tiger tiger common german heavy tank second world war final official german designation tiger shortened tiger ordnance inventory designation known informal german tiger translated literally royal tiger somewhat incorrectly king tiger allied soldiers especially american forces tiger successor tiger combining thick armour armour sloping medium tank tank weighed tonnes protected armour armed long anti tank cannon chassis basis tank destroyer tiger issued heavy tank battalions army combat heavy battalion allied invasion normandy july eastern unit outfitted tiger heavy battalion september listed tiger operational development development heavy tank design initiated initial design contract awarded design contract followed given prototype series turret design krupp main differences hull transmission suspension automotive features version conventional hull design sloped armour resembling layout tank rear mounted engine steel tired eighty centimeter diameter overlapping road wheels internal mounted transverse bars similar manner original designed tiger maintenance steel tired road wheels later tiger hulls wheels overlapping rubber system use nearly german half tracks design later inherited early production versions tiger hull designs included rear mounted turret mid mounted engine suspension tank destroyer road wheels mounted paired sprung short longitudinal bars integral wheel pair saved internal space facilitated repairs version gasoline electric drive fundamentally identical diesel electric transmission gasoline fueled engine prime similar gasoline electric hybrid storage battery separate drive trains parallel tank consisting hybrid drive train gasoline engine electric generator electric motor drive method propulsion attempted tiger later prototypes designs production suspension later later tank destroyers proposal use hydraulic drives unorthodox designs gathered little favour design won design contract tiger produced firm turret designs production vehicles initial design called turret belief designed prototype fact initial krupp design prototypes turret rounded sloped sides difficult manufacture curved turret left accommodate commander early turrets mounted hull action common production turret called turret simplified significantly thicker flat face shot trap created curved face earlier turret sloped sides prevented need commander added additional room ammunition storage turrets designed mount gun combined german turret sight sight early tiger accurate deadly weapon practice estimated probability round hit high wide target dropped percent ranges percent metres percent depending ammunition type recorded combat performance lower percent 60s penetration armoured plate inclined degrees respectively armour piercing shell ranges high explosive round available soft targets heat high explosive anti tank round penetration range dual purpose soft armoured targets powered turret traverse provided variable speed hydraulic motor driven main engine secondary drive shaft high low speed setting available gunner right turret rotated degrees seconds low gear independent engine rpm seconds high speed setting engine rpm seconds maximum engine speed rpm direction speed traverse controlled gunner control near left arm power lost tank ran fuel turret slowly traversed hand assisted additional wheel turns wheel necessary degree turn turret total turns circle hydraulic system precise gunners preferred use manual system aim like german tanks petrol engine case powered lighter tiger tanks tiger powered like heavy tanks world war consumed lot fuel short supply germans transmission model giving forward gears reverse drove steering gear double radius design proved susceptible failure transverse bar suspension supported hull overlapped diameter road wheels rubber steel tyres rode inside tracks like tiger tank issued sets tracks normal battle track narrower transport version rail movement transport tracks reduced overall width load drive tank short distances firm ground crew expected change normal battle tracks soon tank ground pressure cm2 psi command variant command variant tiger designated tiger versions carried rounds ammunition provide room accommodate extra radios equipment additional armour engine compartment radio sets notable external changes metre long rod antenna mounted turret roof star antenna mounted base protected large armoured cylinder equipment located rear position originally deep equipment radios metre rod antenna mounted turret roof metre rod antenna mounted rear deck production tiger developed late war built relatively small numbers orders placed tiger slightly tiger tanks produced tiger production severely disrupted allied bombing raids september october destroyed percent floor area plant estimated caused loss production tiger units produced production ran end war tiger served basis production variant tank destroyer proposed self propelled mount heavy guns reached production proposed upgrades engine born developments initiated attempting convert fuel injection increased power unanimously decided immediately included engine design program explored alternative drive train research development department found offered inferior driving characteristics retained krupp proposed mounting new main weapon supportive accepted cannon suggested improvements included sights main gun automatic ammunition feed range heated crew compartment additional rounds air system protect poison gas got proposal stage enter production war ended specifications gearbox forward reverse radio command tank version ammunition rounds turret rounds turret usually limited number replaced armour piercing core longer range lower penetration explosive filler armour piercing core shorter range higher penetration high explosive hollow charge rounds gun sight operational history organisation apart research training tank attachment tiger issued heavy tank battalions german_army standard battalion comprised tanks units tiger follows reliability mobility early tiger proved unreliable owing principally leaking seals drive train originally intended lighter vehicle double radius steering gear initially particularly prone failure lack crew training problem drivers originally given limited training tanks sent directly operational units way arrived eastern tanks operational faults drive train failures tiger delivered division broke combat destroyed prevent capture introduction modified seals drive train components improved driver training sufficient maintenance improved tank mechanical reliability statistics march reliability rates percent tiger equal percent better percent operational period initial reliability problems tiger remarkably heavy vehicle contemporary german records testing results indicate tactical mobility good better german allied tanks combat history combat use tiger 1st company heavy battalion battle normandy opposing operation atlantic july losses combat plus company commander tank trapped falling bomb crater created operation eastern august heavy battalion resisting offensive attacked soviet river near road tiger destroyed ambush german tanks suffered ammunition explosions caused crew fatalities main gun rounds longer allowed turret reducing capacity fourteen tiger lost area august flank attacks soviet tanks assault guns sandy terrain october tiger heavy battalion played crucial role operation supporting troops taking hungarian capital ensured country remained axis end war took battle remained hungarian theater operations days accounted soviet tanks anti tank guns artillery pieces aircraft train set loss tiger knocked soviet troops burned sent vienna factory overhaul thirteen blown crews reasons usually prevent falling enemy hands kurt highest scoring tank ace time enemy destroyed served killed action april tiger tiger present heavy battalions offensive december soviet east prussian january german lake offensive hungary march battle heights april battle berlin end war heavy battalion claimed approximately kills period january april eastern loss tiger abandoned destroyed crews mechanical lack fuel gun armour performance heavy armour powerful long range gun gave tiger advantage opposing western allied soviet tanks attempting engage head especially true western arrival british forces brought heavy tanks service report estimated tiger frontal aspect heaviest best penetrating tank gun allied hand document february estimated british pounder gun armour piercing shot theoretically capable penetrating tiger turret nose lower hull respectively given lack stated angle presumably ideal degrees angle result thick frontal armour flanking manoeuvres tiger attempt shot thinner rear armour giving tactical advantage tiger engagements main armament tiger capable knocking allied tank ranges exceeding kilometres effective range allied tank guns soviet wartime testing august tiger tanks captured soviets near soon moved testing grounds transfer tanks suffered mechanical break downs cooling system insufficient excessively hot climatic conditions engine tended cause failure gearbox right suspension tanks completely replaced functionality established tank broke gave positive results penetration accuracy par proved capable passing completely colleague tiger turret range armour vehicle tested firing shells calibre despite careful significantly worse similar designs result shells penetrate armour large inside plates damaged transmission rendered tank testing showed armour plate exhibited deficiencies quality compared earlier german tanks tiger analysis tiger armour plate showed absence ascribed loss supply replaced giving armour low expanded firing test states projectiles gun penetrated tiger turret ranges metres suggests quality factor tiger turret firing test tiger turret conducted removal gun resulted close armour openings vision slits gun location right gun opening influenced previous penetration hits armour damage tank hull turret plates penetrated shot domestic american guns ranges penetrate joints hull ranges metres shots despite wartime testing reliable evidence armour king tiger penetrated combat surviving vehicles working example displayed des france production turret accessible public survivors include tank museum tiger early production turret display vehicle second soft steel prototype active service tiger engine removed use restoration tiger working example tiger production turret tiger loan defence academy defence academy united_kingdom tiger production turret vehicle hull number turret number comprehensive coating claimed sergeant roberts squadron 23rd 11th armoured division tank near disabled abandoned crew following damage tracks final drive photograph showing vehicle final action field turret turned vehicle currently display tank museum collection private collector kevin start restoration rebuild complete tiger project include parts individual tiger parts new manufacture stated original parts needed reconstruction parts sourced continuously known shown parts complete plate main armament engine deck plates hull rear set tracks left hull plate parts aim project complete tiger running order france complete wrecked tiger production turret buried regional road parts turret recovered limited excavation excavation currently halted financial reasons plans fully restore tiger battle memorial tank museum russia tiger production turret turret number captured red army museum open public december museum belgium restored tiger production turret hull number built october turret number displayed entrance december museum collections museum devoted entirely battle tank abandoned december advance halted gun barrel restored gun barrel muzzle brake restored stripped exterior internal fittings bars broken gearbox engine place germany tiger production turret displayed interior location accessible public payment entrance fee hull number turret number museum cavalry armor fort united_states tiger production turret hull number built september turret number abandoned near captured army december left cut open educational purposes proving ground late 1940s tank left fort december route proposed army armour museum fort united_states switzerland tiger production turret previously displayed tank museum loan september completely restored running condition long term project tank given switzerland france war hull number tanks comparable role performance era


