CHAPTER FOUR: SITE DESCRIPTIONS

CHAPTER FOUR: SITE DESCRIPTIONS

James P. Delgado and Larry E. Murphy

INTRODUCTION

During two field sessions at Bikini andKwajalein, eleven shipwrecks from the Able andBaker tests were surveyed. The results includegraphics, photographs, and narrative sitedescriptions included in this report, as well asseveral hours of video footage. Time spentunderwater on each site was limited by bothfield session lengths and diving constraints.Most dives were decompression dives between100 and 180 feet in depth. Typically, two diveswere done each day, and in the two sessionswhich cumulatively totalled four weeks, therewere 24 diving days.

In addition to site descriptions, which are theprincipal archeological fieldwork products, weevaluated the Bikini wrecks in terms of siteformation processes, Rather than emphasizingthe unique nature of wreck events caused byan atomic blast, we take the position thatwhatever the agency of destruction, ships aredamaged and sunk by forces governed byphysical processes that are repetitive, oftenquantifiable, and that ultimately may bepredictable. In addition to describing thetarget ships and evaluating their currentcondition as the result of a unique set ofhistorical circumstances that may never berepeated, we present the analysis in terms thatmay be useful for comparisons with otherwreck processes. A comparative approach istaken for those ships sunk by the same blast,between categories of ships and between shipssunk by the two blasts. The site descriptionspay particular attention to variables of shipclass, proximity, and orientation to the blast,pre-blast vessel condition and alterations. Wehave also included contemporary observationsfrom immediate post-blast vessel evaluations asa control for natural deterioration resultingfrom submersion for nearly 45 years.

This particular approach incorporates into thesite description some of the remarkable amount

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of quantified data collected by the numeroustest-instrument arrays. The Able test included5,000 pressure gauges, 25,000radiation-measuring instruments, 750 cameras,and four television transmitters within andaround the target array. 1 Eighty percent of theinstruments were recovered after each test fromthe sunken test ships.2 These data, recentlydeclassified, offer a rare chance to observestructural hull damage that can be attributed tomeasured peak-pressure waves of knownduration. These observations provide acomparison against which other wreckprocesses, whether conventional explosives ornatural effects, can be measured forsteel-hulled shipwrecks,

The discussions in this chapter follow thecategorical sequence of Pre-Test Alterations,Immediate Post-Blast Observations, and 1989/90Site Descriptions. Pre-Test Alterations includesthe recorded changes to each vessel inpreparation for Operation Crossroads. Inorder to make the atomic test reliable, thevessels had to be in good repair. Most testvessels were recent combat veterans andrequired some repairs. Post-Blast Observations,like Pre-Test Alterations, are derived fromhistorical records. This section presents bothsurface observations of each ship’s sinking andunderwater observations made by diversexamining the wrecks shortly after each blast.Apparently there were two diving evaluationsmade by the Navy, one soon after the blast andanother a year later, Unfortunately, with theexception of Saratoga, most of the detaileddescriptions of the 1947 dives on these vesselsare not available; only general descriptionswere microfiche, the rest are missing from thearchival record.

Two target vessels were lost in shallow waterinside Kwajalein Atoll lagoon. The Germancruiser Prinz Eugen and an infantry landingcraft, LCI-327, were lost to capsizing orgrounding and left in place. All but nine of

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the other target vessels not sunk in BikiniLagoon were scuttled in deep water. Thisleaves a group of 21 wrecks associated withOperation Crossroads accessible to divers atBikini and Kwajalein atolls. Nine were divedand assessed during two field seasons by theNPS; two others were ROV dived by the Navyand subsequently assessed by the NPS.

This Site Descriptions section contains the 1989and 1990 fieldwork observations as well asobservations made by divers and through use ofsurface-monitored Remote Operated Vehicles.Each site discussion is a composite drawn fromdirect observations, video, photographic andfield illustrations. The amount of time spent

on each site was variable, which is reflected inthe amount of detail in each site discussion,

RECONSTRUCTING THE NUCLEARDETONATIONS

The “nominal yield” of the two plutonium,implosion-core Mk III “Fat Man” bombsdetonated during Operation Crossroads hasbeen variously estimated in secondary sourcehistories to have been between 20 to 23kilotons, or a force equal to 20,000 to 23,000tons of TNT. The formerly classified officialanalysis of the “Able” detonation of July 1,1946, noted that one measuring techniqueindicated that the bomb’s yield was 19.1kilotons.3 The “Baker” detonation of July 25,1946, was noted to have yielded approximately20.3 kilotons, described as a “normal” yield for“an atomic bomb of the Nagasaki type.”4

The Able Detonation

The proximity (VT) fuze of the “Able” bombwas set for an altitude of 515 feet over theocean surface. Even though the bomb missedthe intended target ship, USS Nevada, by 710yards, it detonated close to the set altitude, at518 feet, 50 yards off, and slightly to starboard,of USS Gilliam .s

The firing of the weapon caused the fissionablematerial in the bomb to become supercritical,and a self-sustaining chain reaction wasinitiated, The fission process released theenergy equivalent to approximately 20 kilotonsof TNT before the bomb was quickly blown

apart and fission was no longer possible. Aluminous mass known as the “ball of fire” wasformed. The ball of fire emitted thermalradiation that started fires as far away as 3,700yards. e The thermal radiation accounted for 35percent of the total energy released in thedetonation. The ball of fire continued toexpand, touching the water, as vapor from thedetonation formed a reddish-brown cloud richin nitrous acid and nitrogen oxide, whichclimbed at a rate of 200 miles per hour, At0,5 seconds after the detonation, the fireballwas nearly 1,500 feet in diameter.

Immediately after detonation, a high-pressurewave was created that swept about 75o feetahead of the fireball. This “blast wave” with itsshock front, accounted for 50 percent of thetotal energy released by the bomb. At 1.25seconds, the shock front had moved out morethan a third of a mile, and had struck thelagoon surface. This created a reflected shockwave that travelled up to collide with the initialshock wave, fusing with it to form a single,reinforced “math effect” front that generated upto 16-pounds-per-square-inch peakoverpressure$’ The math front continued togrow, so that three seconds after detonation, itwas nearly a mile from the zeropoint and 185feet high, creating winds at the front of 165miles per hour.e

Ten seconds after detonation, the math frontwas 2.5 miles from the zeropoint, moving at 40mph with a peak overpressure of one psi, Theblast effect of the bomb at this time waseffectively over, as the hot, gaseous ball of firerose, drawing up air and producing strong aircurrents, or “afterwinds” that sucked up waterand debris to form the stem of thecharacteristic “mushroom cloud.”e Only 30seconds after detonation, the cloud was abouta mile and a half high. Ten minutes afterdetonation, the water sucked up into the cloudor vaporized by the ball of fire was releasedwhen a light, radioactive rain fell.

Apart from the initial release of nuclearradiation, which accounted for five percent ofthe total energy expended, residual radiationnear the point of detonation was reported tobe minimal, which was attributed to thecarrying up by the afterwinds of the radioactivematerials into the cloud and their distribution

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into a diffuse, light fallout that did not, for themost part, land on the target fleet.

1946 “Able” Damage Assessments

A summary of damage to the target ships wasprepared by Joint Task Force One. Thefollowing discussion is drawn from thatdocument and not from the archeologicalrecord prepared by the NPS.

The worse damage was done to ships within athousand-yard radius of the zeropoint. Fiveships were sunk: Gilliam (50 yards from thezeropoint); Sakawa (420 yards); Carlisle (430yards); Anderson (600 yards); and Lamson (760yards). Additionally, six other target vesselswere “immobilized” by blast damage, andanother eight suffered “short- or long-termserious loss of military efficiency” by havingtheir boilers, radio, or radar and fire controlsystems disabled. These were Skate (400yards); YO-160 (520 yards); Independence (560yards); Crittenden (595 yards); Nevada (615yards); Arkansas (620 yards); Pensacola (710yards); ARDC-13 (825 yards); Dawson (855yards); Salt Lake City (895 yards); Hughes (920yards); Rhind (1,012 yards); LST-52 (1,530yards); and Saratoga (2,265 yards).Additionally, four ships suffered “short- orlong-term moderate loss of military efficiency”:Talbot (1,165 yards); Barrow (1,335 yards);Pennsylvania (1,540 yards); and New York(1,545 yards). Based on these reports, JointTask Force One concluded after plotting theactual damage and determining its relationshipto the structural strength of the specific shiptypes and methods of construction, that therange of damage was “very serious” to 900yards, “serious” to 1,000 yards, “moderate” to1,300 yards, and “slight” to 1,500 yards.10

The worse damage from the blast was thatsuffered by vessel superstructures. Hulldamage, including decks, sides, and bottoms,was next in severity, followed by damage tomasts and stacks. The worse hull damage wasthat done to Giliiam, which was described as“badly ruptured, crumpled, and twisted almostbeyond recognition.’” 1 Gilliam sank within aminute. The other attack transport, Carlisle,

sunk, was dished, and had hull breaks.However, the transport Crittenden, 165 yardsfarther out from the zeropoint than Carlisle,

survived sinking, although it suffered “severedishing and deflection of the deck.” Carlisle’ssinking was attributed more to its beam-onorientation; hence Crittenden’s “bow-onorientation may have saved her from beingsunk.”12

The loss of Sakawa, which sank in 25 hoursfrom tears in the stern plating, was attributedto its “considerably lighter construction,” asopposed to the two U.S. cruisers moorednearby, which suffered dished decks and stacksand superstructure damage.13 The destroyersAnderson and Lamson, two of three destroyersanchored within the thousand-yard radius ofthe zeropoint, sank because of extensive hulldamage. USS Hughes, at 920 yards, was dishedbut survived. Three other vessels sufferedmajor damage without sinking. The lightcarrier Independence’s hull was “blown in andthere was buckling of bulkheads.” Additionally,the flight deck was “badly warped and buckled,and the sides enclosing the hangar deck wereblown through.”14 USS Skate suffered seriousdamage which prevented the submarine fromsubmerging, including a bent conning tower anda “badly stripped and crumpled superstructure.”YO-160’S concrete hull was broken and spalled,exposing bent reinforcing bars, its concretedeckhouses were smashed, and all of the woodin the vessel was burned by a thermal-radiation-induced shipboard fire.15

Flash scorching on painted surfaces was foundon vessels up to 3,700 yards distant from thezeropoint. Fires were started on severalvessels, usually in cordage, canvas, or burlapwrappings on exposed Army test items, notablyon USS Saratoga, the most distant vessel (2,265yards) from the zeropoint to suffer any Abledamage. Fires aboard USS Anderson probablyexploded shipboard ordnance, hastening itssinking. The only fuel oil fire was startedaboard Sakawa.

The Baker Detonation

The Baker bomb was detonated by Los Alamosscientists inside its steel and concrete caisson,suspended 90 feet beneath LSM-60, andapproximately 90 feet above the lagoonbottom.18 Energy release was similar to theAble shot. A fireball was formed thatilluminated the water with an orange-white light

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for a few millionths of a second before thehigh-pressure gases of the ball erupted to thesurface, The shock wave formed a “blast slick”of white water on the surface, emanating outfrom the zeropoint in a “rapidly advancingcircle” formed by the hurtling of small waterdroplets short distances into the air.17Immediately, within four millionths of a second,the gas bubble burst into the air, throwing upa mound of super-heated steam and watercalled the “spray dome,” at a rate of 2,500 feetper second. 16 ‘Tile spray dome climbed into a

column in which the water in the center movedfaster than the water farther out, at a rateestimated at 11,000 feet per second, Thisformed a hollow center in the column thatacted as a chimney for the hot gases andsuperheated steam from the now nearlyexhausted fireball to climb, carrying excavatedlagoon bottom and radioactive products up toform, with water vapor, a cauliflower-shapedmushroom cloud.le At the same time, thecondensation of the water formed a vast“Wilson Cloud” around the column 18 secondsafter detonation, which dispersed into a

dissipating ring of clouds that vanished after30 seconds,

The height of the column and cloud, containingsome 2,000,000 tons of vaporized and boilingwater (estimated at four cubic feet of waterper thousand cubic feet of column andweighing at least two million tons), was 4,1oofeet at 10 seconds after detonation, and 7,600feet at 60 seconds.20 At that time the stemradius was 975 feet in diameter, formed by300-foot-thick walls of water with a 75-foot-diameter hollow stem.21 The column alsocontained approximately 2,000,000 tons oflagoon bottom from a crater nearly 700 yardsin diameter and 20 feet deep. The blastgenerated a seismic effect equal to anearthquake measuring 5.5 on the Richter scale,Ten percent of the energy released by thebomb was represented in the formation of thecolumn and crater,22

The peak pressure wave lasted twomilliseconds. The peak overpressures, recordedat a 90-foot depth, were considerable. At 835

The most famous photograph of Baker. The dark spot in the column marks the position of the capsizingArkansas. Crossroads mytholog mistakenly insists this photo shows the upended form of the battleship.(U.S. Naval Institute)

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feet from the zeropoint, the peak overpressurewas 7,000 psi. Other readings were 5,900 psi(928 feet); 5,200 psi (996 feet); 4,400 psi (1,084feet); 3,200 psi (1,278 feet); 2,300 psi (1,554feet); 1,400 psi (2,060 feet); 800 psi (3,040feet); 560 psi (3,700 feet); and 330 psi (5,000feet) .23 It was later found that the shipsshielded some of the blast. The underwaterpressure on the remote sides of hulls wasmeasured at 40 percent of those on theexposed sides.24 Peak pressures were alsorecorded in the air that were equal to a 4-kiloton air or surface burst. The pressuresmeasured in the air were 16 psi at 550 yards,diminishing rapidly to 9.6 psi at 650 yards, 6.6psi at 800 yards, 4.8 psi at 100 yards, 3.8 psi at1,200 yards, and 2.8 psi at 1,500 yards.25

The velocity of the pressure wave was the samein the water and in the air: at two seconds theshock front had travelled two miles from thezeropoint. Another effect of the shock frontand the eruption of the fireball was thecreation of a series of waves that moved at 45knots. At seven seconds after detonation, a94-foot-high wave passed the thousand-yardmark. It was followed by a 47-foot wave at2,000 feet at 20.5 seconds, and a 24-foot waveat 4,OOOfeet at 47.5 ieconds. These were theonly three waves of height. Four lesser wavesfollowed, diminishing to a nine-foot wave at12,000 feet 156 seconds after detonation. Thenearby islands of the atoll, notably Bikini, werewashed by 15-foot breakers.28 The creation ofthese waves accounted for one percent of thebomb’s total energy.

