“i
‘ CHAPTER 2
EXPERIMENTAL DESIGN
2.1
OPERATIONAL CONCEPT
Project 6.5 was conducted in close coordination with Project 6.)
which operated two especially equipped liberty ships by remote radio
control through regions of high intensity fallout following each of
several surface thermonuclear detonations on land and over relatively
shallow water. The two ships, designated as the YAG 39 (Transit Able)
and the YAG hO (Transit Baker}, respectively, were identical
externally except that the YAG 39 was equipped with a salt water
washdown countermeasure system, designed to operate prior to and
during the contaminating event, to minimjze the residual contamination
level,
Previous work in the laboratory?
and in field tests on
ships!2,13 using simulants indicates that washdown countermeasures are
highly effective.
,
Sets of 1), four foot square test panels (Table 2.1) of widely
used building construction surfaces were mounted on tubular steel
racks (to facilitate removal from the ships). These racks were
mounted on the weather surfaces of each of the two ships, near the
stern, in such manner as to be exposed to the fallout.
the rack and panel set on board the YAG 4O,
sew 7
Fig. 2.1 shows
After the contaminating
event and following recovery of the ships, the panels were
transferred to a clean land area on Parry Island where decontamination
operations were performed free from the excessive radiation background
found on the ships,
Participation of Project 6.5 on board the above ships included
Shots 1, 2 and h. Shot 1 occurred on land and the remaining two
shots were on barges in shallow water. Shots 2 and h produced
desirable amounts of contamination on the panels while the levels
resulting from Shot 1 were negligible and of practically no value for
analytical purposes, For participation in Shot 6, a complete set of
the same panels, mounted on one of the racks, was placed on a Navy
Type YC 500 ton barge which was anchored in the Eniwetok Lagoon at
Station 650. This location was estimated to be beyond serious thermal
and blast effects, but well within the area of fallout. An
additional set of small scale (16 in. x 32 in.) painted wood panels
Uy
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