Proprietary and Confidential Company Information
Specification Document Information
TITLE Number ENG SPE 001
Fibre Optic Cable Specification
Issue Number 2.0
Revision 0.2
Effective Date 2020-11-26
Print Date 2020-11-26
96 Koranna Avenue,
Doringkloof, Centurion
Document History
Rev Date ECP Paragraphs Amended
© DARK FIBRE AFRICA
(Pty) Ltd
The copyrighted designs, products and processes contained
or described in this document are confidential.
This document, either in part, or
as a whole, may not be copied or
reproduced by any means whatsoever, nor disclosed to
third parties for purposes other
than for which it is supplied, without the prior written consent
of
DARK FIBRE AFRICA (Pty)
Ltd
And shall not be furnished to any
third party without the prior written consent of
DARK FIBRE AFRICA (Pty)
Ltd.
1.0 15/06/2010 NA Document reformatted. New issue. Replaces previous version
numbered ‘DRC-SPE-001-01-F1 R1’.
1.1 01/02/2009 NA Reformat Paragraph 4.11. Annual review.
1.2 01/07/2010 TechC General update.
1.3 23/10/2012 TechC General update. Include all mechanical tests to be performed on
the optical fibre cables.
1.4 01/07/2013 TechC Update cable sheath coloring based on RAL colour chart. Include
the core and junction cables.
1.5 11/06/2014 TechC
Par 4.3.1 Tensile Strength c) and d) amended; Par 4.3.3
Crush Resistance d).
Par 4.4 . Replace old 144F cable with new 144F cable (24F
tubes);
Appendix A - Update bare fibre colour coding;
Inserted Par 5. Aerial Cable Requirements.
Par 10. SHE Management amended.
1.6 04/09/2014 TechC
Annual review of document.
4F subscriber cable specifications inserted; Figure 4.3.1, Figure
4.3.6
and Figure 4.4.1.3 added.
1.7 09/12/2015 TechC Annual review of document. Include the Aerial and the push-able
Subscriber cables.
1.8 29.11.2016 TechC Annual review of document. Include the following cables: 4F and
48F access cables, 288F route cable.
1.9 06.12.2017 TechC Change fibre type to G.657.A1 for 72F cable. Include OSP
retractable cable for FTTH installations.
2.0 2018.10.04 TechC
Annual review. Various updates.
Par 2.2 Associated Documentation; Figure 4.2.1.2: Mode-field
diameter specification values for DFA; Figure 4.2.4.2: Fibre
maximum macro-bending loss; Pa 4.3 Mechanical Performance
Requirements and Tests.
2.1 2020.02.06 TechC Annual review. Par 4. Optical Fibre Cable requirements amended
and updated.
2.2 2020.11.26 TechC Annual review. Update temperature cycle graph Figure 4.3.5.
Approved: 2020.11.26
Registered on MRI Date
Signature By
Document Owner:
Name Corné Brand Signature Date
DARK FIBRE AFRICA Fibre Optic Cable Specification ENG SPE 001 2.0 0.2
Proprietary and Confidential Information Print Date: 26 November 2020 Page 2 of 27
Position Product Development and Network Specialist
Company Dark Fibre Africa (RF) (Pty) Ltd
Accepted By:
Name Derek Koekemoer
Signature Date
Position Network Architecture and Strategy Manager
Company Dark Fibre Africa (Pty) Ltd
Name Jacques van Loggerenberg
Signature Date
Position Executive: Network Architecture and Strategy
Company Dark Fibre Africa (Pty) Ltd
Name
Signature Date
Position
Company
Authorised By:
Name Andreas Uys
Signature Date
Position Chief Technical Officer
Company Dark Fibre Africa (Pty) Ltd
2020.11.26
2020.11.26
2020.11.26
2020.11.26
DARK FIBRE AFRICA Fibre Optic Cable Specification ENG SPE 001 2.0 0.2
Proprietary and Confidential Information Print Date: 26 November 2020 Page 3 of 27
Table of Contents
1. SCOPE 5
2. REFERENCE DOCUMENTATION 5
2.1 APPLICABLE DOCUMENTATION 5 2.2 ASSOCIATED DOCUMENTATION 5
3. DEFINITIONS AND ACRONYMS 5
3.1 DEFINITIONS 5 3.2 ACRONYMS 6
4. OPTICAL FIBRE CABLE REQUIREMENTS 6
4.1 DFA REQUIRED CABLE TYPES 6 4.2 OPTICAL PERFORMANCE REQUIREMENTS 6
4.2.1 Mode Field Diameter 6 4.2.2 Cladding Diameter 7 4.2.3 Core / Cladding Concentricity Error 7 4.2.4 Cladding Non-Circularity 8 4.2.5 Fibre Curl 8 4.2.6 Cable Cut-off Wavelength 8 4.2.7 Macro-bend Loss 8 4.2.8 Attenuation Coefficient 9 4.2.9 Chromatic Dispersion (CD) 9 4.2.10 Polarization Mode Dispersion (PMD) 10 4.2.11 Refractive Index 11 4.2.12 Fibre Materials 11
4.3 MECHANICAL PERFORMANCE REQUIREMENTS AND TESTS 11 4.3.1 Mechanical Test Setup 11 4.3.2 Tensile Strength 11 4.3.3 Impact Test 12 4.3.4 Crush Resistance 13 4.3.5 Environmental Performance 13 4.3.6 Repeated Bending 14 4.3.7 Cable Flexibility (Bending) Test 15 4.3.8 Cable Torsion Test 15 4.3.9 Cable Water Penetration Test 16 4.3.10 Cable Kink Test 16 4.3.11 Cable Filling Compound Flow Test 16 4.3.12 Buffer Tube Kink Test (Omega Test) 17 4.3.13 Cable Jacket Marking Abrasion Resistance 18 4.3.14 Cable Reliability (MTTF) 18
4.4 CABLE DESIGN AND CONSTRUCTION 18 4.4.1 Cable Design 18 4.4.2 Optical Fibers 20 4.4.3 Loose Tubes and Fibres 21 4.4.4 Strength Member 21 4.4.5 Filling Material 21 4.4.6 Cable Core 21 4.4.7 Cable Outer Sheath 21 4.4.8 Material 22 4.4.9 Cable Workmanship 22 4.4.10 Compatibility 22
5. AERIAL CABLE REQUIREMENTS 22
5.1 OPTICAL PERFORMANCE REQUIREMENTS 22 5.2 CABLE DESIGN AND CONSTRUCTION 22 5.3 MECHANICAL PERFORMANCE REQUIREMENTS 23
6. CABLE PACKING, HANDING AND STORAGE 24
6.1 CABLE SHEATH MARKINGS 24 6.2 CERTIFICATION OF CABLE 24
DARK FIBRE AFRICA Fibre Optic Cable Specification ENG SPE 001 2.0 0.2
Proprietary and Confidential Information Print Date: 26 November 2020 Page 4 of 27
6.3 PACKING AND SHIPPING 25
7. TRANSPORTING AND HANDLING OF CABLE DRUMS 25
8. GUARANTEES / WARRANTIES 25
9. RELEVANT MANUFACTURER DOCUMENTATION 25
10. SAFETY, HEALTH AND ENVIRONMENTAL MANAGEMENT (SHE) 25
11. APPENDIX A 27
DARK FIBRE AFRICA Fibre Optic Cable Specification ENG SPE 001 2.0 0.2
Proprietary and Confidential Information Print Date: 26 November 2020 Page 5 of 27
1. SCOPE
a. This specification document covers the minimum fibre and cable attributes to which the individual fibres
shall comply with for the provisioning of dark fibre links for DFA.
