S>THE UNITED STATES ; STRATEGIC BOMBING SURVEY Meqvaclect unelassitiec/ by Dept arag eireala Te. 25° Mey } /9S5°O THE EFFECTS OF THE ATOMIC BOMB ON HIROSHIMA, JAPAN Volume I Spon s67 Physical Damage Division PLEASE Remuid2@bromPTLy TO ROOM 326 SEGREF- NATIONAL LIBRARY OF MEDICINE Bethesda, Maryland THE UNITED STATES STRATEGIC BOMBING SURVEY THE EFFECTS OF THE ATOMIC BOMB ON HIROSHIMA, JAPAN Volume I Physical Damage Division Dates of Survey: 14 October—26 November 1945 Date of Publication: May 1947 SECRET OO —Vn FOREWORD The United States Strategie Bombing Survey was established by the Secretary of War on 3 November 1944, pursuant to a directive from the late President Roosevelt. Its mission was to conduct an impartial and expert study of the effects of our aerial attack on Germany, to be used in connection with air attacks on Japan and to establish a basis for evaluating the importance and potentialities of air power as an instrument of military strategy for planning the future develop- ment of the United States armed forces and for determining future economic policies with respect to the national defense. A summary report and some 200 supporting reports containing the findings of the Survey in Germany have been published. On 15 August 1945, President Truman requested that the Survey conduct a similar study of the effects of all types of air attack in the war against Japan, submitting reports in duplicate to the Secretary of War and to the Secretary of the Navy. The officers of the Survey during its Japanese phase were: Franklin D’Olier, Chairman. Paul H. Nitze, Henry C. Alexander, Chairmen. Harry L. Bowman, J. Kenneth Galbraith, Rensis Likert, Frank A. McNamee, Jr., Fred Searls, Jr., Monroe E. Spaght, Dr. Lewis R. Thompson, Theodore P. Wright, Directors. Walter Wilds, Secretary. The Survey’s complement provided for Vice 300 iit civilians, 350 officers, and 500 enlisted men. The military segment of the organization was drawn from the Army to the extent of 60 percent, and from the Navy to the extent of 40 percent. Both the Army and the Navy gave the Survey all possi- ble assistance in furnishing men, supplies, trans- port, and information. The Survey operated from headquarters established in Tokyo early in September 1945, with subheadquarters in Nagoya, Osaka, Hiroshima, and Nagasaki, and with mobile teams operating in other parts of Japan, the islands of the Pacific, and the Asiatic mainland. It was possible to reconstruct much of wartime Japanese military planning and execution, engage- ment by engagement, and campaign by campaign, and to secure reasonably accurate statistics on Japan’s economy and war production, plant by plant, and industry by industry. In addition, studies were conducted on Japan’s over-all stra- tegic plans and the background of her entry into the war, the internal discussions and negotiations leading to her acceptance of unconditional sur- render, the course of health and morale among the civilian population, the effectiveness of the Japanese civilian-defense organization, and the effects of the atomic bombs. Separate reports will be issued covering each phase of the study. The Survey interrogated more than 700 Japa- nese military, government, and industrial officials. It also recovered and translated many documents which not only have been useful to the Survey, but also will furnish data valuable for other studies. Arrangements have been made to turn over the Survey’s files to the Central Intelligence Group, through which they will be available for further examination and distribution, ACKNOWLEDGMENT This present report was prepared by the Physical Damage Division of the Survey. The Division officers for the Japanese phase were: Harry L. Bowman, Director. Lt. Col. Cuartes R. Cuapman, Chief. Maj. Letanp N. Sreap, Executive. Iv TABLE OF CONTENTS Volume I: MRERPCUGUIONGO MME ats ose i ee MeRRERICE he DIOR 2 sete). le ee Section I. Object of study-_--------- rere herbals Piersotnniatyes oof 0 oe: Z Appendix A. Photo summary- III. General information - IV. The target. rea » a 7 " £ _ = iu =, e j— beled ‘ > es : - = ‘ c Ys | . Fig ' < c , iy aA ri by a ” : ; * a >: : ; s . ea . : b : + , ed 4 = , 7 * . 5 : B - ‘ 4 ‘a : - . z 4 a Th on ae K : | : ce be , A ° “ c +S, i? a # i 4 :. " ee oe 4 : rok z St iia ee é ¢ PS ee ate ; ap hete hath Ma eee = Meier rae ect, = ae | 7 VAPRIL 13 1945 —. 31 Summary of structural damage Bldgs. Percent Cause 80 31 Blast 81 None Bridges 40 55 Fire. 50 None 51 None DATE OF PHOTOS BEFORE — 13 APRIL 1945 AFTER — 11 AUGUST 1945 PHOTO SCALE 0 250 500 750 1000 FEET Summary of structural damage Bldgs. Percent Cause 72 100 Blast. 74 None 75 None 76 12 Blast. 77 100 Mixed. 78 50 Blast. 79 69 Fire, 129 None Bridges 25 15 Flood. 26 None DATE OF PHOTOS BEFORE — 13 APRIL 1945 AFTER — if AUGUST 1945 PHOTO SCALE 0 250 500 750 1000 ce A 2G. ais! 67 (8 fat —t aed an iN cic 6 17 ))18 wae ofa 4 //|20/ 2 22| 23| Summary of structural damage Bldgs Percent Cause 70 100 Mixed Bridges 10 15 Flood, 11 None 26 None DATE OF PHOTOS BEFORE — 13 APRIL 1945 AFTER — iI AUGUST 1945 PHOTO SCALE 34 Summary of structural damage Bldgs. None Bridges 41 42 48 19 Percent Cause None 100 Flood None 100 Flood DATE OF PHOTOS BEFORE — 13 APRIL 1945 AFTER — it AUGUST 1945 PHOTO SCALE ° 250 A | 248, at to” } y ANG 07 4 | /g\ Hy | 12 | ie ee ee en J/ | 67 19 16 | 17 (=| jf tet j = 23 iy? | PON ES Sy / c\Sy - y 5 ] é ds | ons Summary of structural damage Pldgs, Percent Cause 82 77 Blast 82 27 Blast 84 100 Blast 85 None 103 None 105 None Rridges 28 100 Flood 38 100 Fire and flood 39 100 Fire and flood DATE OF PHOTOS BEFORE — 13 APRIL 1945 AFTER — it AUGUST 1945 PHOTO SCALE ° 250 500 750 1000 FEET 36 A) 23 “— Y : Te ac fold Deatd PF LU | 12. 5/3 3 t+ 4 ys ne a 47°15) 16, 7 18 - : oo + -4 ‘ | 9 | 20) eI | 22/23) Summary of structural damage Pidgqs. Percent Cause 67 100 Blast 68A 100 Blast 68B 100 Blast 68C 100 Blast 69 100 Blast Pridges 27 None 28 100 Flood DATE OF PHOTOS BEFORE — 13 APRIL 1945 AFTER — it AUGUST 1945 PHOTO SCALE —k = : o 250. 500 750. 1000 FEET : ou 2.8 bash Poy y | 2 i 147 15 ane /® | pore! |e | 25 Summary of structural damage Bldgs, Percent Cause 64 None 65 None 66A 100 Blast 66B 100 Blast 66C 100 Blast 66D 100 Blast Bridges 8 None 9 None DATE OF PHOTOS BEFORE — 13 APRIL 1945 AFTER — i! AUGUST 1945 PHOTO SCALE ° 250. 500 750 1000 FEET 38 cla Ba a) ea a 4°56, 16 7.18 | 8 20/2 (22/23) Summary of structural damage Bldgs. Percent Cause 118 100 Blast Bridges None DATE OF PHOTOS BEFORE — 13 APRIL 1945 AFTER — tl AUGUST 1945 PHOTO SCALE o 250. 500 750 1000 FEET 39 Summary of structural damage Bldgs Percent Cause 102A 26 Blast 102B Is Blast 102C 66 Blast 108 100 Blast Bridges 13 100 Mixed 44 None 45 15 Flood DATE OF PHOTOS BEFORE — 13 APRIL 1945 AFTER — 11 AUGUST 1945 PHOTO SCALE oO 250 500 750 1000 FEET 40 la 5 Ne 2} 3\ 2 ae i Fs (6 p78 } ae 4 +y—4 aa) yo 2. 6 Se a4 dee 4 4? 5 | 16 Le ba 9 20/21 | 22/23, { L Summary of structural damage Bldgs. Percent Cause 86 1 Blast 92 100 Blast 93 100 Blast 107 100 Blast Bridges 30 60 Flood 304A 10 Blast 34 100 Fire 35 100 Flood 36 100 Flood 37 55 Flood DATE OF PHOTOS BEFORE — 13 APRIL 1945 AFTER — tl AUGUST 1945 PHOTO SCALE Summary of structural damage Bldgs. Percent Cause Blast Blast Blast Blast Blast Blast Blast Blast Blast Blast Blast Blast Blast Blast ; Blast 11 Blast None Blast 25 6 Blast 41 None 42, 94 100 Blast 95 1 Blast 96 31 Blast 100 None 101 100 Blast Bridges 22, 23 None 24 10 Blast 29 100 Blast DATE OF PHOTOS BEFORE — 13 APRIL 1945 AFTER — il AUGUST 1945 PHOTO SCALE 500 FEET Summary of structural damage Pidgs. Percent Cause 38 None 39 None 40 None 44 39 Blast 45 100 Blast 46 100 Mixed 47 None 48 None 49 None 50 None 51 None 52 100 Mixed 58 100 Mixed 59 None 60 100 Mixed 61 None 62 None 63 100 Blast DATE OF PHOTOS BEFORE — 13 APRIL 1945 AFTER — tl! AUGUST 1945 PHOTO SCALE 500 FEET | 231 ais 6i718 fF) | el Ist 4 16 ue 8 | 82 20 el | 28 23| Summary of structural damage Bldgs. Percent Cause 110 100 Mixed 120 None 121 70 Mixed 122 None 133 None 134 None 135 None Bridgex 4 None 2] None 5A None 7 None 7A None 12 None 13 25 Blast and flood IBA 100 Blast and flood 31 60 Flood DATE OF PHOTOS BEFORE — 13 APRIL 1945 AFTER — itt AUGUST 1945 PHOTO SCALE ° 20 S00 750 1000 FEET 44 45 Summary of structural damage Bldgs. Percent Cause None Bridges 33 70 Flood DATE OF PHOTOS BEFORE — 13 APRIL 1945 AFTER — i! AUGUST 1945 PHOTO SCALE ° 250. +500 750 1000 FEET Summary of structural damage Bldgs. Percent Cause None Bridges 31 60 Flood DATE OF PHOTOS BEFORE — 13 APRIL 1945 AFTER — tl AUGUST 1945 PHOTO SCALE o 250. 500 750 1000 FEET 46 47 Summary of structural damage Pldgs. 15 16 26 27 28 29 32E 37 Bridges 19 20 Percent 100 None None 6 None 100 None 100 None None Cause Blast Fire Blast Blast DATE OF PHOTOS BEFORE — 13 APRIL 1945 AFTER — 1 AUGUST 1945 PHOTO SCALE ce) 250 500 750 1000 ("| 2 ESM ais 6h7(e 9) 0141 | 12 |)! “143 | 6 Ge ® 20 21/28/23] v - "- Summary of structural damage Pligs, Percent Cause 53 100 Blast 54 100 Blast 55 100 Mixed 56 100 Blast 57 100 Blast Rridges 16 None DATE OF PHOTOS BEFORE — 13 APRIL 1945 AFTER — tl AUGUST 1945 PHOTO SCALE 0 250 500 750 1000 FEET \* 7 el 22 ee Summary of structural damage Pldg:. Percent Cause 111 100 Blast Pridyes 15 None 16 None DATE OF PHOTOS BEFORE — 13 APRIL 1945 AFTER — i! AUGUST 1945 PHOTO SCALE 0 250 500 750 1000 FEET his y} } ( Summary of structural damage Bldgs. Percent Cause 87A 100 Blast 87B None 88 100 Blast 89 None Bridges 32 70 Flood DATE OF PHOTOS BEFORE — 13 APRIL 1945 AFTER — tl AUGUST 1945 PHOTO SCALE ° 250 500 750 1000 FEET 50 S & f| 2 | 34 ats” 5 6 | 7 ( 8 ; és } S| 0, 2 is (ae 16 7 | 8) By i a Bei 22 23, Summary of structural damage Bldgs. Percent Cause 132 50 Fire Bridges None DATE OF PHOTOS BEFORE — 13 APRIL 1945 AFTER — iI AUGUST 1945 PHOTO SCALE Summary of structural damage Bldgs. Percent Cause 30 100 Blast | 31 None 324 None | 32B None 32C 100 Mixed 33 None 34 100 Mixed 97 100 Blast OSA 50 Blast 98B None 99 100 Blast | Bridges 18 None DATE OF PHOTOS BEFORE — 13 APRIL 1945 AFTER — il AUGUST 1945 PHOTO SCALE Clas 4i5'6i7is Ag) wy 2s 4) ele 7B) ome | UF, 9 20 21 Ze 23 { 1 (a LOY Summary of structural damage Pldjs, Percent Cause 32D None 32H None B5A None 35B None 36 27 Blast 112A 34 Blast 112B None 112C 100 Blast 112D 100 Blast 112K 63 Blast 113A 100 Blast 113C None 113D None 113K None 113G 100 Blast 128 100 Blast DATE OF PHOTOS BEFORE — 13 APRIL 1945 AFTER — il AUGUST 1945 PHOTO SCALE ° 250 500 750 1000 54 Summary of structural damage Bldgs. Percent Cause 116A None 116B None 116k None 116H 3 Blast 1161 3 Blast Bridges None DATE OF PHOTOS BEFORE — 13 APRIL 1945 AFTER — tI AUGUST 1945 PHOTO SCALE PHOTO 1-IIT (PS) PHOTO 2-II (PS) PHOTO 3-II (PS) 56 PHOTO 4-TT (PS) PHOTO 5-IT (PS) PHOTO 6-IT (PS) PHOTO 7-II (PS) PHOTO 8-II (PS) PHOTO 9-II (PS) 58 59 ae PHOTO 10-II (PS) PHOTO 11—IT (PS) PHOTO 12—-II (PS) SECTION III GENERAL INFORMATION Page DD ALOR ONSURUGY et ces geet. oF en hw ae oe ween sab sa cei ese ceca eee eee See 62 BIRD Weld Team Vn, sooo a — 2S» apa hboes tet Shed seco nc aa aie ed ee, 62 Boope of inwvéntigation |. - 51-22 Lodo ie aes oes res Se, ot og NE oe a 62 Beknnwibagmeny. o> ooo o cies <2 scape bd oan ense na sane weat2 Sosa ees 62 Diivulties enecuntered...-<- - 6... Uscce Solel cesc cies ck iogs (eo. 62 PRVOTOINS EROHOR a5 se61ms (6f) yuouesnelq JOx|DM JepuDWWOD jUDUe}Ne!7 S3ILITILA 8 39IANSS sa9diug SONIGTING auld 9148409 JepuDWWOD juDUajNeI7 yOLIGZ 4D}JOG juDUeyne!7 WO}JOH JepudWWOD juDUEjNeI7 ONILAVYG JOVNONVT 49juN}H juDUEyNe!7 (dIHS) S3OIAN3S ee ee ee ee ee ee ee ee 2 ee ee ee ee ee ee Z}19y juDUEyNeI] ZON3Z9SITISINI 819409 sepUuDWWOD juDUE{Ne!7] ¥39I4d0 3AILNDAXS 11840 40fow (3YOHSV) SSOIANSS Mn ee os oll woy6uog solow J3IHO WV3L SYSLYVNOGV3H TVNOISSY GV6l 49QWAAON 9a 9} GHEI 4999490 HI LYVHO NOILVZINVSYO uodor ‘owiysodiy T woe] uoisinig ebowng |ps1skyd ASAUNS ONISWOS OISSLVYLS SALVLS G3SLINN upwyulsg sofow SLOBLOYd WIDd3dS J@UPsDH juDUEjNe!7 Y3SLIYdY3SLNI OLOHd usoquos s0fow ASMVWiI9adS 3ul4d 61 1. Dates of Survey The survey of Hiroshima was started on 14 October 1945 and completed on 26 November 1945. 2. PDD Field Team 1 Physical Damage Division Field consisted of the following personnel: Team 1 Maj. J. F. Bangham, Jr., AC, team chief. Maj. E. A. Brinkman, CE, chief engineer. Maj. F. J. Sanborn, AC, fire study. Maj. J. M. Wolverton, AC, fire engineer. Lt. Comdr. R. L. Corsbie, CEC, executive officer, architect. Lt. Comdr. J. H. Holtom, 5 (1), language. Lt. Comdr. N. C. R. Penna, CEC, civil engineer. . Comdr. G, P. Piper, CEC, civil engineer. . Comdr. C. B. Walker, S (A), fire engineer. . BE. G. Dollar, A, architect. .J. W. Gardner, A, photo interpreter. _J. F. Garrison, Jr., A, photo interpreter. . H. C. Montgomery, Jr., A, photo inter- preter. Lt. (jg.) L. W. Galloway, S (O), ordnance specialist. Lt. (jg.) W. F. Swiger, A, civil engineer. Mr. E. M. Hall, civilian, language. J. A. Meuenster, ChPhoM, photographer. EF. G. Anderson, SF2/c, draftsman. J. P. Harmon, Y2/e, yeoman. C. R. Adamson, Jr., PhoM3/c, photographer H. Fagin, S (X) 3/e, draftsman. C. A. Schmeider, Y3/c, yeoman. E. W. Waller, S (P) 3/c, draftsman. Cpl. J. J. Delaney, photographer. Cpl. T. K. Matsuura, interpreter. Cpl. K. B. Van Beukering, photographer. C. Y. Cain, S1/c, draftsman. Pfe. C. A. Cramer, photographer. Pfe. G. E. Curtis, photographer. Pfe. R. D. Hall, photographer. Lt 3. Scope of Investigation Physical Damage Team 1 was concerned only with the assessment of physical damage to Hiro- shima and, except where judged pertinent to the report, did not attempt to study any other effects of the atomic bomb such as medical aspects, effeet upon morale or civilian defense. The team con- fined itself to the study of buildings, machine tools, bridges, utilities, services, fire damage, stacks; the gathering of intelligence data; and the 62 interrogation of witnesses and city officials. Mem- bers of the team also conducted surveys of the physical damage to the city of Ube and the oil refinery at Otake. 