UNITED STATES DEPARTMENT OF AGRICULTURE 

Rural Utilities Service 

RUS BULLETIN 1753F-601a 

(PE-90a)

RD-GD-2009-61

SUBJECT: MINIMUM PERFORMANCE SPECIFICATION FOR FIBER OPTIC CABLES 

(FOR BACKBONE, FEEDER AND DISTRIBUTION PLANT) 

TO: All Telecommunications Program Borrowers, Cable Manufacturers and Staff 

EFFECTIVE DATE: Date ofApproval. 

OFFICE OF PRIMARY INTEREST: Technical Support Branch 

INSTRUCTIONS: This bulletin replaces RUS Bulletin l 753F-601. 

AVAILABILITY: This bulletin can be accessed via the Internet at 

http://www. usda.gov/rus/telecorn/publications/bulletins .htm 

PURPOSE: This bulletin updates the fiber optic cable specifications to meet current industry 

standards; includes additional requirements to meet the construction requirements offiber-to-thehome construction; clarifies certain existing definitions; and separates the existing bulletin (RUS

Bulletin l 753F-601) into two distinct bulletins. This bulletin covers minimum requirements for 

cables intended to be used for backbone, feeder and distribution plant systems (RUS Bulletin 

1753F-60la). For service entrance cables, see RUS Bulletin l 753F-601b. 

This bulletin is a user friendly guide and a reformat of the text codified in 7 CFR 1755.900, 

1755.901, and 1755.902, published at 20560 Federal Register / Vol. 74, No. 85, dated Tuesday, 

May 5, 2009. Every effort has been made to ensure the accuracy of this document. However, in

case of discrepancies, the regulations at 7 CFR 1755.900, 1755.901, and 1755.902 are the 

authorized sources. 

ACKNOWLEDGMENT: The reproduction of copyrighted Insulated Cable Engineers 

Association (ICEA) tables is with permission of ICEA and is for information purposes. The 

reader is cautioned that the ICEA Standards are under constant revision and is advised to check 

ICEA for subsequent changes or modifications. RUS thanks ICEA for granting permission to 

reprint many of the tables found in ANSI/ICEA S-87-640-2006, Standard for Optical Fiber 

Outside Plant Communications Cable, 4

th edition, December 2006. The reproduction of these 

tables makes available general information of interest to our borrowers, engineers, and 

contractors. 

Date 

Disclaimer: The contents of this guidance document does not have the force and effect of law and is 

not meant to bind the public in any way. This document is intended only to provide clarity to the 

public regarding existing requirements under the law or agency policies.
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TABLE OF CONTENTS 

ABBREVIATIONS 

DEFINITIONS 

APPENDIX TO §1755.902 (Qualifications Test Data) 

1 INCORPORATION BY REFERENCE 

2 MINIMUM PERFORMANCE SPECIFICATION FOR 

 FIBER OPTIC CABLES 

a Scope 

b Optical Fibers 

c Buffers 

d Fiber Identification 

e Optical Fiber Ribbon 

f Strength Members 

g Cable Core 

h Core Water Blocking 

i Water Blocking Material 

j Core Wrap 

k Inner Jackets 

l Outer Jacket 

m Armor 

n Figure 8 Aerial Cables 

o Sheath Slitting Cord 

p Identification Markers 

q Performance of a Finished Cable 

r Mechanical Requirements 

s Pre-connectorized Cable 

t Acceptance Testing 

u Records Tests 

v Manufacturing Irregularities 

w Packaging and Preparation for Shipment 
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ABBREVIATIONS 

ADSS All dielectric self-supporting 

ASTM American Society for Testing and Materials 

 °C Centigrade temperature scale 

dB Decibel 

CSM Central strength member 

dB/km Decibels per 1 kilometer 

ECCS Electrolytic chrome coated steel 

EIA Electronic Industries Alliance 

EIA/TIA Electronic Industries Alliance/Telecommunications Industry Association; 

FTTH Fiber-to-the-Home 

Gbps Gigabit per second or Gbit/s 

GE General Electric 

HDPE High density polyethylene 

ICEA Insulated Cable Engineers Association, Inc. 

Km kilometer(s) 

LDPE Low density polyethylene 

m meter(s) 

Max. Maximum 

Mbit Megabits 

MDPE Medium density polyethylene 

MHz-km Megahertz-kilometer 

Min. Minimum 

MFD Mode-Field Diameter 

nm Nanometer(s) 

N Newton(s) 

NA Numerical aperture 

NESC National Electrical Safety Code 

OC Optical cable 

O.D. Outside Diameter 

OF Optical fiber 

OSHA Occupational Safety and Health Administration 

OTDR Optical Time Domain Reflectometer 

% Percent 

ps/(nm·km) Picosecond per nanometer times kilometer 

ps/(nm2·km) Picosecond per nanometer squared times kilometer 

PMD Polarization Mode Dispersion 

RUS Rural Utilities Service 

s Seconds(s) 

SI International System (of Units) (From the French Système

international d'unités) 

μm Micrometer 
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DEFINITIONS 

Accept; Acceptance means Agency action of providing the manufacturer of a product with 

a letter by mail or facsimile that the Agency has determined that the manufacturer’s 

product meets its requirements. For information on how to obtain Agency product 

acceptance, refer to the procedures listed at 

http://www.usda.gov/rus/telecom/listing_procedures/index_listing_procedures.htm, as well 

as additional information in RUS Bulletin 345-3, Acceptance of Standards, Specifications, 

Equipment Contract Forms, Manual Sections, Drawings, Materials and Equipment for the 

Telephone Program, available for download at 

http://www.usda.gov/rus/telecom/publications/bulletins.htm. 