oak ridge national laboratory oak ridge tennessee known clinton pile pile world second artificial nuclear chicago designed built continuous operation built world war manhattan_project chicago demonstrated feasibility nuclear manhattan_project goal producing atomic bombs required thousand times powerful facilities separate bred products intermediate step considered step project construction techniques procedures developed training conducted centerpiece air cooled nuclear pure natural metal form fuel commenced construction clinton engineer works oak ridge february went critical november produced early supplied los laboratory significant amounts bred product studies samples heavily influenced bomb design chemical separation plant provided experience engineers technicians operators safety officials moved site operated production plant january turned research activities production radioactive scientific medical industrial agricultural uses shut designated national historic landmark origins discovery nuclear german followed theoretical explanation naming opened possibility controlled nuclear chain reaction columbia_university leo began exploring drafted confidential letter president united_states franklin roosevelt explaining possibility atomic bombs warning danger german nuclear weapon project convinced old friend collaborator albert sign lending fame proposal resulted support government research nuclear manhattan_project april national defense research committee asked arthur nobel prize winning physics professor university_of_chicago report program report submitted prospects developing weapons nuclear propulsion ships nuclear weapons recently discovered october wrote report atomic bomb john heavy odd atomic numbers likely university california produced inch found times thermal capture cross section time minute quantities produced possible produce sufficiently large quantity way discussed eugene princeton_university produced nuclear robert produced separated final draft november report mention discussing latest research lawrence convinced bomb feasible december placed charge project objectives produce convert find ways separate design build atomic bomb fell decide different types designs scientists pursue successful built felt having teams columbia princeton university_of_chicago university california creating collaboration concentrated work laboratory university_of_chicago site selection june manhattan_project reached stage construction production facilities contemplated june office scientific research development executive committee located moving directly production plant looked like big step given industrial processes easily scale laboratory production size intermediate step building pilot plant considered pilot separation plant site wanted close laboratory research carried reasons safety security desirable locate facilities densely populated area like chicago selected site forest forest preserve district cook county miles southwest chicago scale production facilities located manhattan_project facilities remote location tennessee acres land leased cook county pilot facilities acre site production facilities selected oak ridge tennessee executive committee meeting september apparent pilot facilities extensive site instead research built pilot facilities built tennessee december decided production facilities built oak ridge remote site washington state staff laboratory reopened question building engineers management particularly roger williams head division responsible company role manhattan_project disagreed felt insufficient space having site accessible especially research staff laboratory feared attempt interfere better location felt production facilities end compromise reached january brigadier general director manhattan_project williams agreed built oak ridge proposed operate williams counter proposed operated laboratory reasoned primarily research educational facility expertise laboratory shocked laboratory university_of_chicago university operating industrial facility miles main campus james told harvard_university wouldn touch foot pole university_of_chicago vice president took different view told accept university president robert returned greeted arthur gone doubled size university design critical design decision cooling system limiting factor fuel clad aluminum operating temperature exceed theoretical group laboratory developed designs found heavy water number produced absorbed known percent efficient november engineers chose production plant largely basis absorb contrast decision use caused little debate heavy water unavailable concern sufficient supply pure agreed decision use particular early proponent liquid major opponent argued strongly favor water cooled design realised water absorbed reduced percent sufficient confidence calculations water cooled engineering perspective water cooled straightforward design build posed technological problems team produced preliminary report water cooling designated april followed detailed titled plant water cooling july chicago constructed west viewing stands original field university_of_chicago went critical december generated demonstrated higher anticipated removed objections air cooled water cooled designs greatly simplified aspects design team submitted water cooled january time concerns engineers water overcome mounting difficulties work terminated february time air chosen pilot plant different design production lost value prototype considered important pilot facility running soon possible order supply quantities needed research hoped problems found time correct production plants training developing procedures construction design complete began construction february isolated acre km2 site valley miles southwest oak ridge officially known area chemical separation plant research laboratories waste storage area training facility staff administrative support facilities included laundry aid center fire station subsequent decision construct water cooled chemical separation plant operated true pilot eventually known clinton laboratories operated university_of_chicago project construction work wait completed design excavation commenced april large pocket soft clay soon discovered necessitating additional foundations delays occurred wartime difficulties building materials acute shortage common skilled labor contractor quarters required workforce high turnover mainly result poor accommodations difficulties township oak ridge construction barracks built house workers special arrangements individual workers increased morale reduced turnover finally unusually heavy rainfall inches falling july twice average inches short tons blocks purchased national carbon construction crews began september cast came metal suppliers cylindrical started production june fuel primarily protect metal occur came contact water prevent radioactive products formed transmit heat absorb aluminum chosen general_electric laboratory developed new technique seal cans new equipment installed production line october construction commenced pilot separation plant chemical process separating selected managers decide use process plant consisted cells separated control room thick concrete walls equipment operated control room remote control work completed november plant operate started producing operation world second artificial nuclear chicago designed built continuous operation consisted huge block feet long nuclear weighing short tons acted surrounded seven feet high density concrete radiation shield feet wide feet deep feet high horizontal rows holes metal channel fuel inserted elevator provided access higher channels clad steel control rods foot rods penetrated vertically held place clutch form system suspended steel cables wound drum held place electromagnetic clutch power lost rods drop halting rods steel horizontally penetrated north known rods controlled sand filled hydraulic event power failure rods driven electric motors cooling system consisted cubic feet minute min electric fans outside air run higher power level cold days going air filtered remove radioactive particles larger inches diameter took care percent radioactive particles expelled air foot chimney operated control room southeast corner second floor september asked physicist martin form skeleton operating staff inaugural director clinton laboratories officially known april permanent operating staff arrived laboratory chicago april time began transferring technicians site augmented technicians uniform army special engineer detachment march people working supervised went critical november short tons week later load increased short tons raising power generation end month created normally operated clock hour weekly safety rods rod completely removed rod inserted position desired power level reached controlled adjusting partly inserted rod batch received december allowing produced early pure metallic natural air tight aluminum cans inches long inch diameter channel loaded fuel went critical short tons later life operated short tons load channel radiation absorbing shield plug removed inserted manually east end long rods pushed way far west end fell slab fell foot deep pool water acted radiation shield following weeks underwater storage allow decay delivered chemical separation building february ton days months efficiency separation process improved percentage recovered increasing percent modifications time raised power july unfortunately operations detect effect poison caused problems operated production plant january turned research activities time processed building steam plant structures added april support laboratory peacetime educational research missions work completed december adding cost construction bringing total cost operational costs added supplied los laboratory significant samples studies group los revealed contained form far higher spontaneous rate meant highly likely gun type nuclear weapon blow apart initial formation critical mass los laboratory forced turn development efforts creating type nuclear weapon far difficult feat chemical separation plant proved