4. Acknowledgment Hiroshima was within the zone oceupied by the United States Army Tenth Corps and Forty-first Division, through which clearance had to be made before the survey could be begun. They furnished valuable aid and information which greatly facili- tated the survey 5. Difficulties Encountered The difficulties that confronted the team in attempting to ascertain the facts in connection with the extent of damage to Hiroshima were important: a. Summer through fall is the typhoon season in Japan and Hiroshima received a full share of damage from these storms. On 17 September floods developing from torrential rains washed out bridges and caused extensive additional dam- age to the already stricken city. Again on 5 October the typhoon which swept up from the Ryukyu island chain took its toll of bridges and other installations. This made interrogation the principal method by which differentiation between bomb damage and flood damage could be checked. b. Almost all records and data in the city proper were either burned by the fires following the drop- ing of the atomic bomb or were lost in the subse- quent floods. As a consequence few records were obtained and those found were usually discovered in the possession of companies located outside the damaged areas. Others were prepared by indi- vidual persons upon the request of team members. c. By the time the team arrived in the field many persons who had escaped from the city im- mediately after the explosion had returned to their former homes and were constructing tem- porary residences on the sites. Consequently, survey personnel found flimsy wooden and cor- rugated-iron shelters interspersed among the remains of the former structures. d. Attempts to interrogate witnesses who were actually in the city when the disaster occurred were made difficult by the extremely high loss of life and by the immediate dispersal of survivors to the outlying areas. Although many persons volunteered information, it was established by questioning that very few of them had actually been in the city at the time of the detonation. Moreover, it was difficult to trace specific persons as possible sources of information, since they had either been killed or no record of their whereabouts was available. e. The work of the team was handicapped to me extent by official regulations governing the ovements of the U.S. S. Sims, which, although erving as a headquarters ship for the survey, was unable to anchor in Hiroshima Harbor as had been originally planned. Although the passage into Kure Harbor and Hiroshima Bay had been wept by Japanese minesweepers the U.S. S. Sims as not permitted to anchor in Hiroshima Harbor, the United States Navy had not declared the ea open to American vessels. Anchoring in iro Bay, which offered the closest utilizable anding area, and driving from there into Hiro- hima entailed a 34-hour round trip by small boat nd jeep. Therefore, the actual working day in he field began at 0930 hours and ended at 1600 ours. f. Considerable work in connection with field otes was accomplished on board the U.S. S. Sims, 63 but quarters were so cramped that the actual work of writing the report was necessarily delayed until the team returned to the United States. 6. Favorable Factor A factor which contributed to the efficiency of the survey was that the city of Hiroshima had been declared off limits to American troops. Toward the end of the survey the city was opened to military sightseeing tours, but these were all nonstop and nonalight. This enabled field teams to have a relatively free hand in conducting investigations. 7. Source of Data Data obtained by the team members were gathered from plant, city, and prefectural records and reports; records drawn up by officials in the city, interrogation, photographs, visual observa- tion, and records obtained from main offices of companies that had branches in Hiroshima. It is the opinion of the members of the team that the information gathered is accurate and reliable. SECTION IV THE TARGET Geopraphidalsdescription 15222. LAs 2 be eet See wseeeet love. Stet. oe eee Climate lis eure el oe bo oc these Socket eel te eee Be se er Historical PACK RrOUnG 2552 Foes Ete ko oe ye oe Wi b>: Seen ee General description of the modern city___.__.______________-___- . Social conditions. ._.-_....-.-...- Economie conditions_________- Highways- - ----- Bbc UP ethane awegy eds Se see oe oa Be a ae ee ee Streets and bridges---_-_--..__-_- RIPPER LA ety tee eS BENS oe 8 Street railway and busses______ __ min faettities. . .;-212.2S8e2 3.22. CE ES es oe ee Soe Communications. 2-25 —-. =< 5-2. -~< si eee Roe Ot ee Sate Ree te ee eee J pao 1 CU ee a ae bee aes 9 A xh ds he ee Ujina Harbor-_-__- -_- 3 2 diy tea ae ao see se eee ne 2 See ee eee ee te a Shipbuilding. = 325. .24--c02ce5 a eae eee ene tes Een, ee A ee ye he Eicopninis Gs © Miltary ClLy.-. 6-22-52 1b Sel ae DNUURen ceeee ok wee ants eeeeee nba. Joe Government ‘offices. _- _._-----..<---2 FLOSpHAlSi oo Shc. wae ene Stow Swe 28 a ah as Dee ee oe Be lie eer 1) | Se oes en Cn ere emer h ee PHOLORTADHBY Son =e as ete eae sks ate es eae toes Hiroshima as a target for the atomic bomb___- Figures 1-8, inclusive. 1. Geographical Description a. Hiroshima (lat. 34°24’ N., long. 132°28’ E.), first urban target for an atomic bomb, was the seventh largest city in Japan and was located in the southwestern portion of the Island of Honshu on the shore of the Inland Sea. 6. The Inland Sea had long been important to Japan on three scores: (1) as a calm and safe water lane interconnecting Honshu, Shikoku, and Kyushu, (2) as a protected anchorage area for naval and merchant vessels; and (3) as one of the most beautiful scenic areas in the world. The southern portion of Honshu which faced the Inland Sea was called Sanyo, or “sunny side of the mountains,”’ indicating the prominence and respect attached to the area by the Japanese. Hiroshima was centrally located along this Sanyo coast. c. The whole of Japan was divided into eight administrative regions, called Chiho Gyoshi. The entire southwestern section of Honshu, beyond the area encompassing Kobe, Osaka, and Kyoto, forms the Chugoku Chiho, or middle kingdom region, the administrative center of which was Hiroshima. Among the places of importance in the Chiho were: Kure, the great naval base, less than 20 miles from Hiroshima; Shimonoseki, the Honshu termi- nus of the Kammon Tunnel; Matsue and Tottori, on the Japan Sea; and Okayama, Fukuyama, Onomichi, Iwakuni, Yamaguchi, and Ube, on the Inland Sea. The Chugoku Chiho had neither high mountains nor extensive lowland plains, but was uniformly rugged country, with steep hogback ridges and chasm-like valleys cut by small, swift streams. Most of the cities were built along the coast at the mouths of streams where silt flats had formed. d. The Chugoku Chiho comprised five prefec- tures (Ken), one of which was Hiroshima Prefec- ture, centrally located on the Inland Sea coast. Kure and Hiroshima were the primary cities in the prefecture, the latter being the administrative center of the prefectural government. The Ota River, rising in the mountains, flowed generally east through the western section of the prefecture, thence southward into the Inland Sea at Hiroshima Bay. In the valley of the lower reaches of the river, alluvial deposits had formed which provided sites for small towns, and, at the mouth of the river, deltaic islands were the site for the city of Hiroshima. Westward and southward from the mouth of the Ota along the precipitous shorelines 65 were a few small residential and fishing villages. Southwest of Hiroshima, 20 miles offshore, was the island of Miyajima, one of the scenic spots of Japan, a mecca for pilgrims and of interest to tourists because of the famous temples, shrines and scenery. Eastward from Hiroshima along the coast were several towns, the closest being Kaitachi, Kure and Hiro, the latter being an extensive and well equipped naval base, were about 18 miles distant; and Fukuyama and Onomichi were farther along the coast in the eastern section of the prefecture. é. The Ota River delta was made up of six islands separated by the channels of the river. Except where small rocky islands no more than 700 feet high, previously offshore, were surrounded by the silt deposits, the islands were uniformly flat, and about 10 feet above mean low water. The natural deltaic formations had been extended by dredging and filling operations to satisfy the needs of a growing city, and, consequently, the southern (or seaward) extremities were more regular in shape. It is on these islands and on the flats along the mainland river banks thatthe city of Hiroshima was located, surrounded by steep, wooded rises except to the south where it faced the Inland Sea. 2. Climate a. In general, an oppressively hot and humid summer and a mild winter characterized the cli- mate of Hiroshima. The mean annual tempera- ture was 57.9° F., which is about the same as that of Baltimore, Md. b. The latter parts of April and June and the entire month of September were the rainy seasons. The amount of snowfal) during the winter was negligible. ec. Light, warm, southerly winds blew from May through October, and northerlies and west- erlies prevailed during the remainder of the year. The typhoon season was June through October. These storms were particularly active during the month of September, when winds ranging up to 75 miles per hour occurred, often accompanied by torrential rains and floods. 3. Historical Background a. Originally a small fishing village at the mouth of the Ota River, Hiroshima’s history really began when Terumoto Mori in 1591 became feudal lord of the region including most of what is now the Chugoku Chiho. Under his direction the Castle of Hiroshima was begun and completed in 1594. The erection of the castle assured the = S=== x " — - WK.’ DI. tf! Tl MN iit ht , ee ee ee eri t S U se Set oO we . ~ eo “G eT ae 7 Co ae W/E E/N ales WAN ' +/74, TOPOGRAPHIG SKETCH MAP HIROSHIMA ELEVATIONS IN METERS UdINA. .KO 56.3 aS : : 67 expansion of Hiroshima from a village into a castle town on the delta below the castle. With the reestablishment of the Tokugawa clan as shoguns of the empire in 1603, Hiroshima castle was taken over by the Fukushimas. In 1619 it passed into the hands of the Asano family, who remained as hereditary chiefs of the castle and lords of the region until the Meiji Restoration in 1868. b. The feudal castle was built on the delta at the mouth of the Ota River and the castle town grew up south of it along the thoroughfare, which cut across the deltaic islands, connecting Kyoto and Shimonoseki. Hiroshima gradually came to assume importance as a communication center because of its position on the Inland Sea and along the Sanyo highway and subsequent. rail- road. The deltaic formations were extended to make more room for the growing town and to enable cultivation of more farm land to feed the increasing population. During the first 100 years that the Asano family was in possession of the region, the land acreage under cultivation was doubled. Since that time there have been periodic reclamation and expansion projects, the latest having been under way at the time of the atomic- bomb attack. c. The establishment of the prefectural govern- ment by the Emperor Meiji in 1868 marked the beginning of Hiroshima’s development into a modern city. More farm land on the delta was taken over for use as residential and industrial sites. The delta was again extended to provide more land, particularly toward the island of Ujina, thereby connecting Hiroshima to an ade- quate harbor area. d. In the sixth year of the Meiji Restoration a military garrison was first established at Hiro- shima, but it was during the Sino-Japanese War (1894-95) that the city began to assume impor- tance as a military center. The Emperor Meiji made the castle his residence and general staff headquarters during that campaign on the Asiatic mainland. The city later served as headquarters for the Japanese “Ever Victorious Fifth Army,” which conquered Singapore, and the Second Gen- eral Army. At the time of the atomic-bomb attack there were 24,158 of the Army and 48 of the naval forces stationed in the city. 4. General Description of the Modern City a. The brief history of the city of Hiroshima shows how it had its origin in a small castle town 68 on the northern end of the deltaic islands at the mouth of the Ota River and increased in size with the natural and man-made extensions of the islands. The street pattern, the built-upness, and the zone occupancy of the modern city reflected its historical growth. b. In general, the street pattern was an irregular block plan with variations imposed by the logical flow of interisland traffic and the irregular shapes of the islands. A large portion of the northern half of the principal island was taken up by the old castle grounds, and the southern portions of most of the islands were used for industrial and military purposes. The portions of the three central islands immediately south of the castle grounds comprised the commercial district where- in most of the multistory office and commercial buildings were located. ce. The bulk of the newer commercial and government structures was representative of post- 1923 Japanese construction. These buildings were relatively modern in plan and design and were substantially constructed. The older strue- tures of similar occupancy were more classical in appearance and were usually of wall-bearing construction. Interspersed among these build- ings were the low, flimsily built shops and offices of typical Japanese design and structure. Exeept for the more modern factories, which were built during or immediately prior to the war and which reflected occidental influence, the industries were housed in exceedingly vulnerable frame or wall- bearing units scattered throughout the city. Most of the remaining flat area in the city was compactly built up with typical Japanese residen- tial or residential-commercial, one-story, wood buildings. 