Agency means the Rural Utilities Service, an Agency of the United States Department of 

Agriculture. 

Armor means a metal tape installed under the outer jacket of the cable intended to provide 

mechanical protection during cable installation and environmental protection against 

rodents, termites, etc. 

Attenuation means the loss of power as the light travels in the fiber usually expressed in 

dB/km. 

Bandwidth means the range of signal frequencies that can be transmitted by a 

communications channel with defined maximum loss or distortion. Bandwidth indicates 

the information-carrying capacity of a channel. 

Birefringence means the decomposition of a pulse of light entering the fiber into “two 

polarized pulses” traveling at different velocities due to the different refractive indexes in 

the polarization axes in which the electric fields oscillate. Different refractive indexes in 

the fiber may be caused by an asymmetric fiber core, internal manufacturing stresses, or 

through external stresses from cabling and installation of the fiber optic cable, such as 

bending and twisting. 

Cable cutoff wavelength means the shortest wavelength at which only one mode light can 

be transmitted in any of the single mode fibers of an optical fiber cable. 

Chromatic Dispersion means the broadening of a light pulse as it travels down the length 

of an optical fiber, resulting in different spectral components of the light pulse traveling at 

different speeds, due to the fact that the index of refraction of the fiber core is different for 

different wavelengths. 

Cladding means the outer layer of an optical fiber made of glass or other transparent 

material that is fused to the fiber core. The cladding concentrically surrounds the fiber 

core. It has a lower refractive index than the core, so light travelling in the fiber is 

maintained in the core by internal reflection at the core-cladding interface. 
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Core means the central region of an optical waveguide or fiber which has a higher 

refractive index than the cladding through which light is transmitted. 

Cutoff Wavelength means, in single mode fiber, the shortest wavelength at which only the 

fundamental mode of an optical wavelength can propagate. 

Dielectric Cable means a cable which has neither metallic members nor other electrically 

conductive materials or elements. 

Differential Group Delay means the arrival time differential of the two polarized light 

components of a light pulse traveling through the optical fiber due to birefringence. 

Graded Refractive Index Profile means the refractive index profile of an optical fiber that 

varies smoothly with radius from the center of the fiber to the outer boundary of the 

cladding. 

List of Acceptable Materials means the latest edition of RUS Informational Publication 

344–2, ‘‘List of Materials Acceptable for Use on Telecommunications Systems of RUS 

Borrowers.” This document contains a convenient listing of products which have been 

determined to be acceptable by the Agency. The List of Acceptable Materials is available 

on the Internet at http://www.usda.gov/rus/telecom/materials/index_listomat.htm.

Loose Tube Buffer means the protective tube that loosely contains the optical fibers within 

the fiber optic cable, often filled with suitable water blocking material. 

Matched Cable means fiber optic cable manufactured to meet the requirement of this 

section for which the calculated splice loss using the formula below is ≤ 0.06 dB for any 

two cabled fibers to be spliced. 

 LOSS (dB) = -10 LOG10 [4/(MFD1/MFD2 + MFD2/MFD1)

2

], 

where subscripts 1 and 2 refer to any two cabled fibers to be spliced.

Mil means a measurement unit of length indicating one thousandth of an inch. 

Minimum Bending Diameter means the smallest diameter that must be maintained while 

bending a fiber optic cable to avoid degrading cable performance indicated as a multiple of 

the cable diameter (Bending Diameter/Cable Diameter). 

Mode-Field Diameter means the diameter of the cross-sectional area of an optical fiber 

which includes the core and portion of the cladding where the majority of the light travels 

in a single mode fiber. 

Multimode Fiber means an optical fiber in which light travels in more than one bound 

mode. A multimode fiber may either have a graded index or step index refractive index 

profile. 
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Numerical Aperture (NA) means an optical fiber parameter that indicates the angle of 

acceptance of light into a fiber. 

Optical Fiber means any fiber made of dielectric material that guides light. 

Optical Point Discontinuities means the localized deviations of the optical fiber loss 

characteristic which location and magnitude may be determined by appropriate OTDR 

measurements of the fiber. 

Optical Waveguide means any structure capable of guiding optical power. In optical 

communications, the term generally refers to a fiber designed to transmit optical signals. 

Polarization Mode Dispersion means, for a particular length of fiber, the average of the 

differential group delays of the two polarized components of light pulses traveling in the 

fiber, when the light pulses are generated from a sufficient narrow band source. The 

differential group delay varies randomly with time and wavelength. The term PMD is used 

in the industry in the general sense to indicate the phenomenon of birefringence (polarized 

light having different group velocities), and used specifically to refer to the value of time 

delay expected in a specific length of fiber. 

PMDQ means the statistical upper bound for the PMD coefficient of a fiber optic cable link 

composed of M number of randomly chosen concatenated fiber optic cable sections of the 

same length. The upper bound is defined in terms of a probability level Q, which is the 

probability that a concatenated PMD coefficient value exceeds PMDQ. ITU G 

recommendations for fiber optic cables call for M=20 and Q=0.01%. This PMDQ value is 

the one used in the design of fiber optic links. 

