JL SSD-66-296 (571) ß CO 3 STUDES OF DVERS' PERFORMANCE DURNG THE SEALAB PROJECT Hugh M. Boweu Brger Andersen Davd Promsel March 1966 Contract No. Nonr 49^0 (00) Prepared for: Offce of Naval Research Washngton, D. C. ' CLEARNGHOUSE FOR FEDERAL SCENTFC AND TECHNCAL NFORMATON HardcopyT Mtorofshe J. Co ; APR /A w J
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ABSTRACT Feld studes of dvers' performance durng the SEALAB project were undertaken by three teams of 10 men each who lved underwater habtat stuated on the bottom at 205 feet. n and operated from an Performance under SEALAB condtons was compared to performance on dry land and to perform- ance n shallow water (15 feet). Tests conducted n the water were: a strength test, an assembly test, a two-hand coordnaton test, a group assembly test, and a vsual test of the detecton and recognton ranges of targets of dfferent forms and colors. A test of mental arthmetc was performed nsde the habtat. Whle performance on the mental arthmetc test suffered no deterora- ton! performance on the psychomotor tasks was less profcent under SEALAB condtons than n shallow water, whch, n turn., was less profcent than dry land performance. The data suggests that performance on short term, smple tasks suffers least mparment, whle performance on larger fcernr ~nd more complex tasks suffers more mparment. The decrements n performance are attrbuted to the varous stresses and hndrances of operatng n he water rather than to any drect physologcal effects (e. g., narcoss) due to pressure or the breathng medum. A concluson from the vson test was that black targets under the condtons are most vsble. Examnaton of the qualtatve materal (vrtten reports and debrefng materal) ndcates that many of the dvers found that tasks proceeded slowly -l-
and that dffcultes were encountered. Among other effects, concern for one's own safety may detract from the amount of attenton one gves to the task at hand. Varous ncdents are related wheren dvers got nto dffculty. Whle many tasks and actvtes were undertaken successfully by the SEALAB teams, yet the amount and varety of work that dvers can accomplsh s lmted by the present technques of dvng. ndvdual dfferences among the dvers were related to dvng perform- ance, and t was found that age and experence had no relaton to dvng actvty. However, the men who ndcated that they were least fearful and least aroused by the condtons dd the most dvng. Also, the men who, n the habtat, were helpful to ther mates, gregarous n ther socal actvtes, and contacted the outsde world least by telephone were most actve n ther dvng.! ( -n- -^ ->
Ths report gves an account of the human performance studes carred out durng the SEALAB project. * The total project had multple purposes and contaned a wde varety of studes n nearly every branch of marne scence, technology, engneerng and medcne, n addton to the studes of human behavor. Ths report s concerned only to report the measures and observatons of human performance taken durng SEALAB. t s a study of men performng varous tests and tasks n a water envronment, subject to a varety of stresses whch, at ther worst, endangered lfe and, at ther least, consttuted dfferences from normal exstence to whch adjustment was requred. An understandng of the sgnfcance and lmtatons of these data wll be enhanced, however, by some knowledge of the operatonal procedures and envronmental condtons of SEALAB. SEALAB SEALAB (O'Neal et al, 1965) had already proved that men could not only survve, but functon n an apparently normal manner and suffer no ll effects from lvng n a submerged habtat for a perod of 11 days, at a depth of 193 feet, and breathng an oxygen-helum-ntrogen gas mxture. SEALAB was desgned to confrm and captalze on ths fndng, and to study the total operaton of placng and mantanng men n a submerged habtat. A major purpose was to evaluate the dver's capablty for dong useful work n the * Ths study was carred out under Contract No. Nonr-4930 (00) and was sponsored jontly by the Offce of Naval Research and the Specal Projects Offce of the U. S. Navy. The conduct of the study would not have been possble wthout the support and nterest of many persona assocated wth SEALAB ; n partcular, thanks go to Dr. J. W. Mller and Cdr. Scott Carpenter for ther actve enthusasm n promotng the conduct of the human performance program.
open sea, leavng from and returnng to the habtat. The prmary advantage of usng a submerged habtat as a dvng base, rather than to conduct dvng opera- tons from the surface, s to elmnate the requrement to decompress (. e., come very slowly to surface pressure). The dver lvng n the same ambent gas pressure as the water pressure outsde (acheved by havng an open entryway n the base of the habtat) suffers no compresson or decompresson penaltes upon extng to the water, provded he remans wthn a depth band referenced to the depth of the habtat (currently 33 feet above and 66 feet below the depth of the habtat). n such Maaturaton" dves, the tme that each dver can stay n the tyater s enormously prolonged over the few mnutes that are safe for a surface dver to stay at any consderable depth. SLALAB 11 s a non-propelled, seagong craft, much lke a small submarne, whch can be lowered nto the ocean and emplaced on the ocean floor. t serves as an underwater habtat wheren up to ten dvers can lve for prolonged perods. The lvng compartment s a cylnder 12 feet n dameter and 57-1/2 feet long. n the submerged state, access s ganed through an ant-shark cage suspended below the hull. The dver swms nto the cage and ascends a ladder through an access hatch four feet n dameter. He emerges nto the entryway. Havng removed hs equpment and taken a hot shower, the dver enters the man lvng compartment. Ths s a long, wde corrdor, dvded nto a laboratory and watch staton, galley and bunkroom. Eleven vewng ports are provded n the hull so that the dvers can observe the marne scene outsde from the comfort of the heated habtat. The atmosphere n SEA LAB contaned approxmately 85% helum, 11% ntrogen, and 4% oxygen. Replenshment gas was brought n an umblcal from the support shp on the surface or from a partal replacement charge stowed n external bottles -2-
strapped to the sde of SEALAB. A gas scrubber contanng Lthum Hydroxde removed CO^, whle charcoal was used to remove contamnants and odors. Elec-! tre dehumdfers kept down the humdty of the atmosphere; convecton heaters and a radant heatng system controlled the space temperature at about 90 F., a comfortable temperature when wearng bathng trunks. The umblcal between the support vessel and the emplaced SEALAB contaned a secondary power cable, a communcaton cable, an atmospherc gas supply lne, a gas samplng lne and a compressed ar lne for power tools. A prmary power cable lad underwater from shore provded power to SEALAB; a fresh-water lne, also from shore, suppled fresh water. A multplex communcatons cable transmttng through a submerged relay staton provded a comprehensve capacty for every type of communcaton between the shore and the SEA LAB. Of the many specal systems used or studed durng SEALAB. the "Hookah" dver breathng system should be noted. Four external lnes were suppled from the habtat atmosphere by means of pumps located n the entryway. The dver donned a mask and could swm freely at the end cf the lne (80 feet) wthout fear of exhauston of hs gas supply. Normally, dvers used the U.S. Navy's MARK V semclosed-crcut scuba equpment, whch provded an endurance of approxmately one hour n the water. The SEALAB habtat was put nto poston on the bottom at 205 feet. t was located about 3, 000 feet off the per of the Scrpps nsttute of Oceanography, La Jolla, Calforna. - 3 -
