely ·nestroyed but also · that dwellings were seriously rlan aged almost to the tdps of the hills The large re- inforced concrete building remaining in l eft center of picture is the Shiroyama School wrecked The outh wing facing zero point was badly • DECLASSIFIED tJ NDiq OOSC Authority 1'-- -- - - ---JI PANORAMA This view is taken from the school ouilrling Shiroysma West of the Urakami River looking H aet toward zero polnt about mile away 1 4 Note ruins of Catholic Church in the left background anc' the builc' ines of the Nagasaki Medical School and HospitP l in the right background All this area was thickly covered with small fact lI T b1 1ildings and dwellings The zero point for the Atomic bomb exoloslonJ that is the point directly under the center of the blast lies abo t half-way between the remains of the stadium and the road 1n the center of the picture on which the trucks are parked Con- crete bridge over Urakami River center of picture sust 4ined only minor damage • j_ • ---- ---n DECLASSIFIED Autborityj ND DECLASSIFIED AuthoritvN N Diq 0091 1 A general view t9 'ken from the Naga-aaki t✓-edical Sch0ol and Hospit'll looking So ithwest In the illlmediate foreground the t p of one of the l ledicrl school builrlings can be seen In the foreground at the foot of the hill on hich the medical school ie located the do ible-track street railway loop to the hospital buildings will be noted There -was practically no da ge to 'the tracks themselves but the xrolley wires · ere knocked down and the tr cks covered with debris The whole area shown in ttiis picture was cover with industrial builclings and small res ldences almost Be clos together as it was poRsiole to ouild them In the background the skeleton remains of a portion of the 1'itsubishi Ste l and Arms '1orlfs can be seen Note that the reinforced concrete office b iild ngs still stand amid the wreckage of steel fr mes A reinforced concrete school buil ling is situated at the foot of the hills in the background Doors windows c eiling and buildj ng conteits were damaged oy the blast DECLASSIFIED Authority 1'J iq N D oOSC PANORAUA ThiR view shows general destruction in the industt-ial valley looking We t from the lla asaki l-edicP l School and Hospital toward the reinforced concrete fsctor v trainin school et the foot of the hills in the background The North end of the fil t ubishi Steel and Arms larks can be seen in the middle nortion of the picture The reinforced concrete chimney though still vertical was cracked by the blast The two reinforced concrete walls are the remains· of two factory buildings and are para llel to the direction of the blast The whole area was covered with factories and homes The tracks of the street railway trolley were covered with debris but ere not damaged FIGURE 2J - DECLASSIFIED Authority 1 NI D'¥10091 PANOlW 'iA A f eneral view looldn$7 Northeast from the Nagasalci 1 edical School nd HoRpital toward zero ooint This whole area was covered with smnll factories and homes rhe reinforced concrete Primary School Shiroyama at the foot - f the hills in the back- gro nd remained standing but was damaged by the blast Ul t LASSIFIICU 1 C C PANORAMA View tflken close to zero point looking ' 7est about 1 4 li ile to Shiroyama Puolic School l ote South irw wrecKed by the blast and the almost complete' devasta ion in this vicinity Authorityl Ni l JOOS'i I r • I J DECLASSIFIED'Of7 Autholltyf1 IJD7'1tJ ' • oECLASSlFlEO uthority oS'i t ND O- 1i J NAGASAKI UWICAL SCHOOL AND HOSPir U From o 4 to 0 55 Miles Southeast of Zero Point This view shows the fine r bble and utter devastation at the foot of the hill belov the 1' edicnl School Note the nile qf oonei in the center of the picture which remained after the cremation of neople who were killed by the Atomic explosion was partil-llly covered with debris but FIGURE s2--7 • WAS Street Railwtiy not damaged • 7 1 t# DECLASSIFIED Authority J J _D OECLASS FlED - Authority NND'¥ oOS9 PANORAl ' A A v lew taken from the hill At the prison looking East toward the ruins of the large Roman Cntholic Church The hative dwellings in the center of the pict 1re vere erected by the Japanese after the blast U µrovide temporAry housing J L I DECLASSIFIED AuthorityN f 7'1 109 I DECLASSIFIED Authority Nt Diq oDSq LITSUBISRI DOCKYAHD Aporoximately 2 6 Pl iles South of Zero Point This is a view of Drydoclt No 3 sho ing d11mage resulting from bombing A single 500-pound demolition bomb was dropped on 1 August 1945 Japanese Ti e The crater ts vislble near 81 Ulken ship Dau- age was localized and minor • The Atomic bllist on 9 Aug st Japanese Time stripp ed corrugated iron