CHAPTER Il, SECTION 3
This station consisted of two steel tanks,
one inside the other, and three sand-filled baffle
boxes. The inner tank was 10 feet in diameter
and approximately 11 feet high. The outer tank
was 30 feet in diameter and 22 feet 7 inches high
in order to maintain 10 feet of water over the
inner tank. The inner tank was made of 7,16inch steel plate, and the outer tank was made
of 3/16-inch steel plate. A 14-inch steel floor
was placed on the 15-inch concrete foundation
to maintain continuity between the tanks. A
structural steel tunnel on the west side of the
tank, equipped with water-tight doors, provided
access from the outside to the inner tank.
A concrete pad, 12x30 feet, was located.
outside the entrance tunnel to provide a stable
surface for loading equipment in the tank. One
lished between the first two sand boxes. A small
4x3-foot elevated platform and ladder were
provided on the south side of the tank for mounting antennas.
The inner tank was equipped with a revolv-
ing one-ton capacity bridge crane on a circular
track with an 8-foot hook height. Two 12-inch
pipes were run through the foundation to the
inner tank to furnish a fresh air supply and
exhaust. By means of two 540-gpm, gas driven,
centrifugal, pumps and wells, the outer tank
was filled with sea water. The tunnel could be
filled from the main tank by closing the watertight doors. The outer tank and tunnel could be
drained independently.
Power was supplied by two 30-kw, 120,::08-
36-inch and one 4-inch-diameter pipe was installed through the tanks on the lines of sight to
volt motor generators through a power panel.
sand baffles, of timber construction and filled
with coral sand, were located on the line of sight
to Station 1211 at distances of 25, 41, and 104
1312. Utility and scientific power in the inner
tank was distributed from an 8-circuit lighting
panel. Timing signals were provided by one 51pair signal cable terminated in a 53-pair signal
Stations 1211 and 1311 respectively. The three
feet from the station working point. The first
baffle was 10% feet high, 5 feet thick, and 15 feet
wide. The second and third baffles were 13 feet
high, 5 feet thick, and 20 feet wide. A fenced
area with stabilized pad and a roof was estab-
Also this power panel furnished power for three
trailer receptacles and the utilities for Station
cabinet. Stations 81.21, 83.21, and 1: :3 were
also connected to this cabinet. Telephone instru-
ments were connected in a similar manner to
those in Station 20.
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Figure No. 2-23.
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(Neg. No. W-V-239-7)
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Station 21 Inner Tank and Access Tunnel.
Page 71