Some of the relevant aspects of the mmedate envronment of SEALAB were: the bottom was composed of slt whch strred up nto a fog when dsturbed by a dver; the water temperature ranged from 47 F., to 56 F., ncreasng as the study contnued; vsblty ranged from a few feet to as much as 30 feet and also tended to ncrease as the study contnued; there was an abundance of marne lfe attracted to the habtat; a speces of scorpon fsh whch became dense on the bottom around the habtat and n the shark cage was capable of nflctng a posonous stng wth ts dorsal spnes when touched, occasonng consderable pan. The Human Behavor Study Program The study was conceved as a jont program nvolvng a physologcal pro- gram, a socal/personalty program, and a human performance program. A prelmnary report on all of these programs s contaned n Anon 1966, detals of the socal/personalty program are provded by Radloff and Helmrech (1966), and Hetmrech (1966), from whch ths report draws n explorng some of the condtons whch formed the context for the performance of tests and tasks. The purpose«of the human performance studes were to: - examne the effects of the envronment and the condton of dvng on the performance of dvers; - study the work capablty of dvers operatng from a submerged habtat; and - extract prelmnary conclusons on tool and equpment desgn and the desgn of task processes wth the am of eventually establshng human engneerng specfcatons o equpment and tasks. -4-
- t wll become evdent that these study goals were only partally attaned and that much further work s requred to acheve defntve conclusons. Ths was one of the frst attempts at a systematc study of dvng operatons and the performance of dvers. Therefore, t was felt that the opportunty would be used best by settng out to acheve a lmted set of specfc quanttatve data plus ac- qurng as much crcumstantal evdence as was possble n order to characterze the overall response and adaptaton of the dver to the condtons. ndeed, ths polcy was mposed rather than chosen, by the crcumstance of the project. There were the typcal restrctons on manpulaton of varables, control over the course of actvtes, achevng objectve and complete data, etc., whch typfy feld measurement of human performance and whch have been dscussed recently by Rabdeau (1964) and Keenan, et al. (1965). The data gatherng operatons were a mxture of procedures whch, although planned n advance, had to be contnually adapted to the exgences of the unfoldng stuaton. From a theoretcal vewpont, the study was thought of as an nstance of men operatng n an unusual and adverse envronment. t was hypotheszed that the generalzed stress of beng closer to danger than usual plus the specfc stresses n the water of neutral bouyancy, reduced vson and sensory capablty n general, lack of communcaton, cold, hgh energy expendture and reduced moblty and motlty would lead to some decrement n measured performance. t was further beleved, n lne wth the results of numerous stress studes, that smple, short-term psychomotor tasks would show the least mparment and more complex, long-term tasks the most mparment. -5-
The Studes ntroducton The lterature on the human performance of dvers s almost totally con- cerned wth the physologcal effects of breathng hyperbarc atmospheres and the effects of pressure and pressure changes. n recent tmes, a few studes have be -u drected to measurng varous forms of psychomotor and cogntve performance as a functon of exposure to varous breathng mxtures at varous pressures for varous tme lengths. Kesslng and Maag (196Z) report on the temporary mparment of performance on a Modfed Purdue Pegboard (7. 90% decrement), choce reacton tme (20. 85% decrement) and a Conceptual Reasonng Test requrng detecton of rules of categorzaton of objects (33 46% decrement) when the decrement was computed between performance at sea level and performance at 100 feet durng a 12-mnute dve n a pressure chamber Adolfson (1965a, b), also workng n a pressure chamber, reports broadly smlar results usng a manual dexterty test (nuts and bolts), a mental arthmetc test and a word A<soeaton test. At the lower depths to whch Adolfson exposej hs subjects (down to 400 feet), the losses n capablty became larger The observed dec re* ments were attrbuted to ntrogen narcoss resultng from breathng normal ar under hyperbarc condtons. Baddeley (1965) has shown that the decrements reported above are probably the mnmal decrements to be expected from dvers workng n the water. Usng a dfferent but smlar test to the Purdue Pegboard, he showed that a 6% decrement n a pressure chamber at 100 feet transformed tself nto a 49% decrement n the water at 100 feet, The mplcaton s that the relatvely slght loss due, t s presumed, to ntrogen narcoss alone s small -6-
compared wth the ] oss due to both rrtrogen narcos' and the varous stresses and hndrarces of dvng. A possble nterpretaton o f the results s that when dvng n the water the reduced capablty of the dver due to ntrogen narcoss has larger consequences; that s, there s some nterac**"e effect between the state of ntrogen narcoss and the dvng condtons and that the dvng condtons alone would not necessarly brng about mpared performance. Alternatvely. t mav be supposed that dvng condtons do nduce mpared performance whch -.uses an addtve decremental effect over that due to rtrogen narcoss Some support <> the latter nterpretaton s found n a report by Baddeley and Flenmng (196^). Eght dvers were studed breathng ar and an oxygen/helum mxture a» 200 feet, currently t s hypotheszed that breathng an oxygen /helum nvxture at 200 fee» produces no narcotc effects (the evdence from bo»h SEALAB 1 and SEA LA b!1 support* ths concluson). However, Baddeley and Flammng found, or. '»stance that on a manual dexterty test d-vers at 200 feet breathng an "xygen'h** urn m x»ure suffered a ^2% decremen», wh le dvers on a:r had a 47% deem». tn bo*h cases the decrement was wth reference to performance at»««n feet. These results ndcate that the effects of d'v;ng at depth alone brought *\M'ut a *2% decrement. But ths concluson must be tempered by the further observaton by Baddeley ana Flemmng that performance or. a merta addton»c»» suffered 20% and *>% decrements on ar and oxyger,/helum respectvely. One need* to hypothesze e'ther that the oxygen/hel-um dd brng about some narcoss or»hat the d'.vng condtons occasoned the loss n mental addton capablty. -7-
