CHAPTER It, SECTION 1A
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permissible latitude in locating a station, and
the required accuracy in determining its relation
to the primary controls. The latitude in locating
a station was specified by the User. The relation of the majority of the stations to a specified
primary station was determined within a linear
tolerance of 1:5,000. Where greater accuracy
was desired for outlying stations the linear
tolerance was stated to be within 1:10,000, the
minimum strength of the primary network.
However, the actual accuracy of location can be
considered to be greater than the minimum
value. Figure 2-13 notes typical example of the
layout of a Scientific Station.
Procedures were established to assure that
the accuracy of layout was within specified tolerances. The working point of a station was established by a measured angle and distance
from a local control point. This working point
was then occupied and check angles observed
Figure 2-13.
Survey Layout of Scientific
Station
In addition to the scientific programs, considerable survey time was expended at Eniwetok
Atoll on the long range improvement program
at sites Fred and Elmer. This efiort included
“as-built”? surveys of existing construction to
facilitate design of new improvements and the
layout for construction of these improvements.
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SCIENTIFIC STRUCTURES. The large num-
ber and variety of Scientific Stations subject to
changes in design and location by Users were
major construction layout items. These varied
from location of moorings in the lagoon to layvul of targe concrete structurcs requiring the
services of a survey party at intervals throughout construction. The laying out of the three
UCRLpipe arrays were unusual surveys due to
the large number of individual items to be laid
out and then checked during construction.
ASSISTANCE TO INSPECTION.
In-plece
checks were performed including the alignment
of concrete forms, interior walls, and location
of equipment. Settlement checks were made
on major structures, and final cross sections
were surveyed to bring causeways and earth
fills over structures to design grade. Close zelations were maintained with the Inspection
Department to assure scheduling which would
meet the daily construction requirements.
LAYOUT AND LOCATION OF SCIENTIFIC
STRUCTURES.
ACCURACY OF LAYOUT.The layout of these
structures was controlled by two factors: the
Figure 2-14.
Precise Measurement Survey
Party
to one or more additional control points. Figure
2-14 shows a precise measurement party at work
and procedure used in holding on rear mark.
The orientation of the station was checked,
where possible, by direct observation to the
primary station. Where this was not possible
the orientation was checked by laying off computed angles from two or more iocal control
points.
LAGOON STATIONS.Scientific Stations were
moored in the Bikini Lagoon and in the Eniwetok Lagoon. Due to the mooring scope of
these stations, a high degree of accuracy in
location was not possible. A procedure was established which was satisfactory to the User
and consisted of determining the location by
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