roof and siding from buildings end damaged roof purlins Hammerhead crane was not damaged FI GURE JO J - DECLASSIFIED 7 tJ091 I Aut Jorityj J 7' '091 DECLASSIFIED Authorirv VND7'1 -- - - - - -- DECLASSWlED Authority NND ¥l 0091 hARBOR VIEW Aporoximately 'l -J 4 t iles South of Zero Point View from West bank looking East Sailing boat sunk by high explosive bomo on l August 194 5 Japanese time ship U s s Haven and cruiser U S s Wichita left background are in customs area Picture by w G Penney Hote hospital Buildings in DECLASSIFIED Author ty NNDiq oosq JAPANESE NATIVES Approximately 0 4 Miles South of zero point FIGURE_J 1 _ _◄ _ L UECLASSlFlED •thority NI D1' oosq JAPANESE NATIVES Aoproximately o 4 ilea South of Zero Point Typical war-time dres of natives Note oomb devastation Buildings in background are Nagasaki l edical S chool and Hospitalo • • IV NAGASAKI ATOMIC BOMB DAMAGE DAMAGE TO REINFORCED CONCRETE BUILDINGS Tho damage sustained by reinforced concrete buildings depended both on the proximity to zero point and to the type and strength of the reinforced concrete construction Some of the buildings with reinforced concrete frames also had reinforced concrete walls ceilings and partitions while others had brick or concrete tile walls covered with either plaster or ornamental s tlbne with partitions of metal-lath and plaster With the exception of the Nagasaki Medical School and Hospital group which was 'designed to withstand earthquakes heavier construction than most American structures most of the reinforced concrete construction could be classified only as Fair with the concrete apparently of low strength and density with many of the columns beams and slabs underdesigned and improperly reinforced These facts account for some of the structural failures described and depicted In general the Atomic Bomb explosion damaged all windows and ripped out bent or twisted most of the steel window and door sash ripped doors from hinges damaged all suspended wood and metallath suspended ceilings dropped onto floors The blast concussion also caused great damage to equipment by tumbling and battering - r'r -r V-l DECLASSIFIED Authority NNDiqoOSC - 22 - l • DAMAGE TO REI NFORCED CONCRETE BUILDINGS Continued In many cases fires generally of secondar r origin consumed practically all combustibl e material caused plaster to crack off burned all wooden trim stair coverings burned wooden frame of suspended ceilings beds mattresses mats fused glass bottles etc ruined all equipment not already destroyed by blast ruined all electrical wiring plumbing and caused spalling of concrete columns and beams in many of the rooms It should be emphasized that fires did not occur in the wings and rooms of all of the buildings even in those relatively close to and facing zero point Many rooms f acing zero point contained combustible materials such as paper straw mats woo l etc without fires occurring Of all the building t 'l es in Nagasaki buildings with reinforced concrete frames withstood the explosion with least damage Damage to equipment and casualties of all types were also smaller in such buildings The most mod rn group of reinforced concrete-frame buildings were those of the Nagasaki Medical School and Hospital Group This group contained 22 heavily built reinforced concrete buildings and 24 wooden buildings varying from 0 4 to 0 55 miles Southeast of zero point See Figures JJ to 35 inclusive - 23 - r DAMAGE TO REINFORCED CONCRETE BUILDINGS Continued Many of these buildings were built as late as 1931 While all of the wooden buildings were completely wrecked and considerable damage was done to buildings with concrete frames as previously described the blast did practically no damage to the reinforced concrete frames themselves These concrete buildings were earthquake resistant and typical of such construction in the United States Figures 34 35 and Figures 36 to 43 inclusive illustrate the concrete buildings at the Nagasaki Medical School and Hospital and show the extent and type of damage sustained DECLASSIFIED o91 A utl101·it y ' ' • • ' • ' - ' ' • _ ' • • • •·6 - • • ---- - v· •• • 1 1'· 1 - • • • • · • I • - 5 -- 0 hCN _ _ j - --1 'I ' - ' J I1 ' 'i ' 0 a ' 1 - kdlot u b 1st11 u h1 1 sh i' 'I 0 ii f I r • t' • • ' r ' ··· q 0 _ ' r - ' f ' •''' - '• ' ' 1'1 1' ·· 0 lo G l ' 1 J1 2 ' 1 ' _ • FIGURE DECLASSrFIED f'J I DiqDOSC Authority J JI ✓ n FIGURE C1Cnrt I ·c -- 'b -Kt '1' CJ f I DECLASSIFIED Authority NND ooSCI J I j J B -- DECLASSIFIED • f u horlty NND ¥l oosct NAGASAKI l EDICAL SCHOOL AND HOSPITAL From 0 4 to 0 55 Liles Southeast of Zero Point One of the court yards showing