b. This specification also covers the available fibre optic cable design for 4, 12, 24, 48, 72, 144 and 288F
strand mini-fibre cables that will be deployed in the DFA fibre optic cable network.
c. The mini-cables shall be SM and can operate at nominal wavelengths of 1310 nm, 1550 nm and 1625nm.
d. Mini-cables are installed in an underground micro-duct infrastructure by means of cable jetting
(blowing) techniques.
e. The mini-cables can also be floated in aerial micro-ducts.
2. REFERENCE DOCUMENTATION
2.1 Applicable Documentation
a. ENG-PRO-001: Dark Fibre Acceptance Test Procedure for Fibre Links.
b. ENG-PRO-026: Optical Fibre Closure Installation Procedure.
c. ENG-PRO-027: DFA Mini Cable Jetting Procedure.
d. ENG-SPE-003: Fibre Optic Splice Closure Specification.
e. ENG-STD-008: DFA Optical Fibre Network Marking and Naming Convention Standard.
f. HSC-SPE-001: Health and Safety Contract Specifications.
2.2 Associated Documentation
a. ITU-T Recommendation G.657 (11/2016): Characteristics of a bending-loss insensitive single-mode
optical fibre and cable.
b. ITU-T Recommendation G.657 (11/2016): Characteristics of a bending-loss insensitive single-mode
optical fibre and cable for the access network.
c. ITU-T Recommendation G.656 (07/2010): Characteristics of a fibre and cable with non-zero dispersion
for wideband optical transport.
d. IEC/TR 62470 ed1.0 (2011-10): Guidance on techniques for the measurement of the coefficient of
friction (COF) between cables and ducts.
e. IEC 60794-1-21: Generic specification - Basic optical cable test procedures - Mechanical tests methods.
f. IEC 60794-1-22: Generic specification - Basic optical cable test procedures - Environmental tests
methods.
g. IEC 60794-1-23: Generic specification - Basic optical cable test procedures - Cable element test.
h. IEC 60794-3-11 ed2.0 (2010-06): Optical fibre cables - Part 3-11: Outdoor cables - Product specification
for duct, directly buried, and lashed aerial single-mode optical fibre telecommunication cables.
i. IEC 60794-1-1 ed3.0 (2011-09): Optical fibre cables - Part 1-1: Generic specification – General.
3. DEFINITIONS AND ACRONYMS
3.1 Definitions
Definition Definition precise meaning
Optical Link An optical link is defined as the continuous fibre connection between
two connectorised end points
Mini-cable
Mini-cables are optical fibre cables above 12F count resembling a very
small fibre cable, but having no outer layers of reinforcement. Mini-
cables offer a high fibre count (up to 144F) in a small blow-able form.
Mini-cables are blown into micro-ducts.
Micro-duct A micro-duct is a small flexible duct usually made from HDPE with
and outer diameter typically less than 16mm. Micro-ducts are used for
DARK FIBRE AFRICA Fibre Optic Cable Specification ENG SPE 001 2.0 0.2
Proprietary and Confidential Information Print Date: 26 November 2020 Page 6 of 27
Definition Definition precise meaning
the installation of mini/micro fibre cables.
RAL
RAL is used for information defining standard colours for paint and
coatings and is the most popular Central European Colour Standard
used today.
3.2 Acronyms
Acronym Acronym in full
ATP Acceptance Test Procedure
BER Bit Error Rate
CD Chromatic Dispersion
DFA Dark Fibre Africa Pty Ltd
FGRP Fibre Glass Reinforces Plastic
FRP Fiber Re-enforced Plastic
FTTH Fibre to the home
ITU International Telecommunication Union
LS0H ‘Low smoke zero halogen’ or ‘low smoke free of halogen’
MTTF Mean Time To Failure
PA Polyamide (Nylon)
PE Polyethylene
PMD Polarization Mode Dispersion Polyamide
SM Single Mode
4. OPTICAL FIBRE CABLE REQUIREMENTS
4.1 DFA Required Cable Types
a. The following three types of SM fibres are required for deployment in DFA based on the transmission
requirements of the end customers:
i. G.657.A1: Metro routes;
ii. G.656: Long-haul routes;
iii. G.657.A1: Access Routes;
iv. G.657.A2: Access / subscriber cables.
b. The optical fibre cables installed for DFA shall only consist of the fibre and cables as specified in this
specification document. Note, that the legacy G.652.D fibre cables are compatible with splicing onto the
G.657 fibre cables.
4.2 Optical Performance Requirements
4.2.1 Mode Field Diameter
a. The Mode-field diameter is a measure of the spot size or beam width of light propagating in a single-
mode fiber. Mode-field diameter is a function of source wavelength, fiber core radius, and fiber
refractive index profile (Figure 4.2.1.1).
Core
Cladding
DARK FIBRE AFRICA Fibre Optic Cable Specification ENG SPE 001 2.0 0.2
Proprietary and Confidential Information Print Date: 26 November 2020 Page 7 of 27
Figure 4.2.1.1: Light distribution in a SM fiber illustrating the Mode-field diameter measurement
b. The optical fibre cables shall adhere to the following Mode-field diameter values as in accordance to the
ITU-T:
Wavelength Nominal Values Tolerance (Range)
G.652.D 1310 nm 9.3 µm +/- 0.5 µm
G.656 1550 nm 8.5 µm +/- 0.5 µm
G.657.A 1310 nm 9.0 µm +/- 0.4 µm
Figure 4.2.1.2: Mode-field diameter specification values for DFA
4.2.2 Cladding Diameter
a. The cladding is the glass material that surrounds the core of the fibre. The gladding has a lower refractive
index as the core and cause the light to be confined to the core by using an optical technique called ‘total
internal reflection’ (Figure 4.2.2.1).