Ribbon means a planar array of parallel optical fibers. 

Shield means a conductive metal tape placed under the cable jacket to provide lightning 

protection, bonding, grounding, and electrical shielding. 

Single Mode Fiber means an optical fiber in which only one bound mode of light can 

propagate at the wavelength of interest. 

Step Refractive Index Profile means an index profile characterized by a uniform refractive 

index within the core, a sharp decrease in refractive index at the core-cladding interface, 

and a uniform refractive index within the cladding. 

Tight Tube Buffer means one or more layers of buffer material tightly surrounding a fiber 

that is in contact with the coating of the fiber. 
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APPENDIX 

1 INCORPORATION BY REFERENCE 

 a The materials listed here are incorporated by reference where noted. These 

incorporations by reference were approved by the Director of the Federal Register 

in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. These materials are 

incorporated as they exist on the date of the approval, and notice of any change in 

these materials will be published in the Federal Register. The materials are 

available for purchase at the corresponding addresses noted below. All are 

available for inspection at the Rural Utilities Service, during normal business 

hours at room 2849-S, U.S. Department of Agriculture, Washington, DC 20250. 

Telephone (202) 720-0699, and email norberto.esteves@wdc.usda.gov. The 

materials are also available for inspection at the National Archives and Records 

Administration (NARA). For information on the availability of these materials at 

NARA, call (202) 741–6030, or go to: 

http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locati

ons.html.

(1) The American National Standards Institute/Institute of Electrical and 

Electronics Engineers, Inc. ANSI/IEEE C2-2007, The National Electrical 

Safety Code, 2007 edition, approved April 20, 2006 (“ANSI/IEEE C2-

2007”), incorporation by reference approved for sections 2a and 2p. 

ANSI/IEEE C2-2007 is available for purchase from IEEE Service Center, 

445 Hoes Lane, Piscataway, NJ 08854, telephone 1-800-678-4333 or 

online at http://standards.ieee.org/nesc/index.html.

(2) The following Insulated Cable Engineers Association standard is available 

for purchase from the Insulated Cable Engineers, Inc. (ICEA), P.O. Box 

1568, Carrollton, GA 30112 or from Global Engineering Documents, 15 

Iverness Way East, Englewood, CO 80112, telephone 1-800-854-7179 

(USA and Canada) or 303-792-2181 (International), or online at 

http://global.ihs.com: ANSI/ICEA S-87-640-2006, Standard for Optical 

Fiber Outside Plant Communications Cable, 4th edition, December 2006 

(“ANSI/ICEA S-87-640”), incorporation by reference approved for 

sections 2a, 2b, 2c, 2d, 2e, 2i, 2l, 2m, 2n, 2p, 2q, 2r and 2u. 
 RUS BULLETIN 1753F-601a

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(3) The following American Society for Testing and Materials (ASTM) 

standards are available for purchase from ASTM International, 100 Barr 

Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959. 

Telephone (610) 832-9585, Fax (610) 832-9555, by email at 

service@astm.org, or online at http://www.astm.org or from ANSI, 1916 

Race Street, Philadelphia, PA 19103, telephone (215) 299-5585, or online 

at http://webstore.ansi.org/ansidocstore/default.asp: 

(a) ASTM A 640-97, (Reapproved 2002) ε1, Standard Specification for 

Zinc-Coated Steel Strand for Messenger Support of Figure 8 

Cable, approved September 2002 (“ASTM A 640”), incorporation 

by reference approved for section 2n; 

(b) ASTM B 736-00, Standard Specification for Aluminum, Aluminum 

Alloy and Aluminum-Clad Steel Cable Shielding Stock, approved 

May 10, 2000 (“ASTM B 736”), incorporation by reference 

approved for section 2m; 

(c) ASTM D 4565-99, Standard Test Methods for Physical and 

Environmental Performance Properties of Insulations and Jackets 

for Telecommunications Wire and Cable, approved March 10, 

1999 (“ASTM D 4565”), incorporation by reference approved for 

2c and 2m; 

(d) ASTM D 4566-98, Standard Test Methods for Electrical 

Performance Properties of Insulations and Jackets for 

Telecommunications Wire and Cable, approved December 10, 

1998 (“ASTM D 4566”), incorporation by reference approved for 

sections 2f and 2t; and 

(e) ASTM D 4568-99, Standard Test Methods for Evaluating 

Compatibility Between Cable Filling and Flooding Compounds 

and Polyolefin Wire and Cable Materials, approved April 10, 1999 

(“ASTM D 4568”), incorporation by reference approved for 

section 2h. 

(4) The following Telecommunications Industry Association/Electronics 

Industries Association (TIA/EIA) standard is available from Electronics 

Industries Association, Engineering Department, 1722 Eye Street, NW, 

Washington, DC 20006; or from Global Engineering Documents, 15 

Iverness Way East, Englewood, CO 80112, telephone 1-800-854-7179 

(USA and Canada) or (303) 792-2181 (International), or online at 

http://global.ihs.com; or from TIA, 2500 Wilson Blvd, Suite 300, 

Arlington, VA 22201, telephone 1-800-854-7179 or online 

http://www.tiaonline.org/standards/catalog: TIA/EIA Standard 455-3A, 

FOTP-3, Procedure to Measure Temperature Cycling on Optical Fibers, 
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Optical Cable, and Other Passive Fiber Optic Components, approved 

May 1989 (“TIA/EIA Standard 455-3A”), incorporation by reference 

approved for section 2r. 