process scale separation facilities finally chemical separation plant provided experience engineers technicians operators safety officials moved site peacetime use war ended facility world produce radioactive peacetime use august oak ridge national laboratory director eugene presented small container director free skin cancer hospital medical use hospital louis missouri subsequent shipments primarily scientific medical industrial agricultural uses shut november years use added national_register_of_historic_places december designated national historic landmark october american society metals listed landmark contributions advancement materials science technology designated national historic chemical landmark american chemical society control room face accessible public scheduled tours offered american museum science energy tours general hour tour clinton engineer works facilities conducted noon june september july similar research nuclear constructed united_states following world war led benjamin construction began reached time august consisted short ton foot cube fueled natural primary mission applied nuclear research medicine biology chemistry physics nuclear engineering significant discoveries facility development production today tens millions medical procedures annually making commonly medical shut fully decommissioned britain began planning build nuclear produce weapons decided build pair air cooled similar natural enriched available similarly chosen toxic hard manufacture heavy water unavailable use water considered concerns possibility catastrophic nuclear densely populated british isles cooling system failed event occur disaster preferred choice gas main source united_states mcmahon act united_states supply nuclear weapons production end air cooling chosen construction began september operational october june decommissioned disastrous fire october major air cooled producing follow designs carbon dioxide instead similar design operation belgian located belgium financed belgian export tax help british experts research critical time scientific purposes activation analysis physics experiments nuclear measurement devices production

Weapons, military equipment and programs


advanced intercontinental missile known weapons system program develop intercontinental missile proposed united_states_air_force 1960s replacement air_force standard funding allocated program project cancelled background department defense began study november evaluate new missile proposal air_force designated advanced intercontinental missile project intended provide successor united_states_air_force service program officially launched april june project received designation prefix indicating project planning stage specifications called large solid fuel powered missile fitted multiple independently vehicles missiles based launchers specified hardened factor existing missiles addition plan develop railroad based deployment system improvements accuracy existing missiles combined penetration aids development enhance effectiveness missile expected capable defeating existing projected soviet anti missile systems cancellation ultimately navy won competition design ohio class missile submarines final report issued august recommended developed accordingly joint chiefs staff recommended secretary defense robert funded starting fiscal year projected entry service recommendation came air_force completed preliminary studies missiles new hardened instead kept missile advanced development stopped work project development new super hardened approved funding missiles result missile development cancelled rationale program influence new missile rendered existing soviet anti missile defenses ineffective saw relative powers strategic basis mutually assured destruction best method soviet_union position negotiate united_states cancellation air_force development new year project begun resulted development entered service mid-1980s served iii service planned replacements


light tank light tank american pre world war light tank saw limited use world war common model equipped gun machine gun machine guns originally developed prototype tank built rock island arsenal vickers type leaf spring suspension suspension replaced superior vertical system series production minor modifications produced main pre war version produced main tank army infantry units pre world war period spanish civil war showed tanks armed machine guns ineffective led gun main armament delivered late april combat use american units marine_corps 1st tank battalion pacific war believed served burma india british 7th 2nd royal tank regiment engagements imperial japanese army 14th tank regiment light tank led stuart light tank medium tank tractor artillery tower stuart saw widespread use war medium tank unsuccessful design led lee medium tanks development history army infantry tank design started light tank 1920s developed series experimental designs didn enter production concept starting years later incorporated design lessons new suspension system copied british vickers ton tank prototype delivered defense act defined tanks support infantry 1920s number outlined independent role tank required high speed rear areas modern version cavalry british referred designs cruiser tanks similar high speed designs developed variety names defense act limited tank development infantry united_states cavalry began tank development combat car keeping high speed role new combat car introduced new vertical spring suspension system proved clearly superior vickers leaf spring system led second prototype april adopting armed inch machine gun mounted fixed turret mounted hull selected production mounted small man turret hull units delivered infantry branch decided switch twin turret configuration caliber machine gun second turret early twin turret tanks given nickname west troops popular movie star twin turret layout inefficient common feature 1930s light tanks derived vickers soviet polish produced model incorporated modified suspension system reduced tank ground pressure weight increased tons following spanish civil war armies including army realized needed tanks armed cannon merely machine guns cavalry opted single larger turret nearly identical combat car december directed single removed assembly line modified heavier armor weapons meet standards infantry vehicle conversion designated equipped main gun inch thick armor seven cylinder gasoline engine upgrades included improved suspension improved transmission better engine cooling production began american car company continued march additional assembled april total production run light tanks army sent press photos showing assembled july assembly line changed successor vehicles light tank led series series light tanks ordnance department viewed tank work improve began june stuart tanks began produced march original closely resembled types occasionally served units easiest recognition feature aft rear wheel raised trails ground increasing heavier vehicle retained continental engine incorporated thicker inch total thickness armor weight increased tons tank initially kept gun forward firing hull machine guns turret incorporated improvements eventually examples variants produced operational use december training majority went army training marine_corps ordered stuart tanks outfit armored units new tank production received point production come line tanks deployed battle assigned company 1st tank battalion typically spread infantry units use generally limited providing mobile fire support marines japanese shot japanese attacks defensive engagements deploy pairs cover machine gun fire japanese soldiers armed charges ultimately marine_corps determined gun powerful defeat japanese replaced tanks armed guns following end campaign company returned australia replaced new preparation battle cape gloucester december remained service areas pacific theater served pacific training britain ordered early delivered order canceled favor improved stuart fate vehicles unclear evidence indicates shipped north_africa british_army 7th 2nd royal tank regiment fighting india burma campaigns japanese 14th tank regiment according historian mike green tanks issued combat units design machine gun mounted main gun machine guns hull mounted ball mount bow gunner mounted fixed orientation upper hull near sides tank machine guns fired driver steering troops mount machine gun turret anti aircraft defense gun manually operated tank commander doubled like tanks time turret basket light tank commander stood right gunner stood left commander turned turret general direction target gunner bring target sight combination mount traverse driving rack traverse gear mechanism pressure gunners shoulder rest overcoming friction mechanism depression elevation gun geared mechanism gears free movement gunner shoulder rest variants initial production type single fixed turret containing machine gun units produced twin turrets single machine gun turrets partly limiting fields fire dubbed west units produced twin turrets machine guns thicker armor slightly lengthened hull improved engine access increased gear better engine cooling improved suspension minor detail changes units produced single turret gun thicker armor units produced orders went american car october request ordnance department early pacific campaigns training service training december specifications long wide high weighed vertical spring suspension speed mph range gun rounds heavy machine guns rounds machine guns rounds armor continental seven cylinder radial engine vehicle operated crew commander gunner driver driver


