Page 90 - Optical Communications Essentials

Optical Fiber Cables

80 Chapter Five

5.6. Installation Methods
Workers can install optical fiber cables by pulling or blowing them through
ducts (both indoor and outdoor) or other spaces, laying them in a trench out-
side, plowing them directly into the ground, suspending them on poles, or lay-
ing or plowing them underwater. Although each method has its own special
handing procedures, they all need to adhere to a common set of precautions.
These include avoiding sharp bends of the cable, minimizing stresses on the
installed cable, periodically allowing extra cable slack along the cable route for
unexpected repairs, and avoiding excessive pulling or hard yanks on the cable.

5.6.1. Direct-burial installations
For direct-burial installations a fiber optic cable can be plowed directly under-
ground or placed in a trench which is filled in later. Figure 5.12 illustrates a
plowing operation that may be carried out in nonurban areas. The cables are
mounted on large reels on the plowing vehicle and are fed directly into the
ground by means of the plow mechanism. Since a plowing operation normally is
not feasible in an urban environment, a trenching method must be used.

Figure 5.12. Plowing operation for direct burial of optical fiber cables. (Photo courtesy of
Vermeer Manufacturing Company; www.vermeer.com.)

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