several of the buildings of modern construction Note wreckage of ' VQoden buildings in the background and that a very large amount of combustiole material did not burn First building on left far end - second story was hit by a bomb eight days before Atomic Bomb hit Nagasaki FIGURE 3f DECLASSIFIED Authority NI Diq oOSC AGASAKI MEDIC ' i L SCHOOL AND HOSPITAL From o 4 to 0 55 l iles Southeast of Zero Point Reinforced concrete foundations of wood ouilding destroyed by Atomic blast and secondary fires Reinforced concrete building still stands but note that windo•s window frarr es and doors were ripped out by the explosion flage Painting on building and chimney is for camou- Both reinforced concrete chimneys were damaged b the blast FIGURE NAGASAKI 1 EDICAL SCHOOL AND HOSPITAL From o 4 to 0 55 Uiles Southeast of Zero Point This view shows the remaining concrete foundations of the Chemical Laboratory a wood building comprising a part of the Medical School and Hosnital Note the large pile of fused glass caused by the secondary fires which consumed the wrecked buildings The reinforced concrete-frame build- ings which can be seen on either side were not destroyed by the blast but falling suspended ceilings ano• secondary fires caused considerable dama e to buildings and contents FIGURE • D J DECLASSIFIED Authodty£' I 121'1 J k • • DECLASSlFlKD Authority N Diq oDSq tiAOASAKI MEDICAL SCHOOL A D HOSPITAL From o 4 to 0 55 Miles Southeast of Zero Point This view shows a room 1n the Hospital Building on the Southeast corner on the seconrl floor facing· way from zero point The damage shown is the result of an inter al explosion caused by a bomb dropped on 1 August 1945 Jaoanese Time eight days before the Atomic Bomb was dropnerl on Nagasaki This pict re illustrates the modern rein- fo reed concrete frame used in 22 of the buildings of the Nagasaki t edica l School and Hospital FIGURE 37 • DECLASSlFIED Authority NNDitl oosct NAGASAKI 1EDICAL SCHOOL AND HOSPITAL From o 4 to 0 • 5 5 L iles Southeast of Zero Point This view shows lft'eckage in the reinforced concrete Surgery Building resulting from a bomb which was dropped on 1 August 1945 Japanese time eight CJ lYll before the Atoinic Bomb was dropped on Nagasaki Note that columns and beams were heavily reinforced end thAt tension bars in the beams were bent up near the quarter ooint to resist diagonal tension __ FIGVRE - 3 ' _ I DECLASSIFIED AuthoritytJIJD t'J DECLASSIFIED • AuthorityNND'¥tDOS'1 __ _ r NAGASAKI MEDICAL SCHOOL From o 4 to AND HOSPITAL 0 55 Miles Southeast of Zero Point Another view showing wreckage in the reinforced cohcrete Surgery Building resulting from a bomb which was dropped on l A gust 1945 Japanese time eight days before the Atomic Bomb was dropped on Nagasaki Note that beams were heavily reini'orced and that the tension bars in the beams were bent up near the quarter point to resist diagonal tension$ Ft GURE_3_ J __ _ I D n ea -- - - SIFIE - DECLAS - qOUT ·ty_f lND Authon I NAGASAKI f EDICAL SOHOOJ AND HOSPITAL From o 4 to 0 55 Miles Southeast of Zero Point This view shows a room the Hospital Building on the Southeast corner on the se ond floor facing away from zero point The damage shown is the result of an internal e xplosion cAused by a b dropoe i on l August 1945 Japanese time elght was dropped on Nagasaki dqys before the Atomic Bomb This oicture illustrates the modern reinforced concrete frame used in 22 of the buildings FtGtJRE _J 1 0 _ LJ DECLASSIFIED Authority l NDiq0091 OECLASSfli'lEO Authority NNDit oosct NAGASAKI MEDICAL SCHOOL AND HOSPIT L From o 4 to 0 55 Miles Southeast of Zero Point Thie view shows a bomo crater and damage to the basement walls and columns at the Southeast' corner of one of the hospital bu11 1nge This damage was ca sed by a bomb dropped on 1 August 1945 Japanese time and was not caused by t e Atomic blast - 1 - -• NAGASAKI MEDICAL SCHOOL A D HOSPITAL From o 4 to 0 • 55 tales Southeast of Zero Point I nterior of one of the Gynecology Clinic rooms Note how the equioment was damaged oy the olast and by the fal 1ing of the susoended metal-lath 8 1'1d plaster ceiling glazed tile wainecoat1ng FIGURE 'l Note No fires occurred tj - · - DECLASSrFiEo- fvD¥f Of J ------------ Authority 'J __ - -- • DECLASSIFIED Authority tJ i iq DQSC lAOASAKI t EDICAL SCHOOL AND HOSPITAL From o 4 to 0 • 55 Viles Southeast of Zero Point This view shows a granite 'mom went o 4 miles from zero point at the I• edical School which w s toppled and moved by the force of the blast Calculations show that lt required differential normal pressure of O 9 pounds per s un re ·inch to topnle the monument This is