Figure 4.2.2.1: Fibre construction showing the total internal reflection technique
b. The optical fibre cladding parameters shall fall within the values as specified by the applicable ITU-T
specification:
Nominal Cladding
Diameter
Cladding Diameter
Tolerance
G.652.D 125.0 µm +/- 1 µm
G.656 125.0 µm +/- 1 µm
G.657.A 125.0 µm +/- 0.7 µm
Figure 4.2.2.2: Fibre cladding parameters as specified by the ITU-T
4.2.3 Core / Cladding Concentricity Error
a. The concentricity error of the optical fiber is the distance between the center of the two concentric circles
that specify the cladding diameter and the core diameter.
b. The core / cladding concentricity error shall be within the values as specified by the applicable ITU-T
specification:
Specified Values Unit
G.652.D < 0.6 µm
G.656 < 0.8 µm
G.657.A < 0.5 µm
Figure 4.2.2.3: Fibre core / cladding concentricity error as specified by the ITU-T
DARK FIBRE AFRICA Fibre Optic Cable Specification ENG SPE 001 2.0 0.2
Proprietary and Confidential Information Print Date: 26 November 2020 Page 8 of 27
4.2.4 Cladding Non-Circularity
a. The cladding non-circularity, or ellipticity, is the difference between the smallest radius of the fiber (Rg
min) and the largest radius (Rgmax) divided by the average cladding radius (Rg). The value of the cladding
non-circularity is expressed as a percentage.
b. The cladding non-circularity shall be within the values as specified by the applicable ITU-T
specification:
Specified Values Unit
G.652.D < 1 %
G.656 < 1 %
G.657.A < 1 %
Figure 4.2.2.3: Fibre cladding non-circularity as specified by the ITU-T
4.2.5 Fibre Curl
a. Optical fiber curl is a characteristic related to the glass geometry and is defined as the amount of
curvature over a specified length of uncoated fiber.
b. Fiber curl results from thermal stresses during fiber manufacturing and thus needs to be measured and
controlled.
c. Curled fiber has an impact on fiber splice loss by fiber misalignment during the splicing process.
d. Fiber Curl (also known as latent curvature) is measured by determining the amount of deflection that
occurs when an unsupported un-coated (bare) fiber end is rotated about fiber axis and the fiber radius of
curvature is calculated by circular mathematical models.
e. The fibre curl is specified as > 4 m for all fibre types.
4.2.6 Cable Cut-off Wavelength
a. The cut-off wavelength is the minimum wavelength at which an optical fibre will support only one
propagating mode (the fundamental mode).
b. The cable cut-off wavelengths of the different SM fibres as per applicable ITU-T specification are listed
in Table 4.2.6:
Detail
Cut-off wavelength
Value
G.652.D Maximum 1260 nm
G.656 Maximum 1450 nm
G.657.A Maximum 1260 nm
Figure 4.2.6: Fibre cut-off wavelengths as specified by the ITU-T
4.2.7 Macro-bend Loss
a. Optical fibers suffer from macro-bending loss at bends or curves on their paths. This is due to the energy
in the evanescent field at the bend exceeding the velocity of light in the cladding and hence the guidance
mechanism is inhibited, which causes light energy to be refracted out of the fibre (Figure 4.2.7.1).
Figure 4.2.7.1: Macro-bending loss illustrated
DARK FIBRE AFRICA Fibre Optic Cable Specification ENG SPE 001 2.0 0.2
Proprietary and Confidential Information Print Date: 26 November 2020 Page 9 of 27
b. The maximum macro-bending loss as per applicable ITU-T specification is listed in Table 4.2.7.2:
Fibre Bending
Radius
Number
of Turns Maximum Loss
Relevant specified bending radii for
ITU-T G.652 and G.657
G.652.D 50 mm 100
0.05 dB at 1550 nm
0.05 dB at 1310 nm
30 mm 1 0.05 dB at 1550 nm
G.656
50 mm 100 0.05 dB at 1550 nm
0.05 dB at 1625 nm
30 mm 1 0.5 dB at 1550 nm
0.5 dB at 1625 nm
G.657.A1
15 mm 10 0.2 dB at 1550 nm
0.5 dB at 1625nm
10 mm 1 0.2 dB at 1550 nm
0.5 dB at 1625nm
G.657.A2
10 mm 1 0.1 dB at 1550 nm
0.2 dB at 1625nm
7.5 mm 1 0.5 dB at 1550 nm
1.0 dB at 1625nm
Figure 4.2.7.2: Fibre maximum macro-bending loss
4.2.8 Attenuation Coefficient
a. The attenuation of an optical fiber measures the amount of light lost over the length of the fibre and is
expressed dB/km.
b. The maximum attenuation coefficient of the fibre cable shall be as per Table 4.2.8:
Wavelength
Maximum
Attenuation
G.652.D
1310 nm 0.35 dB/km
1550 nm 0.21 dB/km
1625 nm 0.23 dB/km
G.656
1460 nm 0.28 dB/km
1550 nm 0.20 dB/km
1625 nm 0.21 dB/km
G.657.A
1310 nm 0.35 dB/km
1550 nm 0.21 dB/km
1625 nm 0.23 dB/km
Figure 4.2.8: Fibre maximum attenuation (fibre span loss)
4.2.9 Chromatic Dispersion (CD)
a. Chromatic Dispersion (CD) is the variation in the velocity of light (group velocity) as a function of
wavelength. It causes pulses of a modulated laser source to broaden when travelling within the fibre, up
to a point where pulses overlap and bit error rate increases (Figure 4.2.9.1).
DARK FIBRE AFRICA Fibre Optic Cable Specification ENG SPE 001 2.0 0.2
Proprietary and Confidential Information Print Date: 26 November 2020 Page 10 of 27
Figure 4.2.9.1: Chromatic dispersion fundamentals
b. The magnitude of the fibre chromatic dispersion for all types of fibres are listed in Figure 4.2.9.2:
Fibre Type Slope at λ0
ps/(nm2.km)
Chromatic Dispersion
ps/(nm.km)
G.652.D, G.657.A @ 1550 nm < 0.092 < 18
G.652.D, G.657.A @ 1625 nm < 0.092 < 22
G.656 (C-Band) < 0.045 5.5-8.9
Figure 4.2.9.2: Fibre maximum Chromatic Dispersion (for G.652.D, G.656 and G.657.A1)
c. The optical fibre cables for DFA shall all comply with 100 Gb/s commercially deployed systems.
4.2.10 Polarization Mode Dispersion (PMD)
a. Polarization mode dispersion is where two different polarizations of light (orientation of their
oscillations), which normally travels at the same speed, travels at different speeds due to random
imperfections and asymmetries causing random spreading of the optical pulse over time and distance.
This limits the rates at which data can be transmitted over the fibre, eventually increasing BER (Figure
4.2.10.1).