A “base surge” also emanated out from thecolumn as it collapsed. “This doughnut-shapedcloud moving rapidly out from the column,..isessentially a dense cloud of water droplets,much like the spray at the base of NiagaraFalls...but having the property of flowing almostas if it were a homogeneous fluid.”27 Moving at45 mph, the base surge was 800 yards distantfrom the zeropoint and a thousand feet high.The base surge contained many of the bombmaterial’s radionuclides as well as radionuclidesproduced because of activation of the seawater, lagoon sand, etc. It has been estimatedby one expert that as much as 50 percent, andno less than 10 percent of the radioactivematerial remained trapped in the seawater.28Radiation levels were measured near the point

of detonation at the surface of the water atmore than 10,000 Roentgens, or at an amountvariously estimated to have been equal toplacing 2,500 to 8,300 tons of radium at thezeropoint.2g

A fatal dose of radiation is generally assumedto be 400 Roentgens per 24 hours. Personnelon ships within 700 yards of the zeropointwould have received that fatal dose in 30 to 60seconds. A dose 20 times fatal--8,000Roentgens--would have been received in thefirst hour. At 7,000 yards, the fatal dose wasadministered in seven minutes, while at 2,500yards, a fatal dose would have beenaccumulated in three hours. Radiation levelson the ship’s decks fell to 65 Roentgens per 24hours four hours after the blast, and to .1Roentgens per 24 hours by five days after theblast, in large part because of radioactive decayand the diffusion of radioactive materials byconvection and current.30 Yet four- to eight-inch-thick contaminated sediments from the50,000 cubic yards of bottom excavated fromthe crater that were estimated to have fallenback in the lagoon demonstrated “high”readings six days after the blast. Similarly, “anumber of vessels were covered withcontaminated coral sand which had beensucked from the bottom of the lagoon” anddeposited by the base surge.3i

1946 “Baker” Damage Assessments

The “Baker” detonation sank nine vessels andbadly damaged another eleven within athousand-yard radius of the zeropoint. JointTask Force One, tallying the results,determined that 700 yards was a “serious if notfatal” damage zone, with serious damage at 900yards, moderate damage at 1,000 yards, andslight damage at 1,500 yards. The majority ofdamage was caused by two factors--underwatershock, and the violent motion caused by it, aswell as the impact with and violent motionfrom the blast-induced waves.32 Five of thevessels not sunk within the 1000-yard radiuswere “immobilized.” USS Pensacola sufferedmoderate hull dishing, damage to bulkheads,stanchions, and machinery foundations, holdingdown clips on turrets and battery mounts.USS Hughes was the closest destroyer to thezeropoint. It suffered major structural damage,including ruptured pipes and sea connections

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recording the expected pressures and failed togive good data, Hence the blast effects onGilliam were difficult for the Navy to quantify,

which flooded the ship, dished plating, and abadly damaged rudder and skeg.33 A nearbyship had worse damage. USS Gasconadesuffered a complete loss of longitudinalstrength, the wrinkling of the bottom and shellplating, and partial flooding, The difference indamage was attributed to ~ughes’ broadsidemooring and Gasconade’s stern-to mooring.Gasconade rode the waves perpendicularly andhogged and sagged, while Hughes rode themparallel and consequently had its bottom andkeel constantly supported by water,34

The transport Fallen was flooded to thewaterline, with “severe structural damage toship girders,” buckled decks and plates, and apermanent “transverse-curvature twist in herhull.” LST-133 had minor hull damage andcracked ballast tanks, Damaged but notimmobilized were the destroyer Mayrant, withbulkhead, stanchion, and weather deck damageand minor flooding from ruptured pipes, thebattleship New York, the transports Briscoe andBride, the already wrecked submarine Skate,and LCT-816,S6

SITE DESCRIPTIONS: VESSELS LOSTDURING THE ABLE TEST

USS GILLL4M

USS Gilliam is the only Able test vessel divedand assessed. It is the most important Ablevessel, given its accidental role as surface zerofor the test,

Pre-Test Alterations

Documented pre-test alterations to Gilliamapparently were limited to addition of variousexposure test instruments and militaryequipment, These included a bulldozer,searchlight and generator, fire-fightingequipment, radiation monitors, water-distillingequipment, and a VF aircraft secured to theaft upper deck.

Post-Blast Observations

Gilliam sank in 79 seconds, going down bowfirst at an estimated 70-degree angle accordingto the Navy’s interpretation of post-blast photosequences,3B Navy divers assessing Gilliam’sdamage soon after the Able test found it nearlyupright in 180 feet of water, with the stem, onebulkhead, and side shell-plating compressed adepth of six to ten feet and pushed to port:“the forward part of the ship is mashed downas though the blast acted like the hammer andthe water an anvil,”s7 The forward main deckwas pushed down to within about five feet ofthe hull bottom, and starboard sideshell-plating was stripped off as far back asframe 30--about 90 feet.

The flattened superstructure was pushed off thedeck to port. According to Navy surveyreports, “the weather deck from frame 60forward was stripped of all deck machinery,deckhouse, hatch coamings, foremast, and other

Because the bomb detonated much closer toGilliam than originally planned, the blasteffects were greater than anticipated, Testinstruments placed had been designed only for

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fittings. The sole fixed object noted on thisdeck was a port 40mm gun, with its roundwelded steel shield (gun tub) stripped off. Thedeck openings for hatches and trunks wereplainly seen by the Navy divers.”3* The blastalso opened up the chain locker, exposing thechain and tearing hawsepipes, with the chainstill passing through them out of the hull.Portions of the vessel were blown overboard bythe blast and littered the lagoon bottom. Navydivers noted bitts, which were retrieved forradiological testing, a 40mm gun, a blast gaugetower, and twisted shell plating lying on thelagoon bottom.

Navy divers recorded the wreckage with 60underwater photographs. Unfortunately, wefound these photographs to be mostlyuninformative. Made from 4x5-inch negatives,the photographs show small areas or individualwreckage pieces, such as bitts and the twistedbulldozer blade. Poor visibility hampered theclarity of the photographs; it appears to havebeen less than six feet. The bulldozer, stowedon the weather deck, would be unrecognizablein the photograph without the label. The poorvisibility probably resulted from blast-displacedsediment still suspended in the water column,indicating the photographs were taken shortlyafter the blast. Another indication of howsoon the underwater photographs were made isthat each is over-exposed, which may be aresult of the high radiation levels noted in theNavy survey dive reports. The Navy divers alsoprepared a plan view and profile sketch of

Gilliam’s shattered hulk.

Site Description

One documentation dive was made on Gilliam.The full five-member NPS team swam over thedeck, at 150 feet below the surface, from sternto bow. Water visibility was 50-100 feetvertically. The basically intact hulk of Gilliamwas found to be upright on the bottom of thelagoon in 180 feet of water. Hull damage nowappears to be more severe than 1946 diverreports indicated. It is possible that additionaldamage was inflicted on the submerged hull bythe nearby Baker test detonation, and that whatis seen, is cumulative damage.

The overall impression is thattaken an enormous downward

the hull hascompressive

P?deo Freeze Frame)

force. The barely recognizable ship has theappearance of being smashed down into itself,with the successive deck levels pancaked downinto the hold. These decks were originallysupported by longitudinal bulkheads, stanchions,and rider frames of welded steel withl-1/2-inch-thick steel gusset plates on lower hullbeams. The hull sides above the waterline arebent inward, in some cases more than ten feet.The hull area below the waterline appears tohave the least distortion.

It should be noted that Gilliam was not alightly built vessel, even though not a combatship. The Victory-type ships were built tocorrect some of the weaknesses observed inearlier Liberty ships. Gilliam was welded steeland very strongly built for heavy service.Gilliam’s hull had transverse frames on 36-inchcenters and a double bottom. There werenumerous watertight compartments that werestrongly built, contributing directly to hullgirder strength.

The majority of damage, as the 1946 reportsindicated, is forward. The bow appearscrumpled and folded. A square frame, possiblya skylight, lies on the deck. The shell platingis peeled back and missing in places; thedeckhouse stripped off and in part smasheddown and to port. The impression uponviewing the hull is one of chaos--ship partscrumbled, torn, and scattered.

There were no deck fittings observed forwardexcept a 20mm gun mount near remains of theaft bulkhead of the forecastlehead. This is the

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\

onlv bulkhead that seems to be in its originalpos”ition, It is bent in an “s” shape that his acorrespondingly distorted door in it.

Forward of the bulkhead is the 20mm gunmount. The remains of the forward hold,which contained railroad iron as test cargo andgas cylinders, is aft the bulkhead. Numerousgas cylinders and angle iron can be seenamong the jumble of what was once theforward hold. The deck seems to have beenripped off, exposing the hold’s contents, Akingpost lies off the starboard side, To port isthe-bulldozer, with its blade bent inward.

Within the jumbled wreckage, hatch coamingscan be discerned as rectangular interruptions ofship scatter. The coamings appear to havebeen torn out of the deck. A perimeter ofbroken deck plate adheres to the hatchcoaming margin,

Gilliam is the most damaged of the vessels theteam examined in Bikini Lagoon, It isunforgettable,

USS CARLISLE

USS Carlisle was dived by the Navy ROV inAugust 1989, Videotapes of the ROV divewere assessed by us for comparison withGilliam.


Carlisle was loaded to 95 percent of itscapacity with fuel and diesel oil. This ship wasalso loaded with 100 percent of its wartimeallowance of ammunition “plus several loadedbut plugged bombs, rocket heads andincendiary clusters throughout the ship, TheBureau of Aeronautics secured a VF airplaneaft on the upper deck.”3a

Post-Blast Observations

Carlisle was moored close to and athwartGilliam, the accidental zeropoint of the Abletest detonation. Carlisle was 430 yards fromsurface zero, Carlisle’s port side faced theblast. The blast displaced Carlisleapproximately 150 feet, toppled the stacks andmainmast, displaced the superstructure tostarboard, and damaged the foremast. The

ship was first seen in photographs less thanthree minutes after the burst; “at that time shewas smoking heavily amidships.,. she continuedto burn and by burst plus 5 minutes 33 secondsshe had assumed a 10 degree list tostarboard. ”4° The ship sank unobservedapproximately one-half hour after detonation.In 1946 Navy divers located the wreck ofCarlisle lying in 170 feet of water, “with a smalllist of about 5 degrees to port.”41

Site Description

One ROV dive was made by Navy operators in1989 on Carlisle, commencing on the port sidenear the bow and heading aft to the fantail,then running back along the port side to thehatch leading into the aft cargo hold. TheROV then headed across the deck, descendedinto the hold, and then came out, dropped tothe starboard side, and ran aft along it for ashort distance before ending the dive,

Comparing the identical, sister ships Gilliamand Carlisle offers a comparison of the Ablebomb’s damage to this type of vessel asobserved at the different positions of 50 and430 yards from surface zero, Gilliam washeavily mangled, as previously discussed, WhileCarlisle is more substantially intact, the shipsuffered considerable and fatal damage at eighttimes the distance of its sistership, which theNavy attributed to Carlisle’s beam-onorientation to the blast. Damage observed inthe ROV dive would confirm this. The portshell plating is buckled, dented, and dishedconsiderable, with a maior failure forward.The supers~ructure, while” more or less intact,has separated from the hull at the port side,and is pushed to starboard, as indicated in1946 reports,

The most interesting damage to Carlisle is thatdone to the decks, which evidence the samecompressive downward force of the blast thatGilliam’s decks do, although not as severely,The port side of the deck around the aft hold’shatch has separated from the bulwark and thehull, and the deck seams have parted. Thehatch coaming is bent and twisted, but remainsattached to the deck plates except in its afterportions, where it has pulled free, The deckhas ~artiallv collamed into the hold. andstanc~ions hive buc~led inside the hold, so that

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the subsequent deck levels are also deformed.A jumble of broken plate lies in the hold.

The after deckhouse is pushed downcompletely. A buckled bulkhead, with theturnbuckles for the wire rope rigging of themainmast welded to it, is twisted down to theweather deck level. The formerly elevated portgun tub for a 40mm gun is now lying on thedeck, without a weapon. Moving aft, bitts andfairleads remain attached to the deck, and twostrands of anchor chain run from the fantaildown into the silt on the lagoon bottom.These chains moored the ship’s stern to a 10-ton mooring clump. Moving forward along theport side, a cargo boom from the mainmastslopes down from the deck to the lagoon floor.On the starboard side, the superstructure leansslightly over the starboard hull, which exhibitsminor dishing. A gun mount on the aft portquarter of the superstructure is missing both itsgun and the armored steel tub that surroundedit. Scattered artifacts, including a ship’srunning light and ammunition boxes,

presumably from the gun tubs on thesuperstructure, lie off the starboard side on thebottom.