(5) The following International Telecommunication Union (ITU) 

recommendations may be obtained from ITU, Place des Nations, 1211 

Geneva 20, Switzerland, telephone +41 22 730 6141 or online at 

http://www.itu.int/ITU-T/publications/recs.html: 

(a) ITU-T Recommendation G.652, Series G: Transmission Systems 

and Media, Digital Systems and Networks, Transmission media 

characteristics—Optical fibre cables, Characteristics of a singlemode optical fibre and cable, approved June 2005 (“ITU-T 

Recommendation G.652”), incorporation by reference approved 

for sections 2b and 2q; 

(b) ITU-T Recommendation G.655, Series G: Transmission Systems 

and Media, Digital Systems and Networks, Transmission media 

characteristics—Optical fibre cables, Characteristics of a nonzero dispersion-shifted single-mode optical fibre and cable, 

approved March 2006 (“ITU-T Recommendation G.655”), 

incorporation by reference approved for sections 2b and 2q; 

(c) ITU-T Recommendation G.656, Series G: Transmission Systems 

and Media, Digital Systems and Networks, Transmission media 

characteristics—Optical fibre cables, Characteristics of a fibre 

and cable with non-zero dispersion for wideband optical transport, 

approved December 2006 (“ITU-T Recommendation G.656”), 

incorporation by reference approved for sections 2b and 2q; 

(d) ITU-T Recommendation G.657, Series G: Transmission Systems 

and Media, Digital Systems and Networks, Transmission media 

characteristics—Optical fibre cables, Characteristics of a bending 

loss insensitive single mode optical fibre and cable for the access 

network, approved December 2006 (“ITU-T Recommendation 

G.657”), incorporation by reference approved for sections 2b(2) 

and 2q(1); and 

(e) ITU-T Recommendation L.58, Series L: Construction, Installation 

and Protection of Cables and Other Elements of Outside Plant, 

Optical fibre cables: Special Needs for Access Network, approved 

March 2004 (“ITU-T Recommendation L.58”), incorporation by 

reference approved for 2a. 
 RUS BULLETIN 1753F-601a

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2. MINIMUM PERFORMANCE SPECIFICATION FOR FIBER OPTIC CABLES 

a Scope. This section is intended for cable manufacturers, Agency borrowers, 

and consulting engineers. It covers the requirements for fiber optic cables 

intended for aerial installation either by attachment to a support strand or by 

an integrated self-supporting arrangement, for underground application by 

placement in a duct, or for buried installations by trenching, direct plowing, 

and directional or pneumatic boring. 

(1) General 

(a) Specification requirements are given in SI units which are the 

controlling units in this part. Approximate English equivalent of 

units are given for information purposes only. 

(b) The optical waveguides are glass fibers having directly-applied 

protective coatings, and are called "fibers," herein. These fibers 

may be assembled in either loose fiber bundles with a protective 

core tube, encased in several protective buffer tubes, in tight buffer 

tubes, or ribbon bundles with a protective core tube. 

(c) Fillers, strength members, core wraps, and bedding tapes may 

complete the cable core. 

(d) The core or buffer tubes containing the fibers and the interstices 

between the buffer tubes, fillers, and strength members in the core 

structure are filled with a suitable material or water swellable 

elements to exclude water. 

(e) The cable structure is completed by an extruded overall plastic 

jacket. A shield or armor or combination thereof may be included 

under the jacket. The jacket may have strength members embedded 

in it, in some designs. 

(f) Buried installation requires armor under the outer jacket. 

(g) For self-supporting cable, the outer jacket may be extruded over 

the support messenger and cable core. 

(h) Cables for mid-span applications for network access must be 

designed for easy mid-span access to the fibers. The 

manufacturer may use reversing oscillating stranding (SZ) 

described in section 6.4 of ITU-T Recommendation L.58, 

Construction, Installation and Protection of Cables and 

Other Elements of Outside Plant, 2004. The cable end user 

is cautioned that installed cable must be properly terminated. 

This includes properly securing rigid strength members (i.e. 
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central strength member) and clamping the cable and jacket. 

It is important that cable components be secured to prevent 

movement of the cable or components over the operating 

conditions. Central strength member (CSM) clamps must 

prevent movement of the CSM; positive stop CSM clamps 

are recommended. The CSM must be routed as straight and 

as short as practical to prevent bowing or breaking of the 

CSM. The cable and jacket retention must be sufficient to 

prevent jacket slippage over the operating temperature range. 

(2) The normal temperature ranges for cables must meet paragraph 1.1.3 of 

ANSI/ICEA S-87-640, Standard for Optical Fiber Outside Plant 

Communications Cable. (See reproduced Table 1.1 from ANSI/ICEA S87-640 below for temperature ranges.) 

Table 1.1 - Cable normal temperature ranges

(°C) (°F)

Operation 40 to +70 (-40 to +158)

Storage and Shipping -40 to +70 (-40 to +158)

Installation 30 to +60 (-22 to +140) 

(3) Tensile Rating. The standard installation tensile rating for cables is 2670 

N (600 1bf), unless installation involves micro type cables that utilize less 

stress related methods of installation, i.e. blown micro-fiber cable or 

All-Dielectric Self-Supporting (ADSS) cables (see paragraph a(4) of this 

section).