Figure 4.2.10.1: Polarization mode dispersion
b. The following PMD limits are specified for all types of fibres (Figure 4.2.10.2):
PMD coefficient
M 20 cables
Q 0.01 %
Maximum PMDQ (Link Design Value),
G.652.D, G.657.A < 0.06 ps/km-2
Maximum PMDQ (Link Design Value),
G.656 < 0.04 ps/km-2
Figure 4.2.10.2: Fibre polarization mode dispersion coefficient (for G.652.D, G.656 and G.657.A)
DARK FIBRE AFRICA Fibre Optic Cable Specification ENG SPE 001 2.0 0.2
Proprietary and Confidential Information Print Date: 26 November 2020 Page 11 of 27
4.2.11 Refractive Index
a. The refractive index is dimensionless number that describes how fast light propagates through the
medium.
i. Neff = c / v (Where c – speed of light in a vacuum and v is the phase velocity)
b. The refractive indexes are specified for all types of fibres (Figure 4.2.11):
G.652.D G.656 G.657.A
Neff at 1310 nm 1.467 1.471 1.467
Neff at 1550 nm 1.468 1.470 1.468
Neff at 1625 nm 1.468 1.470 1.468
Figure 4.2.11: Refractive index of fibre types
4.2.12 Fibre Materials
a. The optical fibres are synthetic, thus not cultivated as the natural glass.
b. The solid glass rod, known as the core preform is made by a processes called ‘Modified Chemical Vapor
Deposition’ (MCVD), Plasma chemical vapor deposition (PCVD) or VAD process.
c. In MCVD, oxygen is bubbled through solutions of silicon chloride (SiCl4), germanium chloride (GeCl4)
and/or other chemicals. The precise mixture governs the various physical and optical properties.
d. The gas vapors are then conducted to the inside of a synthetic silica or quartz tube (cladding) in a special
lathe. As the lathe turns, a torch is moved up and down the outside of the tube. The extreme heat from
the torch causes two things to happen:
i. The silicon and germanium react with oxygen, forming silicon dioxide (SiO2) and germanium dioxide
(GeO2);
ii. The silicon dioxide and germanium dioxide deposit on the inside of the tube and fuse together to form
glass;
iii. The core is then build up by either the VAD or the OVD process to form the porous glass preform;
iv. The porous preform is then sintered to coalesce the material into a solid glass preform which is the
ready for the drawing process.
4.3 Mechanical Performance Requirements and Tests
4.3.1 Mechanical Test Setup
a. The cable under test shall be spliced as follows:
i. 4F / 12F cables: All fibres / channels monitored;
ii. 24F / 48F / 72F / 144F / 288F: 12 Fibres / channels monitored.
b. For the stranded cables, the fibres monitored shall be evenly spread over all the elements (tubes) in the
cable.
c. The total length of the cable under test shall not be less than 200 meters.
d. The mechanical tests are performed by monitoring the change in attenuation of all channels at 1550 nm
and 1625 nm.
4.3.2 Tensile Strength
a. The tensile strength is the ability of the material to withstand stretching or pulling forces before
permanent material damage occur.
b. The optical fibre cable shall have sufficient strength to withstand a total load of:
i. 48F / 72F / 144F / 288F stranded cable: 2 x W in Newton;
ii. 4F / 12F / 24F mono-tube cable: 1 x W in Newton;
iii. 4F push-able subscriber cable: 2 x W in Newton;
iv. 12 x 2F / 24 x 2F / 48 x 2F outdoor retractable cable: 1 x W in Newton.
Where W is the weight of 1 km of cable. E.g. Load = 9.81 x 2 x 35 = 686.7 N for the 72F cable.
DARK FIBRE AFRICA Fibre Optic Cable Specification ENG SPE 001 2.0 0.2
Proprietary and Confidential Information Print Date: 26 November 2020 Page 12 of 27
c. The load shall not produce a principle strain (elongation) exceeding the following ranges in the fibres:
i. 72F / 144F / 288F cable: 0.25% fibre strain;
ii. 4F / 12F / 24F / 48F cable: 0.5% fibre strain;
iii. 4F push-able subscriber cable: 0.5% fibre strain;
iv. 12 x 2F / 24 x 2F / 48 x 2F outdoor retractable cable: 0.5% strain.
d. The tensile test is performed in accordance to specification IEC 60794-1-21. The cable length under
stress shall be > 50 m (minimum distance between the clamping devices) with the distance between
pulling force and measuring ends > 20 m (span length).
Figure 4.3.1: IEC 60794-1-21 Cable tensile test setup
e. There shall be no permanent damage caused to any component of the fibre cable during the tensile
strength test. There shall be no strain or remaining attenuation when the load is removed.
f. The test is performed by monitoring the change in attenuation as the load is applied from the resting
position to the position of maximum pulling force. The force shall be kept for a duration of 10 minutes
and the change in attenuation shall not exceed 0.05 dB at 1550 nm and 1625 nm.
4.3.3 Impact Test
a. The impact test provides information on how a specimen will respond to a suddenly applied stress and
ascertains whether the material is tough or brittle.
b. The optical fibre cable shall have sufficient strength to withstand an impact twice on the same spot and
repeated 3 times 100 mm apart (a total of 6 impacts) with a hammer (Anvil: R = 300 mm curvature
radius). The optical fibre cables shall comply with the following impacts (energy):
i. 72F / 144F stranded cable: 2 J (Nm);
ii. 48F / 288F stranded cable: 1 J (Nm);
iii. 4F / 12F / 24F / mono-tube cable: 1 J (Nm);
iv. 4F push-able subscriber cable: 2 J (Nm);
v. 12 x 2F / 24 x 2F / 48 x 2F outdoor retractable cable: 3 J (Nm).
c. The test is performed by dropping a steel hammer of weight ‘W’ with a curved bottom profile from a
height ‘H’ onto the cable under test (e.g. 2 J = 2 x 9.81 x 0.1 Nm).
d. There shall be no damage to the outer sheath of the cable, no breakage of any fibre in the cable and the
attenuation shall not increase by more than 0.05 dB at 1550 nm and 1625 nm during the test and after
the test.
L span length > 20 m
Load Cell
Pulling
Equipment
Clamping
Device
Clamping
Device
Fibre Measuring
Equipment
L cable under stress > 50 m
DARK FIBRE AFRICA Fibre Optic Cable Specification ENG SPE 001 2.0 0.2
Proprietary and Confidential Information Print Date: 26 November 2020 Page 13 of 27
Figure 4.3.3: Cable impact test setup
4.3.4 Crush Resistance
a. The crush resistance test is to determine the ability of the optical fibre cable to withstand crushing for
long and short-term loads.
b. The optical fibre cable shall have sufficient strength to withstand a compression of:
i. 72F / 144F / 288F stranded cable: 1000 N;
ii. 48F stranded cable: 500 N;
iii. 4F / 12F / 24F mono-tube cable: 500 N;
iv. 4F push-able subscriber cable: 800 N;
v. 12 x 2F / 24 x 2F / 48 x 2F outdoor retractable cable: 2000 N.
c. The test is performed by subjecting the cable to a compression between two plates with dimensions of
100 mm by 100 mm at a speed of +/- 5 mm/min until the force is achieved. The force shall be maintained
for 10 minutes.
d. There shall be no damage to the outer sheath of the cable, no breakage of any fibre in the cable and the
attenuation shall not increase by more than 0.05 dB at 1550 nm and 1625 nm during the test. There shall
be no remaining attenuation after the test (e.g. when the force is removed).
Figure 4.3.4: Cable crush test setup
4.3.5 Environmental Performance
a. The temperature cycling test is to determine the stability behavior of the attenuation of the cables
submitted to temperature changes.
b. The optical fibre cable shall be able to operate at a temperature range of -20°C to +65°C.
