ATTACHMENT 10
REPORT OF PARTICIPATION
IN SELECTED VOLUNTEER
PROGRAM OF DESERT ROCK V-ILLEGIBLE
25 APRIL 1953
Prepared by: Captain Robert A. Elmers, USN
Headquarters, Armed Forces Special Weapons Project
DECLASSIFIED BY ORDER
OF THE SEC ARMY BY TAG
PER 3
ILLEGIBLE
MEMORANDUM FOR AFSWP FILES
SUBJECT: Report of Participation in Selected Volunteer Program of
ILLEGIBLE ILLEGIBLE ILLEGIBLE, and Description of Effects
on 50 ILLEGIBLE Burst as Observed at 2,000 Yards from
Ground Zero
1. The undersigned participated in the Selected Officer
Volunteer Program of ILLEGIBLE ILLEGIBLE Book 7-7 held on Saturday,
25 April 1953 at the Nevada Proving Grounds. Arrangements for my
participation were made with the Exercise Director, Brigadier
General W.C. Bullock, by Colonel ILLEGIBLE of AFSWF Field Command
in accordance with request from this headquarters. The AFSWF
report had stipulated that my proposed participation, if arranged,
should not be permitted to result in the displacement of any
officer who might previously have been selected for this group by
the Army. This condition was met without difficulty, since several
of the Army officers originally selected had been unable to attend
the exercise. In requesting my participation, Colonel ILLEGIBLE
also informed the Exercise Director's representative (Colonel
Thelma) that I would be acting in the capacity of a representative
of AFSWF rather than of the Naval Service.
2. The volunteer group selected for this shot consisted of
a total of eight officers. The other seven were all from the Army,
and included Colonel K.P. ILLEGIBLE and Lt. Colonel J.E.K. Hines of
the staff of the Special Weapons Course at Ft. Leavenworth and
Colonel M.M. Irvine of ILLEGIBLE. In the interest of continuity,
General Bullock designated it Lt. Colonel Don Davis, Inf, USA, as
the group leader. The latter and functional in a similar capacity
for the previous shot. A complete list of the officers in this
group is appended hereto (Tab A).
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Security Information
SUBJECT: Report of Participation in Selected Volunteer Program of
ILLEGIBLE ILLEGIBLE 7-7, and Description of Effects
ILLEGIBLE ILLEGIBLE and Observed at 2,000 Yards from
Ground Zero
3. Prior to final acceptance as a member of the group, each
officer was required to personally and individually compute the
effects to be expected in an open trench on the basis of the
expected yield of 35 to 40 ILLEGIBLE, and to recommend a distance
for positioning the group which would not exceed the effects
criteria which had been established for this exercise. Each
officer also was required to exercise a certificate confirming his
volunteer status. Attached hereto (Tabs B and C) are copies of the
forms used for this purpose. In submitting my own forms, I
recommended a distance of 2,000 yards.
4. General Bullock reviewed the ILLEGIBLE at a briefing
conference held in his office on the day before the shot. Since
there was substantial agreement between all of the officers of the
group as to the 2,000 yard distance, this distance was approved by
the General. Trenches previously had been prepared at 500-yard
intervals, so that the final decision could be made with some
flexibility on the basis of the weather conditions and any other
last-minute considerations having any bearing on the predicted
efforts. At the final briefing, General Bullock also informed us
that although there had been a rather complete press release on the
*The actual yield, as of the time of preparation of this report (26
May 1952), as reported to have been between 50 and 55 ILLEGIBLE.
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SECRET
SECURITY INFORMATION
SUBJECT: Report of Participation in Selected Volunteer Program of
ILLEGIBLE ILLEGIBLE V-7, and Description of Effects of
ILLEGIBLE Burst as Observed at 2,000 Yards From Ground
Zero.
volunteer program following the first ILLEGIBLE ILLEGIBLE ILLEGIBLE
exercise, more recent security restrictions precluded public
release of the exact distance at which we would be positioned
relative to ground zero or of any of the other details of our
position and observations.
5. We were given physical examinations at the camp ILLEGIBLE
the day before the shot, and also were interviewed by psychologists
from the Army contract group known as the "ILLEGIBLE ILLEGIBLE
ILLEGIBLE Office" (ILLEGIBLE).