t was ntended that the SEALAB experments would llumnate these ssues and, n partcular, ndcate the type and amount of behavor loss due to dvng condtons other than narcoss. The Tests The tests were planned to sample basc features of man's psychomotor behavor. n desgnng the tests, t had to be recognzed that the test nstru- ments would be mmersed n water and subject to rough handlng, that only a short tme would be avalable for each test run, that the tests had to be self- admnstered by the dvers, and that the envronmental condtons would be adverse and changeable. Therefore, the test apparatus and test procedures were nu.de as smple as possble. The tests range from requrng smple, short-term behavor to relatvely complex, prolonged behavor. The focal sklls requred n the (our tests were: applcaton of maxmum force, manpulatve dexterty, eve-hand coordnaton, and cooperatve assembly of components. The Strength Test The strength test conssted of two torque wrenches mounted on the shark cage of the SEALAB structure. The handle of one wrench was horzontal; the other, vertcal. The M hft N test, carred out usng the horzontal handle, con- ssted of hracmg one's feet on a platform and lftng upwards on the handle, whch w*s postoned about 50" above the platform. The "pull" test was carred out t wth the vertcal handle. t conssted of graspng the handle wth the left hand at about shoulder heght and graspng a grp wth the rght hand«by havng the -8-
poston of the rght-hand grp adjustable, each man could acheve a full arm- stretch poston. n both tests, the subjects were told to exert maxmum force. j * The forces acheved were recorded by a deflecton arm whch moved a recordng marker along a scale. The ft. -lbs. appled were then read drectly from the 1 number opposte the recordng marker. These strength tests were chosen because they are representatve of the actons requred when dvers are used as prmary power sources and because they provde data applcable to the desgn of hand tools. n addton t was ex- pected that the forces recorded n the lft test would be about 2 to 3 tmes as j large as those recorded n the pull test, thus gvng an apprecable range n terms of muscle actvty. The Trangle Test The trangle test conssted of assemblng three one-foot lengths nto a trangle by jonng the ends of the lengths together wth nuts, washers and bolts. The subjects were requred to assemble each corner by placng a washer on each sde of the two lengths, a bolt through these four peces and securng the whole by affxng a nut on the end of the bolt to fnger-tghtness. four forms. The test was gven n Bolt stes were ether 5/32" or S/8" (referred to as "small" and "large"). The holes at the ends of the lengths were placed ether symmetrcally, so that any end of a let.gth would ft to any end of the other two lengths; or asym- metrcally, so that an end of one length would ft only to one end of one of the other two lengths (referred to as "same corners" or "dfferent corners"). Whle t was possble to assemble the "dfferent corners" verson of the test wth any combna- -9- ' g-*,- 1 -"»,"^^ - '- - " T^*«P«^- ^t«««-^..^»-^^ -. ""' * S 4 *^^-
Hon of lergths, the one, and only one» correct manner of assembly resulted \n the exact supermposton of two lengths at each corner. Thus, the four versons of the test (small, same corners; large, same corners; small, dfferent corners; large, dfferent corners) vared the challenge to the subject n terms of thn fneness of fngertp dexterty requred and the degree of perceptual-cogntve nvolvement. The test was selected as beng representatve of tasks requrng the assembly adjustment and general handlng of small tems of equpment. Performance of the test n the water was expected to deterorate when compared to dry-land condtons, as a functon of lowered effcency of the musculature, partcularly the hands (e, g., due to cold, wearng gloves, etc. ); of decreased vsblty and of problems n mantanng body orentaton wth respect to the work components. The Two-Hand Coordnaton Test The two-hand coordnaton test requred the dver to move a peg along a track by means of turnng two knobs whch controlled the poston of the peg n X, Y coordnates. The test, requred the contnuous vsual montorng of the poston of the peg wth respect to the track and the coordnaton of rotary move- ments between the two hands. The test was selected as beng representatve of tasks whch requre contnuous control or adjustment of equpment, dynamc systems, or vehcles..10-
The mechansm box was placed on a stand four feet hgh. On two sdes! of the mechansm box were two knobs, 2" n dameter. Turnng the rght- hand knob caused a peg to move n the X coordnate, whch was a maxmum dstance of 9 H ; turnng the left-hand knob caused the peg to move n the Y co- ordnate, whch was a maxmum dstance of 12". The peg stood up 1" above the top of the box. One of nne templates could be placed on the top of the mechansm box. n each template, a track was cut, at the start of each test, the peg was postoned at one end of the track (Y coordnate). The subject then had to move the peg along the track to the other end as quckly as possble. The characterstcs of the tracks cut n the nne templates prepared for ths test were as follows: Group 1-Orthogonal Lnes Plate #1 Plate #2 A square S Sams as #1 except for a "bump" Plate #3 Same as #2 except for two "bumps 11 Group 2-Slopng Lnes Plate #4 Plate #5 A straght lne S Same as #4 except for a "bump" Plate #6 Same as #4 except for two "bumps 1 * Group 3-Curved Lnes Plate #7 Plate #8 Plate #9 A curved lne S Same as #7 except for a "bump" Same as #7 except for two "bumps" -11-
Tracks n Group 1 requred the subject to move the peg only n ether the X drecton or the Y drecton for any one porton of the track. Tracks n Group 2 requred hm to set up a constant rato between X and Y movements for any one porton of the track. Tracks n Group 3 requred the subject to adjust the rato of X and Y movements constantly, all along the track. Wthn each group, the frst track conformed to an S-shape, the second track had one perturbaton n t, and the thrd track had two perturbatons n t. These per- turbatons n the tracks requred the subject to make a number of quckly suc- ceedng changes n hs control of the peg. Group Assembly Test The group assembly test requred four subjects to cooperate n as- semblng a structure»portrayed to the subjects by a perspectve drawng, from lengths of ppe and approprate connectors. Eghty-four separate peces had to be used. The purpose of tns test was to represent the type of lght-duty struc- ture that dvers have to manpulate and to study the effects of the dvng stuaton on cooperatve acton. Form/Color Test n addton to the four psychomotor tests, one test of sensory functon was conducted successfully n the water. * The form/color test measured the detecton of form and color underwater. Four targets were used: a whte square, 1 a black crcle, a whte cross, and a yellow trangle. Each target measured 30 Tests of tactle senstvty, vsual acuty, audtory acuty, and sound localzaton were attempted; these tests faled due to napproprate or malfunctonng equpment. -12-
centmeters across ts maxmum dmenson. They stood n a lne separated by 3 feet between centers and 4 feet above the bottom. The dvers swam toward the targets along a tape and noted the dstances at whch they could detect the targets and dentfy postvely the forms. Mental Arthmetc Test Ths test was performed nsde the habtat and was scheduled for the 2nd, 7tb and 14th days of the 15 day submerson perod. Each test tem conssted of multplyng a two-dgt number by a one-dgt number; zero's, fve's, and mul- tples of eleven were excluded. The subject was nstructed to complete as many terns as possble n a two-mnute perod. Procedures Tranng, and Collecton of Base Lne Data On two occasons pror to the submerson of SEALAB, the dvers were avd ldble for nstructon, practce, and the gatherng of baselne data on the psychomotor tests and the mental arthmetc test. Due to the pressures of the. program, the amount of practce accomplshed vared consderably from dver to dver. However, all 28 dvers receved wrtten nstructons on test procedures; 26 dvers receved some practce on the psychomotor tests; 27 dvers completed at least two trals on the mental arthmetc test. The dvers were also nstructed n the method of reportng ther performance on a "Sorte Report Form". Ths form contaned approprate checklsts and open-completon parts so that the dver could report on hs dvng equpment, the actvtes undertaken, the envronmental -13-