SITE DESCRIPTIONS: VESSELS LOSTDURING THE BAKER TEST

USS ARIL4NSAS

In addition to the Navy dives of 1946 and 1947,USS Arkansas was dived twice by the NavyROV in 1989 and three times by the NPS teamin 1989 and 1990.


Arkansas’ modifications for OperationCrossroads included blast gauge towers and testequipment installation. Also aboard was testordnance. One photograph of Arkansas’ deckshows a howitzer and a 90mm antiaircraft gunsecured by turnbuckles and wooden chocksheld by angle iron bolted to the teak deck.

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Able Post-Blast Observations

Arkansas was part of the Able tm.t array, andwas heavily damaged by the aerial burst.According to Operation Crossroads: The OfficialPictorial Record, “although little damage wasdone to her hull and turrets, her wreckedsuperstructure showed the hammer-like effectof the bomb. Amidships she was ashambles.”42 Arkansas’ damage was furtherdescribed in Bombs at Bikini:

When the lagoon was first recentered, shewas still sending up clouds of smoke fromsmoldering fires on her decks, But theshock wave did the worst damage. Stacks,masts, and mast supporting structuressuffered, as well as pipe rails, bulwarks,stowage spaces. Much dishing occurred.Many doors, stanchions, and bulkheadswere badly damaged,43

If any alterations were made to the ship priorto the Baker test, they were not recorded inthe documents reviewed,

Baker Post-Blast Observations

In 1946, after Baker, Navy divers found thewreck “lying buried in the silt, bottom sideup..,. Most of the superstructure, includingstacks, boat cranes and mast is not visible andis presumed to have been driven into the coralsilt on the lagoon bottom,”44 They observedmajor hull damage:

Little is left of the shafting and therudder has not been found, Only theport forward shaft without the screw hasbeen found, and it is seriously out of line.No struts have been sighted and two largeholes aft indicate the after two shafts havebeen completely torn out, stern tubes andall, leaving the surrounding area badlydistorted and broken.45

The hull’s shell plating either dished in (insome cases as much as six feet), tore, bent, ordented around the frames, parting butts andplate seams. In some cases the transverseframing failed. The torpedo blisters dented,bulged, and separated from the hull in severalareas. Rivets failed throughout the hull, andnear the No, 2 turret, a 15-to-20-foot wide dent

of undetermined depth ran from the bottom upto the turn of the starboard side bilge.

The Navy determined that the upsurging blastwater “acted on Arkansas from below and tostarboard at a point approximately one-third ofher length from the bow.”48 This mass ofupsurging water capsized the ship to port. TheNavy concluded, “The many holes and rivetsseams which were opened throughout the entirelength of the shell plating by the underwaterexplosion were the probable sources offlooding. A water wave which smashed overthe Arkansas... may have partially aided inswamping the ship,”47

Site Description

The 1989 and 1990 surveys found that theseriously damaged Arkansas lies inverted onthe bottom of Bikini Lagoon in 180 feet ofwater roughly aligned east-west, bow to theeast, The battleship was aligned close to thisposition for the test. The former weather decklevel is located at approximately 160 feet belowthe water surface; the port casemate, oraircastle, is located at 170 feet, while thedeformed keel is at the 100 to 120-foot level.

Arkansas has a slight list to starboard. Theport side is more or less intact, while the

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Perspective sketch of Arkansas. (NPS, Jeny Livingston and Larry Nordby)

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starboard side is crushed and flattens out ontothe lagoon bottom. The forward hull area isheavily damaged; the bow structure twists andis bent down and to starboard.

The hull bottom is markedly dented andrippled along the series of longitudinalsupports, creating a series of “steps” thatgradually slope down from the port bilge keels,past the deformed keel to the smashedstarboard side, where frames splay out fromthe shell plating on the lagoon bottom. Theshell plating has parted in some areas, Somepieces of wreckage containing frames,identifiable by their lightening holes, lie off theside.

In the stern, the propeller shafts have beentorn away, The forward port shaft, with itsthree-bladed screw, is intact but deformed andbent outward. The shaft struts are missing.The after port shaft is bent to port. There isno trace of the starboard shafts or screws; it ispossible that the entire 142-foot shaft lengthswere torn free of the hull, The rudder andstern are missing. Broken hull fragments lieoff the starboard side,

At the bow, the only identifiable features arethe bulbous stem, which normally protrudesforward below the waterline, a chock on theport bow, and the two hawsepipes forArkansas’ two port anchors, This battleshipcarried three anchors, two to port and one tostarboard. Two anchor chains extend from theforward hawses into the sand, The hull iscracked just below the gunwale forward of theNo, 1 turret.

The chains, which are still attached to the deckby stoppers, hang down below the inverteddeck. The ship is raised on the port side,allowing access to the deck. The vesselappears to be supported on the forward turret,the two 12-inch gun barrels of which can beseen pointing forward and slightly to port.

The ship’s superstructure was not observed byNavy divers in 1946 because of a heavy siltlayer that lay over and around the wreck. Thissilt layer, created by the blast, has now beenscoured away, exposing the hard coral and sandof the lagoon floor. The lagoon bottom is lessthan six feet below the weather deck in most

locations observed forward. This spacingaccommodates the turrets and a smashedsuperstructure reported in the Able post-blastassessment.

The 1946 Navy reports suggest the ship wassmashed nearly straight down into the !agoonfloor. This observation is supported by theship’s nearly level position on the bottom, withonly a slight starboard list. The flattened hullbottom and the superstructure being directlybeneath the hull also reflect a straight downpressure on the hull. Superstructure elementswould be expected to be visible on one side orthe other if the vessel had rolled. Apparently,the hull was capsized by the uplifting waterand smashed straight downward by the millionsof tons of collapsing water column.

The portside casemates, known as “air castles,”built of 6-inch-thick steel armor plate, areintact. Three 5-inch/51 caliber Mk13 guns onsingle mounts are visible. These n-l/2-ton,22-foot-long weapons were manually operated,fired a 50-lb. projectile with an eight-milerangeat a 20 degree elevation. The guns are slightlyelevated and have swung to port.

Most of the gunport shutters are missing.Reportedly damaged in the Able test, theseshutters have fallen away, probably when theship capsized. At least two lie beneath theport side on the bottom. Splinter shields for40mm antiaircraft guns were noted beneath theinverted aircastle; the weapons themselves wereremoved before the test.

Inside the casemate, two 5-inch rounds remainin the ready rack. The guns still haverange finders and sights. In the casematemessing and berthing spaces, stanchions, whichonce provided support for the gun crewhammocks, remain in place but slightly bentfrom compressive forces. Remarkably, the glasscover and bulb for a battle light was locatedundamaged on the inverted ceiling. Overhead,the teak deck is missing, presumably consumedby marine organisms, leaving only metal deckfasteners attached to the steel underdeck. Awire-cable reel for the port paravane is stowedat the aft end of the compartment. Anammunition hoist hangs open from the deck.

This 21-foot-wide compartment was enteredthrough a seven-foot wide longitudinal

Mutphy)

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Looking forward in the port aircastle of Arkansas, at Bikini in 1946. The light that Lenihan investigated in1990 is visible in the upper right corner of the photograph. (National Archives)

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passageway that runs from port to starboard,The passageway leading to the starboard aircastle was not entered. The port air castleincluded the entrance to the admiral’s cabin;Arkansas was fitted as a flagship. This cabinwas not entered. There was also a 32-foot-wide space between each passageway thatcontained boiler uptakes, evaporators, and theship’s enlisted cafeteria with steam tablesopening into each passageway. Thesepassageways were not entered,

USS SARATOGA

USS Saratoga was the principal focus ofassessment and documentation during the Bikinifield seasons. The vessel is one of the mostaccessible to divers, and consequently ofprimary interest for evaluation as a dive site.


Saratoga was modified for OperationCrossroads. Nearly two-thirds of the ship’sarmament was stripped, including two of thehouses with the twin 5-inch guns. Otherfixtures, including compasses and the ship’s bell(now at the Washington Navy Yard), wereremoved. To measure the effects of thebombs, aircraft, vehicles, and radar were placedon Saratoga. Blast gauge towers and otherinstruments were mounted at desired locations.

Loaded with 700 gallons of fuel oil, 15 tons ofdiesel, and 66-2/3 percent of its ammunition,Saratoga was sent to the bottom in anear-combat-ready state.48


After the Baker detonation, the ship was blownto a position 800 yards out from its originalposition before drifting back in and sinking 600yards from the detonation point. Thedetonation of the Baker test device on July 25created a blast wave crest that lifted Saratogaout of the water. Eleven seconds afterdetonation, the 94-foot-tall wave crest was 330yards from the detonation point; at 23 seconds,it was 660 yards off and 47 feet tall,diminishing to 24 feet tall at 1,330 yards at 48seconds after detonation. Official reports statethat Saratoga’s stern rose 43 feet and the bowat least 29 feet. A large wave of water washedover the ship, sweeping away five TBM-3E andSBF-4E aircraft stowed on deck, as well asvehicles and equipment placed there for thetest, According to test data analysis, “itappears highly probable that shortly after therise on the first wave crest, the Saratoga fellinto the succeeding trough and was bodily hitby the second wave crest.,..”4e

In 1946, Navy divers made limited dives on thewreck and reported that the forward starboard

~s island stack and No. 1, 5-inch mount after stripping the ship for Crossroads. This photographwas taken at the Naval Air Station, Alamedq Calfomia, Februa~ 2Z 1946. (Floating Dydock)

strut in the stern had torn free, buckling shellplating and tearing out the doubler plates.The flight deck at the stern was dished in toa maximum depth of 12 feet that splintered thewood deck but did not penetrate the steel deckbeneath. The funnel had collapsed to theflight deck, with three-quarters lying on thedeck and the remaining quarter “erectbut...twisted about 20 degrees counterclockwise.”The top foremast was broken off above the SKradar platform. The starboard side of the hullexhibited a three-to-six-inch dishing in thecentral area of the ship.60

When Navy divers inspected the wreck, theyreported it lying in 180 feet of water on theport bilge at a 10- to 15-degree angle. Thebow reportedly tilted up at an approximatefive-degree angle, The ship had settled intothe bottom, to the shaft level, leaving thescrews exposed. The starboard bilge was aboutseven to eight feet above the bottom. TheNavy determined from oil leaks that the bottomshell plating had ruptured. This, theyconcluded, along with a tear in the hull nearthe starboard quarter, and the failure of seachests and valves, had sunk Saratogu.51

Site Description

In 1989 and 1990 dive surveys found that thevirtually intact USS Saratoga still lies uprighton the bottom of Bikini Lagoon inapproximately 180 feet of water. The vesselrises to within 40 feet of the surface, with theisland and mast visible from the surface,Numerous hatches and the elevator bay standopen. The vessel strongly retains its integrityas a ship and is easily identifiable as Saratoga,Although the carrier’s entire exterior wassurveyed, emphasis was upon the starboard side(which faced the blast) and the flight deck,Few interior spaces were examined other thanthe hangar deck amidships, as well as theisland, the flag plot, navigation bridge, andserological office, Additionally the auxiliaryradio room and windlass area was enteredthrough a hole in the flight deck,

Saratoga readily evidences the effects of theBaker test bomb’s detonation, More precisely,the ship shows the aftermath of a nearbynuclear detonation’s pressure wave, the effectsof being lifted 29 to 43 feet, being hit by

enormous waves, and the results of tons ofwater thrown up by the blast falling on thedecks, Below the flight deck level, damageprimarily consists of dishing along the starboardhull shell plating, most noticeably on thetorpedo blister, which is pushed inwardbetween frames to a depth of six feet in someareas. Shell plate dishing increases toward thestern. Some hull cracks show; it is not knownwhether they resulted from bomb damage orpost-depositional settling.

The worst hull damage is starboard side aft.Here, shell plating and doubler plates abovethe turn of the bilge and the torpedo blisterare torn free, exposing frames. Navy reports in1946 and 1947 indicated that all shafts andscrews were visible, with the starboard strutsbroken, This was also noted in the 1989survey, with the forward starboard strut brokenviolently enough to damage the shell platingaround it.

Flight Deck. The flight deck shows extensivedamage. A combination of blast wave andthousands of tons of water falling from theblast column collapsed and compressed the aftflight deck, beginning close to the stern andcontinuing forward nearly to the funnel about200 feet down to a distance of 12 to 20 feetbetween the outermost longitudinal bulkheads.These bulkheads, which provide the main flightdeck support, are 70 feet apart.

Navy reports in 1946 noted “the indentation [ofthe flight deck] is gradual with no abruptbreaks or bends. There is no indication thatthe steel deck has ruptured but the wooddecking has been splintered and broken...,”52The steel deck is now ruptured, It could havebeen ruptured in 1946, with splintered woodobscuring the break to observers. A largebreak about 100 feet aft of the stack is clearlyvisible and another open deck crack can beseen on the starboard side near the boat bay.