arrow israeli missile arrow hebrew pronounced family anti missiles designed fulfill israeli requirement theater missile defense system effective missiles patriot surface air missile jointly funded produced israel united_states development system began continued drawing contested criticism undertaken israel industries boeing overseen israeli ministry defense hebrew pronounced administration missile defense agency arrow system consists joint production arrow anti missile green pine early warning radar golden tree center israel industries brown tree launch control center system moved prepared sites following construction testing arrow technology production deployment began arrow version missile arrow considered advanced missile defense programs currently existence operational missile defense system specifically designed built intercept destroy missiles arrow battery declared fully operational october components exported israeli air defense command israeli air_force israel defense forces currently sole user complete arrow system background arrow program launched light acquisition arab states long ranged surface surface missiles chosen armament development authority missile defense system arrow judged complete concept greater range system criticized merely improved hawk system designed outset missile interception united_states israel signed memorandum understanding fund arrow program united_states department defense strategic defense initiative organization placed order israel aircraft industries arrow technology gulf war exposed controversial performance patriot missile iraqi missiles gave impetus development arrow initially designed intercept missiles derivative operated syria operated saudi_arabia arrow evolved eye advanced missile programs iran defense minister israel viewed emerging missile threat dangerous future threats israel security said program israeli administration development weapons technological infrastructure israeli ministry defense runs arrow development project administration administration commonly referred israel missile defense organization responsible coordinating industrial activities israel different defense companies involved development arrow system funding dollar development program arrow undertaken israel financial support united_states development program began projection total cost development manufacture including initial production missiles estimated billion price single arrow missile estimated million billion reportedly invested arrow program percent funded united_states israel contributes approximately million annually criticism opposition arrow program encountered opposition traditional doctrine use strikes stand sharp contrast nature missile addition feared costly missiles diminish resources allocated offensive projects fighter aircraft criticism concept missile defense israel aired comprehensive study published center strategic studies arguments study opinions numerous defense officials analysts echoed arguments strategic defense initiative critics united_states argued simple fool arrow type defensive system simple cheap easily installed render arrow system ineffective doubted israel defense industries rise challenge complex system citing anonymous experts predicted system available envisaged enormous costs billion priorities divert funds vital capability forcing profound revision israel national security doctrine argued effective missiles conventional chemical biological arrow relevant future threats missiles nuclear able supply defense impact single nuclear israel densely populated urban area threat israel time john pike worked federation american scientists stated given technical problems systems radar command system coupled high development cost arrow program soon fall victoria research associate center defense information stated october arrow system track incoming missile split june group israeli chief engineers project managers awarded israel defense prize development production arrow system according director passage time predictions proven israel defense industries overcame technical challenge system development completed decade ahead predicted indications expenditures arrow harmed plans degree whatsoever insists israel missile defense established fact warnings issued critics failed remained development arrow launch arrow took place august designed test missile control guidance systems test came halt seconds missile intentionally destroyed fears track hit settled location caused failure ground tracking radars track missile trajectory test number took place march designed check missile components launch conducted ship sea missile malfunction resulted abortion experiment test designed examine arrow interception capabilities conducted october missile launched ship sea aborted repeat previous september test missile components launch systems finally operated planned arrow reached designated point sky seconds launch planned missile destroyed successful experiment ended system preliminary testing phase fifth sixth seventh tests took place february july october respectively arrow managed pass close proximity target missiles proving ability intercept surface surface missiles test number march missile launched ground computer failure ninth test launch june known arrow demonstration test saw arrow successfully intercepted target missile launched ship anchored middle mediterranean arrow reportedly stage solid missile overall length body diameter launch weight estimated second stage length command update mid course guidance terminal infrared focal plane array missile described relatively high speed thrust stages range capability described hand arrow single stage missile development big arrow ceased research continued smaller faster lethal arrow arrow successful tests designated steering control cruising systems conducted target missiles july february successful took place august march designated interception test conducted august missile destroyed steering system fault corrected time ensure success comprehensive test entire system september system components successfully countered computer simulated threat november israel industries delivered operational arrow israeli ministry defense system interception test held november test arrow system located tracked intercepted target missile missile launched steep trajectory ship located offshore target missile based arrow march complete arrow battery rolled ceremony speech commander ben said arrow test took place september time new target missile advanced defense systems black airborne target missile launched israel coastline trajectory intercepted destroyed consequently following month saw arrow battery declared operational israeli air defense command black target tests reportedly june arrow missiles test fired course joint american israeli turkish exercise code named eagle southeast turkey august arrow system successfully intercepted target shore highest arrow tested date october second battery declared operational successful test arrow took place january missiles launched simulated targets order examine performance special flight conditions system performance sequence launches test include actual successful test held december examined system ability intercept destroy incoming missiles significantly high altitudes reportedly tested integration arrow patriot batteries july israel united_states carried joint test naval air station point point missile test center california arrow launched real missile test represented realistic scenario tested israel test field safety restrictions enable test battery shipped point green pine radar command control systems deployed base arrow installed offshore island forms test range test success destroying flew trajectory altitude west san island twelfth arrow test seventh test complete system interception real significant test known following test defense minister israel said conducted point month later august test aimed examining arrow ability detect splitting separating missile detected true target technical malfunction reportedly prevented maneuvering strike leading suspension testing march april ability green pine golden work patriot system elements operated army successfully tested simulated targets regular series israeli exercises code named cobra actual testing complete arrow system resumed december system successfully intercepted target unspecified reported record low altitude test fourteenth test arrow missile ninth test complete system february arrow successfully intercepted destroyed black target missile missile high altitude called distributed weapon system test conducted israel required arrow units deployed apart share data incoming threats coordinate launching assignments time link data distribution system connect arrow units system previous tests connect arrow patriot batteries furthermore improved cobra exercises ran march computer simulation cobra similar computer simulation cobra precursor block launched target march order gather information flight performance introducing unspecified modifications hardware electronics reduced manufacturing costs percent director said arrow operational system doubt deal operational threats middle_east particularly iran syria april arrow weapon system successfully detected simulated intercept new target missile blue successor black capable missiles reportedly iranian test target missile launched height feet missile split multiple making harder intercept green pine tracked intercept september attempted test actual arrow missile blue drill aborted target missile shortly launch eventually arrow successfully tested blue april july joint test arrow airborne target missile range point reportedly aborted final second launch missile failed establish communications link target released iii aircraft radar detected target transferred tracks launched tracking target worked tracking trajectory information radar transferred battle management center erroneously showed prescribed safety range mission aborted program source said aborted interception came earlier setbacks planned test initially scheduled july try scuttled technical aircraft planned july attempt electric battery providing power key element arrow system test widely referred failure objectives missile defense systems achieved february arrow system successfully intercepted long range target missile flight test conducted point target missile launched mobile launch platform coast california point test range test new versions designed improve capabilities arrow body body impact completely destroyed target february developers successfully conducted final target tracking test prior delivery arrow system blue target missile detected tracked radar intercept solutions plotted battle management controller transferred launch units according upgrades improve process discrimination happens sky transmission target data better control upgrades guidance coupled improved target identification discrimination capabilities improves expected include new battle management center armored launchers high shooting availability better communication missile systems wider ranges september intercept test conducted mediterranean_sea versions operational system outcome inconclusive remained data fully analyzed february official acknowledged test successfully acquired narrowly missed target exact reason failure provided officials initially attributed easily software issues recently launched initial definition new upgrade complete arrow system merge lower tier arrow arrow single national missile defense system according planned include new airborne sensors command control system new target missile silver simulate potentially nuclear capable delivery vehicles developed iran according missile defense agency expected able deal stressing regional threats increasing total defended area percent planned existing super green pine radar operate radar radars commanding anti missiles aboard united_states_navy destroyers radars support closed loop operations israel targets region come attack arrow august united_states israeli governments initiated development upper tier component israeli air defense command known arrow development based architecture definition study conducted determining need upper tier component integrated israel missile defense system according main element upper tier jointly developed boeing specifications arrow system originally designed intercept short medium range missiles ranges intended intercept military aircraft artillery rockets second relatively small short ranged contrast standard missile patriot use direct impact destroy target hit kill arrow relies explosive arrow able intercept targets high nuclear chemical biological weapons israel developers intention perform destruction sequence away populated locations according missile tested determine chemical warfare