(4) ADSS and Other Self-Supporting Cables. Based on the storm loading 

districts referenced in Section 25, Loading of Grades B and C, of 

ANSI/IEEE C2-2007, National Electrical Safety Code, 2007 and the 

maximum span and location of cable installation provided by the end user, 

the manufacturer must provide a cable design with sag and tension tables 

showing the maximum span and sag information for that particular 

installation. The information included must be for Rule B, Ice and Wind 

Loading, and when applicable, information on Rule 250C, Extreme Wind 

Loading. Additionally, to ensure the proper ground clearance, typically a 

minimum of 4.7 m (15.5 feet), the end user should factor in the maximum 

sag under loaded conditions, as well as, height of attachment for each 

application. 
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(5) Minimum Bend Diameter. For cable under loaded and unloaded 

conditions, the cable must have the minimum bend diameters indicated in 

paragraph 1.1.5, Minimum Bend Diameter, of the ANSI/ICEA S-87-640. 

(See table below for ANSI/ICEA S-87-640 bend diameters.) For very 

small cables, manufacturers may specify fixed cable minimum bend 

diameters that are independent of the outside diameter. For cables having 

a non-circular cross-section, the bend diameter is to be determined using 

the thickness of the cable associated with the preferential bending axis. 

Minimum Bend Diameters

Residual (Installed) 20 x Cable O.D.

Loaded Condition (During 

Installation) 40 x Cable O.D.

(6) The cable is fully color coded so that each fiber is distinguishable from 

every other fiber. A basic color scheme of twelve colors allows individual 

fiber identification. Colored tubes, binders, threads, strippings, or 

markings provide fiber group identification. 

(7) Cables must demonstrate compliance with the qualification testing 

requirements of this section to ensure satisfactory end-use performance 

characteristics for the intended applications. 

(8) Optical cable designs not specifically addressed by this section may 

be allowed if accepted by the Agency. Justification for acceptance 

of a modified design must be provided to substantiate product utility 

and long term stability and endurance. For information on how to 

obtain Agency product acceptance, refer to the procedures listed at 

http://www.usda.gov/rus/telecom/listing_procedures/index_listing_p

rocedures.htm, as well as additional information in RUS Bulletin 

345-3, Acceptance of Standards, Specifications, Equipment Contract 

Forms, Manual Sections, Drawings, Materials and Equipment for 

the Telephone Program (hereinafter "RUS Bulletin 345-3"), 

available for download at 

http://www.usda.gov/rus/telecom/publications/bulletins.htm. 

(9) All cables sold to RUS telecommunications borrowers for projects 

involving RUS loan funds must be accepted by the Agency's Technical 

Standards Committee "A" (Telecommunications). Any design change to 

existing acceptable designs must be submitted to the Agency for 

acceptance. As stated in paragraph 2a(8) above, refer to the procedures 

listed at 

http://www.usda.gov/rus/telecom/listing_procedures/index_listing_proced

ures.htm as well as RUS Bulletin 345-3. 
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(10) The Agency intends that the optical fibers contained in the cables meeting 

the requirements of this section have characteristics that will allow signals 

having a range of wavelengths to be carried simultaneously. 

b Optical Fibers

(1) The solid glass optical fibers must consist of a cylindrical core and 

cladding covered by either an ultraviolet-cured acrylate or other suitable 

coating. Each fiber must be continuous throughout its length. 

(2) Zero-dispersion. Optical fibers must meet the fiber attributes of Table 2, 

G.652.B attributes, found in ITU-T Recommendation G.652. However, 

when the end user stipulates a low water peak fiber, the optical fibers must 

meet the fiber attributes of Table 4, G.652.D attributes, found in ITU-T 

Recommendation G.652; or when the end user stipulates a low bending 

loss fiber, the optical fibers must meet the fiber attributes of Table 7-1, 

G.657 class A attributes, found in the ITU-T Recommendation G.657.

(3) Non-zero-dispersion. Optical fibers must meet the fiber attributes of 

Table 1, G.656 attributes, found in ITU-T Recommendation G.656. 

However, when the end user specifies Recommendation A, B, C, D, or E 

of ITU-T Recommendation G.655, the optical fibers must meet the fiber 

attributes of ITU-T Recommendation G.655. 

(4) Multimode fiber. Optical fibers must meet the requirements of paragraphs 

2.1 and 2.3.1 of ANSI/ICEA S-87-640. (See reproduced Table 2.1 from 

ANSI/ICEA S-87-640 below for requirements.) 

Table 2.1 Multimode optical fiber specification requirements (1) 

Fiber Type TIA/EIA Specification Reference

Sectional Blank 

Detail

Sectional Blank 

Detail

Sectional Blank 

Detail

50 μm 492A000 492AA00 492AAAB

50 μm (2) 492A000 492AA00 492AAAC

62.5 μm 492A000 492AA00 492AAAA

Fiber Attributes (Informative) (3)

Fiber Class

 and 

Subclass

Diameters (μm) Numerical 

Core Cladding Aperture

Ia 50 +/- 3.0 125.0 ± 2.0 0.200 +/- 0.015

62.5 +/- 3.0 125.0 ± 2.0 0.275 +/- 0.015

Notes: 

1) Fiber specifications listed herein are provided for convenience, but are dynamic and subject 

to change. Users should refer to the relevant TIA-492 detailed fiber specification for current 

requirements. 

2) 850 nm laser-optimized 50 μm fiber. 