The major flight deck failure is near thefunnel, A partial deck break beneath thecollapsed funnel is probably attributable to thelatter crashing down on it. A roughly squaredepression aft roughly conforms to the No, 2elevator position, which was sealed off in early1945 during Saratoga’s last pre-Crossroads refit,The platform that covered the elevator was

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reported missing in 1946: “This platform wasreported found on the starboard quarter of theship.”53 During our dives we observed theplatform had collapsed into the hangar deck.What the 1946 Navy divers thought was theplatform on the starboard quarter is probablythe fantail drip pan, which is still in place.This drip pan was under one of two SBF-4EHelldivers mounted on the fantail for the test.The starboard aircraft, BuAer serial number31859, was secured to the pan with its wingsspread; according to the BuAer final report forthe plane, it was “blown over the side from theSaratoga before the ship sank. The steel drippan in which the airplane was secured was lefton deck and sank with the Saratoga.”54 A briefunsuccessful search was made for this plane.

Saratoga’s main flight elevator, forward thefunnel, lies at the bottom of the shaft,diagonally bent nearly 90 degrees. Theelevator was stowed in the “locked up” position

for the test, as it had been for Able. In thattest, it had dished down “slightly,” with “anumber of broken welds, in a number of placesbelow the platform, on the structuralmembers,”55 The Baker blast compounded thisdamage; 1946 aerial photographic analysis anddiver’s reports showed

the platform was dished in considerablyin the center and slightly to port, to adepth of...four to six feet probably fromthe effect of falling water and blasteffect .... The port side of the elevatorhad been depressed downward aboutthree feet and the whole platform tiltedto starboard, so that the starboard sideof the platform extended above the flightdeck level about one foot~e

The elevator platform’s location at the bottomof the shaft in its current position is attributedto post-depositional settling.

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Near the bow, the flight deck is partiallycollapsed. This collapse generally conforms toan area damaged by kamikaze attack off IwoJima on February 21, 1945, and subsequentlyrepaired for quick return to service. Diverreports in 1946 noted that “the flight deckforward appeared to be intact” and that “theflight deck in the area of the catapults wasundamaged by the blast.”57 The deck collapsein this area may also be postdepositional andattributable to a twice-damaged area weakeningwith corrosion and finally collapsing after thesinking.

Su~erstructure4 Above the flight deck level,the most apparent damage is to the ship’sfunnel. The funnel split at the 04 level andfell to port across the flight deck, slightlyangling toward the bow, indicating a lateraltwisting probably from the angle of the 90-footwave that hit it. The blast wave or the watercolumn’s falling mass likely contributed to thepresent distortions. The funnel completely torefree at the base, exposing the intakes. In 1946,the funnel after-quarter remained standing,Post-sinking funnel collapse has left only a fifthof the original funnel standing.

The funnel has completely collapsed into itself,with only the major longitudinal and transverseframing left intact, The plating lies brokenand scattered inside the frames on the deck.Blast and wave effects have bent the funnel’shorizontal framing to port, in some cases morethan six feet, The forward end of the toppledfunnel is intact, The secondary conningposition and the broken SM fighter-directorradar mounted atop the funnel’s forward endare recognizable. Diver reports in 1946 notedthat this “radar equipment.,.on the forwardportion of the stack was damaged.”5a

Damage to Saratoga’s island and mast includesshattered deadlights, hatches and doors blownoff their hinges, toppled Pelorus stands, andsheared antennae. The single-pole mast aft theisland was blown off at its crosstree; the wirerope that rigged the mast lies festooned on theafter area of the island. The SK radar antennaatop the mast fell forward; pieces of theantenna lie tangled and broken on the island infront of the flag plot bridge. The mount for awhip antenna lies on the deck outside thenavigation bridge. One level below, asearchlight that once stood on the platform aft

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Perspective painting of Saratoga. (Tom Freeman)

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Mark 37 director at the air defense level~S island” (Np$ Larry Mu~hy)

of the mast lies face down on the deck. Thestub mast that projected aft the pole mast isnow bent 90 degrees to port and broken. Aspar from the mast lies on the flight deckoutboard the funnel; a cable runs from it overthe starboard side. From this cable a whipantenna mount is suspended. Other antenna,such the Mark 12-22 array atop the MK 37director on the air operations bridge, as wellas all other observed director locations, aremissing. This conforms to 1946 Navy reports:“the SK, YE, and Mk 12-22 antennae aremissing. The whip antenna installed forward,at the starboard side of the flight deck, weremissing after the blast.”59

The various starboard hatches are mostly blownin, partially collapsed, or altogether missing.All porthole deadlight blast covers are closed;the glass in every porthole observed wasmissing. Wire-rope life nets, once strung abovethe sponson deck, are missing with theexception of some loose netting hangingforward of the starboard boat bay and near thestern.

Armament. Saratoga’s primary armament wasthe 81 to 83 aircraft aboard. When subjected

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No. 1, 5-inch138caliber mount on Saratoga. Theisland is faintly visible in the background.(National Geographic Socie@, Bill Curtsinger)

to the Baker test blast, Saratoga had fiveaircraft secured to the fllght deck, all wereswept off the ship by the blast or waves. In1988 Holmes and Narver and U.S. Navy diversreported an airplane on the bottom off thestarboard hull. This aircraft was not observedin 1989. The four aircraft stowed for theBaker test--three “Helldiver” Navy single-enginedive-bombers and an Avenger single-enginetorpedo bomber--were observed in the hangar.A more detailed discussion of these planes willbe found in the section detailing Saratoga’sinterior.

Saratoga also carried eight paired 5-inch/38caliber guns in four houses--two forward, twoaft. Before Crossroads, during the ship’s 1946stripping at Hunter’s Point, two of the houseswere removed: the No. 2 gun position forwardthe island (though its barbette remains atop thehandling room) and the No. 4 gun positionabaft the funnel. The remaining two guns inthe No. 1 position are elevated 20 degrees andtrained forward, whereas the two guns in the

. . .

Gun tub, with quad 40mm mount, aft of Sarato~a’sisland. Abaft the 40mm mount is a Mark 51 gundirector;further aft is stack wreckage. (NPS, LarryMurphy)

No. 3 position are level and pointed tostarboard,

Other weapons were also removed for the tests,but a representative sample was left to assessthe blast effect. For Baker Saratoga carried inaddition to the paired guns, 12 single .5-inch/38caliber guns; four were noted in the 1989-1990dives. Six of the original twenty-four quadBofors antiaircraft 40mm guns were alsolocated. The carrier also mounted 52 Oerlikonantiaircraft 20mm guns on the sponson deck;five of these were located, two lying on thelagoon bottom aft close to the sheared offstern sponson gun platform on which they weremounted. The sponsons were torn off eitherby huge bomb-generated waves or falling waterfrom the collapsing column. Twelvesponson-mounted Mk 51 gun fire-controldirectors were noted next to the antiaircraftguns.

Saratoga carried 66-2/3 percent of its normalammunition complement for the tests.Presumably live five-inch/38 caliber shells wereactually found inside the 5-inch gun turrets.Aerial bombs and torpedoes were found in thehangar and will be discussed later.

Various fire-control radars were also noted; theonly types specifically identified were the SKand SM, as well as the Mark 37 director atop

the island on the air-operations bridge, whichis missing its Mark 12-22 array.

The steel flight deck, once covered with teakdecking, is now exposed, allowing theobservation of battens used for aircrafttie-downs, with small wood pieces surroundingthe iron deck pieces. The area of the

palisades is discernible, as are the tracks forSaratoga’s Mk II hydraulic catapults forward.Aft, 21-inch bitts and other arresting gear, withwire rope attached and running athwartship,are still in place. Other extant deck furnitureincludes the forward aircraft crane, which hasdropped and lies on the deck. The crane wasnoted in 1946 reports as not appearing “to bedamaged by the blast.”e” It was, however, lyingon the deck when observed by Navy Divers in1947, The collapse of the crane may bedepositional. The airplane jettisoning ramp,which lies portside abeam the island, andvarious valves and fittings as well as fuelingbooms lie to starboard outboard the funnel.Both the bomb and torpedo elevators wereseen. The bomb elevator hatch is open; thetorpedo elevator is secured.

Ground tackle aboard includes an anchorstowed in a port bow hawsepipe and an anchorchain that runs from the bow to the seabed.The chains run into the sand but are no longerattached to a mooring. Saratoga was mooredby 10-ton “clumps” made of anchors andconcrete; one of these clumps is off thestarboard side of the ship. Others were

Single 5-inch/30 caliberstarboard bow gallery orMurphy)

AA gun on Saratoga’ssponson. (NPS, Lany

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Live 5-inch138caliber cam”dges,without warheads,in aluminum ca~”dge cases in Saratoza’s handlingroom for the No. 3, 5-inch mount. (NPS, LarryMurphy)

carrier and displaced it several hundred yards.A Navy stockless anchor, attached with wirecable to a bitt, lies on the fllght deck aft thefunnel to starboard. It may have been amooring that was displaced by the blast anddumped on the ship by the falling watercolumn; it lies in the indentation of the flightdeck.

Test Ecmiument. As part of the tests, militaryteams and scientists placed recordingequipment and gauges aboard Saratoga. Muchof this equipment remains, in some cases astraces of badly damaged instruments or mounts.Mounting brackets and pallets for military fieldequipment lie aft the funnel on one of thesepallets, on the port side flight deck near theafter elevator, around frame 120, stands theremains of Army Signal Corps test equipment.On the pallet are the remains of the packingcase and “safety trough for an SCR-399 radioset and an air-cooled diesel power unit thatwere mounted to the deck “by means of ring

Five-inch ca~”dge case, showing the ca~”dge. l%ewarhead was added by the gun crew in thehandling room. (NPS, Candace Clifford)

pads, l/2-inch wire cables and turnbuckles justinboard of the port rail...at frame 120.”81Another power unit, M7A1, with atrailer-mounted SCR-584-B radar set, wasplaced aft of this set-up on the flight deckweather edge “approximately 50 feet aft of themain stacks and superstructure.”82 Nearby wasa “shock-mounted” trailered PE-237 powerunit’3 Perhaps these are the source for some

of the observed wreckage; a portion of atrailer, with rubber tires, lies in the indentedarea of the flight deck in this area. Anothertrailer lies on the seabed off the port side.

The most obvious piece of test equipment is anArmy long antiaircraft gun bolted to the deckon the port side abaft the funnel. It isreported that the Army Ordnance Task Unit1.4.3 placed six items on the carrier for Baker:1) a light tank, 2) a heavy tank, 3) an Mlcable system, 4) a 90mm GMC, Mark 36, 5) a155mm Mark 2 gun, and 6) a 90mm Mark 2antiaircraft gun. The weapon on the deck isprobably the 155mm.84

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Also on deck are two blast gauge towers, oneforward and one aft, The forward tower liesoff the port forward corner of the elevator; theafter tower is set about 50 feet abaft thefunnel, These roughly pyramidical towers wereknown as “Christmas trees” and served asmounts for peak-pressure measurement gauges.To mount the gauges in proper position, testaccounts state “typically, they [the gauges] werebolted to ‘Christmas trees,’ sturdy 9-foot-highstructures of heavy steel pipes. The Christmastrees were ordinarily welded to the upperdecks of the target vessels.”e5 The pressuregauges were made of l/4-inch-thick brass plateswith round holes of various diameters up totwo inches bored through them, Tin foil wassandwiched between two plates, which werethen enclosed at the rear by a “sturdy air-tightcover, to prevent instantaneous equalization ofpressure,”o* Blast effect in the range of O to50 psi was measured by foil rupture; a greaterblast effect ruptured smaller diameter foil,while a lesser blast only ruptured the moreexposed foil in the larger diameter holes,

Another instrument mount type was observedon the flight deck aft, Welded to the deck onthe centerline, but arranged in a nearly squarepattern are three plate-steel boxes, each with adifferently shaped bracket atop it. These areprobably mounts and housings for delicategauges and recording devices. The primaryrequirement for most instruments used in theOperation Crossroads tests was that they be

really rugged. Despite the need forusing ingenious recording systems, thegauges and their mounts must survive theterrific overpressure, It is pointless touse a precision gauge which is promptlyflattened or blown overboard, Hencedelicacy was not a characteristic of theinstrument cases taken to Bikini; on thecontrary, many of the designers encasedtheir instruments’ delicate works in casesbuilt of 2-inch-thick steel which couldwithstand the pressure,e7

A large number of l-inch-thick lead plates,some with large square holes cut in ‘their

middles, were observed lying atop the No. 3gun house, and on the flight deck near theradio set pallets and inboard the 155mm gun.Nearly all lay bent or crumpled. These leadplates are probably the remains of indentationpeak-pressure gauges used to measure pressurein the range of 20 to 1,000 psi or 100 to 6,000psi, depending on the thickness of the lead.eaOne report notes “pressure is recorded interms of indentation produced by a small steelball forced against a sheet of lead. Thegreater the pressure, the deeper theindentation.”Eg The last type of test equipmentseen on the ship were two parabolic chromed,polished metal dishes. A 12-inch dish lies ina rubble pile at the after starboard corner ofthe deck outside the navigation bridgechartroom. A 24-inch dish lies in a rubble pileat the after port corner of the same deck.These are the remains of a “pendulum typeinclinometer” developed by the materiallaboratory of the New York Naval Shipyard forthe tests. The inclinometers were used toautomatically record angles of rolls and pitchof target ships. Mounted on steel plate with aweighted arm designed to remain vertical at alltimes, the discs were scratched by the armwhich left its record on the “shiny discsprovided.’”o

Island Because of the time limitations caused—.by the depth of the dives and the need tofocus effort on documenting the ship’s exterior,

only a few compartments were entered. Mostwere on the island. The compartments enteredon the island were the flag plot, navigationbridge pilothouse, and the serological office.All hatches and doors that enter the flag plotstand open--most blown off their hinges--withthe exception of a closed hatch on the afterstarboard corner. Navy divers noted in 1947,that most of the hatches were distorted orblown down. Some inward and others outward.This indicated damage from both positive andnegative pressure.