agents reach ground intercepted conclusion reach ground destroyed jet stream flows west east blow chemical arrow capable low altitude interception multi tactical missiles interception stage missile equipped solid rocket motors missile uses initial burn carry vertical hot launch container secondary burn sustain missile trajectory target maximum speed thrust control boost phases flight second stage motor stage assembly separates arrow missile launched threat missile trajectory intercept point accurately known trajectory data available intercept point precisely defined missiles guided kill vehicle section missile containing terminal equipped moving delta aerodynamic control fins low altitude interception capability dual mode missile passive infrared acquisition tracking tactical missiles active radar home air breathing targets low altitudes infrared focal plane array kill vehicle designed achieve hit kill interception achieved proximity direct fragments target shortly reaching closest point target high explosive directed blast capable destroying target radius manner arrow differs patriot standard missile rely purely hit kill technology force precise impact causes destruction threat according senior developer dubbed father arrow anti missile single arrow percent probability destroying target missile highest altitude possible case failure launched target short time intervals destroys target second directed target technique independent interception possibilities provided raise interception probability percent percent satisfying rate requirement arrow capability simultaneously intercept incoming missiles target missiles arriving second span capability currently possessed united_states russia according arrow arrow battery equipped typically launchers manning requires personnel trailer mounted weighs tonnes loaded launch tubes ready fire missiles firing launchers hour system mobile moved prepared sites set green pine green pine active array solid state radar operating band range operates search detection tracking missile guidance modes simultaneously capable detecting targets ranges able track targets speeds radar target guides arrow missile target super green pine advanced version radar called super green pine green pine block great pine hebrew pronounced place original green pine versions active super green pine extends detection range advanced upgrade super green pine development golden golden hebrew pronounced truck mounted net centric open systems architecture battle management command control communication intelligence center control simultaneously world advanced net centric systems system provides fully automatic human loop options stage battle operation management capable theater missile defense systems systems notably link communications altered allow patriot fire control units assigned targets handed patriot fire control radar tests carried israel successfully linked arrow israeli versions patriot tree banks operator consoles laid shape center sits officer command oversees engagement links parts battery headquarters commander right sits engagement officer ensures targets assigned engagement officers sitting right hand leg assigned geographical area defend officers senior overview patriot batteries left commander resource officer monitors status readiness missiles left sits sky picture officer contact home command uses center ability predict impact point alert civil authorities consoles intelligence officer action officer uses recordings impossible absorb information engagements golden manned operators brown brown hebrew pronounced launch control center located launch site golden fire control center employs microwave radio data voice communications links green pine golden launch method vertical hot launch sealed providing coverage brown missile maintenance capabilities production israel initially produced arrow system domestically february boeing signed agreement valued million fiscal years establish production facilities manufacture components arrow missile united_states march awarded million production contract boeing total contract value exceed million second quarter result successful implementation contract boeing responsible production percent arrow missile components including electronics section motor case missile alabama facilities prime contractor arrow system responsible integration final assembly arrow missile israel boeing coordinates production arrow missile components manufactured american companies located states boeing delivered arrow israel produced tested february final deliveries israel air_force planned end major contractors produces green pine super green pine radar produces golden center advanced defense systems produces motor israel military industries produces motor produces motor cases stage lockheed martin produces active radar produces infrared produces deployment according original schedule arrow system supposed enter operational service operational arrow battery deployed march near city south metropolitan area declared operational october reached capacity march deployment second battery airfield near city district northern israel delayed strong opposition local residents feared radar hazardous health situation eventually resolved israel second battery completed deployment turned operational linked battery october reportedly decided modify missile defense doctrine order counter possible syrian iranian missile quietly modified deployment arrow northern israel planned battery battery estimated cost million reportedly great pine radar deployed alongside green pine radars israel originally planned deploy arrow batteries sought won promises funding battery reports stated battery deployed development south claimed decision deployment battery discussion service entry report stated israel planned deploy additional arrow batteries defend country southern region covering sensitive sites nuclear research center decision battery taken october new battery expected operational use center country according jane defence weekly sources indicate new arrow battery operational israeli air_force facility roughly halfway jerusalem near export apart israel country purchased arrow system india acquired deployed green pine radars august indian government sought purchase arrow system early vetoed israel request sell arrow missiles india exercising right major funding contributor officials argued sale violate missile technology control regime arrow possibly achieve range designed shorter ranges unclear carry range specified indian army official said arrow india missile defense solution turkey planned buy anti missile air defense systems worth billion arrow considered potential contender rejected political grounds past united_kingdom japan singapore mentioned potential foreign customers arrow system netherlands reportedly expressed interest golden center november late 1990s officials jordan expressed concern israel iraq iran impact territory problem difficult jordan conventional benjamin term office prime minister israel reportedly offered jordan defensive umbrella arrow allowing israel forward deploy arrow launchers close iraqi border option israel sell jordan arrow system likely prime minister meant israel reportedly requested approval selling arrow batteries jordan apparently approval given armed marketing approval respective governments israeli industrial team plans offer arrow system south_korea potential deal estimated exceed billion united_states arrow provided important technical operational data remains key element missile defense agency plan layered missile defense architecture example successful affordable program moment united_states plans deploy arrow september arrow system mentioned secretary defense robert gates vice chairman joint chiefs staff general james alternative proposed missile defense assets europe arrow system incorporated anti capability europe said june interview lieutenant general patrick reilly said arrow integrated regional defense array planned middle_east according interview protect arab countries allies israel diplomatic ties october countries gulf cooperation council interested arrow system


infantry anti tank british man portable anti tank weapon developed second world war designed response british_army need effective infantry anti tank weapon entered service based mortar system launched pound bomb powerful spring cartridge tail possessed effective range approximately yards direct fire anti tank role yards indirect fire house breaking role advantages infantry anti tank weapons period included lack muzzle smoke reveal position user inexpensive barrel type difficulty weapon barrel powerful problems ammunition reliability allied invasion sicily remained use british commonwealth forces early 1950s supplied obtained nations forces including soviet_union lend lease french resistance polish underground israeli arab israeli war members british commonwealth armed forces received victoria crosses use combat development beginning second world war british_army possessed primary anti tank weapons infantry boys anti tank rifle rifle grenade particularly effective anti tank weapon anti tank grenade designed fired fitted muzzle rifle meant grenade light deal significant damage resulting rarely action boys inadequate anti tank role heavy meant difficult infantry handle effectively outdated effective short ranges armoured cars light tanks november operation north african campaign staff officers british eighth army unable find single instance boys knocking german tank limitations new infantry anti tank weapon required ultimately came form infantry anti tank commonly abbreviated origins traced far american engineer charles edward experimenting discovered explosive yield great deal damage facing target phenomenon known effect german scientist found lining metal enhanced damage dealt 1930s henry swiss engineer developed technology created hollow charge ammunition consisted metal cone placed explosive hit target explosive detonated turned cone extremely high speed spike speed spike immense pressure caused impact allowed create small hole armour plating send large pressure wave large amounts fragments interior target technology utilized anti tank grenade technology existed remained british designers develop system deliver hollow charge ammunition larger size greater range possessed time developing hollow charge ammunition lieutenant colonel stewart royal artillery investigating possibility developing lightweight platoon mortar conventional system firing mortar shell barrel fixed wanted use mortar system instead barrel steel rod known fixed bomb charge inside tail mortar fired bomb pushed exploded charge blew bomb air effectively putting barrel inside weapon barrel diameter longer limitation size eventually designed lightweight mortar named submitted war office turned favour spanish design continued experiments decided try hand held anti tank weapon based design found generate sufficient velocity needed penetrate armour abandon design eventually come bombard style system launch pound bomb approximately yards bombs fired actually penetrate armour severely damage tanks large number issued home guard anti tank weapons aware existence hollow charge