equivalent to 130 powirls per · s usre foot • t 3 _ ' FIGURE_j 1 _ • IV DAMAGE TO REINFORCED CONCRETE BUILDINGS Continued One of the closest buildings to zero point was a reinforced concrete school building Shiroyama Public School located on the West side of the Urakami River approximately 1 4 mile West of zero point The damage sustained by this building is shown in the following photographs Figures 44 to 5JC inclusive Casualties were probably very light because a large number of school children were evacuated to rural areas following the bombing of l August 1945 Japanese time and prior to the explosion of the Atomic Bomb Many of the GovernDent Schools however had been converted into factories or factory-schoal Sand casualties in such buildings were relatively large SECRtT - 25 - DECLASSlFlED Authority NNDiel oOS9 REINFORCED OCNCRETE sOHOOL BUILDING ShiroyamA Puolic School Aporoxima tely 1 4 V ile West of Zero Point This is a genernl view of the building showing the demolished South wing Windows and window frames were knocked out by the force of the blast Note wreckage of wooden building just left of the de- molished wing FIGURE i'f ◄ UECLASSlFll U i uthor ty NND'¥ oosct REINFORCED CONCRETE SCHOOL BUILDING Shiroyama Public School Apryroximately 1 4 Mile West of Zero Point Olose- p of central wing facing the blast Building was completely stripped of windows window frames and all interior partitions Wreckage visible through building is portion of collapsed South wing Picture by W G Penney • DECLASSIFIED Authority Ni D'¥1 oOSC REINFORCED CONCRETE SCHOOL BUILDING Shiroyama Public School Approximately 1 4 Mile 1'1 eat of Zero Point This is n view of the entrance to the South wing which was badly damaged by the blast Note however that beams and columns are covered with heavy thicknesses of ornamental stone which added nothing to the strength of the builoing out made it appear much more substantial Also note the large amount of timoer framework used on the too floor where the damage wa s most severe demolished Wooden ouildings in this vicinity Tere completely The steel frame buildings in the right background are the re- mains of the Litsubishi Steel and Arms lorks and the reinforced concrete buildings in the l eft background are the stractures of the Nagasaki f 1 edical School and Hospital FIGURE 9'-J DECLASSIFIED Authority_ 11 Diq D091 REINFORCED CONCRETID SCHOOL BUILDIHG ShiroyRmn Public School Apnroximately l 4 laile West of Zero Point A close-up of the South wing facing the olast showing severe dB l lage to the reinforced concrete frame Note that reinforced con- crete columns are relatively so Rll and were cove red with heavy thick- nesses of ornamental stone and plaster giving this portion of the building a more suostantial appearance than it actually possessed FIGtmE '-Ii RE NFORCED CONCRETE SCHOOL BUILDING Shiroy41 1A Public School Approximately 1 4 t' le 'est of Zero Point No-rth side of Southwest w ing sho¥'ing severe structur1 tl damage ca used by the blast• • DECLASSIFIBD -J AuthorityNND¥JOOSC J DECLASSIFIED Authority NND'¥ oosct 1_ _ _ _ ___ _ Y REI FOROED CONCRETE SOHOOL BU lLDING Bhiroyama Public School Aonroximately 1 4 Mile Vest of Zero Point Interior view of one of the school rooms on the first floor facing the blast This is a close-up of one of the beams support- ing the celling showing reinforcing and structural failure in dia- gonal tension This beam was 12-inches wide and 16-inches deep E nd had a span of 15-feet steel bars The reinforcing confdsted of 1-inch round Note that none of the bars were bent up to take c1-tre of the diagonal tension and that vertical stirrups were extremely light FIGURE_'- l_ DECLASSIFIED Authority NND'¥10091 REINFORCED CONCREI'E SCHOOL BUILDING Shiroyama Public School Approximately 1 4 ile West of Zero Point Interior view of one of the school rooms on the first floor facing the blast Note that the wooden flooring tias been ripned loose And the schoolroom equipment tumbled about by the blast nut that no fires occurred here o te that the overhead beams genera tly 12-i nches wide and 12-inches deep show f a ilure in shear diagonal tension and that many of the light wall colu ns hAve failed completely P'IGUBE 'f - DECLASSIFIED Authority iq NND oosct _ _ _ __ _ ___ _ _ _ v REINFORCED CONCRErE SCHOOL BUILDING Shiroyama Public School Approximately l 1 t' ile Vest of Zero Point Pas age way in central wing showing wood debris from floor end wainscoating No fires occurred here Picture by W G P enney f OECLASSlFlEO A uthority N ND fl oOS9 R€UiFORC11 D CONCRETE SCHOOL BUILDil· U Shiroyama Public School Ap iroximately 1 4 Mile