Supports
Guide
Hammer (d = 20 mm, r = 300 mm)
Steel Immediate striking face
Sample
Steel base
H =
Tra
vel
dis
tance W = Weight in kg
DARK FIBRE AFRICA Fibre Optic Cable Specification ENG SPE 001 2.0 0.2
Proprietary and Confidential Information Print Date: 26 November 2020 Page 14 of 27
c. The environmental performance of the cable is confirmed by performing the ‘Temperature Cycling’ test.
This test is done by placing a cable drum (not less than 2000 m) in an environmental chamber with 12
fibres monitored (from different tubes). The cable ends shall be outside the chamber connected to the
test equipment.
d. The temperature is changed over a 24-hour cycle as follows: ‘+20°C → -20°C → +65°C → -20°C →
+65°C (Figure 4.3.5).
T1 T2 T3 t1 t2
+20°C -20°C +65°C 4 hours 2 hours
Figure 4.3.5: Temperature cycle for environmental performance test
e. The temperate test is run over 3 cycles (72 hours).
f. The change in attenuation shall not exceed 0.05 dB/km to the mean value of all fibres over the
temperature cycle at 1550 nm and 1625 nm.
4.3.6 Repeated Bending
a. The purpose of this test is to determine the ability of the cables to withstand repeated bending.
b. The repeated cable bending test is performed by repeatedly bending a cable length of 1 meter over 180°
for 35 cycles.
c. The bending radius of the curvature shall not be more than 65 mm (E.g. 20x OD for 6.5 mm cable).
d. A force of 50 N shall be attached to fixed vertical end of the cable.
e. The repeated bending speed is +/- 30 cycles per minute.
Figure 4.3.6: Repeated bending test
T1
0°C
T2
T3
t2 t1 t2 t1 t2 t1 t2 t1
DARK FIBRE AFRICA Fibre Optic Cable Specification ENG SPE 001 2.0 0.2
Proprietary and Confidential Information Print Date: 26 November 2020 Page 15 of 27
f. The change in attenuation shall not exceed 0.05 dB at 1550 nm and 1625 nm during the test. There shall
be no remaining attenuation after the test.
4.3.7 Cable Flexibility (Bending) Test
a. The optical fibre cable shall be flexible enough to withstand the necessary bending conditions. The
minimum cable bending radii shall be:
i. During operation / handling: D = 15 x the cable OD;
ii. During installation: D = 20 x the cable OD;
b. This test is performed by repeatedly wrapping an unwrapping 4 completed turns for 10 compete cycles
around a mandrel with diameter set at 20 times the nominal OD of the cable (Figure 4.3.7).
Figure 4.3.7: Mandrel used to perform the cable bending test (D = 20 x cable OD)
c. Care should be taken not to introduce unnecessary torsion on the cable when performing this test.
d. The change in attenuation shall not exceed 0.05 dB at 1550 nm and 1625 nm during this activity. There
shall be no remaining attenuation after the test.
4.3.8 Cable Torsion Test
a. Torsion on a fibre cable is the stress or deformation caused when one end of the cable is twisted in one
direction and the other end in the opposite direction, so this test it to establish the ability of the cables to
withstand mechanical twisting.
b. The torsion test is performed by clamping a fibre cable 1 m apart between 2 capstans. The one end of
the capstan shall be fixed with a 100 N force while the other end is rotating through 330° for a number
of cycles (Figure 4.3.7).
c. The torsion machine can be set as follows:
i. Torsion angle: 330° (E.g. 0º to +330º to 0° to -330º to 0º etc.);
ii. Torsion speed: Not less than 2 cycles/min;
iii. Force (weight): 100 N for stranded and 50 N for mono-tube cables;
iv. Perform 10 complete cycles, wait 60 seconds and perform another 10 complete cycles.
d. During the torsion test the attenuation of one any one fibre may not exceed 0.05 dB at 1550 nm and
1625 nm. There shall be no remaining attenuation after the test.
e. Upon completion of the test there shall be no visible damage to the cable sheath and cable elements.
Figure 4.3.8: Cable torsion test setup
DARK FIBRE AFRICA Fibre Optic Cable Specification ENG SPE 001 2.0 0.2
Proprietary and Confidential Information Print Date: 26 November 2020 Page 16 of 27
4.3.9 Cable Water Penetration Test
a. The purpose of this test is to determine the ability of the cable to block water migration along a specified
length.
b. The water penetration test is done by fitting a watertight gland over one end of a 3 m cable connected to
a 1 m vertical water column. The water shall contain a sufficient quantity of water-soluble dye for easy
detection of leakage (Figure 4.3.9).
Figure 4.3.9: 1 Meter water column for cable water penetration test
c. The cable shall be cut open and examined after 24 hours to determine the penetration distance of the
dye.
d. The water penetration distance may not exceed 2 meters.
4.3.10 Cable Kink Test
a. Normally the purpose of the kink test is to determine the minimum loop diameter at the onset of the kink
in the optical fibre cable.
b. This test shall be performed by restraining the cable at the crossing point of the loop and verify that the
cable is able to withstand a kink that equates to the required bening radius of the cable as specified in
Section 4.3.7.
Figure 4.3.10: Cable kink test performed up to D = 20 times the nominal cable OD
c. When reducing the diameter of the cable up to a point of 20x OD, keep the cable in position for 3
minutes.
d. The change in attenuation shall not exceed 0.05 dB at 1550 nm and 1625 nm. There shall be no remaining
attenuation when the cable is relaxed.
4.3.11 Cable Filling Compound Flow Test
a. This test is to verify that the filling and flooding compounds shall not flow from a filled or flooded
optical fibre cable at a certain temperatures.
3 m fibre cable horizontally placed
Watertight gland
1 m vertical water column
DARK FIBRE AFRICA Fibre Optic Cable Specification ENG SPE 001 2.0 0.2
Proprietary and Confidential Information Print Date: 26 November 2020 Page 17 of 27
b. The cable compound flow test is performed by pacing two 300 mm cable samples vertical in an
environmental chamber with the buffer tubes exposed 80 mm pointing downwards (Figure 4.3.11). Do
not expose the fibres inside the buffer tube.
c. With the mono-tube cables, the fibres might move under their own weight during the test, in these cases
the fibres shall be secured at the unprepared end of the specimen in such a matter that it does not disturb
the remainder of the specimen.
d. Set the chamber to 80°C and wipe off the leaked filling compound when the temperature is stabilized.
e. Leave the sample cable in the chamber and examine any compound material dripping out of the buffer
tubes after 60 minutes by placing a blank paper towel below the specimens.
Figure 4.3.11: Filling compound flow test setup
4.3.12 Buffer Tube Kink Test (Omega Test)
a. The purpose of this test is to determine the ability of fibre tubes to withstand mechanical stresses
encountered during cable installation and splicing.
b. The buffer tube kink test is performed with the test apparatus as indicated in Figure 4.3.12. The buffer
tube kink test apparatus consist of a stationary clamp, a movable clamp, a fix guide for the tube and an
area to loop the tube (circular approximately 100 mm diameter) with a transparent cover.