6. The final weather prediction on Friday evening indicated
fairly strong cross-winds (from the west) at both the 10,000 and
20,000 feet elevations, and very little ground wind. This was
considered to be about as favorable as we could expect from a
contamination standpoint. The actual weather at shot time was as
predicted.
7. The personal equipment issued to us for use on shot day
consisted of standard Army field helmets and liners, gas masks,
flashlights, and canteens. We each receive three file badges and
were instructed to place one in a ILLEGIBLE pocket, pin one to our
back or place it in a hip pocket and tape the third inside our
helmet. In addition, various types of ILLEGIBLE, and several
survey ILLEGIBLE, were distributed throughout the group. We also
were issued cotton for use in keeping dirt out of our ears.
8. On the morning of the shot, we rode to the forward area
on ILLEGIBLE of the ILLEGIBLE of the regular troop observer convey.
The Army psychologists accompanied us as far as the main troop
positions at the 4,000-yard point. Our group continued on alone by
truck to the general vicinity of the 2,000 yard position arriving
there about one hour before shot time. Communication was
established by field telephone with Colonel ILLEGIBLE, the Deputy
Commander for Operations, who was with the main body of troops. He
relayed the usual AEC time announcement to us. We remained above
3
SECRET
SECURITY INFORMATION
SUBJECT: Report of Participation in Selected Volunteer Program of
ILLEGIBLE ILLEGIBLE V-7, and Description of Effects of
ILLEGIBLE Burst as Observed at 2,000 Yards From Ground
Zero.
ground until about 15 minutes before shot time, at which time we
entered our trenches. There were two trenches in line, each about
20 feet long, 3 feet wide and 6 feet deep, with their adjacent ends
separated by about five yards of concentrated earth. One was
reinforced with a solid rock lining on the front and rear ILLEGIBLE
and cross-braced with wood timbers at about 4-foot intervals. The
other one was ILLEGIBLE. Each trench had a row of sandbags placed
flat on the ground around its top perimeter, and had a loose fill
sloped to about a 45o angle at each end to facilitate ILLEGIBLE in
ILLEGIBLE. We were permitted to choose our respective positions.
I chose the ILLEGIBLE trench, along with two other officers of the
group. Both trenches were bare of any equipment accept for several
shovels. See Tabs D and E for photographs of the trenches, taken
after the shot.
9. The telephone was placed in the ILLEGIBLE trench, but
those of us in the other trench could hear the time signals without
difficulty as the talked called them out. Just before shot time,
we all squatted close to the forward wall in order to obtain
maximum shielding, and faced away from ground zero as a precaution
against spelling. Due to the alight time lag involved in relaying
the time signals by telephone, the actual detonation occurred when
our talker had reached a count-down of about 3 seconds before zero
time.
10. The following is a summary of the variable effects as we
observed them at 2,000 yards from ground zero, in the positions
described:
a. Light - The intense white light was the first
manifestation of the explosion, and seemed to persist for at least
six seconds, as it
4
SECRET
SECURITY INFORMATION
SUBJECT: Report of Participation in Selected Volunteer Program of
ILLEGIBLE ILLEGIBLE V-7, and Description of Effects of
ILLEGIBLE Burst as Observed at 2,000 Yards From Ground
Zero.
continued well beyond the time of arrival of the shock wave. I was
wearing Navy safety goggles with clear glass lenses, as I was
carrying a high-range experimental type of radiation survey meter
and had hoped to get an early reading of the prompt nuclear
radiation by opening my eyes very slightly. This proved to be
impossible; I not only could not see the meter scale or pointer,
but could not even see the profile of the instrument, the bottom of
the trench, nor any other surrounding objects. There was nothing
but white light on all sides. However, I had no sensation that it
was hurting my eyes; it merely blanked out all vision for the
duration of the fireball. When the fireball finally cooled off and
the light gradually diminished, I had no ILLEGIBLE of any monetary
flash-blindness; so far as I could tell, my eyes ILLEGIBLE to the
rather dim early morning light (which was further reduced by the
very heavy dust cloud) as fast as the fireball disappeared.
b. Earth Shock. This was the second manifestation of the
explosion to be felt at our position, and in our case never
exceeded a rather slight trembling ILLEGIBLE. I was squatting on
the balls of my feet with one shoulder braced lightly against the
forward wall of the trench. In spite of this rather ILLEGIBLE
position, at no time did I lose my balance due to ground motion,
nor did I feel any appreciable ground shock against my shoulder.