ammunition realized exactly kind ammunition looking develop hand held anti tank weapon depended energy contained sheer velocity fired developed hollow charge bomb charge tail fitted shoulder fired consisted metal containing large spring bomb placed trough trigger pulled rammed tail bomb fired approximately metres away called weapon baby bombard presented war office weapon tested proved host problems war office report june stated fire trigger pulled bombs provided exploded contact target time developed baby bombard sent war office working government department known given task developing delivering weapons use resistance groups occupied europe shortly trial baby bombard posted duties left anti tank weapon hands colleague department major took prototype baby bombard apart floor office rebuilt combined hollow charge mortar bomb create called shoulder gun small number prototype armour piercing heat rounds took weapon tested small arms school warrant officer took shoulder gun firing range aimed armoured target pulled trigger shoulder gun pierced hole target unfortunately wounded warrant officer piece metal exploding round flew hit took place warrant officer fired rounds pierced armoured target wounding impressed weapon ordnance board small arms school faults ammunition corrected renamed shoulder gun infantry anti tank ordered issued infantry units hand held anti tank weapon production began end august disagreement given new weapon press report gave credit bombard took exception suggested divide award equally expenses ministry supply paid expenses relation bombard churchill got involved argument writing secretary state war january asked shoulder gun changed objected boys rifle odd ring churchill supported claims way received equivalent board design inches long weighed pounds effective direct fire range approximately yards maximum indirect fire range yards carried operated man usually assigned man team second man acting ammunition carrier tube constructed thin sheets steel contained trigger mechanism firing spring small trough bomb placed ran middle trough user shoulder fitted end rudimentary sights fitted aiming bombs launched possessed hollow tubular tails small cartridge inserted hollow charge initiate firing weapon trigger mechanism essentially large spring difficult awkward process user place butt place feet shoulder turn weapon unlock body simultaneously lock firing pin butt user bend pull body weapon upwards pulling spring attached trigger weapon achieved body lowered turned rest weapon fired users small stature found sequence challenging sufficient height required pull body far weapon difficult lying prone position case weapon action trigger pulled spring pushed firing pin forwards bomb ignited bomb launched trough air caused blew firing pin backwards spring automatically weapon subsequent shots eliminating need manually tactical training emphasized best utilized trench surprise team possible enemy armoured vehicles engaged flank rear possible use crude mortar placing shoulder pad weapon ground supporting giving weapon approximate range yards combat knock enemy positions located houses despite difficulties firing weapon advantages barrel replaced require high grade materials expensive produce little muzzle blast user position away size barrel meant accommodate relatively large calibre munitions weapon heavy meant unpopular british commonwealth troops issued problems power theoretically able penetrate approximately millimetres armour field experience allied invasion sicily trials conducted confirmed trials skilled user unable hit target time yards faulty meant bombs fired detonated target operational history entered service british commonwealth units action canadian troops allied invasion sicily war establishment british platoon contained men single attached platoon headquarters alongside inch mortar detachment issued company headquarters level issuing discretion allowing weapon platoon british_army royal marines issued action australian_army allocated known infantry tank attack australian service infantry platoon jungle divisions differed standard british organisation late contemporary canadian army survey questioned army officers recently left combat effectiveness different infantry weapons survey ranked number effective weapon followed gun second place analysis british staff officers initial period normandy campaign found german tanks destroyed british forces knocked compared rockets fired aircraft found german tanks fitted armoured skirts detonated hollow charge ammunition penetrate tank armour weapon effective theatres british commonwealth troops served remained service early 1950s replaced american australian_army briefly start korean war alongside inch quickly replaced weapons inch super lend lease agreement october march soviet_union supplied rounds ammunition utilized resistance groups occupied europe warsaw uprising weapons polish underground resistance fighters german forces occupied france french resistance absence mortars artillery end second world war israeli arab armour israeli war independence victoria crosses awarded members british commonwealth armed forces actions italian campaign frank jefferson destroy tank repel german counterattack launched unit assaulted section line june company sergeant major stanley actions day attack german field gun june 7th rifles knock japanese tanks attacking unit india given burma official citation despite sustaining injuries approached thirty yards enemy tanks having knocked moved attack crews tried escape asked army commander william slim went close replied certain hitting thirty yards september battle major robert henry disable assault gun advancing company position force german tanks retreat later assault night october private smith destroy german mark tank self propelled guns attacking small group self propelled vehicles knocked thompson gun kill repel enemy soldiers actions secured river italy december captain john henry utilised weapons help repel attack german division users users included australia canada free french forces kingdom greece india israel italy army partisans new_zealand polish underground soviet_union united_kingdom yugoslavia malaysia


project project given work performed california institute technology support manhattan_project world war activities included development equipment testing bomb shapes dropped boeing bombers salt wells pilot plant explosive components nuclear weapons manufactured background early 1930s emergency landing field built works progress administration desert near small town california opened acquired united_states_army air forces bombing gunnery range office scientific research development contracted california institute technology testing evaluation rockets navy suitable test area required near california area transferred army navy october commissioned naval ordnance test station december workshops laboratories facilities constructed men worked development testing inch inch inch tiny tim rockets late rocket development testing work began production models started reach navy quantity director bush saw opportunity use expertise secret wartime project involved manhattan_project bush arranged charles head rocket team visit los laboratory meet project director major general laboratory director robert senior scientists los laboratory knew worked war addition scientists possessed experienced team headed group worked closely counterpart los headed lieutenant colonel robert work behalf manhattan_project came project said come remark los scientist meaning gets nose tent hard manhattan_project drop testing manhattan_project conducted extensive series drop tests evaluate bomb shapes initially conducted scale models bomb dropped navy test range virginia starting august new airfield constructed manhattan_project funding feet feet feet long feet wide accommodate boeing fuel storage gallons gasoline gallons oil opened june named field navy lieutenant john killed testing tiny tim rocket august based drop testing developed instrumentation evaluate test drops aircraft based army air field getting fat man fall properly difficult officer described crazy bomb built like streamlined brick fly reasonably resolution problem involved extensive testing fin configurations commander chick initially thought test bombs dropped easier recover dropped sands proved considerable ability penetrate desert floor required digging commander project alberta captain parsons bomb assembly kits produced kits fully contained facilities included number air conditioning shipped pacific island atomic bombs assembled kept spare erected assemble explosive non nuclear bombs testing design fat man required number explosive lenses detonated simultaneously learning los laboratory encountered problems supply exploding required found manufacturers los_angeles area produce ordered thousand bomb expended tests required verify lenses worked perfectly responsibility development testing critical shared group robert henderson group los object produce week meeting target proved challenging reliability key problem initial containing high numbers failures box manufactured fell truck mountain found working order pilot plant explosive lenses required fat man fabricated small explosive plant established los known site appalled work practices safety site considered matter time blew parsons recommendation decided establish pilot plant experience building operating pilot ordnance plants thought navy far workplace safety parsons met bruce sage built china lake pilot plant rockets agreed build operate plant site chosen salt wells valley work commenced buildings permanent cost million wanted plant working days site sufficient capacity explosive components bombs unlikely meet expected demand months come construction program fact los finalized processes plants involved challenges facilities fabricated purpose items hard locate short supply wartime economy manhattan_project priority overcame problem cases army representatives factories items designated use project felt fears excessive safety realized reinforced concrete blast proof doors electrical drove costs end days explosives melted mixed poured july war atomic bombing hiroshima nagasaki secretary war robert sent telegram men women employed project today world knows secret helped months pleased able add japan know effects better atomic bomb helped develop high devotion patriotic duty devastating military weapon country able turn enemy worked entire project known story job kept secret today speak grateful nation thank hope continue secrets kept need security continued effort fully great proud production site ceased late cold weather work salt wells plant completed january equipment installed working work initially large number defects form cracks explosive blocks core problem techniques los scale production site different methods required special instrumentation devised assess quality explosive blocks temporary nature accommodation longer acceptable war atomic energy commission took manhattan_project january spent million sets family quarters streets electricity water small school named opened improved techniques facilities allowed plant triple output pilot plant employed people pilot plant helped design equip train workers new plant took responsibility manufacturing explosive lenses salt wells pilot plant closed