condtons, and hs subjectve re spouse to the dvng sorte. t was scheduled to be completed for every sorte undertaken from the habtat. Durng the practce perod, as much "dry-land" base lne data on the psychomotor tests were taken a3,was possble. The actual data take was: Strength Test: 14 subjects; one recorded measurement each on "Lft" and "Pull" after practce. Trangle Test: 12 subjects accomplshed at least one recorded measurement on each of the four versons of the test after practce; 2 subjects provded ncomplete data. Two Hand Coordnaton Test: 27 subjects performed at least one tral on Plate No. 5 after practce; also each of the 27 subjects had trals on 4 of the other 8 plates. Group As- sembly Test: 6 teams of four subjects performed the test once each. A lmted opportunty was afforded to gather data on a shallow water dve n a fresh water lake. The tests were undertaken at 15 feet depth, n water that was exceptonally clear (approxmately 100 feet vsblty) and at 70 F. The data -14-
take was: Strength Test: Trangle Test: No data. 12 subjects accomplshed at least one recorded measurement on each of the four versons of the test. Two Hand Coordnaton Test: 14 subjects accomplshed at least on. -ecorded measurement on Plate No. 5. Also, each of these 14 subjects had trals on 2 of the other 8 plates. Group Assembly Test: 2 teams of four subjects performed the test once each. SEA LAB Procedures Three teams of ten men each followed one another n occupyng SEA LAB for S days for each team. One man remaned from Team to contnue wth Team, and another member of Team made up the complement of Team. Whhe the psychomotor and other tests were scheduled wthn the general schedule of dvng, t quckly became apparent to all concerned that the tests would have to be ftted n at and when they could. There exsted also the problem -15-. &~
of motvaton n the sense that the teams faced a multplcty of tasks, and were reluctant to devote anv consderable tme to the human performance tests at the expense of other and, often, operatonally more urgent tasks. t would be tresome to the reader to recount all the dffcultes, makeshft solutons, and mpromptu schedulng that occurred. Suffce t to sav that n retrospect, the pre-plannng was hopelessly optmstc but the gatherng of the test data that was acheved was, under the condtons, a credt to all concerned. t turned out that each dver dd perform one or more of the tests, and t was noted whether the performance was done at the start of the sorte (.e., wthn fve nv~.ut»s or so after leavng the habtat) or at the end of the sorte. The data returned each day on the "Sorte Report Forms" was put onto punch o*rds for later statstcal reduct on. After each team completed ts ffteen* dav stay, each team member was debrefed wthn 3 days by means of a ques- tonnare and an ntervew. Results and Analyss of Tests The Strength Test Table 1 gves the mean u dsuremer.f and standard devatons on the strength test of all the data that were collected. Where a dwer dd more than one tral, hs data was frst averaged. 16-
Stretch Lft No. of No. of Subjects Mean S D. Subjects Mean S.D. 14 (11) 238 (238) 27.4 14 (12) 614 (628) 103.5 Sea Lab 22 (11) 187 (200. 1) 42.3 23 (11) 557 (600) 104.5 % Dff. 21% (16%) 9% (5%) Table 1. Strength Test: data gven nft-lbs. The number of subjects, means and % dfference gven n parentheses are for dvers who dd the test both on dry land and under Sea Lab condtons. - 17 -
^w A more drect way of estmatng the loss of effectve strength by gong from Dry Land to SEALA3 condtons s to restrct the data to those dvers who dd the test both on dry land and under SEALAB condtons. These data are gven n parentheses n Table 1. t can be seen that the dfferences be- tween takng all the data and only the data from matched observatons s relatvely slght. The data were nspected for any dfferences between dong the test at the begnnng versus the end of the sorte; no dfferences were found. Also, the data showed no trends across the 15 day perod of each team's stay. The results ndcate that a dver suffers only a slght loss n the max- mum force he can apply to a torque arm. The greater loss found for the stretch condton may be attrbuted n part to the neutral buoyancy condton. When the dver pulled between the two hand grps n the water, he was lfted off hs feet and hs body weght dd not exert much nfluence on the recorded pull as t would do on land. Otherwse, the drop may be attrbuted, con- servatvely, to possble stffenng of the torque wrench mechansm, to some dffculty n achevng good hand-grp and, possbly, an mpatence to get the test over wth and be about one's busness or return to the habtat. To the extent that the decrement exsted, therefore, t s reasonable to attrbute t to the condtons under whch the measurement was taken rather than to an ntrnsc loss of muscular energy. - 18-
The Trangle Test Fgure 1 records the mean values obtaned on the trangle test takng nto account all the observatons that were made. Eleven subjects performed the test on dry land and n shallow water; t can be seen there s very lttle dfference be- tween the total grou^ ard the pared measurement group. The data taken under SEALAB condtons was sparse; however, the data shows a consstent pattern whch ncreases ts credblty as to beng representatve of the performance levels to be expected under SEALAB condtons. The average percentage ncrease n tme taken to assemble the trangle wth respect to dry land condtons was for shallow condtons 21% and for SEALAB condtons 49%. The data also ndcate that the four versons of the test do not j become equally more lengthy to perform as a functon of the depth condton. t can be seen (Fgure 1) that performance on the smple verson of the test (Tr- angle Number 1) and on the hardest verson of the test (Trangle Number 4) J worsens more than performance on the ntermedate versons of the test. The data permts the hypotheses that t s dffcult to perform even smple tasks exped- tously compared to somewhat more demandng tasks (due, perhaps, to decreased mothty) and that dffcult tasks» become dsproportonately more dffcult. The } hypotheses deserves more defntve testng n future studes. n nterpretng the data, several condtons of performance need to be recognzed. Whle for the dry-land and shallow water condtons, all subjects * -19-
140 no f 120 Tme to Assemble n Seconds no 100 <)0 80! * 70 1 t 4 + 1 ^^BK 0 >* (0-0 (0 0 -«4 (ft «9 0»4 OT4 0 oo * 1 s (12)(2)(6) <14){U,<4) (U)(12>(5) Q Q»4 Q h Q 1 2 \ Tran^e Number (UHU) (3) No. o( Subjects Condton Fgure 1. Trangle Test: Mean tmes to assemble trangles for Dr\ Land, Shallow Water, and Sea Lab cond: on«. Trangle No. 1, Large Bolts, Same Crners; No. 2, Small Bolts, Same Corners; No. 3, Large Bolts, Dfferent Corners; No. 4, Small Bolrs. Dfferent Corners. N*.»ber of subjects provdng data for each mean gven n parentheses, the symbol ndcates mean performance of tne eleven subjects who performed the test for both Dry Land ana Shallow Water condtons. - 20 - \ * ~.
