i
and many had to be replaced during the operation. After Shot 1, several
rafts capsized although they were designed to withstand the effect of 4
.
10-MT weapon, 5 miles distant.
3.2.3
Free-flosting Sea Stations
The performance of free-floating buoys as collecting staticns
was important to the main objectives of the present work. Although
little data on fallout were secured from these stations, sufficient
information was obtgined to determine the performance of the equipment
and the suitability of the method. The following observations are
pertinent:
(a)
satisfactory.
Pesformance of the buoys and associated equipment was
;
‘the low-frequency transmitters together with the radio
direction-finding gear aboard Naval units provided an adequate system
for locating and identifying the buoys.
The handling problem in place-
ment and recovery raised some difficulties, perticwlarly in increasing
seas, but was satisfactorily met.
(b)
The free-floating buoy syste was unsatisfactory for docu-~
menting fallout under the conditions of shot scheduling which prevailed
after the first test. This statement would be true of any similar system having the prerequisite that the test take place within a 24-hr
period specified 24 to 48 hr in advance.
3.2.4
Total Collectors
From evidence giyen in Sections 4.2.1 and 5.1.2, modifications
in the design of total collectors are indicated, Nevertheless, both
devices used made satisfactory collections under some exposure conditions.
As exrected from other experience, the principle of using simple continuously open (collecting) sampling devices was found satisfactory whenever
only total radioactivity deposited per unit area was to be determined,
Such devices are not satisfectory where it is desired to preserve the
characteristics of the fallout because dilution by extrameous rain and
dust occurs.
3.2,5
Belt Sampler
The belt sampler was handicapped by too many moving parts which
were exposed to the elements. It was badly corroded by sea spray; sand
lodged in the gears or under the belt and caused the sampler to function
poorly. The collecticn from this sampler on Shot 1 was much better than
on subsequent shots. Considerable valuable data were obtained as shown
in CLupter 4,
3.2.6
Liquid Droplet Sampler
~
The prototypes tested at CASTLE failed to operate in most
instances. This failure was due both to a faulty triggering mechanism
for indexing the trays and to the absence of liquid droplets in the
fallout from most shots. Nonetheless this differential collector has
42