chicago chicago world nuclear achieve construction manhattan_project allied effort create atomic bombs world war built manhattan_project laboratory university_of_chicago west viewing stands original field man self sustaining nuclear chain reaction initiated december supervision described apparatus crude pile black bricks wooden assembled november team included leo chain reaction anderson walter martin george contained blocks weighing short tons fueled short tons metal short tons pile free produced natural decay absorbed causing nuclear release additional free unlike subsequent nuclear radiation shield cooling system operated low power shape pile intended roughly spherical work proceeded calculated critical mass achieved finishing entire pile planned moved red gate woods chicago operated dismantled buried stands field demolished august site national historic landmark chicago landmark origins idea chemical chain reactions forth german chemist max situation molecules react form molecules final reaction products unstable molecules react parent molecules cause molecules react concept nuclear chain reaction hungarian scientist leo september realized nuclear reaction produced caused nuclear reactions process self proposed lighter known produced amounts entertain possibility fuel filed patent idea simple nuclear following year discovery nuclear german followed theoretical explanation naming opened possibility creating nuclear chain reaction initial experiments unsuccessful order chain reaction occur additional emitted columbia_university new_york john anderson eugene booth francis conducted nuclear experiment united_states january subsequent work confirmed fast produced obtained permission head physics department columbia george use laboratory months persuaded walter collaborator conducted simple experiment seventh floor hall columbia source bombard discovered significant natural proving chain reaction possible suggested use carbon form felt need tonnes long tons short tons tonnes long tons short tons plan considered find tons heavy water absorb like ordinary hydrogen better carbon difficult expensive produce believed enormous quantities required atomic bomb concentrated producing controlled chain reaction determined produced average careful design called minimize losses met representatives national carbon company manufactured important discovery found contained manufacturers produce free concluded germans unsuitable use government support drafted confidential letter president franklin roosevelt explaining possibility nuclear weapons warning german nuclear weapon project encouraging development program result creation help eugene edward approached old friend collaborator albert august convinced sign letter lending fame proposal letter resulted establishment research nuclear government advisory committee formed scientist director national bureau standards meeting october attended persuaded army navy provide purchase supplies experiments particular april national defense research committee created special project headed physicist arthur nobel prize winning professor university_of_chicago report program report submitted prospects developing weapons nuclear propulsion ships nuclear weapons recently discovered october wrote report atomic bomb report worked calculations critical mass discussed prospects john heavy odd atomic numbers likely university california produced inch found times thermal capture cross section time minute quantities produced possible produce sufficiently large quantity way discussed produced nuclear robert produced separated report submitted november stated bomb feasible final draft november report mention discussing latest research lawrence convinced bomb feasible december placed charge project objectives produce convert find ways separate design build atomic bomb fell decide different types designs scientists pursue successful built proposed schedule achieve controlled nuclear chain reaction january atomic bomb january development nuclear achieved rate production equal rate losses including absorption simplest case bare steady state nuclear absorption equal production order reach critical radius spherical calculated formula migration area medium factor generation reaction produce second produce order self sustaining nuclear chain reaction occur greater practical configuration needs percent christened apparatus pile later recalled thought term refer source nuclear energy analogy use italian term denote great invention source electrical energy disillusioned told simply common english word pile synonymous surprise thought relationship pile grant time obtained committee purchase materials august began plan new test pile proposed build feet long feet wide feet high large fit physics laboratories recalled went dean man carry magic university explained needed big room scouted campus went dark corridors heating pipes visit possible sites experiment eventually big room discovered hall pile built september inch blocks iron cans cans inch filled weighed pounds cans surrounded blocks form structure heated remove moisture packed cans hot shaking table cans shut workforce secured services columbia football team custom time football players perform odd jobs university able manipulate heavy cans ease final result disappointing felt having teams columbia_university princeton_university university_of_chicago university california creating collaboration resolved concentrate work location wanted everybody argued favor location january soon united_states entered world war decided location university_of_chicago knew support university administration factors decision scientists technicians facilities readily available midwest war work taken away chicago central location contrast columbia_university engaged efforts john hesitant add secret project leaving chicago team attempt build working pile columbia cans absorbed instead heated dry pressed cylindrical holes inches long inches diameter entire pile sheet metal contents heated boiling point water remove moisture result choice site chicago samuel found suitable space feet long feet wide feet high sunk slightly ground level space stands field originally built court field largely unused university_of_chicago given playing american football courts west stands playing woods anthony played intended exercise area nearby north stands pair ice skating ground floor seldom melted winter court area construct foot experimental pile group arrived united_states_army corps engineers assumed control nuclear weapons program june laboratory came called manhattan_project brigadier general director manhattan_project september visited laboratory time october september november groups anderson walter constructed experimental piles field stands designed new pile spherical maximize predicted achieving woods completed doctoral thesis detailed build helped anderson locate large number inch required lumber yards chicago south shipments high purity arrived mainly national carbon high purity dioxide louis producing short tons month metallic began arriving larger quantities product newly developed techniques june army office scientific research development selected site forest near chicago pilot plant known site acres leased cook county august september apparent proposed facilities extensive site decided build pilot plant piles posed little danger felt locate critical pile fully functional nuclear remote site building house experimental pile commenced completion scheduled october industrial disputes construction fell schedule clear materials new pile hand new structure completed early november came proposal build experimental pile stands field safety building operational running populated area significant issue physics system suggested pile safely shut event runaway reaction fuel undergoes releases strike fuel leads chain reaction time absorbing undergoing measured convenient unit purpose shake noted reaction leaves products release longer periods long minutes slow reaction like pile products build account percent total argued delayed carefully controlling reaction rates power pile reach rates slightly chain reaction relying solely prompt reactions rate release depends events taking place time earlier delay power spikes later event time gives operators spike prompt seen minutes causes runaway reaction poison injected time period shut felt delay provide critical margin safety allowed build chicago field fear catastrophic nuclear united_states major urban areas radioactive products later explained responsible officer university_of_chicago according rule organizational protocol taken matter superior unfair president position independent judgment hazards involved based considerations university welfare answer given answer wrong informed decision november meeting executive committee wisdom suggestion interfere james chairman reported turned white urgency confidence calculations objected construction chicago pile balloon air inside replaced carbon dioxide anderson dark gray balloon manufactured tire rubber company foot cube shaped balloon somewhat unusual manhattan_project aaa priority rating ensured prompt delivery questions asked block tackle haul place secured ceiling sides walls remaining facing balcony directed operation like circle drawn floor blocks began morning november layer placed entirely blocks layers alternated layers containing enclosed unlike later radiation cooling system intended operated low power work carried hour shifts day shift night shift anderson work force hired thirty high school eager earn bit money drafted army blocks pieces metal arrived manufacturers inch bars lengths cut standard lengths inches weighing pounds drill inch holes blocks control rods hydraulic press shape cylinders rounded ends drill bits holes worked hour dust soon filled air floor slippery group wilson responsible instrumentation fabricated control rods sheets nailed flat wooden strips potent line manila rope cut drop control rod pile stop reaction richard fox control rod mechanism pile remarked manual speed control operator rods simply variable controlling electric motor wire lead weights attached ensure fail safe return zero position released layers laid shift woods counter inserted 15th layer readings taken end shift divided square radius pile intensity obtain metric counted pile approached 15th layer 19th 25th 36th original design spherical pile work proceeded clear necessary pure hitherto short tons pure metallic began arrive project iowa state university team frank developed new process produce metal lamp plant supplied short tons produced rush makeshift process inch metallic cylinders known eggs dropped holes lieu process filling balloon carbon dioxide necessary layers according new calculations countdown reach 56th 57th layers resulting pile anderson called halt 57th layer placed completed wooden frame supported elliptical shaped structure feet high feet wide ends feet middle contained short tons metal short tons short tons estimated cost million nuclear chain reaction day december everybody assembled experiment