Study of the photographs forces. the conclusion that AOC was in error, and that the ship's
own data are correct. Use of the AOC data leads to an apparent maximum cloud height
of 52,000 feet, in disagreement with other results and with all past experience with bombs
in this range of yields. The navigator's data lead to the eminently reasonable figure of
70,000 feet, in exact agreement with the data from the other plane.
The results are given in Figure 5.5. The dashed lines represent intervals during
which the particular feature was hidden by natural cloud and are thus reasonable interpolations. It is felt that a «5 percent uncertainty applies for the entire 10-minute
TABLE 5.5
Film
EG&G
Number
LML
472
ALDAS
24473)
ALDI2B
24450
24451
24457.
24463
24464
FILMS EXPOSED, SHOT 6
Loca~
tion
24467
125C3
24468)
«=—:192B3
24469
—«13SB
24470-1354
24471
ALDI2A
»
RB36
5561
5615
5482
RB3I6
.
5616
5482.—«:
PARRY
PARRY
PARRY
/
:
é
Nav.
Data
Comments
OK
OK
OK
OK
OK
Clouds,
Clouds,
Clouds,
Clouds,
Clouds,
NG
NG
read 3 minutes
NG
NG
OK
OK,
Clouds,
Clouds,
Clouds,
Clouds,
Clouds,
read 5 minutes
read 8-minutes
NG
NG
NG
.
PARRY
.
|
Clouds, NG
PARRY
Clouds, NG
' interval. It should be noted that the height-to-top measurements are reliable in spite of
the poor photographic quality, because the cloud height was less and the camera distance
greater than usual,
_
;
.
5.7
|
,
DISCUSSION
Although the results presented here cover a shorter time interval than had been expected and although unforeseen operational difficulties were encountered, it is believed that
TABLE §.6
Shot
Castle
Height to Top
(thousands of fect)
Max.
1 min.
4
110
94
47
44
356
5
ilo
“4
98
39
72
Ivy
Mike
King
-
76
‘
s
7
28
14.8 2 062
11.0 4 04
6.88 2 0.12
38
33
26
370
316
125
13.6 + 0.2
34
270
aad
30
200
1.69 = 0.03
:
.
6.550 + 0.028
+
!
Diameter
(thousands of foet)
1 min.
10 min.
Fireball
Yield O17) -
,
1
2
4
6
SUMMARY OF CLouD PARAMETERS
12
.
tt
=
uz
—_
90
{
4
these measurements are good over the most~important time period, prior to cloud stabilization. Over this period tho data are by far the best we have ever had to work with.
The results of the cloud-rise measurements are generally in good agreement with
the less-accurate results from Operation Ivy. For purposes of comparison, Table 5.6
lists for the Ivy and Castlo shots the following pertinent information: the- maximum ob-
served value for height-to-top, the height-to-top at 1 minute, and the cloud diameters at
The height at 1 minute is a fair measure of the upward ve~
locity of the rising cloud. This appears to increase with yield although the data for Shot
26
SECRET
A ee ee ak cant te»
7
1 minute and at 10 minutes.