performed barehanded, all subjects under the SEALAB condtons v;r>re some form of glove on both hands except for one dver who wore only one glove. The gloves ranged from thn skn-tght gloves,used to protect aganst cuts and abrasons rather than to provde thermal nsulaton, to 3-fnger 3/8" dvng gloves. The data does not ndcate any systematc relatonshp between type of glove and speed of test; perhaps there s a trade-off between cold hands versus encumbered hands. Vsblty was, of course, much poorer under the SEALAB condtons, uhch would tend to make the "dfferent corners" verson of the test more lengthy to do. Part- ly due to the low vsblty condton, some dvers performed the test float- ng upsde down so that ther face masks were close to the surface on whch they had the bag contanng the trangle parts. Add the possblty of a scorpon fsh or twc floatng across the scene, and the pcture of the SEALAB test condtons begns to be realzed. Evdently the test r suts do not n- dcate necessarly the nherent loss, f any, of manpulatve skll but rather the dffculty of exercsng whatever skll one may have under the operatonal condtons of dvng. t s nterestng to note that the decrement n performance between shallow and SEALAB dvng condtons for the trangle test was 23%, uhch compares wth the 32% found by Baddeley and Flemmng for a comparable test performed under comparable condtons whch has been cted above. Ths degree of agreement s encouragng to the belef that the performance capablty of dvers can be measured and predcted wth some consstency. - 21 -
The Two-Hand Coordnaton Test Unfortunately, the data gathered on ths test from the trals run under SEALAB condtons s unrelable. The machne suffered from cor- roson; the tmng equpment (a cable runnng from swtches on the machne to a stop-clock n the habtat) malfunctoned, and the runs were tmed on wrst watches; and the tmes actually reported are a mxture of tmes taken for a sngle run along a track and a two-way run (out and back) along the track. Dscountng the wdely devant data and the data taken when the machne was stfl to operate due to corroson, t s estmated that Plate No. 5 took about 150 seconds (average of 4 dvers) whch compares wth averages of 125. 8 seconds and 144. 3 seconds for dry land and shallow condtons respectvely (see Fgure 2). The SEALAB data estmate s re- ported because, whle the measurement was probably not very accurate, t s reflectve of the reports of the dvers concernng ther dffcultes n manpulatng the controls and seeng the pn n the track clearly enough (at tmes) to obtan good eye-hand coordnaton. The data for the dry-land and the shallow condton s shown n Fgure 2. The data shows consstent trends n that n shallow water the tme to complete the runs on any one of the tracks s lengthened«there s also the suggeston that the dfference r performance tme between tracks of dfferent dffculty also ncreases,. e., the dfferences between tracks 2 and 5, 8 and 9 (but not S and 6) for the two condtons. 22-
190 180 170 160 150 Tme 140 n 130 Second«120 n 110 100 90 80 70 a l u o 1 (5) (10)(8) 6) (6) (4) ( >T )(14) (8) (4) (4) (4) <7><4) (1)11) Number of Subjects ptr Condton Fgure 2. 1 234 f 6 7 8 9 Plate Number Two s 1 Coordnaton Test: Mean tmes of performance for Dry Land and ShaU-* Wter condtons for each of the mne test plates. Number of subj««ts provdng data for each mean jven n parentheses. -23-
The Group Assembly Teat Only one tral of the group assembly test was conducted durng the SEALAB submerson. The tme taken for assembly was 12 mnutes and 20 seconds. The crcumstances of dong the test were that for about one hour before extng from the SEALAB, the four men concerned practced buldng the structure and decdng precsely how to do t. Each man had also assembled the structure before on dry land or n shallow water. Under these crcumstances, t seems most.approprate to select for comparson the best tmes acheved under shallow water and dry land condtons; these were 8 mnutes 10 seconds and 6 mnutes even respectvely. The other tme for shal- low wa»er condtons was 22 mnutes, and for dry land trals the tmes ranged from 6 mnutes to 40 mnutes and not completed. The dffculty was that wth- out some practce at assembly, the team could become very confused n how to acheve correct assembly and the dvers had only very lmted tme to de- vote to the 1 man performance test program. The SEALAB team reported only one or two abortve moves durng ther assembly, and t seems far to con- clude that ther degree of prepax-aton was deal for the task. The major df- fculty facng the underwater teams was the lack of verbal communcaton. Other dffcultes were low vsblty and the lack of control over body motons whch caused a lot of bumpng and movement between the dvers clusterng around the work tem. ndeed, the SEALAB team reported that ther task would have taken much longer f they were not workng on the platform attached to the shark cage and thus had somethng to hang onto. r -24- p «
Form/Color Test Sx dvers were used to obtan a total of 20 observatons on each of four targets. Table 2 shows the mean detecton and recognton dstances. t s apparent that the black dsc s both detected and dentfed at greater dstances than ether of the whte or yellow targets. Ths s par- tcularly nterestng when consderng that t s the smallest of the four targets n area. (Black dsc = 707 sq. cm., whte targets = 900 sq. cm.) Mental Arthmetc The mental arthmetc test was conducted at the begnnng, n the mddle, and at the end of eac*- team'«stay. The results were nspected frst to see whether there was any trend across tme; there was none so the data was pooled. Complete data was collected on 27 of the dvers. Table 3 summarzes the results..1 1-25-
.^e- Targets Black Whte Yellow Whte Crcle Square Trangle Cross Detecton 24.4 18.3 16.7 16.5 Recognton 20.0 14.2 13.5 13.4 Table 2. Mean Detecton and Recognton Dstances n feet for the Form/Color Study: 6 subjects provdng 20 observatons. Dry Land Sea Lab (Mean No. Attempted 25.84 29.67 Std. Dev. of No. Attempted 7.53 9.07 \ Mean No. Correct 23.76 27.20 Std. Dev. of No. Correct 7.43 8.69 Mean Rato of Correct/ Attempted 9. 12 9. 12 Std. Dev. of Rato of ' Correct/Attempted.07.07 Table 3. Mental Arthmetc Test, Dry Land and Sea Lab Data: mean scores for 27 subjects. r f r - 26-
t s evdent that the dvers n SEALAB suffered no mparment of ablty to perform ths test. n fact, they performed, on the average, more multplcatons wth the same rato of corrects as they had done on dry land. We now turn to other forms of data whch are descrptve of the work capablty of the dvers n SEALAB. Number and Length of Sortes The average number of sortes undertaken per day and the average duraton of the sortes for the three teams broken nto succeedng fve- day perods for each team are shown n Table 4. t s evdent that, as tme went on, there was a cumulatve facltate ng effect whch enabled more tme to be spent n dvng. Much of ths can be attrbuted to an ncreased famlarzaton on everyone's part wth the equpment and operatons. Durng the sortes a large varety of tasks and actvtes were ac- complshed n addton to the tests prevously descrbed. The fact of ther accomplshment was an adequate demcn*traton of the operatonal capablty of dvers for these tasks. Unfortunately we know very lttle more than that certan tasks were done. These tasks ncluded settng up nstruments and 1 equpment on the bottom or around SEALAB: carryng out marne lfe sur - 27 -
Succeedng Fve-Day Perods 1st 5 days 2nd 5 days 3rd 5 days Combned Team N T N T N T N T 1 1.04 38. 5f.98 41.00 2 1.38 35.16 1.22 42.24 3 1.90 61.44 1.78 64.86 1.12 42.82 1.05 40.79 1.53 54.30 1.38 43.90 1.40 60.97 1.69 62.42 Table 4. Number of sortes and dvng tme per team (10 dvers) and for succeedng fve-day perods where N s the average number of sortes per day per dver and T s the average length of sorte n mnutes. \ - 28 -