West of Zero Point Gro11nd floor main v ing Debris of wooden floor and wains-- coating has been removed Note wreckage of South win visible through window openings Note absence of false ceilings and that plaster was applied directly to concrete roemberso Picture by W G Penney OECLASSlFlEO Authority ND'¥ 0091 Rii IIJFORCED COlvCREIE SCHOOL BUILDil Q Shiroyama Public School Ap- roximately 1 4 Mile West of Zero Point Ground floor main v ing Debris of wooden floor and wains- coating has been removed Note wreckage of '9011th wine visible through window openinp s Uote absence of false ceilings and that plaster was applied directly to concrete memberso Picture by w G Penney • DECLASSIFIED Authority NNDiq oOSCI REINFORCED CONCRETE SCHOOL BUILDING Shlroyama Public School Approximately 1 4 tJiile West of Zero Point Interior view on the thirrl floor showing blast and fire dam ge Note thAt the reinforced concrete frame has suffered only minor damage but that outside brick walls and all of the metal lath and plaster partitions have been completely destro ·ed by the concussion The metal lath and plaeter ceilings which were suspended on steel angles from the concrete beams failed and dropped to the floor beneath The falling ceil - ings and partitions caused severe damage to the building contents Note that secondary fires broke out in this part of the building ca usi ng additional damage FIGURE 1 f REH FORCED CONCRETE SCHOOL BUILDING Shiroyama Public School Approximately 1 4 ile West of Zero Point This view sho e the 1n terior of a passageway on t he top floor between the South wing and the remainder of the buila i ng Note that the force of the blast has broken the reinforced concrete ceiling and that both columns and beams show s t ructural failure This portion of the building was gutted by secondary fires which caused considerable spalling of the concrete Most of the columns were 1 2-inches sauare and were reinforced with four to eight l-inch roWld bars The beams were about 10-incbes to 1 2-inches deep ano were reinforced with three l-inch round bars FIGURE_S o - - - DECLASSIFIED Authori tyt ND OOSC • UECLASS1 FIED Authority iq NND oosct REINFoRCED CONCRETE SCHOOL BUILDING Shiroyama Public School Approximately 1 4 t' ile est of Zero Point Interior view of room in connecting wing on the top floor facing away from the blast CA The failures sho vn here are appa rently used by the f ailure of the light wall columns in bending pushed over to the right at the tops permitting t he failure of reinforced concrete ceiling beams and slabs Secondary fires also damaged this room FIGO'RE _ _ _ _ • DECLASSIFIED Authority NND oDSq - _ rt EINFOROED CONCR E SCHOOL BUILDING Shiroyama Public School Approximately 1 4 t'ile West of Zero Point Interior view of room showing close-up of ceiling beam which failed in diagonal tension made Note that in this beam an attempt as to truce care of the diagonal tension by bending uo the regular tension bars near the quarter point The vertical stirrups however were extremely light FIGtJR E_f _ 2-_ _ REINFORCED CONCRETE SCHOOL BUILDING Shiroyama Public School Approximately 1 4 'ile 'Yest of Zero Point n A view showing failure of reinforced concrete roof and top floor in connecting wing The slab was apuroximately L -inches thick out the steel reinforcing was very light DECLASSIFIED Authority N Diq oosct DECLASSIFIED Authority N D¥10091 R ITNrORCED CONCRJt TE SCHOOL BUILDING Shiroyama Public School Approxi m'ltely 1 4 N ile West of Zero Point View snowing damage to reinforced concrete and t ile roof resulting from olast wave • rr 5J l DECLASSIFIED Authoritv 'J ND 0091 RSUirORCED COHCRETE SCHOOL BUILl INO Shiro vama Public School Approxicately 1 4 Aile West of Zero Point View of concrete roof shorlng failure reeu1 t1ng from downward pres ure of blast Parapet walls were also damaged ground are aoout 1 000 feet high Hills in back- DECLASSIFIED Aut Jonty V vD7 JIJ051 RIDIHFORCED CONCREI'E SCHOOL BU ILDING Shiroyama Public School Approximately 1 4 Mile V est of Zero Point View showing failure of reinforced concrete roof slab from blast Slab was about 4 -inches thick end lightly re- inforced as shown DECLASSIFIED- -Authority j'J ND11DOSCf I • SECRET DAMAGE TO REINFORCED OONCREI'E BUILDINGS Continued Another reinforced concrete-frame building seriously damaged by the blast was the 0hinsei Middle School See Figure 54 and Figur e 128 constructed in 1928 and located approximately O J rr iles Southwest of zero point on the West side of the Urakami River I t consisted of a central building of reinforced concrete a gymnasium a dormitory and other buildings of wood or