5. Social Conditions a. The city was badly overcrowded, with over 31,600 persons per square mile, which is approxi- mately 1.23 times the average density for the 5 boroughs making up greater New York City, despite the fact that almost all residences in Hiroshima had only 1 or 2 stories. This popula- tion density was largely attributable to the geo- graphical limitations imposed by the islands and to the fact that such a large percentage of utilizable land area within the city was monopolized by the Army. b. From 1888, when the first census recorded 84,873, to June 1942, when the peak population of 380,000 was reached, the city steadily grew in civilian population, and coincidentally increased in in physical size with the reclamation of land and the incorporation of suburban communities under the city government. As the probability of aerial attack became more evident, the civilian poupla- tion had been decreased to approximately 245,000 as of 5 August 1945, the day before the attack, due to voluntary and government-planned evacuation. 6. Economic Conditions a. The city of Hiroshima was unique among the sizable urban communities in Japan in that the bulk of its workers was dependent upon employ- ment in civil and military governmental agencies and small and moderate-sized private enterprises which directly performed services required by these agencies. Since the Chugoku district did not produce enough hydroelectric power, coal, or iron to support heavy basic industry, Hiroshima had few large industries. Since only 20 percent of the Ujina Harbor facilities was available for other than military purposes, relatively little trade was pos- sible. What surplus of foodstuff was raised in the locality was largely disposed of to the Army pro- curement agencies and shipped by them. Because of the absence of industry and large-scale trade, bank deposits in the city scarcely went beyond petty, middle-class savings, insufficient as com- mercial or industrial capital to accelerate active enterprises. : b. Some concerns with main offices in other cities of Japan had established subsidiary branch factories in Hiroshima. Such were the Japan Steel Works, Toyo Industries, Mitsubishi Indus- tries, all relatively new plants, Banks, department stores, railroad, newspapers, and numerous other small industrial and commercial establishments gave employment to many. 7. Public Utilities a. Electricity. Electricity for lighting and in- dustrial purposes was furnished by the Chugoku Electric Co., which obtained it from Nippon Elec- tric. The Japanese reported that all houses in the city were equipped with electric lighting. b. Gas. The Hiroshima Gas Co. manufactured and distributed producer gas for domestic and industrial purposes. Approximately 75 percent of the residences received service. c. Water. Hiroshima had an adequate mu- nicipal water supply system for both industrial and domestic use, due largely to Army influence. ater was taken from the Ota River, purified, and distributed to all sections of the city at the rate of 69 50 gallons per person per day, which, although ap- proximately one-half of the usual United States quantitative standard, was sufficient by Japanese standards. d. Sewage. As a result of the oriental custom of using night soil as fertilizer, no sanitary sewers were necessary. Hiroshima had an adequate storm-water sewer system into which domestic waste water was drained. 8. Railroads (Fig. 3-IV) Hiroshima was one of the principal intermediate stations on the Sanyo main line of the government railway system running along the Inland Sea from Kyoto to Shimonoseki, one of the most vital links in the Japanese railway networks. W Ags ee 7 IMPORTANT MILITARY AREAS HIROSHIMA -DRILL FIELD AND GLIDER TRAINING ORDNANGE Q : Z DEPOT A> QM CLOTHING BARRACKS AND WAREHOUSE ARES MAJOR INDUSTRIES HIROSHIMA ~TOYO LIGHT ALLOY CO. CHUGOKU PAPER CO TEIKOKU RAYON KUMIHIRA MFG. CO. _ DIAWA “ RAYON CO. _-FUJINO COTTON CO _-JAPAN STEEL WORKS (NISIKANIYA) TOYO INDUSTRIES FIGURE 6-IT 19. Government Offices (Fig. 7-IV) Hiroshima was the administrative seat of the governments of Hiroshima Prefecture, Chugoku District and Shikoku District, as well as the mili- tary and commercial center for the area. For that reason, several of the important structures in the city were devoted to office space for the various governmental bureaus. Some of the more im- portant buildings are shown on the sketch map. 20. Hospitals (Fig. 7-IV) Eight hospitals, including the Red Cross hos- pital, governmental, military and private hospitals, were within the city limits. The Red Cross hos- pital and the Communication Bureau hospital were housed in sizable, modern buildings and were well equipped. The military and prefectural hospitals were in wood-frame structures and the remainder consisted of small, private, or special treatment institutions. 21. Schools (Fig. 7-IV) The Hiroshima University of Literature and Science and Higher Normal School was one of the best known and respected Japanese institutions of higher learning. In addition to the university, 65 other schools, including grammar, middle, high and technical schools, both public and private, were a part of the educational facilities of the city. 22. Photographs On the following pages are prewar photographs of Hiroshima which give some impression of the built-up density of the city and the types of build- ings, parks, and streets which were found there. The photos were probably taken before 1930. 73 23. Hiroshima as a Target for the Atomic Bomb It is considered desirable, as an addendum to “The Target,” to summarize the physical charac- teristics of the city of Hiroshima which contributed to or detracted from its value as a target for the atomic bomb: a. The city of Hiroshima had received only an insignificant amount of prior damage; therefore, what damage resulted could be attributed to the atomic bomb. b. Being built on a deltaic formation, it was nearly flat for a distance of 6,000 feet ia all diree- tions from the aiming point, and for more than 15,000 feet in the southerly quadrant. c. At various intervals within a 6,000-foot radius from the aiming point there were enough substan- tially constructed, multistory, commercial build- ings of representative structural types to allow comparative study of the effects. d. Because of the prevalence of wood construc- tion throughout the city, and the pattern of the water courses which formed natural firebreaks, the incendiary effects of the bomb could be analyzed. e. Within the area were representative types of short-span, fixed bridges in sufficient numbers to permit a relative study of the effectiveness of the weapon against them. f. Hiroshima was well equipped with public utilities (water, gas, electricity, sewers) and inter- urban transportation so that conclusions could be drawn regarding the relative vulnerability of these facilities. g. The principal feature which detracted from the target value was the remoteness of the indus- trial concentration from the center of the city. SCHOOLS, HOSPITALS AND GOVERNMENT OFFICES HIROSHIMA PREFECTURAL OFFICE ee HIROSHIMA PRISON CHUGOKU CHAMBER OF COMMERCE GOURT OF APPEALS : DISTRIGT COURT SCHOOLS CITY HALL MONOPOLY BURE AU MARITIME TRANSPORT BUREAU ) GOVERNMENT OFFICES ea f) EARLY PHOTOGRAPHS ot a2 2 MILE \ HIROSHIMA NOR | )) RR saci tc ids | ff oat hay cs hee Te . ff & é . PHOTO IZ ll PHOTOS ON FOLLOWING PHOTO IWS AN -PHOTO IV-i2 y yj Le \— PHOTO 17-64 " PHOTO Iv-2 - | PHOTO PHOTO lv-4 /-; l-3 PHOTO Iv-8 PHOTO IV-1 ZS Ws Bo ss set PHOTO I-10 \ —————— ’ ‘iio FIGURE 8-Iv ~- PHOTO 1-1V. Aerial view of the densely built-up area along the Motoyasu-gawa looking upstream. Except for very heavy masonry structures, the entire area was devastated. Ground zero of the atomie bomb was upper right in the photo, opposite the second bend in the river. PHOTO 2-IV. Early photograph looking up- stream on Motoyasu- gawa at Bridge 22 and City Commercial Dis- play Building (domed building) which were im- mediately adjacent to ground zero. ~ i > ) } : i : i? | if Ls PHOTO 3-IV. Photo- graph of the downtown shopping district near the center of town. Only rubble and a few utility poles remained after the explosion and the result- ant fires. This street was equivalent to the very famous Tokyo Gin- za. Photo was taken facing east. PHOTO 4-IV. north-northeast along Tera-machi, the Street of Temples. This road is considerably wider than most roads found Looking in residential areas. This district was completely ruined. PHOTO 5-IV. Old photo looking north from vicinity of T-bridge. The picture shows extremely combustible wood houses along the bank of the Ota-gawa, and the char- acteristic Jap river craft. PHOTO 6-IV. RADIOSTATION JOFK. This modern building in the northern see- tion of the city housed the studios, offices, and transmitter unit for the JOFK radio station. This was one of the few stations that operated on over 10,000 watts in the Japanese homeland. This building was typical in design of most of the modern one- and two-story commercial buildings in Hiroshima. Additional transmitting unit located approximately 5 kilometers north of the city was connected by cable. PHOTO 7-IV. FORMER IMPERIAL HEADQUARTERS. During the Sino- Japanese War the Emperor Meiji made Hiroshima his headquarters; this building within the grounds of the old castle is part of his administrative center. Early in the recent war this area was the headquarters of the 5th Army, and later, the 2d General Army, responsible for the defense of south- west Japan. PHOTO 8-IV. HIROSHIMA UNIVER- SITY OF SCIENCE AND LITERA- TURE, AND HIGHER NORMAL SCHOOL. The Higher Normal School was one of two such institutions in Japan. In 1929 the Hiroshima University was first founded and combined with the Normal School. This building located 4,500 feet from ground zero was completely destroyed. ; ' ! PHOTOS 9-IV and 10-IV. UJINA HARBOR. This relatively small harbor was developed as port for the city of Hiroshima, and has been one of the principal embarkation depots for the Japanese Army since the Sino-Japanese War. Only 20 percent of the harbor facilities were available for civilian activities. One of the important functions of Ujina Harbor was to act as the base for trade and communications with the Matsuyama area on the Island of Shikoku. Passenger steamers plying between Hiroshima, Osaka, Etajima and various ports on Shikoku and Kyushu stopped here. Fish is a Japanese dietary staple, and a fishing fleet based in Ujina Harbor operated on the Inland Sea. The harbor was never open to ships of foreign countries, but reports show that foreign trade amounting’ to about 500,000,000 yen was handled at the port by Jap ships in 1935. Puoro 11-IV. NIKITSU SHRINE. Nikitsu Shrine, near the foot of Futaba Mountain, is a part of Enko Park in north- eastern Hiroshima. Although considered one of the most beautiful ones in the city, in general design it is more or less typical of Shinto Shrines found all over Japan. The woody hillside is a characteristic design feature. Puoro 12-IV. SENTEI POOL. The Sentei Pool, with its beautiful natural setting, was one of the most famous sightseeing and recreation places in Hiroshima. It was located east of the castle near the bank of the Kyobashi River. The building shown in the photo was the public tea house. Shinto shrines, Buddhist temples, and Christian churches were all found in the city of Hiroshima. In State Shinto, adopted during the early days of the Meiji Restoration, the emperor had an effective religious weapon for obtaining the complete loyalty of his subjects. In addition to State Shinto, there are 13 formal sects of the religion with formal systems of worship, and Popular Shinto, the most basic type, which deals with more personal problems, such as the success of the rice crop and the welfare of the family. The Buddhist religion was imported from China, and has an enormous following in Japan. It isa purely mystical faith. Christianity has never been fully sanctioned by the leaders of Japan, and has not had any marked effect on Japanese civiliza- tion as it has in other countries. SECTION V HIGH-EXPLOSIVE ATTACKS ON HIROSHIMA Attack of 30 Apravlotoe. =~ 2 es 2 oa a - 5 Figure 1_- ee i . 80 : "Facing p. 82 81 1. Summary a. The attacks of 19 March 1945 by four or five Navy planes and of 30 April 1945 by a lone B-29 constituted the only aerial action against, Hiroshima City reported by the Japanese prior to the atomic-bomb attack of 6 August 1945. Of the two attacks, only the Navy strike is listed by the Office of Statistical Control, Headquarters, AAF (Table 1). b. The 2 small bombs (presumed to be 250 pounds each) dropped in the attack of 19 March 1945, together with the 10 500-pound bombs dropped in the heart of the city in the attack of 30 April 1945, give a total weight of 5,500 pounds. c. Since the area affected by these attacks later suffered severely from the atomie bomb it is impossible to evaluate accurately the effective damage done. The following figures are therefore offered only as a recapitulation of damage figures obtained from interrogation of residents and city Of the total buildings damaged, 22 were typical Japanese domestic structures, 3 were wood-frame, and 1 was of load-bearing, brick-wall construc- tion. 2. Attack of 19 March 1945 Two small bombs were dropped on Hiroshima between 0730 and 0800 (local time) on 19 March by four or five carrier-based planes, presumably Grummans. Most of the information in connec- tion with this attack was ascertained through interrogation of Mr. Shintaku, of the east fire station, and Messrs. Watanabe and Kobayashi, of the city engineering department. a. The carrier-based planes came in from the northwest and while in the vicinity of the Hiro- shima railroad station dropped one bomb in a river causing no damage, and one in a residential section causing two deaths and destroying two houses of domestic construction. In addition, the 81 officials. For bomb falls refer to figure 1. planes strafed along the railroad tracks but caused no damage. For bomb falls refer to figure 1. Casualties — : 3. Attack of 30 April 1945 Attack of— Killed Wounded Total ; cal tenes: tz Ten 500-pound bombs were dropped on Hiro- eS os ie a ; shima during this attack. The bombs were ee = pala “5 lag dale date dropped from a lone B-29 on 30 April 1945 at 0655 30 Apr. 1945__-___- 10-15 | 25-30_..........