3) These attributes are defined by the detailed fiber specifications called out above. The values 

are subject to change, and are included here for information only. Refer to the latest fiber 

specifications for current normative values. 
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(5) Matched cable. Unless otherwise specified by the buyer, all single mode 

fiber cables delivered to a RUS-financed project must be manufactured to 

the same MFD specification. However, notwithstanding the requirements 

of paragraphs 2b(2) and 2b(3), the maximum MFD tolerance allowed for 

cable meeting the requirements of this section must be of a magnitude 

meeting the definition of “matched cable,” as defined in this bulletin. 

With the use of cables meeting this definition the user can reasonably 

expect the average bi-directional loss of a fusion splice to be ≤ 0.1 dB. 

(6) Buyers will normally specify the MFD for the fibers in the cable. When a 

buyer does not specify the MFD at 1310 nm, the fibers must be 

manufactured to an MFD of 9.2 μm with a maximum tolerance range of ± 

0.5 μm (362 ± 20 microinch), unless the end user agrees to accept cable 

with fibers specified to a different MFD. When the end user does specify 

a MFD and tolerance conflicting with the MFD maximum tolerance 

allowed by paragraph 2b(5), the requirements of paragraph b(5) must 

prevail. 

(7) Factory splices are not allowed. 

(8) Coating. The optical fiber must be coated with a suitable material to 

preserve the intrinsic strength of the glass having an outside diameter of 

250 ± 15 micrometers (10 ± 0.6 mils). Dimensions must be measured per 

the methods of paragraph 7.13 of ANSI/ICEA S-87-640. The protective 

coverings must be free from holes, splits, blisters, and other imperfections 

and must be as smooth and concentric as is consistent with the best 

commercial practice. The diameter of the fiber, as the fiber is used in the 

cable, includes any coloring thickness or the uncolored coating, as the case 

may be. The strip force required to remove 30 ± 3 millimeters (1.2 ± 0.1 

inch) of protective fiber coating must be between 1.0 N (0.2 pound-force) 

and 9.0 N (2 pound-force). 

(9) All optical fibers in any single length of cable must be of the same type, 

unless otherwise specified by end user. 

(10) Optical fiber dimensions and data reporting must be as required by 

paragraph 7.13.1.1 of ANSI/ICEA S-87-640. 

c Buffers

(1) The optical fibers contained in a tube buffer (loose tube), an inner jacket 

(unit core), a channel, or otherwise loosely packaged must have a 

clearance between the fibers and the inside of the container sufficient to 

allow for thermal expansions of the tube buffer without constraining the 

fibers. The protective container must be manufactured from a material 

having a coefficient of friction sufficiently low to allow the fibers free 
 RUS BULLETIN 1753F-601a

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movement. The loose tube must contain a suitable water blocking 

material. Loose tubes must be removable without damage to the fiber 

when following the manufacturer’s recommended procedures. 

(2) The tubes for single mode loose tube cables must be designed to allow a 

maximum mid-span buffer tube exposure of 6.096 meters (20 feet). The 

buyer should be aware that certain housing hardware may require cable 

designed for 6.096 meters of buffer tube storage. 

(3) Optical fibers covered in near contact with an extrusion (tight tube) must 

have an intermediate soft buffer to allow for thermal expansions and 

minor pressures. The buffer tube dimension must be established by the 

manufacturer to meet the requirement of this section. Tight buffer tubes 

must be removable without damage to the fiber when following the 

manufacturer’s recommended procedures. The tight buffered fiber must 

be strippable per paragraph 7.20 of ANSI/ICEA S-87-640. 

(4) Both loose tube and tight tube coverings of each color and other fiber 

package types removed from the finished cable must meet the following 

shrinkback and cold bend performance requirements. The fibers may be 

left in the tube. 

(a) Shrinkback. Testing must be conducted per paragraph 14.1 of 

ASTM D 4565, using a talc bed at a temperature of 95°C (203°F). 

Shrinkback must not exceed 5 percent of the original 150 

millimeter (6 inches) length of the specimen. The total shrinkage 

of the specimen must be measured. (Buffer tube material meeting 

this test may not meet the mid-span test in paragraph 2r(16) of this 

bulletin). 

(b) Cold Bend. Testing must be conducted on at least one tube from 

each color in the cable. Stabilize the specimen to -30 ± 1°C (-22 ± 

2°F) for a minimum of four hours. While holding the specimen 

and mandrel at the test temperature, wrap the tube in a tight helix 

ten times around a mandrel with a diameter to be greater than five 

times the tube diameter or 50 mm (2 inches). The tube must show 

no evidence of cracking when observed with normal or correctedto-normal vision. 

Note to paragraph 2c(4)(b): Channel cores and similar slotted 

single component core designs do not need to be tested for cold 

bend. 
 RUS BULLETIN 1753F-601a

 Page 16 of 44 

d Fiber Identification

(1) Each fiber within a unit and each unit within the cable must be identifiable 

per paragraphs 4.2.1 and 4.3.1 of ANSI/ICEA S-87-640. 

(2) For the following items the colors designated for identification within the 

cable must comply with paragraphs 4.2.2 and 4.3.2 of ANSI/ICEA S-87-

640: loose buffer tubes, tight tube buffer fibers, individual fibers in multifiber tubes, slots, bundles or units of fibers, and the units in cables with 

more than one unit. (See reproduced Table 4.1 from ANSI/ICEA S-87-

640 below for identification colors.) 