masonry All of the buildings except the central building were totally destroyed After the air-raid alarm all students except a skeleton force were dismissed prior to the Atomic explosion which no doubt reduced casualties This group of buildings was used as a f acto ry and fac- tory training school for the manufacture of small arms In the concrete building most of the columns were 21 11 square The outside walls were 7¼' 11 with a spacing of approximately 20 feet thick The chief injury t o this building consisted of damage to the steel roof trueses on the North end top floor apparently used as a Gymnasium The light wall columns supporting the steel trusses fail- ed and permitted the roof to collapse Some of the lighter wall columns on the first floor were damaged from the concussion but in general very little of the reinforced concrete frame was injured walls were of metal-lath and plaster and were totally destroyed Many of the wooden floors which were laid over concrete were blrned by S CRET ' All part ition • DAMAGE TO REINJ tORCED CONCRETE BUILDINGS Continued Another reinforced concrets-frrune building seriously damaged by the blast was the Chinsei Middle School See Figure 54 and Figur e 128 constructed in 1928 and located approximately 0 3 ir iles Southwest of zero point on the West side of the Urakami River It consisted of a central building of reinforced concrete a gymnasium a dormitory and other buildings of wood or masonry All of the buildings except the central building were totally destroyed After the air-raid alarm all students except a skeleton force were dismissed prior to the Atomic explosion which no doubt reduced casualties This group of buildings was used as a factory and fac- tory training s chool for the manufacture of small arms In the concrete building most of the columns were 21 square The outside walls were 7¼ 11 with a spacing of approximately 20 feet thick The chief injury to this building consisted of damage to the steel roof tru eses on the North end top floor apparently used as a Gymnasium The light wall columns supporting the steel trusses fai1- ed and permitted the roof to collapse Some of the lighter wall columns on the first floor were damaged from the concussion but in general very little of the reinforced concrete frame was injured All partition walls were of metal-lath and plaster arid were totally destroyed Many of the wooden floors which were laid over concrete were burned by c0 ET _ 1 w l - 26 - r • SECRET rv DAMAGE TO REINltORCED CONCRETE BUILDINGS Continued Another reinforced concrete-frrune building seriousl y damaged by the blast was the Chinsei Middle School See Figure 54 and Figure 128 constructed in 1928 and located approximately o J miles Southwest of zero point on the West side of the Urakami River It consisted of a central building of reinforced concrete a gymnasium a dormit ory and other buildings of wood or masonry All of the buildings except the central building were totally destroyed After the air-raid alarm all students except a skel eton force were dismi ssed prior to the Atomic explosion which no doubt reduced casualties This group of buildings was used as a factor and fac- tory training s chool for the manufacture of small arms In the concrete building most of the columns were 21 square wi th a spacing of approximately 20 feet thick The outside walls were 7¼ The chief injury to this building consisted of damage to the steel roof trueses on the North end too floor apparently used as a Gymnasium The light wall columns supporting the steel trusses fail- ed and permitted the roof to collapse Some of the lighter wall columns on the first floor were damaged from the concussion but in general very little of the reinforced concrete frame was injured All part ition walls were of metal-lath and plaster arid were totally destroyed Many of the wooden floors which were laid over concrete were burned by s·F CRET I DEcfXssi Authority o s q -- I • IV • DAMAGE TO REINFORCED CONOREI'E BUILDINGS Continued Another reinforced concret frame building seriously damaged by the blast was the Chinsei Middle School See Figure 54 o J and Figure 128 constructed in 1928 and located approximately rr iles Southwest of zero point on the West side of the Urakami River It consisted of a central building of reinforced concrete a gymnasium a dormitory and other buildings of wood or masonry All of the buildings except the central building were totally destroyed After the air-raid alarm all students except a skeleton force were dismissed prior to the Atomic explosion which no doubt reduced casualties This group of buildings was used as a factory