This was in apparent contrast to the experience of some of the
members of the volunteer group at an earlier shot (V-1) who,
although at a 500-yard greater distance from ground zero, reported
considerable ground motion. Several persons with when I discussed
this afterwards expressed the opinion that this difference probably
was due to varying geological at the two locations.
5
SECRET
SECURITY INFORMATION
SUBJECT: Report of Participation in Selected Volunteer Program of
ILLEGIBLE ILLEGIBLE V-7, and Description of Effects of
ILLEGIBLE Burst as Observed at 2,000 Yards From Ground
Zero.
of the shock wave required slightly less than 4 seconds to reach
our position. It was loud enough to be startling, but not at all
painful. In this latter respect, I did not find it as annoying,
for example, as the "crack" of a three-inch AA gun. It was more of
a "boom" than a sharp crack. It was accompanied by a shower of
light pebbles and heavy dust, but no other missiles of any kind
were felt or observed at our range. I could not recall afterwards
having had any ILLEGIBLE of increase of pressure from the positive
phase of the shock wave, or reduction due to the negative phase,
but this might easily have been obscured by the startling effect of
the noise. Calculations made afterwards for yield of 50 ILLEGIBLE
indicated that the overpressure at this position was about 4 psi on
the surface, with a possible increase to 5 psi at the bottom of the
trench due to reflections. There was no appreciable caving or
spalling of the trench either from ground shock or air blast."
d. Heat - There was no sensation of heat in the trench; not
even on my face, which was entirely exposed except for the small
area covered by the frames of my safety goggles.
e. Nuclear Radiation - The first reading which I was able to
obtain on my survey meter was exactly 100 r/hr. I estimate this to
have been at about 8 seconds after the detonation, as soon as the
light had diminished ILLEGIBLE for me to regain my sight. At this
time, the pointer on the instrument was moving smoothly downward.
The decrease in the
___________________________________
The soil in this area consisted of hard ILLEGIBLE. A looser
material might not have stood as well. For further evidence on
this, see AFSEP Report ILLEGIBLE, "ILLEGIBLE Type ILLEGIBLE
ILLEGIBLE Shelters"; also see tab marked "Supplement".
I carried an IM-71/PD ("CASPER") miniature ion chamber survey
meter, which has a range of 0.02-500 r/hr.
6
SECRET
SECURITY INFORMATION
SUBJECT: Report of Participation in Selected Volunteer Program of
ILLEGIBLE ILLEGIBLE V-7, and Description of Effects of
ILLEGIBLE Burst as Observed at 2,000 Yards From Ground
Zero.
reading was fairly rapid at first - down to 50 r/hr during the next
ten seconds or so - but the note of decrease then gradually slowed
down so that it required about one additionalminute for it to drop
down to a reading of between 20 and 25 r/hr. I was calling the
readings over to the group leader in the other trench, and at this
point he directed us to leave the trenches. I watched the meter as
I climbed out, and it moved up to 40 r/hr as I left the trench for
the open ground. We stopped briefly to examine some sheep which
had been tethered in a dugout, in shallow trenches, and in the open
in the vicinity. As we did so, I noticed that the meter reading
was gradually increasing, so that it was again up to about 50 r/hr.
by the time we started walking down the road away from ground zero.
It was then about 4 or 5 minutes after the burst. During all this
time, particles of sand or other debris was continually raining
down on our helmets; the sound ILLEGIBLE light alerting.
11. As we walked away from ground zero, the survey meter
reading steadily decreased, but whenever we stopped to look at
something, it would gradually increase again which indicated that
a substantial amount of fall-out was still being deposited at those
distances (between 2,000 and 2,500 yards from ground zero). After
we had walked for about a quarter of a mile, we were met by our two
evacuation trucks; by this time the instrument reading was down to
about 10 r/hr. The reading
___________________________
A study of the cloud motion pictures of this burst indicates that
the height of the cloud was roughly 5,000 feet at the end of the
first 20 seconds, and that 60 seconds later it had risen to about
ILLEGIBLE feet.