-.-- 35-45 F See , z: (local time) and fell within grid areas 5H and 6H r= = Fs as shown on the bomb plot map, figure 1 included Damage to buildings in this section. The following data are a summary 7 ai... of information gathered through observation and Sra Ot stroyed | ne ae bis interrogation of residents and substantiated on 10 ™ Sl at ; November 1945 by interrogation of Y. Yamani, 19 Mar. 1945______- 2 | None reported_____- 2 chief of the west side fire department, and 8S. 30 Apr. 1945___-__- 22 | | 24 Nimura, city architect-engineer. Mr. Yamani : was the most valuable source of information since Tare 1.—Air attacks on Hiroshima Prefecture ~ ; ,) ’ - . ) ~_ ‘ . ‘ ‘ + ee hs EN “ . A. z cs ’ ae A or \ ‘ 4 J ’ - rf > 4 bo ~~ = ’ = J ts / HE ATTACKS ON HIROSHIMA | 0) LEGEND ANG « ft = ; / [e] ATTACK 19 MARCH 1945 Ske RD bw @ ATTACK 30 APRIL 1945 PUSS ee u | NOTE: NUMBERS NOT REFERRED TO THESE SYMBOLS re IDENTIFY BUILDINGS COVERED IN SECTION X OF l | REPORT t ef ~y ap . ' . Ay : L ¢ Se A ; : eS, gpa $ PinS/ ae — | S $ . r {-“< \ rf Hh “ ~ ti < Red Pet GROIA a -— \ [‘cé~ = : a b AGL ~ — ff ~ X 7 , Ha, , a |) mn : on Oa a“ { (cq HIROSHIMA AIRPORT | | HIROSHIMA-KO | (HARBOR) | ! | HIROSHIMA WAN (BAY) ee — z / . le tas "* in = a - HIROSHIMA |ROSHIMA PREFECTURE, HONSHU, JAPAN rr a : ape veces = ‘ a0 vos KAITA WAN (BAY) CONTOU® STERVEL 70 wr TERS | oo mas reba? = | — afoot | | } od . = 7 F / | \ | ; Maas ae Lh eee ag | . J SS / HE ATTACKS \ 7 i Coa HIROSHIMA JAPAN id ~ ‘| FIGURE |- tis Tae a 95 731566 O - 47 (Face p. 82) SECTION VI THE ATOMIC-BOMB ATTACK Page SAP Lac pe = ge pee a ero eee ae ee eee 84 a BL BS a a ee ee Ee See ree ee 84 TER SOUR ee ES en he ne ee oe aaa 84 a nILT@CLIC OL AtAGK.-— 5. --=---.-=----<2- 222 aoe non sn oe eos Sone woe oes cn wwsesoeec= 84 EM RTI RRMNOTE 2 2-6 28 ot cea t obs seo st cele ee nn ea ee 85 re IERGMENUCIE TIM) 2) NS eat SS 8 se ee eek Se ee ee ee Sse 85 inv Greconse and fire-fighting organizations:_.-.............--.---.-=-=---<------22-2----==s-+--- 86 CECT eee to Say te oe ae on ned n eee ee pas ne een eee seane- 86 ES TST i pS aR eR SR yee gy 86 Diagrams 1-4, inclusive 83 1. Source of Information a. No details of the attack preparations, ap- proach to the target, dropping of the bomb, ele- ments of the explosive, or method of detonation of the bomb dropped on Hiroshima are available for this report. It is, therefore, necessary to de- scribe the attack as experienced and reported by the Japanese themselves. The information con- tained in this section was obtained through inter- rogation, and from Japanese atomic-bomb reports prepared by the Kure Naval District and the governor of Hiroshima Prefecture. The originals and translations of these reports are on file with the Intelligence Section of the United States Stra- tegic Bombing Survey. 2. General a. Although Hiroshima Bay and surrounding airfields had received several attacks, the city itself had experienced no large-scale bombing at- tacks prior to the atomic-bomb attack on 6 August 1945. Residents stated, however, that it was not an uncommon sight to see formations of American planes pass over the city on their way toward other targets. Two small-scale, high-explosive attacks had been made on the city: one with four or five carrier-based planes on 19 March 1945, and the other by a single B-29 on 30 April 1945 (See. V). b. Defense plans for the evacuation of personnel and construction of firebreaks were drawn up in the fall of 1944 when the Japanese people began to realize that their island empire was no longer beyond the reach of American land-based bomb- ers. At the time of the atomic-bomb attack the city had entered what was termed the sixth evacu- ation period, although just what stage of comple- tion this involved is not known. 3. Conditions on Morning of Attack a. The morning of 6 August 1945 was clear with a small amount of clouds at high altitude. Wind was from the south with a velocity of about 4} miles per hour. Visibility was 10 to 15 miles. b. An air-raid “alert”? was sounded throughout Hiroshima Prefecture at 0709 hours. the number of planes causing this alert were con- flicting. The governor of the prefecture stated that four B-29s were sighted, while the Kure Naval District reported three large planes. ce. The aircraft apparently came out over Hiroshima from the direction of Bungo Suido and Kunisaki Peninsula, circled the city, and withdrew Reports of: 84 in the direction of Harima-Nada at 0725 hours. “All-clear’’ was sounded at 0731 hours. d. The following cireumstances account in part for the high number of casualties resulting from the atomic bomb: (1) Only a few persons remained in the air-raid shelters after the ‘‘all-clear’’ sounded. (2) No “alert”? was sounded to announce the approach of the planes involved in the atomic- bomb attack. (3) The explosion occurred during the morning rush hours when people had just arrived at work or were hurrying to their places of business. This concentrated the population in the center of the city where the principal business district was located. (4) Many persons residing outside the city were present for reasons of business, travel and pleasure. (5) National volunteer and school units were mobilized and engaged in evacuation operations. 4. Time, Altitude and Direction of Attack (Diagram 1) a. Although some confusion exists as to the exact time of the explosion, it is safe to state that it took place within a minute before or after 0817 hours. b. Although no air-raid ‘‘alert’’ sounded, the planes committed in the attack were sighted as early as 0806 hours when Matsunago lookout station reported two enemy planes proceeding northwest. This was corrected to three planes at 0809 hours. (1) The sound of aireraft engines from the direction of Saijo was picked up by Nakano searchlight battery at 0814 hours. (2) Enemy aircraft were reported over Saijo proceeding west at 0815 hours. (Nakano search- light battery reported sighting two aircraft flying 700 to 1,000 feet apart at 23,000 feet, heading southwest. Diagram 2.) c. Planes arrived over Hiroshima at an altitude of 28,000 feet. There were varying reports on the number of planes, but it was generally agreed that three aircraft were sighted—one plane was in the lead, and two followed abreast separated by a distance of 700 to 1,000 feet. The lead plane was seen to change course to the right while the two following planes were observed at 0817 hours to release parachutes and turn to the left. Nakano searchlight battery reported the release of an object attached to a parachute which failed to open. At this moment the bomb detonated. d. Following the detonation, the lead plane was seen heading east or northeast. Nothing further was reported concerning the activities of the other two planes, although one light aircraft was sighted heading south at a low altitude. e. It was not definitely established which plane dropped the bomb, but it was presumed by the Japanese that the lead plane carried the bomb since the two following aircraft released para- chutes. 5. Japanese Description of Explosion a. Survivors of the atomic-bomb attack stated that the detonation seemed like a vast combustion of magnesium filling the entire sky. These persons reported that the flame contained various colors such as greenish-white and yellowish-red. Reports of the duration of the flash varied from instantaneous to 2 to 4 seconds. At the same time an overpowering heat wave emanated from the source of the flash. b. The entire city of Hiroshima was darkened by a dense pall of smoke and dust, which limited visibility to a few feet. From a distance, a mushroom-shaped cloud was seen expanding and covering the entire city. It then rose, reaching a height of 23,000 feet 4 minutes after the explosion. The column began to disintegrate after 8 minutes, the top of the mushroom separating itself from the column and remaining intact. The color of the column was gray and white while the ball on top was white tinged with crimson. ce. In the center of the city a violent blast of air immediately followed the flash, knocking down trees and poles, stripping branches off trees, tear- ing sheets of galvanized metal off buildings, derailing streetcars, and squashing or knocking over houses. d. A slight interval between the flash and the blast was noted by persons who were removed from the center of the city. e. Few persons in the downtown area heard any noise of explosion. They were aware only of a blinding flash and the overpowering heat and wind. Outside the city, however, a loud rumbling noise was heard. f. Fires soon broke out throughout the city and developed into an engulfing inferno in the central area of destruction. Some of the fires were caused by direct ignition of thatched roofs, cur- tains, trees, and the like but the majority resulted from secondary effects. g. Directly after the explosion survivors re- 85 ported finding in some places a “substance”? which emitted a weak, bluish-white fluorescent light. This substance, upon contact, burned through or ignited combustible objects. When it fell upon clothing it burned through to the flesh, producing water blisters which gradually diffused and be- came extremely painful. h. Following the explosion, strong, changeable winds arose, attaining velocities of 25 to 35 miles per hour. Whirlwinds were reported at a few points. i. While the fires were spreading, there was a light rainfall throughout the central part of the city, with occasional heavy showers in the north- western section. 6. Eyewitness Accounts of Explosion a. A Kure Navy Yard war worker who was 2}s miles west of Hiroshima at the time of the explo- sion stated, “I saw a single enemy airplane flying over Hiroshima. It released (or fired) a brilliant object. I thought at first that it was an incen- diary bomb, but then I saw someting that looked like a smoke ring from a funnel gradually falling toward the ground. It grew larger almost imme- diately and increased in brilliance and soon cov- ered an area almost equal to that of the city of Hiroshima. A flame appeared which was even brighter than the sun. I thought I might get hurt so I fell flat on the ground.” b. Two Kure Navy Yard war workers who were located 6 miles northwest of Hiroshima when the bomb exploded said: We felt a blast of hot air accompanied by a bright light. Looking at the sky immediately afterward we noticed an enemy plane in the center of a dark-colored column, surrounded by the blue of the sky. The column undulated. At two places in the column we noticed white smoke which gradually expanded. We fell to the ground and heard a loud explosion. White smoke could be seen rising in the direction of Hiroshima, e. A technician from Kure Navy Yard who was at Hiroshima Railroad Station, Advance Ter- minal, said: I noticed what appeared to be an enemy B—29 turning to the right at a high altitude as it proceeded north directly overhead. Immediately afterward I saw what seemed like an incendiary bomb exploding to the rear of the plane (in the sky to the south). It was followed by a flash (1 to 2 seconds in duration). Thinking it was an incendiary bomb, I started to take shelter in the station building but had gone only a few steps when I felt a tre- mendous concussion strike me from behind. I immedi- ately fell to the ground and covered my face. 7. Inactivity of Defense and Fire-Fighting Organizations a. Fire-fighting and defense units were helpless _against the explosion and resultant fires. About 70 percent of the fire-fighting equipment was destroyed but the remainder was usable. An appeal for help was made immediately to fire com- panies outside Hiroshima, but it was not until approximately 1100 hours that this help was able to get through to the outskirts of the city. No attempt was made to fight fires in the center of the city and all equipment was engaged in attempt- ing to control fires on the outskirts. b. Air defense, civilian defense, and neighbor- hood volunteer units completely disintegrated. Escape from the surrounding confusion and agony was the thought foremost in the minds of the sur- vivors. ) 1?) 20 40 60 80 100 120 140 DIAGRAM 3 89 wovIe = yNOVIe MOTTIBA , a1dund 3YNSS3ud ¥ SLNHOVEVd OL GSHOVLLIV YSLLINSNVYL SAVM-LYOHS Valin YOs WVHYSVIO LINDYIO ak DIAGRAM 4 90 SECTION VII DETERMINATION OF AIR ZERO Page NN a Sie See 8 26 oS ako pi aan ase loses gs ae fat Bee shee ae 92 ce ee no ts ea eo wig ee eo ae ee ee ee eee 92 Ty wes meena fee ee PY me ee or see 2 Pa oe fee ee A eS et Se se een oot San eae se nnee 92 rete eevee Sm Pe ys 2 Se le 2 oS ee ee See es ele lee 92 Photos 1 to 4, inclusive. Figure 1. 91 1. Summary The point of burst of the atomie bomb is re- ferred to as “zero,’’ a point determined to be in grid 5H approximately 700 feet southeast of the T-bridge, at an elevation of slightly over 2,000 feet. The location of zero in both plan and eleva- tion was developed from flash marks found on surfaces readily scorched or spalled by radiation of heat from the explosion. Marks or unscorched areas which were delineated by ‘shadows’ on surfaces that were shielded by some object in the path of the radiation or heat wave afforded direc- tions and elevations for the location of the point of detonation. 