and fao- tory training school for the manufacture of small arms In the concrete building most of the columns were 2111 square The outside wall s were 7¼11 with a spacing of approximately 20 feet thick The chief injury to this building consisted of damage to the steel roof tru ses on the North end top floor apparently used as a Gymnasium The light wall columns supporting the steel trusses fail - ed and permitted the roof to collapse Some of the lighter wall columns on the first floor were damaged from the concussion but in general very little of the reinforced concrete frame was injured All partition walls were of metaL-lath and plaster arid were totally destroyed Many of the woodai floors which were laid over concrete were burned by SF CRET DECLASSIFIED tJ Nt '¥J_Q_ #f Authority II DAMAGE TO REINFORCED CONCRETE BUILDINGS secondary fires All of the windows were knocked out and most of the steel sash was bent explosion Continued One room showed evidence of an internal The concrete appeared to be of low strength and density Figures 55 to 57 inclusive show damage sustained by an- other reinforced concrete-frame building mately o 4 miles Northeast of zero point This b ilding was approxiIt was used apparently as a heavy machine shop and as a factory training school - 'Zl - • DECLASSIFIED D°¥1 oDSq Aut11ority_tJ I REDlFORCED CON0'RETE SCHOOL BUILDING Chineei Middle School Approximately o• 3 iles Southwest of Zero Point View of Chinsei Middle School - used as factory training school Damage on left end resulted from a parapet wall pulling loose Damage on right enrl was caused by failure of wall columns which permitted collapse of structural-steel roof trusses FI GURE _ J 7 -__ DECLASSIFIED Authority NND'¥1 oosq FACTOR TRAINING SCHOOL Heavy Machine Shop Aoprox1 mate1¥ o 4 r 11es Northeast of Zero Point This building with reinforced concrete frame was used as a factory training school 1n heavy machine work col'1mlls failed completely on tof of floo - causing failure of the roof Note that wall fioor B d p rtla3t ty on second ' • L • DECLASSIFIED AuthorityNND7 fl tJ7' • FACTO RY TRAINING SCHOOL Heavy r1iachine Shop Approximately o 4 Miles Northeaet of Zero Point Close-up showing failure of light reinforced concrete wall columns and collapse of roof - DECLASSlFlED icJ 0091 Authority t FACTORY T UNING SCHOOL HeRvy Machine Shop Approximately o 4 Ailes Northeast of Zero Point North side l¼way from blast• Note st vuctural failure o top floor and roof A any wall columns on ground floo Z also failed Picture by r o Penney • DECLASSIFIED Authority NNDicf oOSCJ FACTORY 1RAINING SCHOOL Heavy Machine Shop Apnroximately o 4 t iles Northeast of Zero Point This is an interior view on the ground floor facing the blast Note that the wall columns and reinforced concrete beams were broken by the concussion Note the absence of suspended ceilings and that plaster was applied directly on the reinforced concrete DalllElge to the equipment was confined to corrosion by exposure to the weather Windows and window frames were ripped out by the blast wave fires developed in this room No SECRFT IV DAMAGE TO REINFORCED CONCRETE BUILDINGS Continued The damage sustained by the reinforced concrete masonry prison approximately 1 4 mile Northeast of zero point is depicted in Figure 2J and in Figures 58 to 6J inclusive It will be noted that although the walls were massive the concrete was not well reinforced and the walls were not substantially anchored to the f ounda t ions The prison was completely destroyed and apparently all of t he occupants were killed SECRl T - 28 - DECLASSIFIED Authority ND'fl oQ 'l DECLASSIFIED • AuthoritvNND Oo9i Approximately l 4 llile Northeast of Zero Point The prison was situated on a hill about 75-feet higher than the valley anrl was constructed of reinforced concrete anct masonry Note wreckage of heavy reinforced concrete wall toppled by the blast The men shown are left to right Captai Henry Barnett Dr Robert Berber Physicist and Captain Harry Whipple They are measuring residual radio activity with Geiger- u ller instrwnents OECLASSlFlED Authority NNDit oosq - PRI SON Aporoximately 1 4 Mile Northeast of Zero Point The hill 1n the riRht center is the site of the Prison completely destroyed by the blast Chimney in bA ckgro ll'ld was cracked in left center was broken off by the blast point looking Northeast Chimney Picture taken fran zero The oole line was constructed after the blast Picture by W G Penney UECLASSIFIED Authority N I Diq oosq PRISON Approximately 1 4 Mile Northeast of Zero Point A general view showing complete wreckage of concrete and masonry buildings The