This document discusses fiber optic cable placement methodology, including pre-survey, trenching, plowing, and standards. A pre-survey is important for planning direct buried cable routes to determine reel locations and potential issues. Trenching involves digging a trench, placing the cable, and backfilling, while plowing inserts the cable into the ground behind a plow blade. Plowing is generally faster but trenching allows better control and avoids underground utilities. Standards cover minimum cable depths, testing, restoration of surfaces, and marker posts along buried runs. Fiber optic cables require careful handling and bending to avoid degradation.

1. Presented by:
Kamran Bashir
InspectorI - Telecom

2. General-(Placement Methodology)
Pre-Survey
Location and Depth
Plowing Method
Trenching Method
Plowing vs. Trenching
FOC Unreel Procedure
Applicable Engineering Standards
for FOC-OSP Execution.

3. Placement methods for direct buried cable are essentially the
same as those used for placing direct buried copper cable.
However, it must be kept in mind that fiber cable is a high capacity
transmissionmedium which can have its transmission
characteristics degraded when subjected to excessive pulling
force, sharp bends, or crushing forces.
Fiber optic cables are more susceptible to performance
degradation due to tight bending than copper cables. The
minimum bend radius of each cable is relative to the cable
diameter. A general guide line is that a cable under tension should
not be exposed to a bend radius less than 20 times the cable
diameter and a cable with no tension not to be exposed to a bend
radius less than 10 times the cable diameter.
Standard FOC cable has maximum recommended pulling tension
of 600 lbs.

4. A pre-survey of the fiber cable
route is very important in
planning for a direct buried
optical fiber project. One of the
objectives of the pre-survey is
to determine where each reel of
fiber optic cable is to be placed.
The pre-survey will verify
construction methods, special
tools required, or possibly
require a revision of preliminary
splice location.
A good pre-survey and proper
planning will preclude reel ends
falling too close to roads,
creeks or any other undesirable
locations.

5. Buried fiber cable route locations
are selected by the Outside Plant
Engineering group.
When burying fiber optic cables
that must cross ditches, avoid
crossinglocations that might
interfere with natural drainage.
Also, avoid areas subject to
surface drainage that may result
in subsequent washing away of
soil and exposing of the fiber optic
cable.

6. Plowing refers to the insertion of
a cable into the ground through
a hollow plow blade or by pulling
the cable into the ground just
behind the plow blade.
When plowing method is to be
used for burying the optical fiber
cables, verify and ensure that
the route is pre-ripped before
plowing in the fiber optic cables,
so that obstacles can be
identified and removed or
necessary precautions taken
prior to the actual placement of
the cable.

7. Trenching is where a trench is dug,
the cable is placed into the trench,
and then the trench is backfilled.
Direct buried fiber optic cables shall be
placed with a minimum cover of:
1200 mm, when placed with no
additional protections.
760 mm to 1200 mm, when placed
inside polyethylene sub-duct.
250 mm to 760 mm, in rocks areas,
when placed inside concrete
encasedconduit.
Fiber optic cables shall not placed
with less than 250mm cover in any
situation.

8. IV. Plowing vs. Trench:
In general, the most desirable and
economical method of cable
placement in open area such as
desert area is plowing. Here there will
be fewer obstacles to impede the
progress of the plowing equipment.
Advantages of Plowing:
Speed of installation in open areas.
Less ground disturbance than may be
caused by trenching.
Disadvantages of Plowing:
Large size and high cost of
equipment.
Requires skilled equipment operators,
quality supervision, and equipment in
good condition.
Possibility of damaging cables or
under ground utilities.

9. In urban or sub-urban areas where
there can be many obstacles such as
underground utilities, side walk and
paved road crossings, trenching has
advantages.
Advantages of Trenching:
Lower cost of equipment.
Digging operation is separate from
cable placement.
Better depth control.
Less risk of damaging underground
utilities.
Provides the opportunity to place
conduit at the same time.
Disadvantages of Trenching:
Slower rate of cable placement than
with plow.
Not suitable for all soil, sands and
terrain conditions .

10. The “figure-eight” configuration should be used
to prevent kinking and twisting when the cable
must be unreeled. The “figure-eight” should be
approximately 4.5 to 9.0 meters in length. Each
loop should be approximately 1.5 meters to 4.5
meters in diameter.

11. PLOWING(typicaltrenchdimension)
When plowing in fiber optic cable a
warning orange terra tape is placed 12”
below the surface of the ground directly
above the cable. Both the cable and
the warning tape are normally plowed
in at the same time.

12. TRENCHING:
When trenching ensure an orange marker tape is placed flat in the trench above
all open trench for direct buried fiber optic cables. The marker tape is to be
placed approximately 300 mm below grade.

13. MARKERPOST
On the straight runs of buried
cable, marker posts shall be
placed no further than 100
meters apart. This clearly
indicate the route and to warn
the public and other workmen in
the presence of the buried cable.

14. CONT’N – APPLICABLE STANDARDS FOR FOC -OSP
FOC TESTING
End-to-end testing shall be
carriedout on all Outside
Plant fiber optic facilities
(define as the span of fiber
from the transmitter to
receiver) to document the
overall optical loss.

15. CONT’N – APPLICABLE STANDARDS FOR FOC -OSP
 All permanent pavement
and sidewalks must be
restoredto the satisfaction
of proper authorities.
 Verify that the surface at
grade level of the
excavated area is restored
to as good or better than
the original condition.

16. SATIP-T-624
CONT’N – APPLICABLE STANDARDS FOR FOC -OSP
SAIC-T-5408

17. “Quality is never an accident; it is always the result
of high intention”