The flag plot bridge, at the forward end,contains radar and communications equipment;on a chart table attached to the starboardbulkhead lies a drafting machine, missing itsdrawing arm. Moving aft, bulkheads aremissing, allowing access to the admiral’s daycabin. The bunk, head, and a small whiteporcelain sink are in the cabin, which is largelyopen to the sea because the exterior bulkheadis missing in several areas. A hatch leads outto the starboard side of the flag plot bridge;on the deck outside, a ladder, with traces oflashings on the handrail, leads below to thenavigation bridge. Forward the ladder andmatched by another to port is a Pelorus.

The navigation bridge portholes are missingtheir deadlights. External blast covers withviewing slits cover all portholes with theexception of the last porthole aft on the

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Institute)

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Lead indentation vressure ~au~es on Saratoga’sflight deck portLenihan)

starboard side.on its hinge.mounts for two

s;de, amid;hip>. (NPS, Daniel

That blast cover hangs downOutside the bridge are the

Pelorus; lying on the deck onthe starboard side are a “b~ttl~ light, an air-raidsiren, and an inclinometer gauge. Anon-watertight interior door, probably from thehatch leading into the pilothouse, lies on thedeck. Badly corroded, it retains a rubbergasket. Aft of it lies the watertight hatch for

the chartroom. The watertight pilothouse dooris open and hangs on its hinges. Through thishatch is an open companionway. Thecorresponding hatch on the port side is closedand dogged.

An open door to the right (and forward) opensinto the pilothouse, Most of the equipmentremains inside. A chart table on the starboardbulkhead is first encountered; beyond it sits thehelm (with the wheel missing), binnacle(missing the compass and cover), the mountsfor the signal telegraph and other instrumentsnow missing, and a navigational radar set.Moving to port, a panel with push switches isIabelled with an engraved black plastic signthat provides “emergency signals.” On thebulkhead above it is an annunciator. Movingaft on the port side, an indicator is nextencountered. This instrument, with a digitaldisplay, is marked “ENGINE TELEGRAPH,”and “REVOLUTIONS AHEAD.” On the aftbulkhead is an open door, with the doorpartially collapsed into the companionway.Moving to starboard is a chart table and theelectrical panel for the ship’s lights. Severalblack plastic engraved labels are fixed to thebulkhead next to switches; among them are“MAN OVERBOARD,” and “MAST HEAD.”

Helm position on Saratoga’s bridge, showing thebinnacie, helm, and radar. The compass, wheel,and other equipment has been removed, presumablyfor Crossroads. (NPS, Lany Murphy)

To starboard of this panel is the doorwaythrough which entry into the pilothouse wasmade. The overhead is covered with a thinfilm of oil.

The chartroom is aft the bridge. The onlyaccess is by a starboard bulkhead hatch; it isblocked by a partially fallen piece of electricalequipment, possibly a SC-3 radar set. Anitrogen bottle for an SC-3 radar is mountedon the after starboard external corner of thechartroom. The chartroom was ventilated onthe port side by a circular vent--once protectedby a hinged cover; the remains of the coverhang down by the hinge.

The serological office is the aftermostcompartment in the serological platform, whichis one level above the flight deck on the island.The starboard bulkhead has fallen away,providing access into the office. The originalaccess, a door on the port bulkhead, standsopen, with the hatch off its hinges. Theinterior of the office is largely open; againstthe port bulkhead is a steel desk bolted to thedeck; forward is an unidentified piece ofelectronic equipment and a steel file cabinet.Beyond this is a companionway that leads to aladder that provides access to the decks aboveand below.

Hangar Deck. Navy divers did not enter thehangar in either 1946 or 1947. The firstrecorded entry into this space was during the1973 filming of the documentary, “DeadlyFathoms,” for which no detailed observationswere made, save the presence of one or moreaircraft. The 44-by-44-foot shaft drops onedeck into the hangar deck, which isapproximately 20 feet high and 70 feet wide.The elevator platform lies on the bottom of theshaft, Navy divers correctly noted in 1946 thatthe platform “was dished diagonally from theforward port to after starboard corner.”7’ Theelevator shaft opens aft into the hangar deck.Just inside the deck, near the after starboardcorner, lies a rack of what the Bureau ofOrdnance’s records show are five 500-lb.general purpose aerial bombs, model AN Mk64, Mod 1, equipped with AN Mk 243 nosefuzes and AN Mk 230 tail fuzes--the primaryarmament of the SBF-4E Helldiver aircraft inthe hangar. These weapons remain in theirtest location at frame 82 on the starboard sideof the hangar deck. Inside the deck, at theafter port corner of the elevator, are four350-lb. aerial depth bombs, model AN Mk 64,Mod 1, “plaster loaded and fuzed”72 equippedwith AN Mk 219-3 nose fuzes and AN Mk230-6 hydrostatic tail fuzes. Navy EOD diversworking with the NPS team confirmed theseidentifications. One of these fuzes was armedand was defuzed by a Navy EOD technicianwho “safed” it with epoxy. These bombs are intheir original test location at frames 80-81 onthe port side of the hangar deck.73

Inside the hangar deck, moving aft, are twoloose fueling drums and loose bomb andtorpedo racks once secured to the bulkheadsand overhead. Pipes for fire sprinklers hangfrom the overhead, some loose. ElectricIightbulbs are intact and line the overhead,which is covered with a thin film of fuel oilreleased from the ship’s bunkers. Three U.S.Navy dive-bombers, Curtiss SBF-4E “Helldiver”single engine aircraft, were observed during thedive, stowed with their wings folded. It wasfound that the forward airplane’s engine,cowling, and propeller have detached from thetiane and lie on the deck. This aircraft, which~hould be BuAer serial number “31894according to the Bureau of Aeronationwas according to the report, stowedhangar deck at frame 90, starboard,

Report,on thefor the

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Baker test. The plane, armed with twin 20mmf~ed M-2 cannon, with twin .30 caliber freeguns aft, was noted as being “intact andoperable, wings folded” and combat-readyexcept for “bombs, ammunition, fuel, safetyequipment, pyrotechnics.” The bolts wereremoved from the guns, which were loadedwith ten rounds. The clock was removed fromthe instrument panel for the tests. Aft ofplane 31894, a second SBF-4E, BuAer serialnumber 31850, was observed, noted in theBureau Report as stowed on the hangar deck,frame 100, starboard, in the same conditionand configuration as 31894.74 Aft of plane31850, a third, partially crushed SBF-4E, BuAerserial number 31840 was found. The BureauReport noted this plane as stowed on thehangar deck, frame 110, starboard in the samecondition and configuration as planes 31894and 31850.

All three aircraft were aboard Saratoga for theAble test; 31894 was on the hangar deck, frame110, port side; 31850 was on the hangar deck,frame 100, starboard; and 31840 was on thehangar deck, frame 110, starboard. All threeaircraft, as well as SBF-4E, BuAer serialnumber 31889 (also on the hangar deck, frame100, port) were undamaged. Plane 31889 wasremoved from Saratoga and placed aboard USS

I .$.,“it: !.. %

A 500-lb. bomb on USS Yorktown. (AT’S, .TamesP. Delgado)

Independence, and 31894 was shifted tostarboard forward of 31850 and 31840, whichremained in their Able test locations, for theBaker test. All aircraft were noted as“missing--Sank with Saratoga,” after the test. Afourth aircraft, a TBM-3E “Avenger”torpedo-bomber, BuAer serial number 69095,noted as stowed on the hangar deck, frame120, starboard, was the only other aircraftaboard Saratoga and in the hangar. Thisaircraft, also “missing--sank with Saratoga,” ispresumably the airplane spotted by divers inthe hangar area at the deck collapse, aft ofplane 31840.75

Five general puqoose 500-lb. bombs, AN-Mk 64, on their bomb carts, on the starboard side of Sarato~a’shangar deck at frame 82. Lying forward of the bombs is a single 350-lb. depth bomb, AN-Mk 64,ori@ally stowed with four others on the port side, which rolled free and lodged against the 500-lb. bombs.(National Geographic Society, Bill Curtsinger)

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Two views of the Helldiver, lMngs folded, an SB2C-4 is readied at the factory. In flight over the Pacific,a carrier task force below, an SB-26-4 shows the trim and features of the aircraft. ‘(U.S. Naval Institute)

The Helldiver was a wartime-production modeldesigned to replace the prewar Douglass SBDDauntless dive-bomber, The Helldiver had acombat range of 1,165 miles and was capableof 295 mph at 16,700 feet. The service ceilingwas 29,100 feet. The SB2C-4/5 (same as theSBF-4E) Helldiver’s wing span was 49 feet, 9inches; the plane’s length was 36 feet, 8 inchesand its height was 13 feet, 2 inches. Theempty weight of the Helldiver was 10,547 lbs.;the loaded weight was 16,616 Ibs. The planewas powered by a Wright R-2600-20, 1,900-hpradial engine and was armed with two fixedforward firing 20mrn cannon in the wings andtwo 0.30-inch machine guns in the rear cockpit.The plane carried up to 2,000 lbs. of bombs(1,000 internal/1,000 external) or eight 5-inchrockets. The Helldivers were used in mountingthe air offensive against Japan; capable, theywere difficult to handle, and earned thenickname “beast.” One hundred SBF-4E(BuAer serial numbers 31836 to 31935), aFairchild-Canada version of the Curtiss SB2C“Helldiver,” were built in 1944-1945.7e

Aft the aircraft the hangar is open; tostarboard lie a number of Mk 13 torpedoes,some missing their warheads. Dating to the1930s, the Mk 13 torpedo was the only aerialtorpedo in use during World War H; it was notreplaced until the 1950s. The Mk 13 was 161inches long, 22.5 inches in diameter, andweighed 2,216 lbs. Propelled by a steamturbine, it developed 33.5 knots with a range of6,300 yards. The control system was air/gyro.

The Mk 13 was replaced after 1950 by the Mk14, an 84-inch long, 680-lb. weapon.77 Thetorpedoes, like the bombs, were placed on theship by the Bureau of Aeronautics for testing,the depth charges and torpedoes were preparedby BuAer in two ways; (1) in normal conditionbut without the booster and detonator but withthe main charge, or; (2) with booster anddetonator installed but with the main chargereplaced by inert material. “Thus a sensitiveexplosive would not necessarily detonate a lesssensitive charge. ”78 Bureau of Ordnancephotographs of the ordnance placed onSaratoga’s hangar deck shows the inert materiallabelled “plaster.” The torpedoes specifically

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I ) 4An Mk 13 torpedo suspended beneath a TBM-3Eon USS Yorktown. (NPS, James P. Delgado)

are noted as having inert warheads, “but theflask is fully charged.” Weapons noted in theBuOrd photographic documentation, but not yetobserved during dives, include a rack of 5-inchHigh Velocity Aerial Rockets with Mk 6-1heads and 149 nose fuzes and 164 base fuzesat frame 160, hangar deck, starboard; 11.75“Tiny Tim” rocket, 2-100-1 Base Fuzes, marked“Inert” in photographs, at frame 162, hangardeck, port; and a mine, Mark 24 (secret), atframe 163, hangar deck, port.7E Aft thetorpedoes is a catwalk that has partiallycollapsed.

Aft of the planes, the hangar deck is emptyexcept for ordnance mentioned above. At thebulkhead that ends the hangar, there is a largepile of piping and debris that could be remainsof bunks from “Magic Carpet.” NPS diverspenetrated to this point and then into onecompartment beyond, The compartment, listedas the aviation metal shop, was mostly empty.Expected lathes and other machinery wereapparently removed. Vessel plans indicatefurther compartments aft, These compartmentswere not entered and their condition andcontents are unknown.

The intakes for the boilers in the funnel areaare clogged with debris, prohibiting visualaccess to the engineering spaces. Numerousopen hatches on the starboard side werevisually inspected; in all cases they opened intocompanionways that quickly terminated withgun hatches leading below or into the ship.These were not entered. The hatch of the

the overhead inside Saratoga’s hangar deck. medark splotches on the overhead are patches of oil.(NPS, Lany Murphy)

handling room below the No. 3, 5-inch/38caliber gunhouse stands open; limited visualinspection from outside indicated that thehoisting machinery is in place, as well as anumber of cartridges in their aluminumcontainers.

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..