L = 80 mm L1 = 100 mm L2 = 350 mm
Figure 4.3.12: Buffer tube kink test apparatus
c. Cut a 400 mm length of each tube from the sample cable. Do not straighten (smoothen) the tubes with
hot air or whatever means. Make 2 marks 350 mm apart (L2) on the tube. Insert the tubes into the
stationary clamp with the mark on the inside edge of the clamp, loop it through the loop area and clamp
it to the moveable clamp, with the 2’nd mark on the inside of the clamp. (Ensure there is 350 mm of
tube between the clamps.)
d. The initial straight-line distance between the clamps is L1 = 100 mm. Move the movable clamp by L =
80 mm at a speed of 1 cm/s. Move the clamp back to the original position. This will complete 1 cycle.
Repeat the cycle 5 times. During the last cycle, the clamp shall be held in the maximum position (Pos.
2) for 1 minute.
L1L
Pos. 1Pos. 2
Movable
clamp
Fixed
Guideway
Transparent
cover
Stationary
clamp
L2
DARK FIBRE AFRICA Fibre Optic Cable Specification ENG SPE 001 2.0 0.2
Proprietary and Confidential Information Print Date: 26 November 2020 Page 18 of 27
e. During and after the test there shall be no damage to any of the fibre cable buffer tubes.
f. With the mono-tube cables, the cable jacket is removed and the test is performed on the mono-tube.
4.3.13 Cable Jacket Marking Abrasion Resistance
a. Abrasion resistance is the ability of the cable jacket marking to resist surface wear caused by flat rubbing
contact.
b. The test is performed by cutting a sample length of +/- 500 mm with the cable markings in the centre of
the specimen.
c. The moving distance (stroke length) of the abrasion test rig shall cover the print from ‘left to right’ as
one cycle.
d. The cable print shall be able to withstand at least 100 cycle rubs with 4 N weight applied with a wet
cloth (Figure 4.3.13).
Figure 4.3.12: Cable jacket abrasion resistance
e. After the test the cable jacket marking shall still be readable and not faded.
4.3.14 Cable Reliability (MTTF)
a. The optical fibre cable shall be designed for a MTTF of at least 20 years.
b. The supplier will provide expected reliability figures and the means of calculation for approval.
4.4 Cable Design and Construction
4.4.1 Cable Design
a. The Dark Fibre Africa cable design shall be a ‘mini’ cable that consists of loose tubes (containing optical
fibers with a gel filling compound) and fillers (super-absorbent yarn) stranded around a fiber re-enforced
plastic (FRP) central strength member.
b. The ‘Mini’ fibre cables refer to cables with a nominal OD suitable for installation in HDPE micro-ducts.
The preferred ratio of ‘cable OD’ to ‘micro-duct ID’ is 65%.
c. The fibre tubes and fiber strands of the cable shall be colour coded.
d. Each fibre tube shall hold 12 fiber strands or 24 fibres per tube. Cable designs with more than 24 fibres
per tube shall not be considered, as it does not complement the splice trays in the DFA approved splice
closures and fibre termination panels.
e. A polyethylene outer jacket shall be fitted around the tubes and a ripcord shall be included. Figure 4.4.1.1
illustrates the cross sectional drawing of a cable for the stranded cables.
72F Cable (12F tubes, 250µm)
144F Cable (24F tubes, 200µm)
Coloured Optical Fibres
Gel filled buffer tubes
FRP strength member
Water blocking yarn
Rip cord
Green PE-Jacket
Coloured Optical Fibres
Gel filled buffer tubes
FRP strength member
Water blocking yarn
Rip cord
Green PE-Jacket
DARK FIBRE AFRICA Fibre Optic Cable Specification ENG SPE 001 2.0 0.2
Proprietary and Confidential Information Print Date: 26 November 2020 Page 19 of 27
288F Cable (24F tubes, 200µm)
Figure 4.4.1.1: Construction of the DFA Metro-cables
f. The DFA access cable comes in 4F, 12F, 24F (mono-tube) and 48F (stranded) variants (Figure 4.4.1.2).
4F / 12F / 24F Cable (loose tube, 250 / 200 µm))
48F Cable (24F tubes, 200µm)
Figure 4.4.1.2: Construction of the DFA access-cables
g. The access cables may also be designed with a low friction PE cable jacket, but need to be evaluated for
sturdiness during floating.
h. The DFA subscriber cable consists out of a ruggedized, flexible LS0H cable jacket with aramid yarn
reinforcing around the optical fibres (Figure 4.4.1.3).
Figure 4.4.1.3: Construction of the DFA subscriber cable (4F)
i. The push-able 4F subscriber cable consists out of a crush resistant durable polymer outer sheath (Figure
4.4.1.4). This cable is used for FTTH deployments.
Coloured Optical Fibres
Gel filled buffer tubes
FRP strength member
Water blocking yarn
Rip cord
Green PE-Jacket
Coloured Optical Fibres
Gel filled buffer tube
Aramid yarns
Orange PA-Jacket
Coloured Optical Fibres (200um)
Gel filled buffer tube
Aramid yarns
Low-friction Orange PA-Jacket
Dielectric Central member and filler rods
Rip cord
LS0H Jacket
Aramid Yarn Reinforcement (Kevlar)
Acrylate coating
Coloured Optical Fibres
DARK FIBRE AFRICA Fibre Optic Cable Specification ENG SPE 001 2.0 0.2
Proprietary and Confidential Information Print Date: 26 November 2020 Page 20 of 27
Figure 4.4.1.4: Construction of the DFA push-able subscriber cable (4F)
j. The outdoor retractable cable consists out of a HDPE outer sheath, or micro-duct, with FGRP rods built
into the wall for strength and stiffness (Figure 4.4.1.5). The cable consist out of pre-installed identifiable
2F elements. The elements can be pulled out (retracted) at intervals up to 30 meters.
Figure 4.4.1.5: Construction of the DFA outdoor retractable cable
4.4.2 Optical Fibers
a. The optical fibers shall consist of doped silica core with a pure silica cladding and two layers of acrylate
for primary protection.
b. The size of the bare fibres are either 250 µm or 200 µm depending on the design of the cable.
c. The colour coding of the bare fibres shall follow the EIA598-A colouring chart (Figure 4.4.2).
Figure 4.4.2: Optical fibre strands and tubes colour coding (EIA598-A standard)
d. The 2’nd set of fibres in the 24F tube shall also follow the EIA598-A colouring chart, but with ring
marking introduced on fibres ‘13’ – ‘24’. Fibre number ‘20’ (back) is either black with white ring
markings or natural colour.
e. The spacing of the ring markings on the fibres shall be 50 mm +/– 10 mm.
