Selecting Cable

runs along masts or in compartments that are subject

Selecting Cable

to sweating. In more recent installations, semicontour

When selecting cable, use all reference data avail-

straps and cable bands are used for certain

able. Electrical cables installed aboard Navy vessels

applications.

must meet certain requirements determined by the

The exact methods of installing cables can be

Naval Sea Systems Command. These requirements,

published in the General Specifications for Ships of

found in the Electronics Installation and Maintenance

the U.S. Navy, NAVSEA S9AA0-AA-SPN-010/

Book, NAVSEA SE000-00-EIM- 110.

GEN.SPEC, are too numerous to cover in detail in this

training manual; hence, only the more basic ones are

Cable Supports

included.

Types of cable supports are the single cable strap,

Installing Cable

cable rack, and modular cable supports.

SINGLE CABLE STRAP.-- The single cable

Before installing new cable, survey the area to see

strap is the simplest form of cable support. The cable

if there are spare cables in existing wireways and

strap is used to secure cables to bulkheads, decks,

spare stuffing tubes that can be used in the new

cable hangers, fixtures, and so on. The one-hole cable

installation. The cable run must be located so damage

strap (fig. 2-44, view A) may be used for cables not

from battle will be minimized, physical and electrical

interference with other equipment and cables will be

exceeding five-eighths of an inch in diameter. The

avoided, and maximum dissipation of internally

two-hole strap (fig. 2-44, view B) may be used for

generated heat will occur. Do not run cables on the

cables over five-eighths of an inch in diameter. The

exterior of the deckhouse or similar structures above

spacing of simple cable supports must not exceed 32

the main deck, except where necessary, because of the

inches center to center.

location of the equipment served or because of

structural interferences or avoidance of hazardous

conditions or locations. Where practicable, route vital

cables along the inboard side of beams or other

structural members to afford maximum protection

against damage by flying splinters or machine-gun

strafing.

Where practicable, avoid installing cable in

locations subject to excessive heat. Never install cable

adjacent to machinery, piping, or other hot surfaces

having an exposed surface temperature greater than

150F. In general, cables should not be installed

where they may be subjected to excessive moisture.

Because attenuation (power loss) in a line

increases with its length, cables should be kept as

short as practicable.

Flexible cables are flexible only in the sense that

they will assume a relatively long bend radius. They

are not intended to be stretched, compressed, or

twisted. Bends are made as large as practicable.

The numbers of connectors are generally kept to

a minimum to reduce line losses and maintenance

problems.

Fabricated straps are used for holding the cables.

They are snug, but not too tight. Back straps (which

keep the cable away from a surface) are used for cable

Figure 2-44.-Single cable strap applications.

2-41