2. Definition The zero point may be defined as the point of detonation of the atomic bomb. The point had location in both plan and elevation, inasmuch as the bomb burst in the air. Throughout this report the ground location of the point immedi- ately under the burst is designated as ground zero, abbreviated to GZ, and the actual point of detonation in the air is designated as air zero, abbreviated to AZ. 3. Location and Elevation GZ was found to be in grid 5H at coordinates 744,200-1,261,850 (fig. 1). Air zero, determined from an average of seven computations, was found to be slightly over 2,000 feet. 4. Method Both AZ and GZ were determined from flash marks found on buildings, bridges, and other structures or objects. The flash marks resulted from the scorching of surfaces such as wood, asphalt, paint, or the spalling of granite from radiation of the intense heat of explosion. Objects obstructing the path of the heat wave cast their “Shadows” which were actually unscorched areas. The edges of the “shadows” upon horizontal surfaces led to the location of GZ, and upon vertical surfaces permitted the computation of AZ. Photos 1 to 4, inclusive, show typical flash marks. a. Ground zero was located by extending to an intersection the lines formed by various flash marks on horizontal surfaces. The lines were extended by sighting by eye across objects placed at two points along the mark and alining stakes ahead to a point of intersection with other lines similarly extended. Six such lines were run from is flash marks found on the granite door sill of build- ing 6, 600 feet east of GZ; on granite objects in the shrine, approximately 800 feet north of GZ; on the granite shrine, 900 feet northeast of GZ; on the asphalt roadway, 250 feet west of GZ; on the orna- mental granite work on building 11, 800 feet southeast of GZ; and on bridge 22, 250 feet south- west of GZ. Other marks were used to check the point obtained by intersection of the lines listed above. b. Air zero was determined from marks made on vertical surfaces, usually outlined by over- hanging objects or members which “shadowed”’ portions of the surfaces. The legs of the triangle formed a and 6 in figure 1, were measured with a scale or steel tape, and the horziontal distance (base line) to GZ was sealed from the map. The base line was checked, where practicable, by actual measurement on the ground. Thus, similar triangles were formed which permitted simple calculation of the height of burst, or AZ. Seven such computations were made with base lines ranging from 600 to 6,600 feet. The marks actually used in determining AZ were on a granite lantern post at entrance to shrine, 600 feet north of GZ; asphalt surface of bridge 20, 2,900 feet southwest of GZ; wooden window frame of penthouse on Electric Building 26, 2,300 feet south of GZ; tile wall surface of Electro-Technical Laboratory Building 74, 6,000 feet north of GZ; asphalt surface of bridge 30, 1,900 feet southwest of GZ; asphalt roof of Communications Building 85, 3,300 feet northwest of GZ; and Gas Holder, 6,600 feet south of GZ. 5. Accuracy The degree of accuracy attained in locating GZ and AZ was limited by circumstance, but it is believed to be adequate for the purpose of evaluat- ing effects of the bomb. All measurements were made from flash marks, which, although easy to see, were not sharply defined along the edges. This lack of sharp delineation was probably caused by the fact that the source was not actually a point but an oblate sphere of fire in which the major axis was vertical. Elevation measurements therefore, could not be made with precision and minor inaccuracies were inevitable. a. Ground Zero. All points of intersection of the lines extended from the six flash marks fell well within a cirele of 50-foot radius. Although the method used in the determination may appear inaccurate, it must be pointed out that more precise methods (such as use of a transit and tape traverse) would have attained no greater degree of accuracy inasmuch as the edges of the flash marks were not sharp lines. The selection of the edge of the “shadow” was a matter of judgment which could nullify the precision of extending a line by means of a transit. Surveys made by the Japanese (Chugoku Electric Co., and the city architect) placed GZ in the same general area as that determined by this team. b. Air Zero. The seven calculations of AZ ranged from 1,600 feet to 2,300 feet and averaged slightly over 2,000 feet. This figure is believed to be correct within 200 feet. Japanese surveys made independently by the Chugoku Electric Co. and the city architect established AZ’s of 500 meters (1,635 feet) and 800 meters (2,620 feet), respectively. A survey was also made by the Kure Naval District, and the following is taken from their report of September 1945, paragraph 5, page 17: The carbonization of timbers in the vicinity of Ushida and the Hiroshima University of Literature and Science caused by the radiated blast showed comparatively clear shadows which were formed by obstacles in the path of the 93 radiated rays. From this, the angle and direction of the source of the rays were clearly determinable. Taking the horizontal distances and angles from these points, the altitude of the center of the blast was calculated and figures of 580 meters and 510 meters, respectively, were obtained. From this, the altitude of the burst was figured to be approximately 550 meters * * *, The average of the four findings of the Japanese. was 1,970 feet. The height of AZ as determined by the British is taken from the preliminary report of the British Mission to Japan, paragraph 2.1.2, page 10, which reads as follows: Enough measurements, however, were taken in each place to confirm the general location of GZ as that marked as the center of the circles on the accompanying maps; and to give reasonable estimates of the height of burst. These are: Hiroshima—Just below 2,000 feet. Nagasaki—Approximately 1,750 feet. These are the distances between GZ and AZ. Since GZ was effectively at sea level at both places, they may be taken as heights of bursts above sea level. The calculations of the British and Japanese surveys placed AZ slightly under 2,000 feet, which closely approximates the result obtained by calcu- lations of this team. SECRET 1,262,000 YOS sigaar ERO 744, 200 YDS 1,261,850 YDS / 000 YD 744, LOCATION OF GROUND ZERO(GZ)AS DETERMINED FROM FLASH MARKS. @ - LOGATION OF JAPANESE DETERMINED GZ ® - LOCATION OF BRITISH DETERMINED GZ / VW a| }S— UNSCORGHED SURFACE TYPIGAL GASE OF FLASH MARK USED IN COMPUTATION OF AIR ZERO (AZ). SECRET U.S. STRATEGIC BOMBING SURVEY DETERMINATION OF ZERO POINTS HIROSHIMA, JAPAN FIGURE |-MIr D+ TYPICAL FLASH MARKS PHOTO 1-VII. Showing flash marks on asphalt deck PHOTO 2-VII. Showing flash marks on granite lan- of bridge. tern post. PHOTO 3-VII. Showing flash marks on celotex- PHOTO 4-VII Showing flash marks on granite steps. type wallboard. SECTION VIII TYPICAL JAPANESE DWELLINGS Page Object of study - - 5 on ccete : eee ee Pe bere: piclel ees 97 Residential areas_-_- —_- Sek : 5 im Sale Oe 3 Ta eto 97 The dwelling..._--_- sons eee z et 97 Rooms and furnishings __ : : Bee, ney chee A bes ES 99 Photographic description, photos 4-19, inclusive___- pee aoe fees ot oe 100 MMatemale.3.<- 222425. 29e2 pee tae =e ee 2 ae ee a a 100 Construction-.---------- Rack fads ae ieee a 107 Blast vulnerability —-------- : : vf ee toes sees tee 107 Fire vulnerability —_----- Jee che seeps aes chek a A ee 115 Other photos, 1-3, 20-26, inclusive. Figures 1-6, inclusive. 96 1. Object of Study Although the Japanese had to a great extent adopted Western construction practices for their industrial, civic and large commercial buildings, their dwellings remained of a design and construc- tion indigenous to Japan and, therefore, unfamiliar to most Americans. Since residences comprised the bulk of any urban area, a complete under- standing of this type of building was necessary before the damage to an urban target, such as Hiroshima, could be fully comprehended. It is the object of this section to present the data per- taining to the typical dwelling, which affected its vulnerability to fire and blast weapons, and their effects thereon. 2. Residential Areas Residential areas in Hiroshima, like those in other Japanese cities, were characterized by a high degree of built-upness resulting from a den- sity of population comparable to some of the worst slum districts in large American cities (photos 1-3). Various sizes of one- and two-story, wood-frame buildings roofed with tile were built close together along the streets, with numerous outhouses, wood garden walls and fences to the rear of the houses occupying most of the remaining ground area within a block. Streets were very narrow and laid out ina rectilinear pattern except where topo- graphical features interfered. Sidewalks were not common, the streets being used for pedestrian as well as vehicular traffic. Open gutters carried drainage and waste water from houses on each side. In areas where the residential section was not clearly defined, small combination shop-dwell- ings were found, with the shop opening directly onto the street and the owners living to the rear or in the second story. These buildings, however, did not differ from the usual dwellings in details of construction. 3. The Dwelling a. Background. The Japanese dwelling was developed into its present form to satisfy the need for a suitable structure in which to carry out the highly traditional family and social life. The characteristics of the house which are usually criticized by the Occidental (flimsiness of con- struction and stark simplicity of interior) can be explained by the fact that the Japanese found in these qualities an answer to his own particular needs. His home was not designed to furnish the maximum of comfort, but to serve primarily as a 97 shelter. Permanency of construction was not considered a particularly desirable feature. This concept of a dwelling was strengthened by, and probably resulted from, his experience with earth- quakes, fires, and typhoons which have ravaged his country since the beginning of time. Thus, if disaster struck, he could rebuild his home at rela- tively low cost from local materials. Superstiti- tion, which was so closely interwoven with Japa- nese tradition, also exerted an influence on the plan- ning of his dwelling in the form of “Kimon”’, the science of conciliating the household gods. Few Japanese would build a house before presenting its plan to one of the scholars of his “‘science”’ to de- termine whether or not the various parts of the house were auspiciously situated in relation to the center, or if misfortune were liable to befall the occupants. Favorable dates for starting con- struction and moving in were also determined in this manner. b. Dwellings in Japan varied from the one-room hut of the poor to the multi-room mansions of the wealthy, therefore no one residence that could be designated as typical in all respects. Except for a few Western style houses, however, most Jap- anese residences were of the same type construc- tion and utilized the same materials. The de- scription below, therefore, can be applied to nearly all Japanese dwellings. c. Description. In general, the dwelling was a one- or two-story, unpainted, wood-frame struc- ture with a heavy tile, wide-eaved roof of graceful lines. Exterior walls were straw-reinforced-mud plaster on a lath mat of split bamboo. The mud was usually finished with a thin coat of fine sand, clay, or white lime plaster. Thin boards were sometimes placed over the plaster along the lower parts of the wall for protection (photos 5-6). On one side, large areas of glazing in sliding sashes made it possible for the house to be opened up on the garden. Sliding sashes with panels of trans- lucent, white rice paper were also used for most interior doors and partitions. Fixed interior par- titions were similar to exterior walls. Floors were covered by closely fitting straw mats (Tatami) except in passageways, baths, toilets, and kitchens. These mats were of a standard size, 6 feet by 3 feet, and 2 inches thick. Room sizes were referred to by the number of mats a room contained. A suspended ceiling of thin wood sheets was used throughout the house. Neither attics nor base- ments were found in Japanese dwellings. Figures PHOTOS 2-VIII and 3-VIII. The high degree of built-up- ness that is a characteristic of Japanese cities and villages is shown in these aerial views of typical residential districts. The lower photo shows a fish- ing village. Its expansion has been restricted by high hills and overcrowding has resulted. PHOTO 1-VIII. Roof- line view of Japanese residences crowded about a small cove on the outskirts of Hiro- shima. Note the typical tile roofs, the nearly uni- form height of the houses and the high degree of built-upness. 4—6, inclusive, are drawings of one- and two-story dwellings. 