DARK FIBRE AFRICA Fibre Optic Cable Specification ENG SPE 001 2.0 0.2
Proprietary and Confidential Information Print Date: 26 November 2020 Page 21 of 27
4.4.3 Loose Tubes and Fibres
a. A loose thermoplastic tube shall be extruded around the fibers. The loose tube shall serve as a protection
mechanism for the fibers. The tubes shall be filled with a thixotropic gel to block water ingress and to
provide stress release.
b. The outer diameter of the buffer tubes for the stranded cables shall be as per Table 4.4.3:
Cable Design Buffer tube OD Tolerance
48F (2x elements) 1.5 mm +/- 0.1 mm
72F, 144F (6x elements) 1.7 mm +/- 0.1 mm
288F (12x elements) 1.4 mm +/- 0.1 mm
Table 4.4.3: DFA stranded cables buffer tube dimensions
c. Each buffer tube (element) shall hold ‘12’ or ‘24’ fiber strands.
d. The dimensions of the tube in the mono-tube cables shall depend on the cable design.
e. The fiber tubes shall be colour coded for easy identification. The colour coding scheme shall follow the
EIA598-A colouring chart (Figure 4.4.2).
f. The fibre tubes shall be nominally round and shall be free from any deviations such as lumps or neck-
downs.
g. The fibre tube shall be kink resistant.
h. The tube shall be readily removable for splicing purposes.
i. The tubes shall not absorb any water and shall be filled with a suitable water-blocking compound.
4.4.4 Strength Member
a. The stranded cables shall incorporate fiberglass-reinforced plastics (FRP) as a central strength member.
b. The central strength member shall ensure that when the cable is bent, the tubes and the fibres maintain
a smooth bending radius.
c. The mono-tube cables does not require central strength members, but is re-enforced with aramid yarns.
4.4.5 Filling Material
a. For the stranded cables, a super-absorbent yarn stranded around a FRP central strength member shall be
used to fill the voids between tubes and/or fillers to prevent the longitudinal ingress of water to the cable
core.
4.4.6 Cable Core
a. The cable core of the stranded cable design shall be formed by stranding the required number of loose
tubes around a central strength member (CSM) with a reverse oscillating lay.
b. A layer of polyaramid binder yarns are helically wrapped over the bundle of the loose tubes.
4.4.7 Cable Outer Sheath
a. The outer sheath shall be either PE (0.5 mm to 0.55 mm) or PA (0.3 mm to 0.45 mm) depending on the
cable design.
b. The outer sheath of the LS0H subscriber cable shall have a thickness of 0.6 mm and not less than 0.5
mm.
c. The cable shall be nominally circular and free of holes and defects.
d. The cable shall have the following maximum diameter and weight:
Mini-cable Capacity /
Count
Mini-cable
OD
Mini-cable
Weight
DFA micro-duct
application
4F push-able +/- 4 mm +/- 16 kg/km NA (FTTH)
2F - 12F (Mono-tube) < 2.8 mm +/- 6 kg/km 5/3.5 and 8/5 mm (Access)
DARK FIBRE AFRICA Fibre Optic Cable Specification ENG SPE 001 2.0 0.2
Proprietary and Confidential Information Print Date: 26 November 2020 Page 22 of 27
24F (Mono-tube) < 3.4 mm +/- 10 kg/km 8/5 mm (Access)
48F (2x elements) < 3.8 mm +/- 15 kg/km 8/5 mm (Access)
72F (6x elements) < 6.7 mm +/- 35 kg/km 14/10 mm (Metro / Long
Haul)
144F (6x elements) < 6.7 mm +/- 40 kg/km 14/10 mm (Metro)
288F (12x elements) +/- 8 mm +/- 60 kg/km 14/10 mm (Metro)
OSP retractable < 15 mm +/- 120 km/km NA (FTTH)
Table 4.4.7.1: DFA optical fibre cable nominal outer diameters
e. The cable outer sheath shall have the following colours based on the DFA cable application:
Mini-cable
Capacity / Count
DFA Mini-cable Type and
Application
Mini-cable
Outer Sheath
Colour
RAL
Colour
Code
4F push-able Subscriber (G.657.A2) White RAL 9010
4F / 12F / 24F / 48F Access (G.657.A1) Orange RAL 2003
72F / 144F / 288F Metro (G.652.D / G.657.A1) Green RAL 6018
72F / 144F / 288F Core (G.652.D / G.657.A1) Red RAL 3020
72F Junction-Aggregation (G.652.D) Blue RAL 5015
72F Junction-Core (G.652.D) Violet RAL 4008
72F Long Haul Hybrid (G.652D + G.656) Pink RAL 4010
OSP retractable FTTH (G.657.A2) Black RAL 9005
Table 4.4.7.2: DFA optical fibre cable sheath colouring
f. The sheath shall be readily removable for splicing purposes.
4.4.8 Material
a. The specification of the material used for the manufacturing of the fibers and cable shall be made
available to DFA on request.
4.4.9 Cable Workmanship
a. The manufacturing plant shall have the necessary measures in place to constantly monitor the
manufacturing process to ensure a high standard of quality.
4.4.10 Compatibility
a. The cables supplied to DFA shall be compatible with cables supplied by other vendors within this
specification.
b. DFA reserves the right to reject any cables not compatible with other cables or within specification.
5. Aerial Cable Requirements
5.1 Optical Performance Requirements
a. The optical performance requirements are the same as all the parameters specified in Section 4.2 for the
mini-cables.
5.2 Cable Design and Construction
a. The aerial cable required for DFA shall be ‘short-span’, dielectric and be self-supporting:
i. Aerial Route Cable (48F): 100 m span length;
ii. Aerial Subscriber Cable (12F): 50 m span length.
b. The aerial cable outer sheath shall be manufactured from track-resistant black thermoplastic high-density
polyethylene.
DARK FIBRE AFRICA Fibre Optic Cable Specification ENG SPE 001 2.0 0.2
Proprietary and Confidential Information Print Date: 26 November 2020 Page 23 of 27
c. The outer jacket shall be providing sufficient insulation for electric field potentials up to 25 kV.
d. The outer jacket shall be protected against UV degradation and shall operate in severe weathering
conditions with elevated ambient temperatures.
e. The cross sectional drawing of the DFA aerial cables are depicted in Figure 5.2.1.
48F Aerial Route Cable
12F Aerial Subscriber Cable
Figure 5.2.1: Construction of the DFA aerial cables
f. The loose tubes and fibres shall have the same dimensions and colour coding as specified in Section
4.4.2 and Section 4.4.3.
g. A layer of polyaramid yarns are stranded over the bundle of loose tubes.
h. The aerial cable shall incorporate fiberglass-reinforced plastics (FRP) as a central strength member.
i. A super-absorbent yarn stranded around a FRP central strength member shall be used to fill the voids
between tubes and / or fillers to prevent the longitudinal ingress of water to the cable core.
j. The cable shall be nominally circular.
k. The cable shall have the following maximum diameter and weight:
Aerial Cable Capacity / Count
Cable
Nominal
OD
Cable Weight
48F (4x 12F Tubes) Route Cable < 12 mm +/- 100 kg/km
12F (Unitube Tube) Subscriber Cable < 6 mm +/- 40 kg/km
Table 5.2.2: DFA aerial fibre cable nominal outer diameter
l. The sheath shall be readily removable for splicing purposes.