veys usng approprate equpment; carryng out smulated salvage of an arcraft hull by blowng n foam to provde postve buoyancy; usng a stud gun on a steel sheet; explorng the bottom and gatherng samples of bologcal or geologcal sgnfcance; takng move and stll pctures; etc. Some ndvdual Dfferences* Overall level of actvty n the water s ndcated by the number of sortes undertaken, average duraton of sorte and number of tests undertaken. When usng these ndcatons as crteron measures of dfferences n nvolvement of dfferent ndvduals wth dvng actvtes, t s necessary to recognze that the expectaton ntally was that all dvers would partcpate n dvng actvtes equally. njury, medcal condton, equp- ment functon and malfuncton, schedulng by team leader, were among the determnants whch caused varaton n dvng actvty. However, there also appeared to observers to be factors of ndvdual dfferences n motvaton toward dvng whch contrbuted to the range of dvng actvty. Age and Experence The correlaton of the dvng actvty ndcatons wth age and dvng experence of the dvers showed that no assocaton exsted. (Table 5.) The data reported here was collected and analyzed by Dr. R. Radloff of Naval Medcal Research nsttute and Mr. R. Helm rech of Yale Unversty. An extended treatment of ths and other data appears n Helmrech 1966 and Radloff and Helmrech 1966. - 29 -
Age Experence No. of sortes +.09 +.27 Dvng tme -.04 +.01 No. of tests performed.00 -.21 Table 5. Correlatons ( r 's) of the 28 dvers* age and experence wth dvng actvty. - 30 -
The range of age and experence was consderable. Mean age was 35. 14 years wth a standard devaton of 5. 52; mean experence was 10. 96 years wth a standard devaton of 5. 84. Apparently men at all levels of 1 age and experence could undertake the amount of dvng actvty requred or, alternatvely, what they were motvated to undertake. A prelmnary > l concluson would be that gven a group of men wth vared background t s not mportant, wthn lmts, how old or how experenced any sngle n- dvdual s n determnng the contrbuton he wll make. Fear and Arousal A self-admnstered mood checklst completed every two days ncluded 13 tems ndcatve of the degree of fear (au&aty, apprehenson) and 8 tems ndcatve of the degree of arousal (reactvty to the condtons). The responses, on a 3-pont scale, were summed over the 15 days and correlated wth the dvng actvty ndcatr AS. t s clear from Table 6 that dvng tme and number of sortes are hghly correlated and can be regarded as provdng one ndcaton of nwater actvty. Ths ndcaton s negatvely correlated wth fear and arousal suggestng that the dvers who dved the most were those who felt least fear of the condtons and who were least aroused from ther normal condton by beng n the SEA LAB stuaton. - 3! - 11 -^JM 1 '
Fear Arousal No. of Tests Dvng Tme Fear Arousal +.56** -- -- No. of Tests -.25 -.14 -- Dvng Tme -.50** -.52* +.22 No. of Sortes -.44* -.47* +.09 +.89** *P <. 05 **P<.01 Table 6. Correlatons (r's) between ndcated "fear" and "arousal" wth dvng actvty. r! F - 32 -
Helpfulness A measure of "helpfulness 11 was generated by drect observaton (by a closed TV system) of the dvers performng chores n the habtat, partcularly meal preparaton and clean-up chores. The correlaton between ths measure and the number of tests performed n the water s 1 +.64(p<.01). Gregarousness 1 A measure of "gregarousness" was generated by drect observaton (by a closed TV system) of the rato of tme spent by each dver n the company of other dvers n the habtat. The correlaton of ths measure wth dvng tme s +. 50 (p <.01) and wth number of sortes s +. 46 (p <. 01). S External Contact The number of external telephone calls (. e., calls other than com- ) muncatons wthn the SEA LAB project communcaton system) was docu- mented for each dver: communcaton content was not montored. The num- ber of external telephone calls correlated wth dvng tme -, SO (p <*01) and number of sortes -.49 (p<.01). The nference may be drawn that the men who most excluded the outsde worlds from ther mnds, or at least dd not feel the need to contact t very much, were the ones who were most actve n undertakng dvng sortes. -33-
These varous ndcatons start to defne the type of men (low fear and arousal, helpful and gregarous and not needful of external contact) who wll be enthusastc about gettng out nto the water and performng tasks there. The prelmnary defnton of these desrable trats wll serve as a bass for the development of future selecton programs. Debrefng Data The debrefng data s rch n materal whch "pants a pcture" of what t s to lke to lve under the sea n close company wth 9 other men and to contend wth the manfold dffcultes of dong jobs under dffcult condtons. The followng samples are selected from the debrefng ma- teral on the bass that the nformaton s drectly relevant to human per- formance. Clothng and Cold The protectve "wet-suts" that the dvers used, left much to be desred. Only three of the dvers reported that they were really satsfed wth ther suts. Whle a very consderable effort was made to equp the dvert wth adequate wet suts, t seems that much more attenton wll have to be gven to ths feature n the future. Wthout departng from the* current concept of a wet sut, t would appear most desrable to have sppers that don't jam or break, and for the suts to fat well enough so that there [ would be only a small flow of cold water nto the sut or that the sut should - 34-
not rase panful welts at flexon ponts. The reported experence of the dvers wth respect to the cold was very vared. Some sad '.hey were never cold; some sad they were always cold. Some sad that they grew used to the cold; others sad that the only thng that changed was that ther wet suts, after ntal com- presson (due to the pressure), expanded and reganed ther thermal pro- pertes. Some sad t was warmer dvng <t nght, however there were no recorded changes n nghttme water temperatures over daytme tempera- tures. There was, further, no evdence that the realtvely slght changes n temperature that dd occur affected measurable performance (. e., on the psychomotor performance tests). Undoubtedly, however, t was cold and some dvers dd become very cold. One dver charactersed the effect on hm of the cold as makng hm become mpatent and more ready to cut corners or leave jobs uncompleted or not attempted, n order to get back to the warmth of the habtat. t s very evdent that better suts and/or heated suts are requred for effectve operaton n the lower tempera* ture ranges. Cloves Nearly everyone used gloves. The majorty dove wth gloves whatever ther task because as a dver put t "t's better to be clumsy and slow wth gloves than to run the rsk of your hands becomng useless through the cold." - 35-
However two dvers sad that they never wore gloves. One of these men was a photographer. He sad hs hands almost never became so cold that he could not work hs cameras and that, provded hs hands were only moderately co'd, he could use hs equpment better than wth gloves on. Tool Usng The dvers consstently reported that they had no trouble usng j tools such as wrenches, screwdrvers, hammers and varous specal tools. However, the real meanng of these comments seem to be that they encountered no unusual dffcultes over the normal dffcultes of usng tools underwater. There are several knds of dffcultes n usng tools; they are due to one's (approxmate) neutral buoyancy, the vscosty of the water and to the problems of transportng and keepng track of tools. The neutral buoyancy and vscous resstance problem s evdent when attemptng to use a Urge hammer. Vrtually all the mpact energy must come from the hammer fallng through the water. One cannot swng a hammer or am t effectvely along a trajectory. Applyng torque to tools s smlarly dffcult; wthout some structure aganst whch to brace one«sell one cannot be very effectve. The problem of tool management s also a consderable one. cause the free-swmmng dver (more generally two dvers swmmng at "buddes") operates as an solated entty, he must car. y ar attach to ht r Be*