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SECRET
SECURITY INFORMATION
SUBJECT: Report of Participation in Selected Volunteer Program of
ILLEGIBLE ILLEGIBLE V-7, and Description of Effects of
ILLEGIBLE Burst as Observed at 2,000 Yards From Ground
Zero.
continued to decrease rapidly as we moved away from ground zero by
truck, and was down to less than 1 r/hr. by the time we reached the
main body of troops at the 4,000 yard position.
12. It was difficult to read our quartz fiber dosimeters
immediately after the shot because of the heavy dust cloud, but
early readings obtained by flashlights indicated that of the total
average dosage of ILLEGIBLE received by the members of the group,
about 10 or 11 ILLEGIBLE, was in the form of prompt radiation
(received within less than a minute after the explosion), and the
balance was residual radiation received during the withdrawal from
the position. Most of the 0 to 10 r self-reading dosimeters
carried by the group went slightly off-scale, but a higher range
dosimeter which I was carrying (1M/91/PD) read 10 r when I left the
trench and ILLEGIBLE r back at ILLEGIBLE.
13. Tab F is a tabulation of the film badge readings for the
group. About the only "pattern" noticeable in this list is that in
most cases, the "chest" reading is the lowest and "hip" reading is
the highest. This is not surprising, since the chest film badges
were in our breast pockets and were shielded from ILLEGIBLE-shine
by our bodies in the squatting positions which we assumed at the
time of the burst. The "head" badges. although closer to the top
of the trench, were shielded by our steel helmets. In addition to
the film badges, each officer carried one phosphor glass locart
type of dosimeter (DT-60/FD) and one holder containing several
Polaroid self-developing film badges (DT-60/PD) which I had
obtained from the radian instrument evaluation group at Camp
Mercury. When checked
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SECRET
SECURITY INFORMATION
SUBJECT: Report of Participation in Selected Volunteer Program of
ILLEGIBLE ILLEGIBLE V-7, and Description of Effects of
ILLEGIBLE Burst as Observed at 2,000 Yards From Ground
Zero.
afterwards, the phosphor glass readings did
not correlate individually with the film badges, but the average
reading for the group (13.6r) checked exactly with that of the film
badges. This agreement was as good as could be expected, since the
DT-60's were designed for a range 0-600r, and could not be expected
to be very accurate at these relatively low readings. All of the
Polaroid badges checked less that 30r, which was the lowest step on
their scale.
14. The principal effect visually observed above-round after
we had emerged from the trench were:
a. Sheep - Those in the vicinity were singed to a dark
brown color on those portions of their bodies which had been
exposed to line-of-sight thermal radiation, but they were all on
their feet and showed no other evidence of physical injury.
b. Trees - A large ILLEGIBLE tree just outside our
trench was partly broken off and on fire. It can be seen in the
upper picture on Tab D. Other ILLEGIBLE trees were burning on all
sides of our position.
c. Dust - The dust was sufficient to make the
visibility very poor beyond a hundred yards or so in any direction,
but was not heavy enough to be suffocating. I did not feel the
need of putting on my gas mask, and did not use it.
15. A stop was made for a monitoring check at the ILLEGIBLE
Rock station across from the ILLEGIBLE ILLEGIBLE on our way back to
camp. It was found that ILLEGIBLE off our clothing and shoes with
a ILLEGIBLE was sufficient to bring the reading down to an
acceptable level.
9
SECRET
SECURITY INFORMATION
SUBJECT: Report of Participation in Selected Volunteer Program of
ILLEGIBLE ILLEGIBLE V-7, and Description of Effects of
ILLEGIBLE Burst as Observed at 2,000 Yards From Ground
Zero.
16. Following our return to camp, we were given an "ILLEGIBLE
interview" by the Army psychologists, and filled out
questionnaires, Tab C. With respect to the question concerning the
ability of troops to carry on immediately after emerging from
trenches under those conditions, it was the ILLEGIBLE of opinion
that there should have been no difficulty except a radiation in
efficiency for about the first five minutes ILLEGIBLE to the heavy
dust cloud and resultant poor visibility.
17. Tab H is enlarged from a frame of a motion picture at 13
seconds after the blast, taken from a camera station seven miles to
the east of ground zero. The position of our trench relative to
the early cloud and fireball is indicated to scale by the white
arrow, i.e., at a point 2,000 yards to the left of ground zero.
R. A. ILLEGIBLE
CAPTAIN, U.S. Navy
5 June 1953
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