4. Rooms and Furnishings a. Plan. The simplest Japanese dwelling con- sisted of an entrance, a living room which also served as a dining room and bedroom, minimum toilet facilities, and a kitchen which might or might not be within the main structure. In larger homes the plan was expanded to include additional rooms similar to the living room, a bath, and, in some cases, one room furnished in Occidental style (Western room). When these additional living rooms were available they ceased to be used as multi-purpose rooms and acquired definite func- tions such as guest, dining or sleeping rooms. The room actually used as a living room probably would be the only one which would include a “Tokonoma”’ (recess for ornaments); otherwise the rooms would be similar in design and furnishings and could be used interchangeably. The different types of rooms usually found in a Japanese dwelling are described in paragraphs b—A below, and their relation to each other can be seen in the plans in figures 4 and 6. b. Entrance (photo 7). The Japanese residence was entered through sliding doors of wood inset with panes of either clear or translucent glass. These doors, which were at grade level, admitted one to the Genkan, a small room similar to a vestibule, which provided the transition between the street and the interior of the house. The finished floor of the house, which was approxi- mately 18 inches above grade, extended part way into the Genkan, necessitating an additional step between the house floor and the stone or concrete floor of the entrance. It was at this step that shoes were removed before proceeding into the house. A cabinet or a series of shelves were provided for the shoes. There was no other furniture in the Genkan. Another set of wood sliding doors with rice paper panels separated the entrance from a hallway which gave access to other rooms of the house. In addition to this entrance the more expensive dwellings had a smaller one for family use only. When two Genkans were present the larger one was more elaborate and some kind of formal decoration was generally used. Sereens or partitions were so placed within the house that the areas used for domestic purposes could not be seen from the garden. c. Living Room. This room (photos 10-14), the largest and most frequently used in the residence, was the center of activity, answering the purposes of living, dining, and bed rooms. It always occupied the most favorable location in the house, usually along the side where it could overlook the garden and be exposed to the winter sun and the summer breeze. At least one and: more often two of its walls were sliding wood sashes with panels of rice paper which could be opened or removed entirely, allowing the room to merge with those adjacent to it or to open up on the garden. Straw mats (Tatami) laid on a thin wood subfloor, gave a soft, resilient quality to the floor, and accentuated the rectilinear patterns which oecurred in all walls and openings. A very light ceiling of thin wood was suspended over the room. It was in the living room that the tradi- tional, ornamental recess (Tokonoma) was found, usually extending the entire width of the room. These recessed areas conformed to certain estab- lished proportions and methods of construction, but the arrangement of the cupboards Wibukuro) and shelves (Tana) might vary somewhat: Closets for clothing and bedding were located in the living room or in an adjacent passage. d. Living Room Furnishings. The following is a list of the articles of furnishings and ornaments most often found in a living room. (1) Dia—A low table used for dining, ete. (2) Zabutona—Small cushion seats. (3) Hibachi—Charcoal brazier. (4) Kakemono— A decorative scroll, hung in the tokonoma. (5) Jibukuro—Storage cupboards within the tokonoma. (6) Tana—Small shelves for ornaments, also within the tokonoma. (7) A small dressing chest with mirrow and drawers. (8) Various ornaments, such as dolls and carvings. (9) Bedding—At night the bedding was re- moved from its closet and spread on the floor, thereby converting the living room into sleeping quarters. (10) Other items, such as large cabinets and sewing machines, were occasionally found in larger homes, but they were not standard furnishings. e. The Kitchen (photo 15). The kitchen of the Japanese house was a small room, located so that it would have direct access to the outside, but never in a conspicuous place in relation to the garden or living room. In some cases it was detached from the house. The floor was of wood or dirt, and usually one step below the level of the other rooms in the house. A small, masonry range heated by charcoal was used for cooking unless gas was available and within the means of the family. This range was crude, consisting of a simple firebox into which charcoal was placed and igvited through an opening near the bottom. As a rule much fanning was necessary before sufficient heat was generated to warm the utensil which rested on a grate over a circular opening in the top of the stove. A sink and drain board were built into one wall. Other furnishings included a work table, cabinets and shelves for the numerous trays, bowls, and dishes. Sf. Toilet (photo 17). The Japanese depended upon night-soil for fertilizer to such an extent that few flush-type water closets were used. The toilet (Benjo) was a simple fixture fitted in an opening in the floor. Beneath the floor was a pit lined with wood or conerete which caught the excrement which was collected periodically and carted to farms for use as fertilizer. The small compartment which the toilet occupied had a tile or wood floor, plaster walls with tile or wood wain- scoting, and sliding doors, sometimes opening di- rectly onto a passageway. Except in the smaller homes, a lavatory was located in an adjoining compartment or in a small recess off the passage- way. The bath was seldom placed in close prox- imity to the toilet and lavatory as is customary in the United States. g. Bath (photo 16). The room in which the Japanese bathed was usually a small, concrete- floored room with a wooden tub built into one corner. Beneath the tub, which was about 2% feet deep, a charcoal stove was installed to heat the water. This stove was usually fired from out- side the room. Wood slats were usually placed over the concrete floor which drained to an open gutter outside the house. Walls were of plaster with wood wainscot, although tile for floor, wain- scot and exterior of the tub was frequently used in more expensive homes. Clothes were removed in an adjoining compartment or on a raised section of the floor and placed on shelves along the wall. The text for Photo 16 describes briefly the pro- cedures followed by the Japanese when bathing. As all Japanese could not afford to have bath rooms in their homes, public baths were main- tained in cities and towns. h. Western Rooms. Japanese in the higher- 100 income brackets usually furnished one room of their residence in what they referred to as the Western style. The typical straw mats were re- placed by a hardwood-finish floor; permanent partitions were constructed; swinging doors were used in place of sliding wall panels; and the room was furnished with Western style furniture. A false fireplace often completed the “Westerniza- tion”’ of the room. 5. Photographic Description a. The photos on the following pages illustrate the principal features of the Japanese dwelling. Most of the photos are of a residence considerably larger and more expensive than could be afforded by the average Japanese family. As indicated in paragraph 36, however, the same materials and construction features were found in all Japanese dwellings, regardless of cost or size. In this respect, therefore, the photos shown can be con- sidered typical. 6. Materials a. Wood. An abundance of timber in Japan and the natural preference of the inhabitants for this medium combined to make wood by far the most common material used in the construction of dwellings. Temperate zone conifers, which are considered the best construction material, were found throughout most of Japan and used exten- sively. Bamboo was sometimes used for struc- tural members in addition to its more common uses as drains, laths, siding, and decoration As cut lumber was expensive, rough timber was utilized to a great extent, being shaped on the job by the carpenter. Japan did not have the wide variety of dimension lumber found in the United States. 6. Plaster. This material, which was used for exterior panel walls and fixed partitions in most Japanese dwellings, was manufactured on the site by reinforcing clay or mud with rice straw. It was applied on lathing or strips of split bamboo tied with straw. A fine sand or white lime plaster was usually used as a finish. c. Tile. Heavy, vitreous tile was used almost exclusively for roofs of residences in urban areas. Glazed tile for wainscoting and floors was found in some baths, toilets and kitchens. d. Glass and Paper. Nonstructural glass and thin, translucent rice paper provided the panes in windows and doors. Some interior sliding sashes were covered with a heavy, opaque rice paper. e. Other Materials. Concrete, brick, and stone were used to some extent for floors in baths and 101 PHOTO 4-VIII. Exterior and forecourt of a large Japanese residence. Note the elaborate tile roof. The wooden shutters seen on the right are locked in place across all entrances at night. PHOTO 5-—-VIIIL. Another view of the above house, show- ing large corner window with sliding sash. The circular window has obscure glass in fixed sash. Opening in fence to left leads to garden. PHOTO 6-VIIT. Photo taken at rear of same residence, The panel walls are mud plaster on bamboo lath with a white lime plaster finish. The bamboo wainscot protects the plaster. Note the numerous roofs and the half-timber con- struction. ent CEILING \ 7 umes So seen ’ ee os ; % 7 . oe CY VV ae = aeal IKKUI 7 _ rome LASTER be age CONCRETE FLOOR PHOTO 7-VILI. ENTRANCE, The entrance (Genkan) of a large Japanese residence. The photo was taken just inside the exterior doors. PHOTOS 8-VIII and 9-VIII, INTERIOR PASSAGE. Interior view of passage along garden side of house from the entrance. The sliding sash on both sides of the passage allows the rooms to be opened to the garden. The relation of the rooms to the garden can be seen in the photo below, 2 muo PLASTER Pate! c PHOTO 10-VIII. Living room showing a Buddhist image in- corporated into the design of a tokonoma, LIVING ROOM: Note that in the above photo the inclusion of the budsudan has not altered the basic proportions of the tokonoma, which are standarized. The cabinet containing the budsudan is called a butsuma, The Japanese warm their hands over the charcoal brazier, or hibachi, which is the only source of heat in most dwellings. Photo 11 shows one variation in the arrangement of the jibukuro, the cupboards in which small articles for the living room are stored. The table with the revolving top is of heavy wood with a lacquer finish, and of a somewhat better quality than is found in average homes. The dolls in the tokonoma are popular forms of decoration in Japan. PHOTO 11-VIII. In- terior view showing the furnishings of a Japanese living room, TORONOMA LORMAMET A rey poraeesee ae KAKEMONO (HANGING BEROLL) in Bh ao N ons ’ t>—¥ [=> = ————————— = TaTams | i (STRAW MATS) 4 103 PHOTO 14-VIII. THE BED. This photo of a Japanese bed shows the ease with which a living room can be converted into sleeping quarters. The bed consists of two heavy blankets similar to our com- forters. When not in use they are stored in the closets on the right. A low mirrored dressing table (not shown here) completes the bedroom furnishings. The unshaded light bulb is typical. —s PHOTOS 12-VIII and 13-VIII. graphs and sketches of interior and fur- nishings of a living room. Construction and materials are typical but the quality is above average. PHOTO 15-VIIL. KITCHEN. This kitchen was described as modern by the owner. Located to the left of the sink was a typical masonry firebox with two grated openings in the top. In such stoves charcoal is placed, ignited, and fanned to provide heat for cooking. Cabinet space in the kitchen provided storage for utensils. PHOTO 16-VIII. BATH. The ritual of the bath in Japan consists of lathering, washing, and rinsing before entering the tub of very hot water to soak and relax. Floors, tubs, and wainscots of wood are more common than tile. Slatted wood floors drain the water from the sponge bath. A charcoal stove, fired from the outside, heats the water. PHOTO. 17-VIIIl. TOILET. Flush-type water closets are seldom found in Japanese residences. The Benjo shown in the photo is a porcelain fixture through which the excrement falls into a pit where it is collected and carted away to farms for use as fertilizer. Large homes usually have a lavatory built in a small recess off the hallway near the Benjo. In more modest residences the Benjo is often loeated near the kitchen and the sink used for washing in lieu of a lavatory. 105 PHOTO 18-VIII. A view of one of the more elaborate gardens. It is so located that it can be seen from all the ‘principal rooms of the house. The entire wall of the house pietured is of sliding sash which can be removed, extending the living area into the garden, GARDENS: Gardening in Japan has become a highly developed art. So exacting is this art that every garden (elaborate as seen in Photo 18 or just a tiny spot of ground) falls into one of the many classes under the two general types: Tsukama (artificial hills) and Hira-niaw (level gardens). Hach is laid out according to established formulae. Religious or philosophical significance is attached to the location or shapes of the trees, rocks, miniature hills, ete., which make up the design. There is seldom a profusion of color but rather an atmosphere of restraint, for the Japanese strive to create in their gardens a refinement so hidden beneath an ordinary outward appearance that only those with the most cultivated taste can recognize and appreciate it. PHOTO 19-VIII. The close relationship be- tween the living room and the garden areas is shown in this view of a modest home. kitchens, but were seldom used as structural material in the frame of the house. 