123

USS PILOTFISH

The five-man team did one dive on the wreckof USS Pilotfish in 1989. A narrated video,site map, and still photographs were obtained,


Known Piiotfish alterations include theinstallation of weights and wire rope moorings,as well as salvage fitting connections, thatallowed the unmanned submarine to submergeand surface for the tests. The two periscop~swere removed and the shears scope tubes wereblanked out,

of 170 feet, with a 30- to 40-degree starboardlist, apparently completely flooded and covered“to about three-quarters height with silt andcoral,” Aft, by the torpedo room, the platingwas dished inward about six inches between theframes (Pikxfish’s stern faced the blast). Navyreports indicated the tank tops andsuperstructure plating were dished in severalplaces and the superstructure plating “hasnumerous tears and holes ,,.superstructure hasshifted to starboard about six inches amidshipsand one inch at the stern, This shift makessalvage connections inaccessible unless part ofthe deck is cut away.”83

Site DescriptionAble Post-Blast Observations

Like the other submarines, Pilot’fish was on thesurface during the Able Test, The bombdetonated 2,506 yards off the vessel’s starboardside, scorching and charring superstructurepaint. The sub’s ability to submerge andconduct normal combat operations wasdetermined unimpaired: “There is no reductionin fighting efficiency from a materialstandpoint. Exposed personnel topside wouldhave been at least temporarily out of action”8°


Pi/otfish was submerged for the Baker test,The eight boats were moored at various depthsthroughout the lagoon target array. Pilotfishwas submerged at a keel depth of 56 feet in 28fathoms (168 feet) of water at a range of 363yards from the blast,81 Pilotfish was the onlysubmarine moored adjacent to USS Arkansasand of three submarines sunk, was closest tothe blast. Post-test diver evaluations in 1946reported Pilotfish on the bottom

with a starboard list.,,. The deck iscovered with silt to a depth of 3-18inches, A few pieces of loose coral areresting on the deck,..it is considered likelythat all compartments are flooded andthat the tips of the ballast tanks are nolonger tight. It is believed that acomparatively lengthy operation would berequired to salvage this ship.82

Navy divers’ post-Baker test reports of 1946noted the vessel was on the bottom at a depth

The 1989 dive survey found that USS Pilotfishlies in 175 feet of water. The deck is reachedat about 150 feet, and the top of the conningtower shears lie at 130 feet. The submarine isreadily identifiable as USS Pilotfish andconforms to late war and Bikini test

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photographs. The boat is upright, listing about15 degrees to starboard. The pressure hull isintact, but the aft portions are dished as muchas six inches between frames; this confirms1946 Navy diver reports and is indicative of theboat’s stern facing the blast. The pressuregives the impression of having been“shrink-wrapped” around the circular frames.

The diving planes are present and stowed,folded up against the hull. The bow torpedoshutters and stern tube shutters are closed.The anchors were not observed and probablyremoved prior to the test; Piloffish was mooredby means of weights and cables to enable theboat to submerge without a crew aboard.

The superstructure is intact, but dented in allareas except the sail front. Here thesuperstructure is broken, deck beams havecollapsed, and debris litters the pressure hulland the lagoon bottom on the starboard side.This damage may be the result of aborted Navysalvage attempts because salvage fitting accessrequired cutting away the shiftedsuperstructure. The teak decking of thesuperstructure is largely missing, apparentlyconsumed by marine organisms. Only stubs ofthe decking around fastenings have survived.

Numerous fittings were noted on the deck.The superstructure and deck are missing in thearea of the forward torpedo loading hatch,which is closed. There is no trace of thehatch deck skid. The forward escape andrescue hatch are closed, as is the aperture forthe marker buoy. The forward tank valvescover is open, probably from 1946 salvageattempts. The aft escape hatch, leading intothe after battery, is open. This hatch wasclosed for the tests; 1946 photographs of thesunken submarine also show it closed, Thehatch was either opened by Navy diversattempting to salvage the boat or was openedafter the Navy salvage effort. The portablecapstan, usually stowed when underway, ismounted on the deck near the bow.

No antennas were noted on the deck, but atopside JP sonar hydrophore is mounted onth; deck to starboard-torpedo loading hatch.

just forward of theThe hydrophore is

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missing its black rubber cover. Powered by thesubmarine’s batteries, the JP hydrophore wasa passive listening sonar often called“iron-board sonar” because it is an oblongmetal tube atop a shaft mount.

Pilot fish’s original armament was a single5-inch/25 caliber gun and a single 40mm gun.The 5-inch gun mount is located aft on thedeck. Another gun mount is forward. The aft5-inch deck gun, mounted near the war’s end,was apparently removed for Crossroads. Asingle 40mm gun is mounted on the forwardfairwater; the barrel is slightly elevated andcants to starboard. This is a typical mountingfor a late war boat engaged in lifeguard dutyoff the Japanese home islands. Navy manualsfor the time indicate the 40mm, while“principally an anti-aircraft weapon, may beused against surface craft. It is a rapid fire,recoil-type weapon.”84 Aft, on the after“cigarette” deck of the sail, a twin 20mmOrelikon gun is mounted. This gun is elevatedand points aft and slightly to port.

The sail is intact and slightly dented. Thenavigating bridge on the sail forward the shearsis open; the mount for a target bearingtransmitter (TBT) is located at the bridgestarboard side, but the instrument is missing,probably reflecting selective stripping of specifictypes of reusable equipment for Crossroads.The shears are intact, but the two periscopeshave been removed. Forward the No. 2periscope shear is an SJ (surface-search) radarantenna of a late-war model. This radar gavethe boat range and bearing of a target. Aftthe No. 2 shear is the antenna mount for anSS (air-search) radar. The antenna, a largerversion of the SJ, is missing.

The interior of the submarine was not entered.The only open hatch is the after escape trunk.It is believed that the boat is flooded, basedon Navy reports from the 1946 dives.

USS APOGON


Apogon’s periscopes were removed, as were itsanchors, for the tests. The vessel retained itstwo single 40mm guns on the sail.


Apogon, like all the other submarines, wassurfaced during the Able test. The bombdetonated 975 yards off the boat’s port side,“moderately” scorching and charring paint onthat side. The boat was left partially open;pressure distorted three internal bulkheads, butApogon was operational!5


The boat was then submerged for the Bakertest; “the submarines proved to be useful‘instruments’ for subjection to the enormouspressures created by the atomic bombs, sincetheir hulls are expressly designed to withstandhigh pressures,,..”ae The submarines weremoored at different depths throughout thelagoon. Apogon was submerged at a keeldepth of 100 feet at a range of 850 yards fromthe bomb. The boat was one of threesubmarines that sank as a result of the blast,“Air bubbles and fuel oil escaped from theApogon as she went down.”a’

The 1946 Navy divers located the submarine in180 feet of water, entered the boat, and begansalvage operations, which included blowing airinto the flooded hulk. The salvage efforts wereabandoned, however, before the boat wasbrought to the surface,

A Navy report states, “All compartments wereflooded or partially flooded with the exceptionof the conning tower.”88 The boat was floodedthrough a 30- by 15-inch hole in the hullforward and through a rupture either in thetrunk or hatch cover for the after torpedoroom. Additionally, a tank top cover on aballast tank was reportedly ruptured, Thewater pressure from the blast was recorded at1,200 Ibs. per square inch.ag The Navy,probably while attempting to salvage the vessel,found that the interior bulkheads were nolonger air or watertight, This was presumablythe deciding factor in the abandonment ofsalvage operations on Apogon.

Site Description

slightly listed to port. The submarine is inbetter condition than Pilotfish. None of thedishing between frames that deforms Pilo~ish’spressure hull aft is discernible on Apogon,Damage seems confined to the superstructure,which is lightly dished and broken, forward ofthe sail, as well as aft on the port side, Amajor section of the superstructure is missingin the area of the forward torpedo loadinghatch, This appears to have been cut away,There are jagged edges of metal visible,indicating a post-Baker intrusion, perhaps froma 1946 salvage attempt or the 1947 resurvey.The hole in the pressure hull in the area ofthe forward torpedo compartment at the bowreported in 1946 was not observed in the ROVvideo dive tape, and is presumed to restbeneath the superstructure debris in this area,

The wooden decking of the superstructure ismissing, like that of Pilotjish. No hatches orother apertures in the hull were observed open.The sail is intact, and the shears mount an SJradar, as does Pilotfish. It also mounts an SVradar, The cigarette, fore and aft, mounts asingle 40mm gun at each end of the sail,Unlike Pilotfi$h, Apogon retains its targetbearing transmitter on the sail, The vesselappears, with the exception of minor foulingand the observed damage, much as it does inCrossroads photographs of its testsubmergence,

The investigation,The submarine’s screws were observed, partially

consisting only of ROVsurveys, found that the intact hulk of USS

buried in the silt. The dive planes are stowed

Apogon lies on a more or less even keel,against the hull, and the torpedo door shutters

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Auogon’s stern has the wire cables that moored thesubme~ed ta~et and rubber air hose connected tosalvage fifi”ngs. (U.S. Navy, ROV)

are closed. Wire cable, part of the system tomoor the submarine and submerge it without acrew on board, remains attached to thefairleads on the hull aft. No sign of the 10-ton anchor to which the stern was moored wasobserved. A rubber air hose is attached to thesalvage connection to the aft torpedo room,left, most probably, from the 1946 salvageattempt.

YO-160


There were no known alterations to YO-160.Blast gauge towers may have been fitted.


YO-160 was heavily damaged by the Able testdetonation. One 1946 Navy report notes, “Thewooden bridge house and all equipment insideburned. Concrete deckhouses had theirbulkheads and overheads blown in. Thewooden catwalk was demolished.”g” Majordamage was done by radiant heat from thebomb, which started fires that raged throughoutthe vessel, burning

practically all inflammable material andequipment aft on the main deck andallove. The areas burned included thevessel’s living and berthing spaces, steeringengine room, engine room, wooden bridge,and part of the catwalk. It is estimatedthat approximately 90 percent of the

electrical equipment in these areas wasdestroyed ....e’

Other damage included spalling of concretesuperstructure which exposed steelreinforcement and partly collapsed decks andoverheads, sending large chunks of concreteinto the spaces below, smashing equipment.The Navy concluded that the “air blast fromabove and aft is considered to be the primarycause of damage ....”g2


Though seaworthy, YO-160 was useless. Itsability to serve was seriously impaired by thedestruction of pumping equipment, electricalsystems, and engines. YO-160 was swampedand sunk by the Baker blast, which lifted thebow before deluging the vessel.g3

Site Description

In 1989, a NPS dive was made on the midshipsdeck area and no observations of bow, stern,or hull area were made. The vessel was foundupright on an even keel with the deck at 140feet below the surface. Intact pipes ran foreand aft along the deck. A hose, about a footin diameter, likely a fuel hose, ran across thedeck. The deck was littered with pipes,broken equipment and steel plates, which werelikely from deckhouse structures. The concretedeck was broken and separated in some areas.

The main feature in the midships deck areawas the standing portion of a large deckhouse,which was missing its roof. Bulkheads, somewith hatches remained. One deckhousedoorway had the door still attached andhanging by the middle hinge. In the deckwere two manway hatches with both covers off.The deckhouse floor seemed clear and sound.Vertical pipes about six inches in diameterwere observed in the floor of the deckhouse,which may have been sounding pipes for themidships tanks.

Other prominent deck features were theremaining stubs of a centerline catwalk support.The vessel was of a well-deck design andcatwalks led to the raised decks fore and aft.There were three pairs of large globe valves--one pair on the centerline and the other two

127

pairs halfway to the gunwale on each side. Noventilators, which would be expected on a fuelship were observed--likely blown off the deckby the blast.

HIJMS NAGATO


The main mast and stack were removed bvJapanese prior to U.S. capture to confoun~identification. At Crossroads, Nagato showedsigns of recent combat. The superstructurewas holed and blasted, The antiaircraftbatteries were put out of commission, the deckwas splintered, but not penetrated, and therewere hull dents near the bilges. Testinstruments were installed belowdecks and a“Christmas Tree” blast gauge tower wasinstalled atop the “C” turret,

Nagato’s sinking was unobserved. I-Me isknown about the specific pretest preparations.Most likely there were two “Christmas trees”;reportedly all ships were so fitted. Apparentlyno Army Ground Group material was placedaboard for either test,


Nagato was moored 400 yards to the starboardof USS Nevada, target ship and ground zerofor the Able test and was moderately damagedby the blast. Light superstructure plating waswrinkled, non-watertight doors were blown offtheir hinges, and paint was scorched during

Able’s detonation. A ship’s report after theblast concluded “Nagato is structurally sound,.,,The poor condition of the ship and herequipment is due to lack of preventivemaintenance and overhaul, and to the fact thather engineering plant sat idle for over ayear,”g4 This is counter to later reports afterthe Baker test that reported holes in the hullshell plating,


The Baker test displaced the battleshipsideways some 400 yards .95 Nagato wasobserved with a 5-degree list 4-1/2 hours afterthe blast. The list increased continually overthe next four days. At one point the ship wasobserved to have increased its listing to anangle of 120 degrees, with the starboard sidedown. Nagato apparently was never reboardedafter the test, despite the slow progressiveflooding. The Director of Ship Material forOperation Crossroads advised the Task ForceCommander on July 29 that “radiologicalhazards prevented salvage operations onNagato,..and that he intended to concentratedecontamination efforts,..on other damagedships which would in time require salvagemeasures.”ge

On the evening of July 29, Nagato sankunobserved. According to the final report, thesinking was caused by

capsizing as a result of progressiveflooding. The watertight integrity of theNagato was found by test to be poorprior to the test... holes discovered bydivers after B test plus known leakagesources were the causes of flooding. Theabsence of internal watertight integritypermitted progressive flooding, Theprobable area of main flooding wasaround frame 190 starboard,*7

Post-Baker test diver inspection reports noteda number of underwater dents:

these include dents between frames, aswell as those where both longitudinal andtransverse framing had given way. Ahole about two feet in diameter aboutseven feet above the port bilge keel atframe 140 where plating had ruptured

128

out, was emitting streams of air bubbles are pointing to the bow and secured at theand fuel oil 29 days after the burst, muzzle, The tampions are in the muzzles ofThere were seven other major leakage the A turret, wtilch is secure and in its properpoints, but it was not determined whether position, The tops of the turrets rest on thethey were caused by loose rivets or holes bottom, obscuring any trace of the Christmasin the shell.ga tree blast gauge tower atop turret “C.”