person the supples that he wll need at the workste. Besde the lmta- ton that ths restrcton mposes n terms of the knd and quantty of tools and materals that can be brought at any one tme to a work ste, there s the dffculty of actually undertakng the transportaton. Carry- ng tools n the hand, strapped to the wrst or n a bag, encumber the dver and slow hm down and can cause hm to become entangled. Once at the work ste, there s the problem of keepng track of the tools. apparently very easy to mslay tools n the mud and murk whch are t s 1 characterstc of many bottom* on whch dvers work. Thus, on one F F sorte from SEA LAB, a dver mslad a hacksaw and an«8-lb. hammer. Varous other tools and tems of equpment were lost or mslad and found agan only after consderable search or by chance. The problem of mantanng vglance over tools and puttng them down at some locaton where they can be found agan takes tme and effort, sometmes much tme and effort. Dve Management The dffcultes of tool management and the errors that occur may reflect a more general dffculty of mantanng currency wth a developng stuaton. One dver ducussng the general topc of conductng a dvng orte sad about hs dffcultes " you pre «plan a dve and you're not able to adjust very well to a stuaton. Your mnd s set. You've got to do somethng a certan *ay. You just don't adjust to t as well as you wsh - 37 -
you could. " The tenor of the remarks of many of the dvers n the debrefng ntervews echoed ths feelng that when one's plans were dsturbed, t was dffcult to adapt effectvely to the new stuaton. Another dver put the proposton n a dfferent way: he sad "a good dver s a good planner. M The mplcaton of ths remark, taken wth the rest of the evdence, s to ndcate that t s very dffcult to cope wth a stuaton unless one has prepared a plan of acton. Ths phenomenon may be n- terpreted as a reflecton of the manfold stesses that dvers are subject-to. Dver Concerns A major theme runnng through nearly all the debrefng ntervews s a preoccupaton wth yourself, your locaton, your equpment and wonder- ng whether everythng s gong rght. The followng quote from one dver would reflect the thoughts expressed by many. "So much of your mental capacty s devoted to lstenng to your exhaust, wonderng whether t's workng rght, keepng n mnd how far you are from the laboratory and takng care of your tools. You're spread pretty thn and you don't have much of your mental capacty to devote to the performance of your task. " Whle t would gve a false mpresson to suggest that the dvers were neffectve or that they dd not, n fact, accomplsh many tasks whch some reported as "gong very easly," "no problem«, " etc., generally the accomplshments were wth respect to smple short-term tasks whch had been - 38 -
thoroughly practced. The other sde of the story s exemplfed by ths feelng of despar whch was wrtten on a daly report form after the dver had been down for 6 days. "Today we completed only one out of 2 smple jobs. don't understand t at all, but t presently seems to be a fact have been dong some stupd thngs, and other people feel the same way. We are tryng to be ultra-careful wth the MK6's (breathng apparatus), but thngs stll happen such as flooded cannsters, and two cases of people gong out wth ther gas off. Once outsde, t seems mmensely slow--t takes much tme to do even smple jobs. We really need about 2 weeks to just get used to ths knd of work; agan, don't understand why. M ncdents There were several ncdents of a more or less crtcal nature. The ncdents that occurred may be categorzed broadly as : 1. Deprvaton or contamnaton of gas supply 2. Sudden change n buoyancy 3. Entanglement Whle there were also occurrences of dvers becomng temporarly dsorented as to ther whereabouts, none of these developed nto an actual state of beng lost. The records ndcate that there were at least sx occasons when dvers suffered a deprvaton of gas supply, and there was one occason - 39 -
when a dver attrbuted z. coughng ft and great dffculty n breathng to baralyme contamnaton fron, the CO2 scrubbng cannster. On all occasons, the acton taken was to return to the habtat entrance way. For one dver, at least, the race between the onset of unconscousness and the ganng of the entrance way through the obstacles of the shark- cage door and the profuson of wres and cables was touch and go. t s notceable that no attempt was made to use the buddy breathng tech- nque whch was possble when swmmng wth a companon usng the Mark V equpment. The mplcaton would appear to be that a companon dver does not consttute a suffcently mmedate safety capablty under the crcumstances of dvng that obtaned. One dver experenced a sudden postve buoyancy due to the n- flaton of one sde of hs chest bag brought about by a free-flowng bypass valve. He was n danger of floatng to the surface whch would have meant certan death. M We were n the process of puttng (a stake n). made a quck turn to assst (hs companon dver) and my bypass started free flowng. Well, before knew t, would estmate was from 15 to 20 feet off the bottom. My bypass was free flowng and one sde of my vest bag popped up--came loose; and 1 feel part of t was my fault. really needed (more) practce on the Mark V before makng the dve down there and got a f lttle shook; n fact, got damn shook. - 40 - was swmmng to the bottom as
hard as could and wasn't makng any headway for a whle. All ths tme was tryng to get the bag down. was tryng to reach my bypass whch was able to do and was pushng on the rod tryng to get the free flow to stop. What should have done was open up my pop-off valve, pulled on t and empted my bag. But ddn't thnk about t.. «Anyway, ddn't, so fnally decded, well, the most mportant thng for me to do s to get to the bottom and got to the bottom and got to that stake we were drvng n and held on. Wth the help of two other dvers, the dver returned to the habtat wth some dffculty. n studyng the protagonsts' accounts of the ncdent, certan nfer- ences can be drawn. t s clearly dangerous to use dvng equpment that can suddenly change ts buoyancy when engaged n a saturaton dve. f the possblty of the contngency cannot be elmnated entrely, adequate tranng and preparaton should be mandatory. The lack of a means of swmmer-to-swmmer communcaton meant that the buddy dver dd not know that serous danger threatened hs companon untl after the worst danger had passed (of poppng to the surface). A thrd dver who came on the scene (breathng from a Hookah hose) faled to comprehend the stuaton very well and n attemptng to help the dver back to the habtat hndered, rather than helped. Ths crtcal ncdent has been reported n some detal so that the reader may become aware of some of the actualtes of dvng and the dangers - 41 - ^^^_^^
that threaten Whle, n fact, ths ncdent ended happly, due, no doubt, to the degree of skll and experence that the dvers possessed, yet t was an ntmate brush wth catastrophe. The ncdent suggests the room for mprovement that exsts for human factors specalsts, jonng wth the dvng fraternty, to apply themselves to. Whle there were many reports of temporary entanglement, only one report ndcated that dvers were n any mmedate danger. One form of "nusance" entanglement s becomng entangled wth equpment one s carry- ng. As soon as the dver s burdened, as sometmes he must be, wth varous objects, some of whch are ted to hm by lnes, there always exsts the lkelhood that the lnes and the equpment wll become snarled around hm. A dver descrbed a potentally dangerous ncdent of entanglement as follows: ( had no especal dffculty) wth the (Hookah) lne but, boy, there are a lot of lnes down there that 1 got tangled up n, both wth the Hookah and the Mark V. One thng that really scared me--one tme when (a dver) and 1 were out--we got a buoyant pot. We snapped ths pot on (to the lne from the surface) and t started to go up. (The other dver's) Hookah lne was hooked up on ths thng and t started up, caught hm, and he started gong up wth t. was rght after hm, and t turned out my lne was tangled up n t too. " - 42 - [