7. Construction a. General. Residential construction in Japan was primarily the work of local carpenters. These men were, as a rule, highly skilled especially in the use of wood, and their high quality of work- manship was displayed in the delicate interiors and cabinet work of the dwelling. The practices followed, however, placed their residential con- struction far below American standards of strength, rigidity, and weather tightness. Apparently, sizes of members were determined by general practice and the materials available rather than by caleu- lation of loads and stresses, and members used under the same conditions might vary greatly in size. A minimum of rough hardware was used, the members being joined by intricate joints which were cut on the job. These joints tended to cause the over-all size of members to be larger than those which would be used in American construction of a similar type. b. Foundations. Most dwellings were supported about 12 to 18 inches above the ground by short, wood posts resting on individual footings of stone or concrete. In better construction, beams be- neath exterior walls and major partitions were found in addition to individual foundations. As a precaution against earthquake, the structure of the dwelling usually was not rigidly anchored to the foundation, thus reducing to some extent the vulnerability of the structure to the effects of ground shock. c. Frame (figs. 4. and 5). The frame of the dwel- ling consisted primarily of a heavy roof system, supported by 4- by 4-inch wood columns spaced about 6 feet apart around the exterior and along all major partitions. The exterior columns were framed into a heavy plate (usually about 9 by 9 inches). Heavy rough timber beams spanned the structure and supported the simple framing system of rough poles on which the purlins rested. Joints were usually mortise and tenon. No diag- onal sheathing or bracing was used in the framing. d. Floors. Interior floors not covered by straw mats were usually a single thickness of '-inch wood flooring. This flooring was nailed to joists (approximately 2 by 1% inches) spaced 1 foot 2 inches on centers. Joists were rough poles of about 4-inch diameter. Beams were spaced ap- proximately 3 feet on centers, and supported every 3 to 6 feet along their length by individual foot- ings. Where straw mats were used, the wood flooring was dropped 2 inches and became a sub- floor for the mats. e. Walls. Two-inch plaster panels between framing members formed most exterior walls of dwellings in Hiroshima. The plaster (par. 46) was applied to a lath of split bamboo (-to 1-inch diameter) which was lashed together with twine or straw. No insulation or inside sheathing was used. However, on some exterior walls a layer of thin boards or bamboo up to about 3 feet above ground served as protection for the plaster. Few walls of concrete, brick or stone were found. ft. Partitions. Stationary partitions were iden- tical to exterior walls except that the protective layer of boards was not found. Movable par- titions were sliding sash covered with cloth or rice paper. g. Roof and Ceiling. Nearly all Japanese dwellings had hipped or gabled clay tile roofs of about 30° piteh. As a rule the tile was set in mud on % to ls-inch sheathing, but in some cases it was wired in place. Open ends of the tile and cracks were sealed with mud to insure watertight- ness. The sheathing was nailed to 2-by 1!-ineh rafters which were supported by rough pole purlins (3-to 4-inch diameter). Wood straps nailed to the purlins supported a series of small strips (1 by 1 inch) across which the ‘-inch ceiling boards were laid. 8. Blast Vulnerability Experimental data on peak pressures or the blast impulses necessary to cause damage of vary- ing degrees to Japanese residential construction are not available. Because of the differences in structural methods, comparison of the vulnera- bility to blast of occidental and Japanese residen- tial construction is not possible except from actual experiments. Consequently, a quantitative eval- uation of the vulnerability of Japanese construe- tion to blast cannot be made. Rather generalized conclusions, however, can be drawn: a. Resistance to blast is roughly inversely pro- portional to mass and strength. The typical Japanese residence (photos 20 and 22) was gener- ally a light-frame structure consisting of a rela- tively heavy roof system supported by slender columns. Lateral rigidity was normally provided by moments developed by mortise and tenon joints between columns and roof beams. The => PHOTOS 20-VIII and 21-VIII. These photos show exterior views of damaged dwellings which show the typical framing of this type of building. Note the simple roof system, the lack of diagonal and lateral bracing, and the extensive use of unsawed lumber. PHOTO 22-VIII. This shows the interior framing de- tails of the same type of building described above. 108 PERSPECTIVE SKETCH W Per | | SLIDING L | | | STRAW MATS SASH PN r i Qh) em //7/) il (NUUNNANIALA INNO NURURTIRUAETONEQUAILAN SS) a ae Te BA SSS SESS SSS SSS SSSA SSS SECTION SHOWING TYPICAL TAWlaan Waceice FLOOR AND FOUNDATION POSTS | Ftoor sections FIGURE |-MZL 109 Zz \ = Z ; N | SECTION THRU HEAD FIGURE 2-VIII. Japanese residence—Walls and partitions. - ae me =a (O2 070 em, Teh - mle hen a . Biss om ramem@t PHOTO 23-VIII. Damage to this typical wall panel has broken away the plaster and exposed the bamboo lath. PHOTO 24-VIII. This photo of a residence under construe- tion shows workers mixing mud plaster for the walls. The straw beside them was used as the binder for the mud. Note straw beside them was used as the binder for the mud, Note the split bamboo lath between the columns. 110 PHOTOS 25-VII1 and 26-VIII. These photos are interior views of a dwelling in which can be seen typical roof and ceiling construction. The drawing below further illustrates this type of construction. ‘2” SHEATHING FIGURE 3-VIII. Japanese residence—Section through roof and ceiling. 111 SECRET ST TAT ES [} Head) oeJL Te SOUTH ELEVATION NORTH ELEVATION WEST ELEVATION 4 y : N N iN N NIN iN ul CONG. FOOTING LU Ct ——— Speen FLOORING PLAN SECRET U.S. STRATEGIC BOMBING SURVEY ONE-STORY JAPANESE RESIDENCE FIGURE 4-2 731566 O - 47 (Face p. 112) —— +... ere nee ¥ | 1. Wit ST 7 % : Mor aK IS HTUOe2 4 i . - Sete ee, ce 7 Te 4. tee | utp ioe! - ' Pt Tac PrAan = “vA JS buss Sesalinelineiianeienatenestiemeaiainaae SECRET D MALT és thy, ms CHOI Ss DO RISO i r) ea TTP eee LT ea a SECTION Ls we) bes = — — — —— =: mails oe 1138 SECRET U.S, STRATEGIC BOMBING SURVEY & w Hi a =< ° ‘ Ae a at es i GES IY RATIO RE: CGN OEE, eA i 2 a. Sar o* r * ‘ ze = > s rire = ee t ° <- = ¥ ae ee 2+ iq RO Gee SECRET a a |e P| We ay LH HAY YY EAST ELEVATION NORTH ELEVATION WEST ELEVATION * SECOND-FLOOR: PLAN: SECRET ‘FIRST - FLOOR: PLAN: TWO-STORY JAPANESE i?) 5 ; RESIDENCE FIGURE 6-MI 731566 O - 47 (Face p. 114) AS . ~ ‘ J bi hae fC REX : “MASS - MOO? - TERIA; “Tia eck GRRE remmemcnrsacmen aru | ry: SPoORy JAPANESE —; te FE SIEN CE ; rte me Pe eee — aoe Bind, : wa 7 j "Oka Os 4 Oem Si) ; a i . f panel walls of mud plaster on bamboo lath were only lightly fastened to the framing and were frequently stripped without rupturing the frame. b. The light weight, slender columns, and weak mortise and tenon joints were points of weakness which rendered the Japanese residence highly vulnerable to damage by blast. Failures com- monly resulted either from buckling of external columns by blast, or by a mass distortion of the structure away from the direction of blast, which disrupted the joints between columns and beams. Because Japanese residential areas were densely built up, walls were usually shielded from blast by adjacent buildings. Consequently, failure by mass distortion was probably the most character- istic damage effect since this could readily result from blast impinging on the roofs of buildings. 9. Fire Vulnerability a. General opinion in the United States had been that Japanese dwellings were “tinder boxes.”’ Considering the dwellings collectively in their natural surroundings in a congested city, this opin- ion is well founded; but considering an individual 115 dwelling set off by itself, the evaluation is inac- curate. b. Collectively, Japanese dwellings were ex- tremely vulnerable to fire because of the high degree of built-upness of residential areas, light exterior wood sheathing, broad, open, wood eaves and air space under the first floor. All these features tend to assist fire spread. On the other hand, the heavy tile covering on the roofs practically precluded ignition of roofs by flying. embers. Thatched roofs were found only outside city limits or in sparsely built-up areas. c. Actually, frequency of fires in individual Japanese dwellings was less than one-half that in American homes. This situation can be attrib- uted to the fact that the Japanese dwelling was generally less susceptible to ignition because of the lesser amount of combustible furnishings and higher moisture content of the wood and furnish- ings. In addition, there were fewer internal sources of ignition and more careful supervision by the occupants. Once a fire progressed beyond the stage of incipiency, however, the Japanese dwelling burned rapidly. UNITED STATES STRATEGIC BOMBING SURVEY LIST OF REPORTS The following is a erg oe eA of reports resulting from the Survey’s studies of the uropean and Pacific wars. Those reports marked with an asterisk (*) may be pur- chased from the Superintendent of Documents at the Government Printing Office, Washington 25, D. *1 *2 *3 20 European War OFFICE OF THE CHAIRMAN The United States Strategic Bombing Survey: Sum- mary Report (European War) The United States Strategic Bombing Survey: Over- all Report (European War) The Effects of Strategic Bombing on the German War Economy AIRCRAFT DIVISION (By Division and Branch) Aireraft Division Industry Report Inspection Visits to Various Targets (Special Report) Airframes Branch Junkers Aircraft and Aero Engine Works, Dessau, Germany Erla Maschinenwerke G m b H, Heiterblick, Germany A T G Maschinenbau, G m b H, Leipzig (Mockau), Germany Gothaer Waggonfabrik, A G, Gotha, Germany Focke Wulf Aircraft Plant, Bremen, Germany Over-all Report Part A Part B Appendices I, II, III Dornier Works, Friedrichshafen & Munich, Germany Gerhard Fieseler Werke G m b H, Kassel, Germany Wiener Neustaedter Flugzeugwerke, Wiener Neu- stadt, Austria Messerschmitt A G, Augsburg, Germany Aero Engines Branch Bussing NAG Flugmotorenwerke G m b H, Bruns- wick, Germany Mittel-Deutsche Motorenwerke G m b H, Taucha, chase Bavarian Motor Works Ine, Eisenach & Durrerhof, Germany Bayerische Motorenwerke A G (BMW) Munich, are | Henschel Flugmotorenwerke, Kassel, Germany Light Metal Branch Light Metals ssa {fer I, Aluminum of Germany Part II, Magnesium 21 *31 38 116 Vereinigte Deutsche Metallwerke, Hildesheim, Ger- many Metallgussgesellschaft G m b H, Leipzig, Germany Aluminiumwerk G m b H, Plant No. 2, Bitterfeld, Germany Gebrueder Giulini G m b H, Ludwigshafen, Germany Luftschiffbau, Zeppelin G m b H, Friedrichshafen on Bodensee, Germany Wieland Werke A G, Ulm, Germany Rudolph Rautenbach Leichmetallgiessereien, Solin- gen, Germany ay 2 Ale Vereinigte Aluminiumwerke A G, Lunen, ermany Vereinigte Deutsche Metallwerke, Heddernheim, Germany Duerener Metallwerke A G, Duren Wiitenau-Berlin & Waren, Germany AREA STUDIES DIVISION Area Studies Division Report A Detailed Study of the Effects of Area on Hamburg A Detailed Study on Wuppertal A Detailed Study on Dusseldorf A Detailed Study on Solingen A Detailed Study on Remscheid A Detailed Study on Darmstadt A Detailed Study on Lubeck A Brief Study of the Effects of Area Bombing on Berlin, Augsburg, Bochum, Leipzig, Hagen, Dort- mund, Oberhausen, Schweinfurt, and Bremen Bombing of the Effects of Area Bombing of the Effects of Area Bombing of the Effects of Area Bombing of the Effects of Area Bombing of the Effects of Area Bombing of the Effects of Area Bombing CIVILIAN DEFENSE DIVISION Civilian Defense Division—Final Report Cologne Field Report Bonn Field Report Hanover Field Report Hamburg Field Report—Vol I, Text; Vol II, Exhibits Bad Oldesloe Field Report Augsburg Field Report Reception Areas in Bavaria, Germany EQUIPMENT DIVISION Electrical Branch German Electrical Equipment Industry Report Brown Boveri et Cie, Mannheim Kafertal, Germany Optical and Precision Instrument Branch Optical and Precision Instrument Industry Report *51 52 *65 81 SSRZSSRE BE —] -_ Abrasives Branch The German Abrasive Industry Mayer and Schmidt, Offenbach on Main, Germany Anti-Friction Branch The German Anti-Friction Bearings Industry Machine Tools Branch Machine Tools & Machinery as Capital Equipment Machine Tool Industry in Germany Herman Kolb Co., Cologne, Germany Collet and Engelhard, Offenbach, Germany Naxos Union, Frankfort on Main, Germany MILITARY ANALYSIS DIVISION The Defeat of the German Air Force V-Weapons (Crossbow) Campaign Air Force Rate of Operation Weather Factors in Combat Bombardment Opera- tions in the European Theatre Bombing Accuracy, USAAF Heavy and Medium Bombers in the ETO Description of RAF Bombing The Impact of the Allied Air Effort on German Lo- gisties MORALE DIVISION The Effects of Strategie Bombing on German Morale (Vol. I and Vol. II) Medical Branch The Effect of Bombing on Health and Medical Care in Germany j MUNITIONS DIVISION Heavy Industry Branch The Coking Industry Report on Germany Coking Plant Report No, 1, Sections A, B, C, & D Gutehoffnungshuette, Oberhausen, Germany Friedrich-Alfred Huette, Rheinhausen, Germany Neunkirchen Eisenwerke A G, Neunkirehen, Ger- many Reichswerke Hermann Goering A G, Hallendorf Germany August Thyssen Huette A G, Hamborn, Germany Friedrich Krupp A G, Borbeck Plant, Essen, Ger- many Dortmund Hoerder Huettenverein, A G, Dortmund, Germany Hoesch A G, Dortmund, Germany Bochumer Verein fuer Gusstahlfabrikation Bochum, Germany Motor Vehicles and Tanks Branch German Motor Vehicles Industry Report Tank Industry Report Daimler Benz A G, Unterturkheim, Germany Renault Motor Vehicles Plant, Billancourt, Paris Adam Opel, Russelsheim, Germany Daimler Benz-Gaggenau Works, Gaggenau, Germany Maschinenfabrik Augsburg-Nurnberg, Nurnberg, Germany Auto Union A G, Chemnitz and Zwickau, Germany Henschel & Sohn, Kassel, Germany Maybach Motor Works, Friedrichshafen, Germany Voigtlander, Maschinenfabrik A G, Plauen, Germany Volkswagenwerke, Fallersleben, Germany Bussing NAG, Brunswick, Germany Muehlenbau Industrie A G (Miag) Brunswick, Ger- many Friedrich Krupp Grusonwerke, Magdeburg, Germany A G, 117 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 Submarine Branch German Submarine Industry Report Maschinenfabrik Augsburg-Nurnberg A G, Augs- burg, Germany Blohm and Voss Shipyards, Hamburg, Germany Deutschewerke A G, Kiel, Germany Deutsche Schiff und Maschinenbau, Bremen, Ger- many Friedrich Krupp Germaniawerft, Kiel, Germany Howaldtswerke A G, Hamburg, Germany Submarine Assembly Shelter, Farge, Germany Bremer Vulkan, Vegesack, Germany Ordnance Branch Ordnance Industry Report Friedrich Krupp Grusonwerke A G, Magdeburg, Germany Bochumer Verein fuer Gusstahlfabrikation A G, Bochum, German Henschel & Sohn, Kassel, Germany Rheinmetall-Borsig, Dusseldorf, Germany Hermann Goering Werke, Braunschweig, Hallendorf, Germany Hannoverische Maschinenbau, Hanover, Germany Gusstahlfabrik Friedrich Krupp, Essen, Germany OIL DIVISION Oil Division, Final Report Oil Division, Final Report, Appendix Powder, Explosives, Special Rockets and Jet Pro- yellants, War Gases and Smoke Acid (Ministerial eport #1) Underground and Dispersal Plants in Greater Ger- many The German Oil Industry, Ministerial Report Team 78 Ministerial Report on Chemicals Oil Branch Ammoniakwerke Merseburg G m b H, Leuna, Ger many—2 Appendices Braunkohle Benzin A G, Zeitz and Bohlen, Germany Wintershall A G, Leutzkendorf, Germany Ludwigshafen-Oppau Works of I G Farbenindustrie A G, Ludwigshafen, Germany Ruhroel Hydrogenation Plant, Bottrop-Boy, Ger- many, Vol. I, Vol. II Rhenania Ossag Mineraloelwerke A G, Harburg Refinery, Hamburg, Germany Rhenania Ossag Mineraloelwerke A G, Grasbrook Refinery, Hamburg, Germany Rhenania Ossag Mineraloelwerke A G, Wilhelmsburg Refinery, Hamburg, Germany Gewerkschaft Vietor, Castrop-Rauxel, Germany, Vol. I & Vol. I Europaeische Tanklager und Transport A G, Ham- burg, Germany Ebano Asphalt Werke A G, Harburg Refinery, Ham- burg, Germany Meerbeck Rheinpreussen Synthetic Oil Plant—Vol., I & Vol. II Rubber Branch Deutsche Dunlop Gummi Co., Hanau on Main, Germany Continental Gummiwerke, Hanover, Germany Huels Synthetic Rubber Plant Ministerial Report on German Rubber Industry Propellants Branch 130 Elektrochemischewerke, Munich, Germany 131 Sechoenebeck Explosive Plant, Lignose Sprengstoff Werke G m b H, Bad Salzemen, Germany 132 Plants of Dynamit A G, Vormal, Alfred Nobel & Co, Troisdorf, Clausthal, Drummel and Duneberg, Germany 133. Deutsche Sprengchemie G m b H, Kraiburg, Ger- many OVER-ALL ECONOMIC EFFECTS DIVISION 134 Over-all Economic Effects Division Report Gross National Product... _. ~~~ Special papers Kriegseilberichte. ............ | which together Herman Goering Works-_-_ ~~~ - | comprise the Food and Agriculture _______- above report 134a Industrial Sales Output and Productivity PHYSICAL DAMAGE DIVISION 134b Physical Damage Division Report (ETO) 135 Villacoublay Airdrome, Paris, France 136 Railroad Repair Yards, Malines, Belgium 137 Railroad Repair Yards, Louvain, Belgium 138 Railroad Repair Yards, Hasselt, Belgium 139 Railroad Repair Yards, Namur, Belgium 140 Submarine Pens, Brest, France 141 Powder Plant, Angouleme, France 142 Powder Plant, Bergerac, France 143 Coking Plants, Montigny & Liege, Belgium 144 Fort St. Blaise Verdun Group, Metz, I’rance 145 Gnome et Rhone, Limoges, France 146 Michelin Tire Factory, Clermont-Ferrand, France 147 Gnome et Rhone Aero Engine Factory, Le Mans, France 148 Kugelfischer Bearing Ball Plant, Ebelsbach, Ger- many 149 Louis Breguet Aircraft Plant, Toulouse, France 150 S. N.C. A. 8. E. Aireraft Plant, Toulouse, France 151 +A. I. A. Aireraft Plant, Toulouse, France 152. V Weapons in London 153 City Area of Krefeld 154 Publie Air Raid Shelters in Germany 155 Goldenberg Thermal Electric Power Station, Knap- sack, Germany 156 Brauweiler Transformer & Switching Station, Brau- weiler, ay 157 Storage Depot, Nahbollenbach, Germany 158 Railway and Road Bridge, Bad Munster, Germany 159 Railway Bridge, Eller, Germany 160 Gustloff-Werke Weimar, Weimar, Germany 161 Henschell & Sohn Gm b H, Kassel, Germany 162 Area Survey at Pirmasens, Germany 163 Hanomag, Hanover, Germany 164 MAN Werke Augsburg, Augsburg, Germany 165 Friedrich Krupp A G, Essen, Germany 166 Erla Maschinenwerke, G m b H, Heiterblick, Ger- many 167 ATG Maschinenbau G mb H, Mockau, Germany 168 Erla Maschinenwerke G m b H, Mockau, Germany 169 Bayerische Motorenwerke, Durrerhof, Germany 170 Mittel-Deutsche Motorenwerke G m b H, Taucha, Germany 171 Submarine Pens Deutsche-Werft, Hamburg, Ger- many 172 Maulti-Storied Structures, Hamburg, Germany 173 Continental Gummiwerke, Hanover, Germany 174 Kassel Marshalling Yards, Kassel, Germany 175 Ammoniawerke, Merseburg-Leuna, Germany 176 Brown Boveri et Cie, Mannheim, Kafertal, Germany 177 Adam Opel A G, Russelsheim, Germany 178 Daimler-Benz A G, Unterturkheim, Germany 179 Valentin Submarine Assembly, Farge, Germany 180 Volkswaggonwerke, Fallersleben, Germany 181 Railway Viaduct at Bielefeld, Germany 1§2 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 *200 201 202 203 204 *205 118 206 207 208 =) *2 *3 *12 *13 "Id Ship Yards Howaldtswerke, Hamburg, Germany Blohm and Voss Shipyards, Hamburg, Germany Daimler-Benz A G, Mannheim, Germany Synthetic Oil Plant, Meerbeck-Hamburg, Germany Gewerkschaft Victor, Castrop-Rauxel, Germany Klockner Humboldt Deutz, Ulm, Germany Rukroel Hydrogenation Plant, Bottrop-Boy, Ger- many Neukirchen Eisenwerke A G, Neukirchen, Germany Railway Viaduct at Altenbecken, Germany Railway Viaduct at Arnsburg, Germany Deurag-Nerag Refineries, Misburg, Germany Fire Raids on German Cities I G Farbenindustrie, Ludwigshaften, Germany, Vol I & Vol IT Roundhouse in Marshalling Yard, Ulm, Germany I G Farbenindustrie, Leverkusen, Germany Chemische-Werke, Huels, Germany Gremberg Marshalling Yard, Gremberg, Germany Locomotive Shops and Bridges at Hamm, Germany TRANSPORTATION DIVISION The Effects of Strategic Bombing on German Trans- portation Rail Operations Over the Brenner Pass Effects of Bombing on Railroad Installations in Regensburg, Nurnberg and Munich Divisions German Locomotive Industry During the War German Military Railroad Traffic UTILITIES DIVISION German Electric Utilities Industry Report 1 to 10 in Vol I “Utilities Division Plant Reports” 11 to 20 in Vol II “Utilities Division Plant Reports” 21 Rheinische-Westfalische Elektrizitaetswerk A G Pacific War OFFICE OF THE CHAIRMAN Summary Report (Pacific War) Japan’s Struggle to End the War The Effects of Atomic Bombs on Hiroshima Nagasaki and CIVILIAN STUDIES Civilian Defense Division Field Report Covering Air Raid Allied Subjects, Tokyo, Japan Field Report Covering Air Raid Allied Subjects, Nagasaki, Japan Field Report Covering Air Raid Allied Subjects, Kyoto, Japan Field Report Covering Air Raid Allied Subjects, Kobe, Japan Field Report Covering Air Raid Allied Subjects, Osaka, Japan Field Report Covering Air Raid Protection Allied Subjects, Hiroshima, Japan—No. 1 Summary Report Covering Air Raid Protection Allied Subjects in Japan Final Report Covering Air Raid Protection Allied Subjects in Japan Medical Division The Effects of Bombing on Health and Medical Services in Japan The Effects of Atomic Bombs on Health and Medical Services in Hiroshima and Nagasaki Morale Division The Effects of Strategic Bombing on Japanese Morale Protection and Protection and Protection and Protection and Protection and and and and *15 *16 *17 *18 *19 *20 *21 *22 *23 *24 *25 *26 *27 #28 *29 *30 *31 *32 ECONOMIC STUDIES Aircraft Division The Japanese Aircraft Industry Mitsubishi Heavy Industries, Ltd. Corporation Report No. I (Mitsubishi Jukogyo KK) (Airframes & Engines) Nakajima Aireraft Company, Ltd. ‘orporation Report No. II (Nakajima Hikoki KK) (Airframes & Engines) Kawanishi Aircraft Compan Corporation Report No. } II (Kawanishi Kokuki Kabushiki Kaisha) (Airframes) Kawasaki Aircraft Industries Company, Ine. Corporation Report No. IV (Kawasaki Kokuki Kogyo Kabushiki Kaisha) (Airframes & Engines) Aichi Aircraft Company Corporation Report No. V (Aichi Kokuki KK) (Airframes & Engines) Sumitomo Metal Industries, Propeller Division Corporation Report No. VI (Sumitomo Kinzoku Kogyo KK, Puropera Seizosho) (Propellers) Hitachi Aircraft Company Corporation Report No. VII (Hitachi Kokuki KK) (Airframes & Engines) Japan International Air Industries, Ltd. Corporation Report No. VIII (Nippon Kokusai Koku Kogyo KK) (Airframes) Tachikawa Aircraft Company Corporation Report No. X Tachikawa Hikoki KK) Airframes) Fuji Airplane Company Corporation Report No. XI alt Hikoki KK) Airframes) Showa Airplane Company Corporation Report No, XII (Showa Hikoki Kogyo KK) (Airframes) Ishikawajima Aircraft Industries Company, Ltd. Corporation Report No. XIII (Ishikawajima Koku Kogyo Kabushiki Kaisha) ‘s ee). ippon Airplane Company Corporation Report No. XIV (Nippon Hikoki KK) (Airframes) Kyushu Airplane Company Corporation Report No. X V (Kyushu Hikoki KK) (Airframes) Shoda Engineering Company Corporation Report No. XVI (Shoda Seisakujo) (Components) Mitaka Aireraft Industries Corporation Report No. X VII (Mitaka Koku Kogyo Kabushiki Kaisha) (Components) *33 Nissan Automobile Company Corporation Report No, X VIII (Nissan Jidosha KIX) (Engines) *34 Army Air Arsenal & Navy Air Depots Corporation Report No. XIX (Airframes and Engines) *35 Underground Production of Japanese Aircraft Report No. XX Basie Materials Division *36 Coal and Metals in Japan’s War Economy Capital Goods, Equipment and Construction Division *37 The Japanese Construction Industry *38 Japanese Electrical Equipment *39 The Japanese Machine Building Industry Electric Power Division *40 The Electric Power Industry of gre *41 The Electric Power Industry of Japan (Plant Re- ports) Manpower, Food and Civilian Supplies Division *42 The Japanese Wartime Standard of Living and Utili- zation of Manpower Military Supplies Division *43 Japanese War Production Industries *44 Japanese Naval Ordnance 45 Japanese Army Ordnance *46 Japanese Naval Shipbuilding *47 Japanese Motor Vehicle Industry *48 Japanese Merchant Shipbuilding Oil and Chemical Division 49 Chemicals in Japan’s War 50 Chemicals in Japan’s War—Appendix 51 Oil in Japan’s War 52 Oil in Japan’s War—Appendix Over-all Economic Effects Division *53 The Effects of Strategic Bombing on Japan’s War Economy (Including Appendix A: U. 8. Economic Intelligence on Japan—Analysis and Comparison; Appendix B: Gross National Product on Japan and Its Components; Appendix C: Statistical Sources). Transportation Division *54 The War Against Japanese Transportation, 1941— 1 5 Urban Areas Division *55 Effects of Air Attack on Japanese Urban Economy (Summary Report) *56 Effects of Air Attack on Urban Complex Tokyo- Kawasaki- Yokohama *57 Effects of Air Attack on the City of Nagoya *58 Effects of Air Attack on Osaka-Kobe-Kyoto 59 Effects of Air Attack on the City of Nagasaki 60 Effects of Air Attack on the City of Hiroshima 119 MILITARY STUDIES Military Analysis Division Air Forces Allied with the United States in the War Against Japan , Japanese Air Power Japanese Air Weapons and Tactics The Effect of Air Action on Japanese Logistics Employment of Forees Under the Southwest Pacifie Command The Strategic Air Operations of Very Heavy Bom- bardment in the War Against Japan (Twentieth Air Force) Air Operations in China, Burma, India— World War II The Air Transport Command in the War Against Japan The Thirteenth Air Force in the War Against Japan The Seventh and Eleventh Air Forces in the War Against Japan The Fifth Air Force in the War Against Japan Ground Army Naval Analysis Division The Interrogations of Japanese Officials (Vols. I and II) Seay rs ns of the Pacific War The Reduction of Wake Island The Allied Campaign Against Rabaul The American Campaign Against Wotje, Maloelap, Mille, and Jaluit (Vols. I, IT and ITI) The Reduction of Truk The Offensive Mine Laying Campaign Against Japan Report of Ships Bombardment Survey Party— Foreword, Introduction, Conclusions, and General Summary Report of Ships Bombardment (En- closure A), Kamaishi Area Report of ships Bombardment (En- closure B), Hamamatsu Area Report of Ships Bombardment (En- (En- (En- (En- Survey Party Survey Party Survey Party closure ©), Hitachi Area Report of Ships Bombardment closure D), Hakodate Area Report of Ships Bombardment closure E), Muroran Area Report of Ships Bombardment closure F), Shimizu Area Report of Ships Bombardment Survey Party (En- closures G and H), Shionomi-Saki and Nojima- Saki Areas Survey Party Survey Party Survey Party SECRET 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 *106 *107 120 108 Report of sar Bombardment Survey Party (En- closure I), Comments and Data on Effectiveness of Ammunition Report of Ships Bombardment Survey Party (En- eoene J), Comments and Data on Accuracy of iring Reports of a Bombardment Survey Party (En- closure K), Effects of Surface Bombardments on Japanese War Potential Physical Damage Division Effect of the Incendiary Bomb Attacks on Japan (a Report on Hight Cities) The Effects of the Ten Thousand Pound Bomb on Japanese Targets (a Report on Nine Incidents) Effects of the Atomic Bomb on Hiroshima, Japan Effects of the Atomic Bomb on Nagasaki, Japan Effects of the Four Thousand Pound Bomb on Japa- nese Targets (a Report on Five Incidents) Effects of Two Thousand, One Thousand, and Five Hundred Pound Bombs on Japanese Targets (a Report on Eight Incidents) A Report on Physical Damage in Japan (Summary Report) G-2 Division Japanese Military and Naval Intelligence Evaluation of Photographic Intelligence in the Japa- nese Homeland, Part I, Comprehensive Report Evaluation of Photographic Intelligence in the Japa- nese Homeland, Part II, Airfields Evaluation of Photographic Intelligence in the Japa- nese Homeland, Part III, Computed Bomb Plotting Evaluation of Photographie Intelligence in the Japa- nese Homeland, Part IV, Urban Area Analysis Evaluation of Photographie Intelligence in the Japa- nese Homeland, Part V, Camouflage Evaluation of Photographic Intelligence in the Japa- nese Homeland, Part VI, Shipping Evaluation of Photographic Intelligence in the Japa- nese Homeland, Part VII, Electronics Evaluation of Photographic Intelligence in the Japa- nese Homeland, Part VIII, bees Intelligence Evaluation of Photographic Intelligence in the Japa- nese Homeland, Part LX, Artillery Evaluation of Photographic Intelligence in the Japa- nese Homeland, Part X, Roads and Railroads Evaluation of Photographic Intelligence in the Japa- nese Homeland, Part XI, /ndustrial Analysis g- 2 ys “ i 5 ; : : a A ~ Z ; ; 3 ¥ Pa | | . | i ; : F 2 : | | e , | ne 4 r z SAS = | | ‘ ‘ ‘ ; . oA, : i ; - wy La | , - »y + : os ’ 5 7 7 f ‘ ’ 6 ‘ h . el F j - - 7 ‘ ;: rs i ? ‘ : a 1 hy age | ; 5 | ' : 3 a4 7 , 5 . : é s “ 7 7 7 : a F ‘ ; ; fv : | x 4 . - wt! 34 ‘ ~_ “ST; eae S44 Lo > eae wa es Cl ees te +4 * mi ae fm es eas . | at ae Mat ‘ — a | = Ss : 7 a to ae 5 tl 3 3 ee ~ > ie, a : : » a >; 3 “ : _ é v3 = | . : - F . ——. we an me S S hee 7 - ©...” 3 | te € : | a - , * - : 2 : > > . > © me : 3 = — .<> k : ‘ ~ > re a5 5 is ~ ¥ ae ; eee 4 , ey - : : &: : = Z > * ee fae ae