Site Description

Nugato received the second greatest amount ofattention from the NPS dive team; the greatestwas given to Saratoga, The ship is layinginverted in 165-170 feet of water. The ship’sfour turrets, lettered A, B, C, and D bow tostern, are intact and in their normal position,though inverted, The turrets have notseparated from the barbette, as in Prinz Eugen,Post-blast diver reports had indicated that theA turret had separated. This mistake might bethe result of low visibility resulting fromsuspended sediment.

The 16-inch gun barrels of both stern turretsare pointing directly aft; the forward turrets

There is a major break aft the rudders andscrews. The vessel stern rests on the bottomat a steep angle; the hull bottom is tilted tostarboard. The hull shell plating is ripped andseparated athwartship, Through the torn platesfloor frames can be seen, These frames aretwisted and splayed about, reflecting the forcesthat tore the hull plates,

Apparently Nagato capsized and sank by thestern, with the transom hitting the sea bottomfirst. The hull folded across the deck aft, thescrews tearing the shell plates as the bowcontinued to sink, Distortion and tearing oftransom hull plates indicates the vessel mayhave been moving toward the stern through the

I

130I

I

I

I

..’/

II

perspective sketches of Na~ato. (NpS, Jew Livingston)

water column as it sank, The port side istilted upward from 180 degrees,

Nagato bow observations confirm the suggestedsinking sequence. Both anchor chains areextended beyond the limits of visibility straightout their hawses. A large mooring weight isdirectly below the bow, The bridge is pushedstraight off to starboard, indicating the shiprolled to starboard as it sank, The ship settledand pushed the bridge superstructure tostarboard rather than crushing it directlybeneath the ship, as was the case withArkansas and to some extent with Prinz Eugen.

The forward turrets are intact and pointingtoward the bow. The range finders are visible.There is a center line capstan forward of theA turret. There is a hatch in the deck belowthe barrels of this turret. A brief search ofthe bow above the waterline was conducted,The chrysanthemum crest was not located. Thebridge is open and accessible, The starboardgun director is located on the bridge. Thereis an approximately 10-foot-square hole belowand slightly aft of the port hawsepipe.

LCT-1175

During the 1989 survey, the outline of abarge-like hull and protruding structure locatedbetween the high and low tide mark in BikiniLagoon along withbeach were observeddump. This wreckJames Delgado, whoBy examining aerial

mooring cables on thenear the present garbagewas briefly snorkeled byidentified it as an LCT.photographs of beached

target vessels, and then plotting their positionand orientation, the wreck was identified asLcT-1175, which was scuttled after the Bakertest.99 Further work is needed to locate other,perhaps less visible, beached craft nearby, suchas LCTS 1187 and 1237, which are noted aslost in the vicinity.


This vessel was noted in the Bureau of Shipsreport on beached landing craft, test Baker, as“the non-target, derelict” LCT-1175, It is notknown why this vessel was considered “derelict.”The LCT’S 20mm gun armament was removed,as is shown in pretest photographs of thevessel. too There was no other pre-testdocumentation located,


Before the Baker test, the vessel was mooredclose to the beach, cabled to the stern of thebeached LcM-4, outside the target array onthe lagoon shore. Wave action caused byBaker displaced several moored landing craft,including LCT-1175, which was pounded oncoral ledges and sank, decks awash. Eightdays after Baker, the LCT was located andexamined, with later documentation by BuShipspersonnel.

The vessel reportedly pounded on coral ledgesin the surf line and may have been swamped,It sank on the sloping beach, starboard sideinshore, with the bow angled toward the beach,pointing west-northwest. The bow ramp wasreported missing. The BuShips observersthought the ramp had been torn off by theblast-induced waves, or by pounding on thecoral,

Site Observations

The 1989 survey found that the LCT lies in aposition that approximates its location andposition shown in August 1946 photographs ofthe beached landing craft. The port side facesoffshore, and is buried to within a foot of thegunwale with the exception of scoured areasnear the bow and port side. The bow is freeof the sand, while the stern is partially buried

132

Larry Nordby maps the afl deck of LCT-1175. (NPS, Larry Mwphy)

to midships. The decks are free of sand, andare variously covered by a foot or more ofwater. The deck plates are uniformly corrodedand covered by biofouling, and do not exhibitdifferential states of corrosion that wet-drycycling would produce. The level of corrosionand fouling is not hea~ weld seams are visibleon the deck plates, as are rivets, bolt heads,and the round seams of deck scuttles inside thedeckhouse areas.

The deck is holed in several locations, mostnotably near the bow, where an approximately10-foot-wide section of the athwartshlp deck ismissing. The longitudinal bulkheads in thisarea are also missing, with worn stubs in thesand indicating their position. This matches upwith the scoured area along the port hull anda hole worn into the portside. The hull platingis missing on the starboard side in this area,indicating current, surf, or other action that hasworn, a channel through the wreck.

The bow is intact and slopes down to theramp, which is either missing, or, if a line of

plating in the sand in front of the bow is anindicator, is down and buried in the sand.

The engine hatches lie atop the engines intheir respective compartments. Thecompartments are divided into two areas, oneforward holding pipes, valves, and electricaljunction boxes. The pipes and valves may befor fuel or are part of a system to pump saltwater ballast into the forward compartments.Three hatches each lead to a marine dieselengine. All three engines were observed to bein place. The midships and starboard screwsand rudders were observed aft of each enginebeneath the transom. The port screw andrudder, not observed because of deeper sand inthis area, are also presumed present.

The deckhouses are missing, although outlinesof the port and starboard houses aft aremarked by remnant bulkheads on the decks.Miscellaneous fittings are present inside thedeckhouse perimeters, including one apparentelectrical through-deck fitting. Hatches at theport and starboard beam on a line with the

133

engine hatches lead to generator compartments.The area around the starboard hatch coamingis holed; a hole in the hull on the starboardside also penetrates this space. Bitts and otherdeck fittings, including centerline tie-downswere noted. The rudder quadrants are ondeck connected by a tie-rod. A taperedthree-pole cage anchor mount is portside aft,A small winch mounted on the portside deckforward was also noted, A cleat on thestarboard declc, aft quarter, has a wire linepassed through it that runs down the hull andaft, past the transom and disappears into thesand--presumably a mooring line.

Some penetration of the LCT wasaccomplished. Piping and wiring, as well asJunction boxes and valves, were observed in theengine compartments. A series of athwartshipdoors connect these spaces with the generatorrooms at either end. The damage to theforward area of the ship provided access toforward compartments that were flooded forballast, These spaces were divided bylongitudinal and athwartship bulkheads, with

Anchor mount at the stern and port quarter ofLCT-117.5. (iVPS, Larry Muqohy)

open doors linking the various compartments,These compartments were separated by solidathwartship bulkheads every ten feet,

Numerous fittings and wreckage lie on theinshore side of the wreck off the starboardside. These include a large winch, pieces ofsuperstructure, a reel of wire rope, piping, apedestal mount for a 20mm gun, and two pairsof bitts attached to decking, Wreckage isclustered along the starboard hull anddiminishes as the bottom slopes up to meet thecoral ledge near the surf line. The scantremains of LCM-4, to which the LCT wasmoored, lie in the surf nearly a hundred feetforward of the LCT. The outline of the hull,the engines, and some loose plating are all thatis left of the LCM.

SITE DESCRIPTIONS: VESSELS LOSTAFTER THE TEST

USS PRINZ EUGEN

Prinz Eugen was dived twice by the team. TheGerman cruiser survived both Bikini test blasts.The ship was towed to Kwajalein Atoli and waslost during a storm that drove it ashore whereit capsized and sank,

Site Description

The vessel was dived by the SCRU teamduring a layover at Kwajalein Atoll. TheKwajalein Dive Club provided boat air tanksand other support, During the two dives onthis target ship, no damage clearly attributableto the atomic blasts was observed.

The sunken hulk of Prinz Eugen inverted at a40 degree angle toward the bow, stern towardshore, was on a steeply-dipping bank, in 26 to110 feet of water, 200 yards off the north endof Carlson (Enubuj) Island in Kwajalein AtollLagoon. The vessel lies on an approximateN-S axis and cants about 30 degrees tostarboard, resting on its starboard gunwale andsuperstructure. The rudder, port shaft, andcenter screw are above the water. Thestarboard screw is attached to the shaft; theport screw was cut off in 1978 and presentedto the Government of West Germany, shellplating has failed on the hull bottom in the

134

stern area between frames and Iongitudinals,and may be the result of wet-dry cyclingbetween tides.

Dropping to the bottom aft, the cruiser sternof Pn”nz Eugen is intact; the rubrail curvesaround the fantail. Another prominent featureis the degaussing cable that rings the ship’shull just below the waterline. No letteringindicating the ship’s name was noted. The

vessel’s fine lines are apparent; Pn’nz Eugenably represents the salient characteristics of acruiser, with a length-beam ratio of 9 or 10.5to 1, indicating a combination of speed andcruising range with limited armor protection.

The two aft turrets (“C” and “D”) lie partiallyunseated with gun barrels pointed sternward asthey would be if the ship was underway.Nearby is a twin-gun house, probably for a4.1-inch antiaircraft gun. A stern capstan isseated to the deck aft, and nearby a hatch liesopen with another open hatch visible leading tothe next lower deck level. Along the port sideof the wreck, portholes, many of them withdeadlights in place, line the freeboard.Considerable damage to the hull side amidshipswas noted, apparently the result of capsizingand rolling over onto the reef.

The center island superstructure is intact; toport the 21-inch torpedo tube loadlng rails arevisibIe. Areas above the upper deck, including

the stack, fire control radar towers, bridge, andmast are crushed; the top of the mast lies bentto port, as does one of the fire control directortowers. The unique “mushroom” head directortop lies detached and off the port side.Forward the superstructure lies the “B” turret,which has also dislodged. The “A” turretremains seatecl. This turret is missing its gun

tubes, which were removed in 1946 prior to theCrossroads tests.

In the port midships area near the torpedotubes there is a cabin containing rack-mountedtorpedoes. Some of these torpedoes aremissing their bronze propellers, likely removed

James Delgado)

135

by visiting divers. It is likely that thetorpedoes are live,

A detailed inspection of the forward areas wasnot made, nor was the wreck penetrated. Thestarboard side of the hull was not observedforward of the struts. The hull bottom wasinspected from stem to stern. The hull isflat-bottomed, with two V-shaped bilge keels,The port bilge keel is broken in several areasaft; a piece of it was found lying detachedagainst the starboard bilge keel. Severe hulldamage is noticeable along the port sideamidships; a large hole has opened and platesand decking have fallen away.

Hull bottom features observed included theintakes for the boilers and several otherthrough-hull fittings. Forward on the bottom isa small housing, probably for sonar. A circularrose was observed on the port side; the hull isbroken near the rose, exposing the pipes thatconnect it to the engineering spaces.

The hull bottom is not fouled; weld seams werereadily evident throughout. Damage to thebottom is confined to the after areas, whererust holes have eaten through the shell plating,exposing the frames and intercoastals. In theport stern area the shafting, thrust bearings,and the shafts are exposed. The centerpropeller, which protrudes above the water,bears the marks of repeated attempts to hackpieces of it away the edges of the blades arenicked and cut,

We were surprised to find that the vesselcarried three screws. Jane’s (1945) wasconsulted during research prior to the firstfield session. This normally reliable resourceindicated Pn”nzEugen carried four screws.

FINAL OBSERVATIONS

All of the major vessels lost during orimmediately after the Able and Baker tests at

136

Bikini were dived with the exception ofSakawa, Anderson, Lamson, and ARDC-13, Ofthese four vessels, only ARDC-13’S wreck hasbeen located. Marked with a buoy placed byNavy and Holmes and Narver personnel whoreport that the wreck lies upside down on thebottom, with one wing wall cracked at itsjunction with the hull bottom and tilted over torest against the lagoon bottom. Of the varioussmall craft, the largest of which were the LCTSthat were lost and then scuttled inside thelagoon, most on the beach of Bikini, only onewas dived, although the visible remains ofanother LCT rises above the water surface nearthe garbage dump area. The remains of anLCM on the beach of Bikini, heading towardEnyn, was also investigated and was determinedto be of more modern origin. Discussions withHolmes and Narver personnel indicate it waslost around the time of the abortedresettlement of Bikini.

The failure to locate Sakawa may be explainedby the fact that after the Able blast, Sakawaprobably sank very close to the location atwhich Baker detonated and lays within a fewhundred yards of the suspended Baker testbomb, submerged 90 feet off the lagoonbottom. While it is unlikely that the bomb’sdetonation would have completely destroyed thevessel, it is possible that it was crushed,possibly broken, and perhaps even partiallyburied by the 500,000 tons of excavatedmaterial from the bomb crater that fell backinto the lagoon in the area in which it shouldlie. We postulate, based on the comparison ofthe arrays for each test, that remains ofSakawa should lie between Arkansas andSaratoga.

Although dived in 1946, but not located in1988, 1989, or 1990, the wrecks of Andersonand Lanzson presumably lie in their originalsinking locations in the prohibited zonequadrangle shown on the Bikini Atollnavigation charts. The failure to locate thewrecks may be due to incorrect positionsprovided by Holmes and Narver during the1988 survey and the high rate of occurrence oftall coral heads encountered during the surveyin 1988 which made detection by sonardifficult. Additional systematic survey efforts inthis section of the quadrant should disclosethese two wrecks.

