18.104.22.168 Application. Use wire-armored cable where extreme tensile strength
and high resistance to mechanical damage are required. In this type of cable,
asphalt-impregnated-jute usually is applied directly over the lead sheath, and
the wire-armor is applied over the jute to reduce mechanical damage and
electrolytic corrosion. An additional covering of asphalt-impregnated-jute
may be applied over the armor.
22.214.171.124 Wire-Armor. Wire-armor is usually made of galvanized steel wire.
The galvanizing protects the armor from corrosion and reduces electrolytic
corrosion of the lead sheath. This reduction, however, may be at the expense
of the armor, because under certain conditions the zinc passes from the armor
to the lead sheath.
Nonmetallic-Sheathed Cable. For submarine service, cables without a
metallic sheath are satisfactory for certain applications. When cables
without protective lead sheaths are used, they should be types manufactured
specifically for submarine service. They may or may not require wire armor.
Such cables are provided with insulation of extra thickness for all sizes and
Shielding. Nonmetallic-sheathed cables should be shielded
throughout their lengths. Normally the voltage rating will already require
Cable termination, splicing, and bonding is
126.96.36.199 Potheads. A lead-covered submarine cable is occasionally connected,
at either or both ends, to an overhead line. Under such circumstances, use a
pothead with an integral wiping sleeve as a convenient method of terminating
the cable. This method eliminates the junction box on shore and associated
labor costs of the extra cable splices. By bringing the submarine cable out
of the ground in a suitable conduit sleeve, or other mechanical protective
arrangement, the cable can be supported on a permanent steel or wooden
structure. Cables in conduit strapped to the supporting structure, are then
run directly into a pothead, which is mounted at the desired height on the
same supporting structure.
188.8.131.52 Three-Conductor Potheads. Adverse atmospheric conditions can make
it dangerous to use three-conductor potheads for such cable terminals. Under
such conditions, the multiple-conductor cable may be spliced out with single-
conductor cable and single-conductor potheads employed to permit increased
clearances between pothead bushings.
Splices. Use maximum lengths of cables to reduce the number of
splices. The types of splices shall be in accordance with NFGS-16301.