5.3 Mechanical Performance Requirements
a. The central strength member shall ensure that when the cable is bent, the tubes and the fibres maintain
a smooth bending radius of:
i. During installation operations: 15 x the cable OD;
ii. During operation: 20 x the cable OD;
b. The operating temperature range of the aerial cable shall be between -20°C and 70ºC.
c. The aerial cable shall conform to the following loading conditions:
i. 48F Aerial Route cable at 100 meter span (Table 5.3.1).
No Loading / Initial Installation All Loading Conditions
Sag 1.5 % 0.5%
Tension < 1000 N < 2500 N
Coloured Optical Fibres
Gel filled buffer tubes
Filling elements
Water blocking yarn
Rip cord
Black track resistant PE-Jacket
FRP strength member
DARK FIBRE AFRICA Fibre Optic Cable Specification ENG SPE 001 2.0 0.2
Proprietary and Confidential Information Print Date: 26 November 2020 Page 24 of 27
Table 5.3.1: DFA aerial route cable loading conditions at 100 m span length
ii. 12F Aerial Subscriber cable at 50 meter span (Table 5.3.2).
No Loading / Initial Installation All Loading Conditions
Sag 1.5 % 0.5%
Tension < 750 N < 1500 N
Table 5.3.2: DFA aerial subscriber cable loading conditions at 50 m span length
d. The following mechanical tests apply to the aerial cable (Table 5.3.3):
Mechanical Test Requirement Testing Method
1 Tensile Test 2 x W with 0.2 % strain As per Section 4.3.2
2 Impact Test 10 J (E.g. 1 kg weight at from 1 m) As per Section 4.3.3
3 Crush Resistance 2,000 N As per Section 4.3.4
4 Environmental
Performance -20ºC to +65ºC As per Section 4.3.5
5 Cable Flexibility
(Bending) Test
15 x OD: During operation / handling.
20 x OD: During installation. As per Section 4.3.7
6 Cable Torsion
Test At a torsion angle of 330° As per Section 4.3.8
7 Cable Water
Penetration Test
1 meter water head on 3 meter cable over
24 hours As per Section 4.3.9
8 Cable Kink Test No kink at 20 x OD As per Section 4.3.10
Table 5.3.3: Aerial cable mechanical requirements
e. The following tests are performed on the buffer tubes:
i. Cable filling compound flow test as specified in Section 4.3.9;
ii. Buffer Tube Kink Test as specified in Section 4.3.10.
6. Cable Packing, Handing and Storage
6.1 Cable Sheath Markings
a. Unless otherwise specified, the following information is printed on a finished cable:
i. Name of manufacturer;
ii. Date of manufacture and unique serial number (for manufacturing referencing and tracability);
iii. Fiber type and number of fiber strands in the cable;
iv. Sequential meter mark.
b. The cable marking shall be permanent and not readily removable (Note the cable jacket abrasion
resistance test).
c. The markings shall be dimensioned and spaced to produce good legibility. The accuracy of the sequential
marking shall be within -0% and +1% of the actual measured length of the cable.
d. Marking on the cable shall be legible and of a color that contrasts with the color of the cable outer sheath.
6.2 Certification of Cable
a. When required, a manufacturer's certification shall be furnished to the purchaser that the cable was
manufactured, sampled, tested and inspected in accordance with this specification, and has been found
to meet the requirements of this specification.
DARK FIBRE AFRICA Fibre Optic Cable Specification ENG SPE 001 2.0 0.2
Proprietary and Confidential Information Print Date: 26 November 2020 Page 25 of 27
6.3 Packing and Shipping
a. Packing of the cable for shipping shall be on non-returnable wooden drums with strong wooden batten
protection. The spindle hole diameter shall not be less that 75 mm.
b. The supplier shall be responsible for any damage arising from inadequate or careless packing.
c. Each cable length shall be wound onto a separate reel. The nominal cable length on a reel shall not be
less than 4000 m.
d. Both ends of the cable on the drum shall be sealed with heat shrinkable end caps to prevent the ingress
of water.
e. The direction in which the reel has been rolled shall be plainly marked on the outside surfaces of both
flanges.
f. The full cable test report and data sheets shall be fixed on one side of the reel.
g. A weatherproof shipping tag with plastic protection shall be attached on both sides of the drum. The tag
shall contain the following information:
i. Drum number / identification;
ii. Delivery address;
iii. Shipping address;
iv. Customer reference or purchase order number;
v. Fibre type and capacity (number of strands);
vi. Manufacturers part number;
vii. Length of cable on the drum;
viii. Nett (cable) and gross (cable plus drum) weight.
7. Transporting and Handling of Cable Drums
a. The correct / preferred transporting and handling of cable drums are covered / highlighted in the
following DFA procedure document:
i. ‘ENG-PRO-027: DFA Mini Cable Jetting Procedure’.
8. Guarantees / Warranties
a. The optical fibre cable shall carry a warranty, against defective material, faulty design and poor
workmanship that will cause non-conformance to any of the requirements in this specification.
9. Relevant Manufacturer Documentation
a. The manufacture shall provide in his literature all information necessary for the proper and safe
installation and use.
b. In addition the manufacturer/supplier shall give instruction for installation precautions following the
national technical rules, if any.
10. SAFETY, HEALTH AND ENVIRONMENTAL MANAGEMENT (SHE)
a. Prior to the execution of any works the contractor shall make itself familiar with the safety requirements
as contained in the employer’s health and safety specification for the works (refer DFA HSC-SPE-001).
b. The employer’s specification shall be read in conjunction with the appropriate acts and regulations
pertaining to occupational safety and environmental compliance, in order to ensure the statutory and
regulatory compliance of the contractor during execution of the works. These include, but are not limited
to:
i. OHS Act 85 of 1993
ii. COID Act 130 of 1993
iii. NEMA Act 107 of 1998
iv. Construction Regulations 2014.
DARK FIBRE AFRICA Fibre Optic Cable Specification ENG SPE 001 2.0 0.2
Proprietary and Confidential Information Print Date: 26 November 2020 Page 26 of 27
DARK FIBRE AFRICA Fibre Optic Cable Specification ENG SPE 001 2.0 0.2
Proprietary and Confidential Information Print Date: 26 November 2020 Page 27 of 27
11. Appendix A
a. The 24F tubes shall be colour coded (based EIA598-A colouring chart) as depicted in Table 11.
Fibre Number Colour Coding
1 Blue
2 Orange
3 Green
4 Brown
5 Slate (Grey)
6 White
7 Red
8 Black
9 Yellow
10 Violet (Purple)
11 Rose (Pink)
12 Aqua (Turquoise)
13 Blue – with ring marking
14 Orange – with ring marking
15 Green – with ring marking
16 Brown– with ring marking
17 Slate (Grey) – with ring marking
18 White – with ring marking
19 Red – with ring marking
20 Black – with white ring marking (or natural)
21 Yellow – with ring marking
22 Violet (Purple) – with ring marking
23 Rose (Pink) – with ring marking
24 Aqua (Turquoise) – with ring marking
Figure 11: 24F single tube fibre colour coding
Document End
Top Related