The graduated levels of damage sought by theplanners of Operation Crossroads in theirplacement of ships of the same type at stagedlocations is demonstrated by the different sitedescriptions of Apogon, Pilot fish, Gilliam,Carlisle, Arkansas, and Nagato. The ships moredistant from each zeropoint showed lesserdamage than those closer, as would beexpected. At the same time, the ships showeddifferent damage. An example is the variationin pressure hull failure in the two submarines.Apogon suffered a ruptured hatch and thus aless catastrophic hull failure, While less dishedthan Pilotfish, however, the boat has a largehole blown through the hull forward. Thedesigned maximum operating depth of theseboats was 412 feet, the crush depth was 600feet, which would be equal to 300 psi.’”’Given the 1,200-4,000 psi peak overpressuresthat hit the two submarines, their hull failuresbecome understandable.

For many of the ships observed at Bikini, itappears that the worst damage resulted fromthe peak overpressures of the shock wave,particularly to Gilliam and Carlisle on thesurface, and the submarines while submerged.The same pressures also did considerabledamage to the underwater hulls of Nagato,Arkansas, and Saratoga. The major contributortoward the sinking of the vessels, however, wasthe overwashing of them by the blast-generatedwaves, particularly in the case of Saratoga, andthe collapse of the blast column, whichmaterially contributed to the sinking ofArkansas by hammering it more or less straightdown into the lagoon bottom. The effects ofthermal radiation, which were visible on theships after Able, is now no longer readilyobservable. Scorched paint and burnedmaterials have now disintegrated in the seawater or are masked by coral and fouling, evenon ships known to have burned fiercely, suchas Carlisle. Other evidence of thermalradiation, such as warped metal, isindistinguishable, if it exists, from pressure orwave damage. Beta and gamma radiation,measured at various levels in 1946 and 1947and noted as “high,” are no longer significantlyabove background (see the appendix authoredby Dr. W. Robison). While these twoparticular effects of the bomb are no longerapparent, the basic fact remains that they werecontributing factors in the sinking of Cariisle,

137

and the as-yet-undiscovered Anderson, andSakawu. More importantly, radionuclidecontamination and its resulting radiation was amajor contributing factor in the abandonmentof salvage efforts on some ships, and in thelimited nature of assessments made in 1946 inradioactive water and silt, The most visiblevictim of radiation is Prinz Eugen, now restingas the major monument to the Able and Baker“spared” target ships that like Pn”nzEugen weretaken to Kwajalein or other ports. Ultimatelymost of the other target ships were scuttledbecause of their radioactive hazard. PrinzEugen, lost by accident before the decision toscuttle other surviving target ships, is now themost accessible of these surplus ships ofCrossroads, It was not salvaged, even when arecent (1989) request for scrapping the shipwas considered by Naval Sea SystemsCommand, but rejected because of concerns ofcontaminating the world steel supply.

The outfitting of the ships at Bikini showssome variation in the historical accounts ofstripping of target ships. Items of potentialvalue for military purposes, such as someweapons and electronic equipment, were leftaboard many of the ships. As indicated by thelarge number of militarily valuable weapons andequipment left on the ships and now on thebottom, the value of military reuse of thestripped items balanced against the need to testthe effect of the atomic bomb reinforces inpart the concept of Crossroads as a potlatch,while also offering another insight into therelative wealth of the U.S. at this time, Asother evidence of this attitude, veterans ofWorld War H service have reported thedisposal of complete silverware sets and dishesthat were in excess of a ship’s allotment atwar’s end, rather than returning them to thequartermaster and filling out paperwork, AGerman veteran of Prinz Eugen’s crew hasnoted his amazement at American wastefulnesson his ship when it was in the U.S. after thewar: leftover and “extra” food, some of ituncooked sausages, were fed to the sea gulls,while a box of bolts, opened to get the fewbolts needed, was thrown overboard to avoidthe paperwork of returning it. This is just onehuman behavior that may be reflected by thematerial record of Operation Crossroads.

The sunken fleet of Operation Crossroads is, asthe significance chapter will discuss, a uniqueunderwater material record of the dawn of theatomic age. It also demonstrates that a forceas powerful as nuclear weapons is nonethelessmeasurable, quantifiable, and understandable.Much more work remains to fully quantify andunderstand the effects of the bombs on theships at Bikini, At the same time, analysis andconsideration must also be given tounderstanding the cultural forces thatassembled the fleet and sank it, and thebehaviors that influenced the artifactual recordon the bottom, as indicated in the outfittingdiscussion above, as well as the ramifications ofthese events in the world after mankind passedover the Crossroads,

NOTES

1

2

3

4

5

6

7

8

9

Samuel Glasstone, cd., Radiological Defense: ThePrinciples of Militaqv Defense Against Atomic Weapons(Washington, D.C.: Armed-Forces Special WeaponsProject, 1951), Vol. 2, p, 5.

Ibid,

Shurcliff, “Technical History,” p. 12.4.

Ibid,, p. 21,1.

Ibid,, p, 30.3,

Ibid,, p. 13.20,

Samuel Glasstone, cd., The Effects of Nuclear Weapons(Washington, D,C,: Government Printing Office, 1957),p. 29. Also see Shurcliff, “Technical Report,” p. 28.9.

Glasstone, Radiological Defense., p, 36.

Ibid,, p. 39,

10Shurcliff, “Technical History,” pp. 13.3-13,4,

11Ibid,, p. 13.6.

12Ibid,

13Ibid., p. 13,5.

138

14Ibid.

15Ibid., p. 13.6

16Ibid., p. 20.3.

17Glasstone, The Effects of Nuclear Weapons, p. 52,

18Ibid.

19Ibid., p. 45.

20Ibid., pp. 45-44 also see Shurcliff, “Technicalp. 28.3.

21Shurcliff, “Technical History,” p. 28.3

22Ibid., p. 28.7.

23Ibid., p. 26.3.

24Ibid., p. 26.4.

25Ibid.

26Ibid., pp. 28.5-28.6.

?-

Histoty,”

AI

Glasstone, The Effects of Nuclear Weapons, p. 46.

28Shurcliff, “Technical History,n p. 28.4.

29Ibid., p. 27.3.

30Ibid., pp. 27.4-27.7.

31Ibid., p. 27.7.

32Ibid., pp. 23.2-23.4 and 23.8.

33Ibid., p. 23.5.

34Ibid., p. 23.6.

35Ibid., pp. 23.6-23.7.

36Director of Ship Material, Joint Task Force One,Bureau of Ships Group, “Technical Inspection Report,USS Gilliam (APA-57), Test Able,” National ArchivesRecord Group 374, p. 5.

37Ibid.

38Ibid.

39Director of Ship Material, Joint Task Force One,Bureau of Ships Group, “Technical Inspection Report,USS Carlisle (APA-69), Test Able, OperationCrossroads,” National Archives Record Group 374, p.9.

40Ibid.

41Ibid.

42Shurcliff, Bombs at Bikini, p. 161.

43Ibid., p. 134.

44Director of Ship Material, Joint Task Force One,Bureau of Shim Groum “Technical Inspection Re~ort.USS Arkan.&s (BB~33), Test Bak~r, Opera~ionCrossroads,” National Archives Record Group 374, p.5.

45Ibid., p. 7.

46Ibid., pp. 6-8.

47Ibid., p. 5.

48Director of Ship Material, Joint Task Force One,“Bureau of Shim Group Technical Inspection Report,USS Saratoga (2V3), T~st Able, Operation Crossro~ds,”National Archives Record Group 374, p. 14. Hereaftercited as “Technical Inspection Report, Saratoga, TestAble”; the identical report, from Test Baker, will besimilarly cited.

49Glasstone, The Effects of Nuclear Weapons, p. 208.

50Director of Ship Material, “Technical Inspection Report,Saratoga, Test Baker,” pp. 6-7, passim.

51Ibid., p. 6.

52Ibid., p. 7.

53Ibid., p. 7.

54Director of Ship Material, Joint Task Force One, “FinalReport of Tests Able and Baker, Bureau ofAeronautics, w (October 11, 1946), copy on file atNational Technical Information Service, p. 204.

139

Hereafter cited as Director of Ship Material, BuAerfinal report.

55Ibid., p. 73.

56Director of Ship Material, BuAer final report, p. 74.

57Ibid., p. 73.

58Director of Ship Material, “Technical Inspection Report,Saratoga, Test Baker,” p. 8.

.59Ibid., p. 8.

60Director of Ship Material, 13uAer final report, p. 74.

61Col. J. D. Frederick, “Final Report of Army GroundGroup (Task Group 1.4), Operation Crossroads AtomicBomb Tests,” (1946), copy on file, National TechnicalInformation Service. Volume III, p. 117. Hereaftercited as Frederick, “Final Report of Army GroundGroup,”

62Ibid., p. 146.

63Frederick, “FinalReport of Army Ground Group,’’ Vol,I, pp. 5, 7.

64Ibid., pp. 5, 8.

65Shurcliff, Bombs at Bikini, p.

66Shurcliff, “Technical History,”

67Shurcliff, Bombs at Bikini, p.

68Shurcliff, “Technical History,”

69Shurcliff, Bombs at Bikini, p,

70

69,

vol. III, p, 9.s,

65.

p, 9,5.

69.

Ibid., Plate 12 caption, between pp. 70-71. Also see W,A. Shu rcliff, Opera tion Crossroads: The OfficialPictorial Record (New York Wm. H, Wise Co., 1947),p. 1s0.

photographs are contact prints of 4x5 negatives; pictureboards in each view indicate they were taken either onJune 17 or June 19, 1946. The BACR stands for“Before Able, Crossroads.” The bombs remained intheir original positions for Baker.

73Photographs, Bureau of Ordnance, BACR Series,National Archives.

74Director of Ship Material, BuAer final report, pp. 129,139, 141-143, 197, 205-207.

7.5Ibid.

76Gordon SwanboroughStates Navy AircraftInstitute Press, 1969),U.S. Military Aircraft1909, p. 222,

77

and Peter M. Bowers, UnitedSince 1921 (Annapolis: Navalpp. 150-153 also see Andrade,Designations and Serials Since

E. W. Jolie, A Brief History of U.S. Navy TorpedoDevelopment, (Newport, R. I.: Naval UnderwaterSystems Center, 1978), pp. 33-34, 43, 45, and 80. TheMk 13 torpedo was produced by Pontiac MotorsDivision, International Harvester Co., the NavalTorpedo Stations at Newport, Keyport, and Alexandria,and the American Can Co., of Forest Park, Illinois. Inall, 16,600 Mk 13 torpedoes were produced during thewar, undergoing refinement through the war’s end. TheMk 25 torpedo was developed to replace the Mk 13 butwas not produced. The most notable Mk 13 successwas the sinking of the Japanese battleship Yamato in1945.

78Shurcliff, “Technical History,” Vol. H, pp. 7.11-7,12.

79See footnote 73.

80Director of Ship Material, Joint Task Force One,Bureau of Ships Group, “Technical Inspection Report,USS Pi/otfish (SS-386), Test Baker, OperationCrossroads, National Archives Record Group 374, p, 7.

81Ibid., p. 6.

82Ibid,

83Ibid., p. 5,

8471 The Fleet Type Submarine, Nav Pers 16169

Director of Ship Material, “Technical Inspection Report, (Washington, D.C,: Standards and Circulation Division,Saratoga, Test Baker,” p. 7. Training, Bureau of Naval Personnel, June 1946) p, 16,

72The ordnance was carefully labelled in 13uOrdphotographs, Record Group 74, Records of the Bureau~f O~dnanc~, photograp~s Iabelled 74-BO-B4, USSSaratoga (CV-3), Still Pictures Branch, NationalArchives, Washington, D.C. Hereafter cited as74-BO-B4. Originally labelled BACR-63-1S63, these

85Director of Ship Material, Joint Task Force One,Bureau of Ships Group, “Technical Inspection Report,USS Apogon (SS-308), Test Able,” National ArchivesRecord Group 374, p. 7,

140

86Shurcliff, Operation Crossroads: The Official PictorialRecord, p. 106.

87Shurcliff, Bombs at Bikini, p. 166.

88Director of Ship Material, Joint Task Force One,Bureau of Ships Group, “Technical Inspection Report,USS Apogon (SS308), Test Baker,” p. 5, NationalArchives Record Group 374.

89Ibid., p. 6.

90Director of Ship Material, Joint Task Force One,Bureau of Ships Group, “Technical Inspection Report,USS YO-160, Test Able, Operation Crossroads,”National Archives Record Group 374, p. 3.

91Ibid., p. S.

92Ibid., p. 6.

93Director of Ship Material, Joint Task Force One,Bureau of Ships Group, “Technical Inspection Report,USS YO-160, Test Baker, Operation Crossroads,”National Archives Record Group 374, p. 5.

94Director of Ship Material, Joint Task Force One,Bureau of Ships Group, “Technical Inspection Report,Nagato (Ex-Jap BB), Test Able, Operation Crossroads,”National Archives Record Group 374, pp. 105-106.

95Ibid., p. 6.

96Ibid.

97Director of Ship Material, Joint Task Force One,Bureau of Ships Group, “Technical Inspection Report,Nagato, Test Baker,” p. 5.

98Ibid., p. 6.

99Director of Ship Material, Joint Task Force One,Bureau of Ships Group, “Technical Inspection Report,Beached Landing Craft, Test Baker, OperationCrossroads,” National Archives Record Group 374, pp.16, 18, 19,21.

100Ibid.

101Norman Polmar, Naval Historian, Alexandria, Virginia,Personal Communication, November6, 1990.

141

A-DA-

142

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CHAPTER FOUR: SITE DESCRIPTIONS

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