Document 3QQL0mG9J5gvjKm56oqa8YDD

Report SAM-TR-80-43 / FIELD STUDY DETERMINATION OF VENTILATORY REQUIREMENTS OF MEN RAPIDLY EVACUATING A SPACE LAUNCH COMPLEX Loren G. Myhre, Ph.D. November 1980 Final Report for Period January 1980 - February 1980 Approved for public release; distribution unlimited. S I- ^ " USAF SCHOOL OF AEROSPACE MEDICINE Aerospace Medical Division ( A F S C ) Brooks Air Force Base, Texas 78235 11 unclassified SECURITY CLASSIFICATION OF This page D.i* i'mnw; REPORT DOCUMEHTATION PAGE READ INSTRUCTIONS BEFORE COMPLETING FORM 1. REPORT NUMBER ^ 2. GOVT ACCESSION NO. 3. recipient's Catalog number SAM-TR-80-U3 4. title <ana Submit) FIELD STUDY DETERMINATION' OF VENTILATORY REQUIREMENTS OF MEN RAPIDLY EVACUATING A SPACE LAUNCH COMPLEX S Type OF REPORT A PERIOD COVERED Final Report Jan 1980 - Feb 1980 s. performing org. report number 7. AU T HOR( > Loren G. Myhre, Ph.D. 8- CONTRACT OR GRANT NUMBERij; . p ER FORMING ORGANIZATION NAME AND ADDRESS USAF School of Aerospace Medicine (VNT) Aerospace Medical Division (AFSC) Brooks Air Force Base, Texas 78235 11. CONTROLLING OFFICE NAME ANO ADDRESS USAF School of Aerospace Medicine (VNT) Aerospace Medical Division (AFSC) Brooks Air Force Base, Texas 78235 1 A. MONITORING AGENCY NAME 6 AOORESSC// dlllertni tram Conltolllnt Othet) 10. PROGRAM ELEMENT. PROJECT. TASK AREA t WORK UNIT NUMBERS 62202F 7930-14-06 12. REPORT DATE November 1980 13. NUMBER OF PAGES 21 'S. SECURITY Class, r*<* rwpvrj) UNCLASSIFIED IS.. DEClaSSiFiCaTion.OOwnGRaOinG SCHEOULE It. DISTRIBUTION STATEMENT (of 1 hi, fit pen) Approved for public release; distribution unlimited. 17. GISTRIBUTIOH STATEMENT (el a6.tr.cf ,nl*r.d In B/ceJt 10, H dWt'-nt Item Rtperl) IB. SUPPLEMENTARY NOTES IS- KEY WORDS (Cenllnui on rixm tide i/ nc*..ry> nd irlcnllly by Joc* nu<n6f/j Work Stress Self-contained Breathing Descending Stairs Escape Device Physiological Effects Hypoxia Heart Rate Hazards Apparatus SAL 000046 20 A B S T R A C T < C ill mi* on r >-ci * mdr II n>c'<>w')' tf i drill ily bv Ior k ruimbttj Physiological variables, including heart rate and minute ventilation, were monitored for 3 men and 1 woman during field trials simulating the emergency evacuation of Space Launch Complexes (SLC) 4E and 4U at Vandenberg AFB in January 1980. Rapid evacuation from the highest work level of SLC-4E to a designated point of safety (tunnel), unencumbered by the wearing of a respiratory protection device, could be accomplished in about 3 min. Monitored heart rates for 3 men, calculated at 30-sec intervals, averaged 145 bpm; peak heart rates dd 1473 12 UNCLASSIFIED SECURITY CLASSIFICATION OF This PAGE O.ia ni*i*d) 1 ..UNCLASSIFIED____________________________ 5ECU *1 T_VCL *5SI FlCATlOH or This RaGEC**#" Oaf Cniatad) 20. ABSTRACT (contirKied) averaging 166 bpm occurred during the last min of the exercise. Ventilatory requirements for this rate of work, estimated to represent approximately 65% of the men's aerobic capacity, were estimated to average approximately 51 liters/ min. Subsequent trials repeating the same rapid evacuation while wearing the currently approved Robertshaw Air Capsule were achieved with considerable diffi culty, producing situations that could seriously compromise the wearer's safety. Most obvious hazards imposed by the air capsule included (1) almost total ob struction (fogging) of forward and downward vision, (2) the early onset and pro gressive severity of dizziness, allegedly the result of hypoxia, (3) the total collapsing of the air capsule around the head and face with each inspiration, and (4) the absence of an anti-suffocation device which would allow entry of outside air into the air capsule when the air reservoir becomes exhausted. How ever, the user is indeed cautioned to walk when wearing the Robertshaw Air Cap sule, and there were no major complaints during evacuation from the SLC when it was used in this manner. Time required to accomplish a walking evacuation aver aged 4 min, 19 sec; total air supply to the air capsule averaged about 4 min, 54 sec for the 5 units tested. It should be noted that although present regula tions and directives state that workers should walk, not hurry down the SLC tower stairway and into the tunnel, such a disciplined evacuation in an emergency (situation may be merely academic. It was concluded that a reasonably fit adult male rapidly evacuating the SLC works at a load approximating 65% of his aerobic capacity. Associated with this level of work is a ventilatory requirement of about 51 liters/min with corres ponding peak inspiratory flow .rates predicted to average about 180 liters/rain. Under these'Tonditions excessive rebreathing of expired air with the concomitant onset of hypoxia was clearly evident when wearing the Robertshaw Air Capsule which delivers air at a rate of 25 liters/min. The Robertshaw Air Capsule is deemed to be unsuitable as a respiratory protection device during rapid evacua tion of the SLC; its limited air supply (about 5 min) renders it a marginal device for a walking evacuation which requires about 4 min, 19 sec. The degree of protection from airborne contaminants provided by the Robertshaw Air Capsule under work stress conditions simulating both (a) rapid anc (b) walking evacuation awaits laboratory testing. oa; , - 13 - UNCLASSIFIED SECURITY CLASSIFICATION OF This R AC Cr*Fh.r. D.ia EniK,^