Table 4.1 - Individual fiber, unit, and group identification

Position number Base color and tracer Abbreviation/print legend

1 

2 

3 

4

Blue 

Orange 

Green 

Brown

1 or BL or 1-BL 

2 or OR or 2-OR 

3 or GR or 3-GR 

4 or BR or 4-BR

5 

6 

7 

8

Slate 

White 

Red 

Black

5 or SL or 5-SL 

6 or WH or 6-WH 

7 or RD or 7-RD 

8 or BK or 8-BK

9 

10 

11 

12

Yellow 

Violet 

Rose 

Aqua

9 or YL or 9-YL 

10 or VI or 10-VI 

11 or RS or 11-RS 

12 or AQ or 12-AQ

13 

14 

15 

16

Blue with Black Tracer 

Orange with Black Tracer 

Green with Black Tracer 

Brown with Black Tracer

13 or D/BL or 13-D/BL(1)

14 or D/OR or 14-D/OR 

15 or D/GR or 15-D/GR 

16 or D/BR or 16-D/BR

17 

18 

19 

20

Slate with Black Tracer 

White with Black Tracer 

Red with Black Tracer 

Black with White Tracer

17 or D/SL or 17-D/SL 

18 or D/WH or 18-D/WH 

19 or D/RD or 19-D/RD 

20 or D/BK or 20-D/BK(2)

21 

22 

23 

24

Yellow with Black Tracer 

Violet with Black Tracer 

Rose with Black Tracer 

Aqua with Black Tracer

21 or D/YL or 21-D/YL 

22 or D/VI or 22-D/VI 

23 or D/RS or 23-D/RS 

24 or D/AQ or 24-D/AQ

25 

26 

27 

28

Blue with Double Black Tracer 

Orange with Double Black Tracer 

Green with Double Black Tracer 

Brown with Double Black Tracer

25 or DD/BL or 25-DD/BL(3) 

26 or DD/OR or 14-DD/OR 

27 or DD/GR or 15-DD/GR 

28 or DD/BR or 16-DD/BR

29 

30 

31 

32

Slate with Double Black Tracer 

White with Double Black Tracer 

Red with Double Black Tracer 

Black with Double White Tracer

29 or DD/SL or 17-DD/SL 

30 or DD/WH or 18-DD/WH 

31 or DD/RD or 19-DD/RD 

32 or DD/BK or 20-DD/BK(2)

33 

34 

35 

36

Yellow with Double Black Tracer 

Violet with Double Black Tracer 

Rose with Double Black Tracer 

Aqua with Double Black Tracer

33 or DD/YL or 21-DD/YL 

34 or DD/VI or 22-DD/VI 

35 or DD/RS or 23-DD/RS 

36 or DD/AQ or 24-DD/AQ

Notes: 

1) “D/” denotes a dashed mark or tracer. That is, D/BL is Dash/Blue, meaning Blue with a 

tracer. 

2) Pertaining to positions 20 and 32, yellow tracers are also allowed. 

3) “DD/” denotes a double dashed mark or tracer. That is, DD/BL is Double Dash/Blue, 

meaning Blue with a double tracer. 
 RUS BULLETIN 1753F-601a

 Page 17 of 44 

e Optical Fiber Ribbon 

(1) Each ribbon must be identified per paragraphs 3.4.1 and 3.4.2 of 

ANSI/ICEA S-87-640. See table below. 

(2) Ribbon fiber count must be specified by the end user, e.g. 2, 4, 6 and 12, 

etc. 

(3) Ribbon dimensions must be as agreed by the end user and manufacturer 

per paragraph 3.4.4.1 of ANSI/ICEA S-87-640. 

(4) Ribbons must meet each of the following tests. These tests are included in 

the paragraphs of ANSI/ICEA S-87-640, indicated in parenthesis below. 

 (a) Ribbon Dimensions (ANSI/ICEA S-87-640 paragraphs 7.14 

through 7.14.2) – measures ribbon dimension. 

(b) Ribbon Twist Test (ANSI/ICEA S-87-640 paragraphs 7.15 through 

7.15.2) – evaluates the ability of the ribbon to resist splitting or 

other damage while undergoing dynamic cyclically twisting the 

ribbon under load. 

(c) Ribbon Residual Twist Test (ANSI/ICEA S-87-640 paragraphs 

7.16 through 7.16.2) – evaluates the degree of permanent twist in a 

cabled optical ribbon. 

(d) Ribbon Separability Test (ANSI/ICEA S-87-640 paragraphs 7.17 

through 7.17.2) – evaluates the ability to separate fibers. 

(e) Ribbons must meet paragraph 3.4.4.6 of ANSI/ICEA S-87-640, 

Ribbon Strippability. 

f Strength Members 

(1) Strength members may be an integral part of the cable construction, but 

are not considered part of the support messenger for self-supporting 

optical cable. 

(2) The strength members may be metallic or nonmetallic.

(3) The combined strength of all the strength members must be sufficient to 

support the stress of installation and to protect the cable in service. 

(4) Strength members may be incorporated into the core as a central support 

member or filler, as fillers between the fiber packages, as an annular 
 RUS BULLETIN 1753F-601a

 Page 18 of 44 

serving over the core, as an annular serving over the intermediate jacket, 

embedded in the outer jacket, or as a combination of any of these methods. 

