were recovered from Stations that had been in place since April. The subsurface floats s howeg
no wear or damage and only slight fouling. One of the subsurface floats, which was coate
a with
polyester resin, appeared as clean as when installed.
The special 0.120-inch-wire clamps and the 0.120-inch mooring wire were in good cond ition,
The problems of electrolysis appear to be solved.
Cursory examination indicated that the Se
moorings were capable of staying in many more months.
At present, the most vulnerable point in the mooring system lies in the possibility of the
nylon pennant fouling on the subsurface float and eventually chaffing through. This fouling can
occur only during the laying of the mooring. It was essential, therefore, that a constant Strain
be maintained on the nylon pennant as the subsurface float was being lowered.
This fouling oc.
curred several times while the subsurface float was still in sight, and the float was hauled in
and cleared.
On those stations where wire rope was used, another cause of fouling, as evidenced bya
recovered nylon pennant, was the torque from twisting during lowering that was not relieved by
the swivels in the system. Galvanized marine swivels are notorious for their lack of performance
As a result, when the float was at its depth and the mooring wire was cut, the subsurface float
would spin, winding the nylon pennant about the float and causing eventual failure. Of course,
under certain static conditions of current and weather, a slack nylon pennant might be subject
to fouling. To prevent this, the floating characteristics of nylon were aided by small plastic
floats spaced along the pennant, and a large glass ball was situated so that a constant strain was
kept on the pennant.
4.6.3
Reliability of Station Positions.
The Sioux (ATF-75) was equipped with BAS-4 loran
and an AN/SPS-5B radar. The loran was checked and calibrated just prior to this operation.
The radar was of a recent type, just installed; however, very few of the stations were in close
enough to the atoll to permit radar positioning. No trouble was experienced with the loran, and
station positions checked out very well.
The positions of the stations were frequently checked.
They usually plotted within a mile of the original position.
The standard deviation of the DAS-4
loran as checked in the area was plus or minus 1.2 miles.
In practice, station positions were
considered unchangedif the loran fix checked within a mile; however, if on recovery the fix
change exceeded a mile, a new position was noted for the station. Several stations dragged
about ¥, mile a day during the first few days they were anchored; however, after this initial dragging the stations stayed in place.
4.6.4 Locating Instrument Skiffs. The Sioux experienced no difficulty in locating the instrument skiffs, either by day or night. Radar pickup on the skiff’s reflector under nominal sea
conditions was about 8 miles. At night, the small (0.8-ampere) light on the skiff was visible
about 5 miles. At times, aircraft reconnaissance was utilized as a check on the stations. This
reconnaissance by aircraft equipped with radar was effective, and in calm weather the stations
could be located at about 40 miles. It was found that aircraft without radar were definitely
handicapped in such a search.
4.6.5 Servicing Instrument Skiffs. The recovery and servicing of instrument skiffs after
each shot went very well. The Sioux was able to recover and service six to eight stations per
day.
The fallout collector samples and the AFOAT samples were sent out ona D+4 flyaway.
No difficulty was encountered in meeting tnis schedule, except following Shot Cherokee. Damage
to the skiff-retrieving ramp prevented complete recovery after that shot. On the basis of the
experience gained in recovery and servicing on this operation, it is believed that twenty instrument skiffs would be the maximum one ship could service in 3 days, assuming the distances as
used during Operation Redwing are not greatly altered. The system of hauling the instrument
skiffs on board for servicing was highly satisfactory.
during previous operations by roughly 75 percent.
in rough weather.
This reduced the time spent on station
The skiff-retrieving ramp worked well, even
Obviously, there are weather limitations, but none were experienced on this
operation.
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