scientists present executive committee chicago present invitation dignitaries present included anderson gathered controls balcony originally intended viewing platform samuel stood ready bucket concentrated throw pile event emergency start began walter removed emergency control rod secured norman stood ready axe cut line allow fall influence gravity woods called count loud voice george floor withdrew control rods ordered remove feet control rod withdrew inches time measurements taken step process abruptly halted automatic control rod trip level set low ordered control rods announced lunch time experiment resumed worked final control rod carefully monitored activity announced pile gone critical reached self sustaining reaction switched scale recorder accommodate rapidly increasing electrical current wanted test control circuits minutes alarm bells went passed safety level ordered release reaction rapidly halted pile run minutes opened bottle drank paper cups notified telephone conversation impromptu code italian navigator landed new world natives friendly later operation december power output increased power light lacking kind radiation hazard vicinity testing continued operation terminated february pile dismantled moved site forest known red gate woods original materials build chicago instead spherical new built cube like shape feet tall base approximately feet square surrounded concrete walls feet thick acted radiation shield overhead protection inches lead inches wood contained short tons short tons cooling system provided ran kilowatts operational march war allowed run clock design easy conduct experiments joined chicago heavy water went critical undertake research related weapons investigations properties wartime experiments included measuring absorption cross section elements compounds albert recalled elements studied month course year accident involving powder caused dangerous drop white blood cell count lasted years dangers things apparent experiments conducted effects radioactive substances laboratory test animals red gate woods later original site national laboratory replaced laboratory july director operated years ordered shut remaining usable fuel transferred chicago national laboratory new site county dismantled high level nuclear waste fuel heavy water shipped oak ridge tennessee disposal rest concrete buried foot deep trench known site plot disposal site marked commemorative boulder 1970s increased public concern levels site local residents recreational purposes surveys conducted 1980s found soil plot trace amounts nearby wells area united_states department energy national laboratory yielded public pressure million million respectively site clean cubic yards radioactive waste removed sent site disposal illinois department public health determined remaining materials posed danger public health significance commemoration commemorative plaque unveiled field december occasion tenth anniversary going critical read december man achieved self sustaining chain reaction initiated controlled release nuclear energy plaque saved west stands demolished august site designated national historic landmark february national_register_of_historic_places created immediately added site named chicago landmark october today site old field occupied university library opened joe library opened henry moore sculpture nuclear energy stands small outside library dedicated december commemorate 25th anniversary going critical commemorative plaques nearby block seen science museum los new_mexico display museum science industry chicago


gun motor carriage gun motor carriage self propelled anti tank gun produced diamond company united_states design incorporated gun production british ordnance pounder mounted half track total vehicles produced originally planned britain receive examples produced lend lease intending use western desert time arrived campaign additionally purpose built tank destroyer armed inch gun later pounder gun british service begun enter production result british transferred half tracks soviet_union soviet aid program britain retained remainder taken british american vehicles converted standard half tracks kept army soviets called designation served operation fighting eastern world war specifications gun motor carriage long wide high weighed tons suspension consisted leaf spring wheels vertical springs vehicle maximum speed mph fuel capacity gallons range miles powered white cylinder gasoline engine compression ratio power weight ratio ton armor armed single gun rounds ammunition crew commander gunner driver radio operator development originated anglo american requirement self propelled pounder anti tank gun requirement met gun production version british ordnance pounder rear half track production batch ordered april americans dropped requirements design tank destroyer intended solely supplied overseas terms lend lease program officially type classified pilot model pilot model built proving ground gun mounted mechanism installed tubular pedestal tubular pedestal soon replaced conical structure designated gun mount gun pilot model traverse degrees centerline total degrees having elevation degrees short caliber british mark iii pounder gun installed pilot longer caliber gun specified production models original travel lock hold gun fixed position vehicle moving proved unsatisfactory replaced travel lock hood original design gun shield taken gun motor carriage tests complete new shield designed inch thick face hardened steel inch thick sides shield extended crew relatively low silhouette experience gun motor carriage philippines campaign resulted accepted production service history deliveries arriving followed british ordered produced intending use western desert campaign time vehicles arrived theater summer british won war western desert gun superseded gun later availability ordnance pounder gun meant surplus british requirements result vehicles immediately shipped soviet_union terms soviet aid program soviets received vehicles designated small number later passed polish people army remainder britain accepted converted carriers took vehicles retained converted standard carriers conversion took place chester tank depot operated number carriers having captured britain soviet_union soviets employed eastern mainly operation soviet 16th separate tank destroyer brigade large number offensive river 19th brigade battle august served soviet 22nd self propelled artillery brigade units took berlin prague polish people army assigned 7th self propelled artillery battery support soviet attacks germany poland soviet service vehicles allocated brigades scale brigade attack vehicles provide mobile fire support placed infantry usually hull position ridge hill fire broad advantage long range gun operators british_army accepted vehicles later rebuilt carriers polish army east received vehicles operated previously red army red army operated designation army rebuilt half tracks rebuilt chester tank depot integrated army units operated small number captured soviet_union


radar radar russian radar russian known nato reporting house generation soviet space surveillance early warning radars radars type built periphery soviet_union starting 1960s provide missile warnings attacks different directions primary soviet early warning radars later cold war common soviet russian early warning radars named rivers radars intended replaced newer radars starting 1990s planned radars operational issues dissolution soviet_union russian early warning network consists radars vintage likely existing radars replaced generation radars radar came work missile defence undertaken late 1950s early 1960s system prototype anti missile system set testing grounds work system led design bureau proposed radar russian radar alternatives sought soviet industry proposed radar russian radar russian standing russian meaning central detection station test site selected development long horn antenna metres long metres high array open structure hardware methods designed signal processing intended computer run built area located detected object september took soviet project nuclear tests tests range examine effects high altitude nuclear explosions missile defence hardware effective satellite tracking chosen radar anti satellite programme programme involved construction sites separated latitude form radar field kilometres long kilometres high sites chosen village near siberia called cape lake near called site received radar systems fan arrangement radar composed radar wings joined story building containing joint computer system command post radar wing covered degree sector degree scanning beam elevation scanning pattern width degrees radar systems arranged create fan shaped barrier radars called cells russian roughly radio location cell faced west faced east degrees degrees elevation construction sites started improvements test model fed deployed units gained computer rest radar vacuum tubes radar systems completed late fourth testing target satellite test ability system radars accepted service soviet air defence forces april space surveillance network parallel implementation space surveillance units modified version original units radar developed act early warning radar identify attacks missiles built northern russia near constituted beginning soviet network equivalent nato completed radars associated command centre accepted service according positioned identify missile launches nato submarines norwegian north seas included improvements previous versions increase pulse length increased range objects identified scanning processing changes version radar built test site called russian completed tests decided upgrade sites keeping radars remained space surveillance radars degrees comparative scanning degrees missile warning radars space surveillance network command posts formally commissioned work improve radar continued improved array designed covered degrees radar built new radar cell entered service second new early warning station new built remaining radars converted exception cells remained space surveillance radars current operational radars described updated technical details array double horn antenna long wide rows slot end set receiving equipment signal covering sector degrees degrees elevation scanning controlled frequency sets mean radar covers degrees degrees elevation degrees involved horn antenna reduced metres height addition filter current status radars installed different radar stations operational anti missile treaty required early warning radars located periphery national territory faced caused problems soviet_union collapsed radar stations newly independent states station close newly independent agreement russia agreed radars stop working fully demolished russia signed agreement ukraine allowing continue radars stations run ukrainian personnel data sent headquarters russian early warning system russia announced pulling agreement ukraine data given russia stations ukrainian government announced stations time space surveillance station remains operational outside russia run russian defence forces remaining stations russia replaced radar close second array new radar operational replaced planned start construction