These cables were laid in trenches at a depth of two feet and entered
Station 69 through pipe sleeves in the concrete wall,
Cables within the
station were terminated in a control and signal cabinet. Extensions from
this terminal cabinet to the timing equipment within the Station 69 were
made by the Users.

After trenches were excavated, a layer of sand was specified at the
bottom. Cables were to be laid in place on this sand bed, using a large
low-boy trailer which could handle six to eight 5,000 foot reels simulta-

neously.

When all cables were in place in the trench, a layer of sand was to

be handplaced and the remaining portion of the trench mechanically back-~
filled to grade. Posts supporting signs indicating direct burial cable
were then installed at appropriate intervals.

Cables serving stations which did not have enclosing structures were
specified to be terminated six feet above the ground and supported on a
driven stake to which was affixed the station number and wire identification. Extensions to equipment were made by the Users.
Cables and wires were identified by metal wrap~around tags with the

site number, timing station number, controlled station or intermediate
terminus, and the pair number stamped thereon. Plastic tags had been

ordered for this purpose, but because of poor delivery they were not used.

TERMINAL CABINETS
Terminal cabinets for control and signal work were planned and specified prior to the firming of the ultimate requirements, in order to avoid
delay in construction. These estimated requirements were increased 20

per cent to allow for spares.

Burk's Series 1000 terminal strips were

specified in galvanized terminal boxes which were complete with hinged

doors and padlock hasps, Ample gutters for wiring space were provided.
The spare capacity was sufficient for a great many of the increases, but
at a few locations it was necessary to install additional terminal strips.
The entire installation of terminal cabinets, with these additions, functioned satisfactorily.

COAXIAL CABLE
At the inception of the Project, it was known that a quantity of com
mercially available flexible coaxial cable would be required for the
transmission of signals from detecting instruments to recording stations.

However, this wae a problem associated with particular experiments and no

difficulties were anticipated by H & N in providing trenching plans to accommodate these signal systems.
As time passed and new experiments were added to the program, the
quantity of coaxial cable to be installed at the various experiment
islands reached large proportions and included, in addition to the flex~

ible cable mentioned above, semi rigid 1 5/8 inch and rigid 3 1/8 inch
5-254

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