force of thP blast knocked a piece of concrete wall from the foundation 1n the foreground place where Oapt in Walter C Youngs Jr is standing a distance of approximately 70-feet to the location in the background near which Dr Robert Serber is standing Notice the hills which bounded the valley and shielded areas to the East and South from the full effect of the blast • L -- I •I ij - - ' i ' ' DECLASSiFIED Authority JND 7117061 DECLASSIFIED Authority NND'¥l oQSlf PRISON Aporox1mAtely 1 4 Mile Northeast of Zero Point Close-up of wrecked concrete wall at prison Building in back- ground is a reinforced concrete factory training school heavy m chine shop damaged by the blast i PRISON Approximately 1 4 Mile Northeast of Zero Point General vtew showing wreckage of concrete and masonry buildings anrl damage fro fires Reinforced concrete chimney 1n the background although sta ndingJ was dall aged by the blast DECLASSIFIED Authority NI D1'1 oOSC PRISON Approximately 1 4 Lile Northeast of Zero Point Re1 nforced concrete building with steel doors practically destroyed by the blast Note how concrete is cracked and doors bent Building in background is a school building Shiroyama on the West side of the Urakami River Fr en mi t 2- _ • f DECLASSIFIED tJ0 9 Authonry WJ f9 f r 1 - _ § f ih -·· - ---- • DECLASSIFIED Authority NNDit oosct PRISON Aporoxima tely 1 4 Mile Northeast of Zero Point View showing concrete walls top led by the bla st • • t 1 I FIGURE G I V DAMAGE TO REINFORCED CONCREI'E BUILDINGS Continued i''igures 64 and 65 show a reinforced concrete wall left standing in the industrial area approximately South of zero point SECRET oECLASSTFIED tJ ND'¥1 oo91 p uthority - 8 - 1 4 mile REINFORCED CONCR n'E ALL Aporoximately l 4 M'i i 'e This reinfo 'ced concrete South of Zero Point vall and another standing nearby are the remains of two fact ey·bu1ld1ngs The wall was parallel to the direction of the blast and this aided in resisting the force of the explosion• • DECLASSIFIED AuthorityN Ni oosct REINFbRCED CQ 'CREI'E TALL 11 rrcroximatel 1 4 1111 - South of Zero Point These Valls part of two fActori' s are parallel to the direction of th• blast and remained tanning _ FIGURE_ °f_ r- 1i Ec1 A SSIF1Eu 7 mlborityNNf l'J 0059 SECRET DAMAGE TO REINFORCED CONCRETE BUILDINGS Continued Although the blast caused severe damage to the a tsubishi- Urakami Ordnance Works the reinforced concrete Research Laboratory building 0 8 miles from zero point was much less severely injured The main damage consisted of the breaking out of windows and the failure of concrete partition walls and several floor panels on the ground floor Figures 66 to 68 inclusive depict the damage In this build- ing there were no suspended ceilings the plaster being applied direct- ly to the concrete ceiling slabs and beams and consequently damage to building contents was much less than in buildings having suspended ceilings SECRET - 30 - DECLASS1 FlED Authority ND ¥ 0091 JI MITSUBISHI-U I ORDNANCE 1' 0RKS Torpedo Works From O 7 to 1 0 iles lorth of Zero Point View of Research Labora -cy- AdministrationY reinrorced concrete 0 8 miles from zero point Picture by W G Penney Builning - of • I 1ITSUBISHI-URAKA1 r ORDNANC' o RKS Tornrdo Work From o 7 to 1 0 of a I ile north of Z -ro Point Reinforced concr t res arch laooratory o· dlding approxlnutely 0 8 of a mile from zero point Thi8 view showe a 4-inch pnrt tion wall on the s cond floor facipg _the blast The fore of the blast ouiokly oroke out a Iarge numoer of windows in tr • out -lde wall and di h tn thi partition wall a shown Th• wall w u of reinforced concr•te aporoximately Lt-inches thick It was reinforc d with 3 8- lnch round oar 6-inch 'e to 8-inch s on center-s ooth Taye affected wae aonroxim8tely 8-f et by l -feet The area Th force required to caue e failure was approY imately 1 1 pounds oer sQuare inch or 160 pounds per square foot DECLASSIFIED Authority t ND O DSC JHTSUBISHLURAKAf I ORDNANCE WORKS Torpedo Workfl From o 7 to 1 0 0f a ue North of Zero Point Reinforcl' d concrete re earch laboratory bailding This view shows a partition wall broken by the force of the blast wos approximately 4-inclies thl ck and ·wa - inf ed with I ' t t ' I I round bare 6-i nch s to 8-ihches on enters both ways ' Th• wall 3 8- inch UECLASSlFlED r' Cd Autl1ority NI D'¥i Durr I UTSJBii FI-URAKAl I ORDL A iCE WORKS Torpedo Works From o 7 to 1 0 of a l ile North of Zero Pol t Reinforced concrete rese·rcb laboratory builninf apnroximately 0 8 cilee from zero point concrete wnll r kne s Inter'lor view howin thl' _ t b i - _ -unrewae rlppea OU by the Of th w l is 7 -inches FIGURE_ 1 f -