They managed to dsengage themselves aded by the prompt acton of the man on watch n the habtat who saw the occurrence and nstructed surface control to slacken the up-haul. The dver who was speakng before contnued: "There are so many lnes down there at the entrance of that thng. was out swmmng wth the Mark V and got t tangled up n the breathng part and t cut off. Just one of these lnes gong out here and there and ddn't even see t. Of course, your feld of vson s not too great anyway, and you can easly swm nto thngs lke that. t actually cut off my ar for a mnute and t scared me un- tl reached around and fgured out what t was. My buddy came over and untangled me. thnk that s a real problem of safety; all those lnes out there." Dscusson Perhaps the most sgnfcant attrbute of the data s the absence of any decrement n measured mental functon nsde the habtat (the mental arthmetc test), combned wth the measured decrement of performance n the water. There s no reason to beleve that gong nto the water from the habtat should have ncurred any degradaton of mental functonng. The gas mxture that the dvers breathed n the water was essentally the same gas mxture, under the same pressure condtons(wthn one atmosphere up and two atmospheres down of pressure whch, t s thought, s qute an nsuffcent change to brng on narcoss) as breathed n the habtat. - 43 -
The attrton of performance and the feelngs of, at least some, dvers that accomplshment fell short of expectaton must be attrbuted to the df- fcultes and mpedments of operatng n the water. Whle the data collected are hardly conclusve, the general pattern of the results suggests that smple, short-term tasks, whch can be conducted accordng to a smple plan (e. g., the strength test and certan of the tasks undertaken n the smulated salvage operatons), suffer very lttle mpar- ment as compared wth dry-land condtons. However, as soon as the task becomes more complex, a progressve mparment of profcency sets n; the trends n the trangle test data are ndcatve of ths nteracton between task complexty and envronmental stress. nsofar as the one test run on the group assembly test may be ndcatve of performance on a group-par- tcpatve task, relatvely gross amounts of mparment appear. There s also an unseen part of the data, namely, that whch would de- scrbe what the dvers dd not do. Compared to dry land, the dver s enor- mously lmted n hs range of behavors. He s vrtually confned to vsual observaton and the manpulaton of relatvely smple objects wthn some qute lmted area (n the case of SEA LAB, a maxmum dstance of about 350 feet from the habtat). Hs work effectveness s lmted by the short length of tme he can stay at a work ste, by hs own slow moton and by hs necessary preoccupaton wth contngency condtons that mght affect hs safety. He s characterstcally cold and has lmted vson; hs sut makes - 44 -
! hm clumsy and hs neutral or slghtly negatve buoyancy complcates the performance of tasks. The tools he uses are lmted n type; for tasks requrng more sophstcated equpment, he s stll dependent on surface support. The mpresson was ganed that the amount of work accomplshed and the comparatvely good showng on the psychomotor performance tests were due to the combnaton of very hgh morale, the agressve achevementorented motvaton, and the hgh expertse and long experence of most of the dvers. t would seem that f future operatons are to become more effectve, wder n range and more nsttutonalzed, a great deal less relance wll have to be put on the dver per se. There s a need to develop many features of dvng equpment so that varous man/equpment combnatons can face the underwater envronment and underwater tasks wthout the present relance or, dver courage and skll whch, hgh though they may be, are often relatvely nadequate resources for the tasks at hand. Consderng the more specfc results of the study, there s no evdence to suggest that dvers cannot perform a full range of manpulatve tasks c r use all of the conventonal hand tools. Ther performance wll be slowed as much by the problems of personal moblty, equpment transportaton, and the lke, as by deteroraton n speed of work at the workste. The dver's - 45 -
strength s not serously mpared, but hs value as a prmary power source s lmted by the problem of applyng force n a buoyant medum. Torquefree power tools would be a boon to dvers, provded the problems of gettng the power to the workste (e.g., by cables) are not too consderable. The data analyzng the personal and socal attrbutes of the dvers who acheved good work records n the water suggests that dvers should be of a relatvely phlegmatc dsposton and able to contend wth stress and danger wthout beng preoccuped wth them. They should be motvated to help out and ready to take on whatever dutes must be performed. Persons who tend to be good mxers wll also be the ones tendng to acheve more n terms of dvng operatons; and persons who can lose ther concerns about the outsde world and accept ther solaton wll tend to be the ones who wll be motvated to engage fully n the dvng operaton. These fndngs of dvers' trats whch, at least n the case of SEALAB, dsposed them to be effectve performers n the water, form a bass for the development of future selecton procedures. - 46-
n^ References Adolfson, J. Deteroraton of mental and motor functons n hyperbarc ar. Scand. j. Psychol., 1965, 6, 26-32. Adolfson, J., and Muren, A. Ar breathng at 13 atmospheres. Psychologcal and physologcal observatons. Sartryck ur Forsvars medcn, 1965, \, 31-37. Anon., Offcal Report, Sea Lab, Offce of Naval Research, 1966 (to be publshed). Baddeley, A. D. The nfluence of depth on the manual dexterty of free dvers: A comparson between open-sea and pressure-chamber testng. J. appl. Psychol., 1966 (n press). Baddeley, A. D., and Flemmng, N. C. The relatve effcency at depth of dvers breathng ar and oxy-helum. Personal communcaton from Appled Psychology Research Unt, Cambrdge (England), 1965. Helmrech, R. L. SEALAB : A feld study of ndvdual and group reactons to prolonged stress. Offce of Naval Research, Nonr (G) 00030-66, Tech. Rep. No. 1, 1966. Keenan, J.J., Parker, T.C. and Lenzyck, H. P. Concepts and Practces n the Assessment of Human Performance n Ar Force Systems. AMRL- TR-65-168, Wrght-Patterson AFP, Oho, September 1965. Kesslng, R. J. and Maag, C. H. Performance mparment as a functon of ntrogen narcoss. J. appl. Psychol., 1962, 46, 91-95. O'Neal, H. A., Bond, G. F., Lamphear, R. E., and Odum, T. An expermental eleven-day undersea saturaton dve at 193 feet. Offce of Naval Research, ONR Report ACR-108, 1965. ~~ ~~ Rabdeau, G. F. Feld measurement of human performance n man-machne systems. Human Factors, 1964, 6, 663-672. Radloff. R. W., and Helmrech, R. L. SEALAB L A tmd study Q f «tr»««personal communcaton to the author, 1966. -47-
Unclassfed Securty Classfcaton DOCUMENT CONTROL DATA R&D (Securty claaatcator, o/ fr/*, body of abstrnct and ndexng annotattr* tnuat ba arlarad whan tha ovarall raport <«claaatad) 1 ORGNATNG ACTVTY (Corporata author) Dunlap and Assocates, nc. 2«REPORT SECURTY CLASSFCATON Unclassfed 26 GROUP 3 REPORT TTLE "Studes of Dvers' Performance Durng the SEALAB Project" 4 DESCRPTVE NOTES (Typ* ol report and ncluatva dmtaa) Fnal Report - March 1966 S A U THORfS; (Laat nama. tnt nama ntal) Bowen, Hugh M., Andersen, Brger and Promse!, Davd ft REPORT DATE March 1966 a CONTRACT OR «RANT NO. Nonr 4930 (00) 6. PROJECT NO 7# TOTAL NO Or PAGES 47 76 NO OPREPS 11 9«ORGNATOR'S REPORT NUMGERfS.) DfcA SSD-66-296 (57 1) Nonr 4930 (00) 96 OTHER REPORT MO(S) (Anyotharnumbarathatmaybrnafgnad 10 A VAlLAtlLTY/LMTATON NOTCES 11 SUPPLEMENTARY NOTES 12 SPONSORNG MLTARY ACTVTY ABSTRACT Offce of Naval Research, Washngton D. C. Feld studes of the three 10 men teams of dvers partcpatng n the SEALAB project were undertaken. Durng each team's 15 day submergence at 205 feet, psycho motor tests and a vson ten were conducted n the water, and a mental arthmetc test n the habtat. Compared to base lne performance (dry-land and shallow water condtons), performance on the mental arthmetc test showed no deteroraton whle performance on the paychomotor tests showed consderable deteroraton. Many dvera found that ther n-water actvtes proceeded slowly; among other causes of a more physcal nature, concern for one's safety may detract from the amount of attenton one gves to the task at hand. The most actve dvers n the SEALAB group were those who ndcated that they were least fearful and least aroused by the condtons and who were helpful, gregarous, and made lernst telephone contact wth the outade world. DD '^1473 Unclassfed Securty Classfcaton
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