(5) The central support member or filler must contain no more than one splice 

per kilometer of cable. Individual fillers placed between the fiber 

packages and placed as annular servings over the core must contain no 

more than one splice per kilometer of cable. Cable sections having central 

member or filler splices must meet the same physical requirements as unspliced cable sections. 

(6) In each length of completed cable having a metallic central member, the 

dielectric strength between the shield or armor, when present, and the 

metallic center member must withstand at least 15 kilovolts when tested 

per ASTM D 4566. The voltage must be applied for 3 seconds minimum; 

no failures are allowed. 

g Cable Core

(1) Protected fibers may be assembled with the optional central support 

member, fillers and strength members in such a way as to form a 

cylindrical group. 

(2) The standard cylindrical group or core designs commonly consist of 4, 6, 

12, 18 or 24 fibers. Cylindrical groups or core designs larger than the 

sizes shown above must meet all the applicable requirements of this 

section. 

(3) When threads or tapes are used in cables using water blocking elements as 

core binders, they must be a non-hygroscopic and non-wicking dielectric 

material or be rendered by the gel or water blocking material produced by 

the ingress of water. 

(4) When threads or tapes are used as unit binders to define optical fiber units 

in loose tube, tight tube, slotted, or bundled cored designs, they must be 

non-hygroscopic and non-wicking dielectric material or be rendered by the 

filling compound or water blocking material contained in the binder. The 

colors of the binders must be per paragraphs 2d(1) and 2d(2) of this 

bulletin. 
 RUS BULLETIN 1753F-601a

 Page 19 of 44 

h Core Water Blocking

(1) To prevent the ingress of water into the core and water migration, a 

suitable filling compound or water blocking elements must be applied into 

the interior of the loose fiber tubes and into the interstices of the core. 

When a core wrap is used, the filling compound or water blocking 

elements, as the case may be, must also be applied to the core wrap, over 

the core wrap and between the core wrap and inner jacket when required. 

(2) The materials or elements must be homogeneous and uniformly mixed; 

free from dirt, metallic particles and other foreign matter; easily removed; 

nontoxic and present no dermal hazards. The filling compound and water 

blocking elements must contain a suitable antioxidant or be of such 

composition as to provide long term stability. 

(3) The individual cable manufacturer must satisfy the Agency that the filling 

compound or water blocking elements selected for use is suitable for its 

intended application by submitting test data showing compliance with 

ASTM D 4568. The filling compound and water blocking elements must 

be compatible with the cable components when tested per ASTM D 4568 

at a temperature of 80°C (176°F). The jacket must retain a minimum of 

85% of its un-aged tensile and elongation values. 

i Water Blocking Material

(1) Sufficient flooding compound or water blocking elements must be applied 

between the inner jacket and armor and between the armor and outer 

jacket so that voids and air spaces in these areas are minimized. The use 

of flooding compound or water blocking elements between the armor and 

outer jacket is not required when uniform bonding, paragraph 2m(9), is 

achieved between the plastic-clad armor and the outer jacket. 

(2) The flooding compound or water blocking elements must be compatible 

with the jacket when tested per paragraphs 7.19 and 7.19.1 of 

ANSI/ICEA S-87-640. The aged jacket must retain a minimum of 85% of 

its un-aged tensile strength and elongation values when tested per 

paragraph 7.19.2.3. The flooding compound must exhibit adhesive 

properties sufficient to prevent jacket slip when tested per paragraph 

7.30.1 of ANSI/ICEA S-87-640 and meets paragraph 7.30.2 of 

ANSI/ICEA S-87-640 for minimum sheath adherence of 14 N/mm for 

armored cables. 

(3) The individual cable manufacturer must satisfy the Agency by submitting 

test data showing compliance with the appropriate cable performance 

testing requirements of this section that the flooding compound or water 

blocking elements selected for use is acceptable for the application. 
 RUS BULLETIN 1753F-601a

 Page 20 of 44 

j Core Wrap

(1) At the option of the manufacturer, one or more layers of dielectric material 

may be applied over the core. 

(2) The core wrap(s) can be used to provide a heat barrier to prevent 

deformation or adhesion between the fiber tubes or can be used to contain 

the core. 

k Inner Jackets

(1) For designs with more than one jacket, the inner jackets must be applied 

directly over the core or over the strength members when required by the 

end user. The jacket must be free from holes, splits, blisters, or other 

imperfections and must be as smooth and concentric as is consistent with 

the best commercial practice. The inner jacket must not adhere to other 

cable components such as fibers, buffer tubes, etc. 

(2) For armored and unarmored cable, an inner jacket is optional. The inner 

jacket may absorb stresses in the cable core that may be introduced by 

armor application or by armored cable installation. 

(3) The inner jacket material and test requirements must be the same as the 

outer jacket material, except that either black or natural polyethylene may 

be used and the thickness requirements are included in paragraph 2k(4) of 

this bulletin. In the case of natural polyethylene, the requirements for 

absorption coefficient and the inclusion of furnace black are waived. 

(4) The inner jacket thickness must be determined by the manufacturer, but 

must be no less than a nominal jacket thickness of 0.5 mm (0.02 inch) with 

a minimum jacket thickness of 0.35 mm (0.01 inch). 

l Outer Jacket

(1) The outer jacket must provide the cable with a tough, flexible, protective 

covering which can withstand exposure to sunlight, to atmosphere 

temperatures, and to stresses reasonably expected in normal installation 

and service. 

(2) The jacket must be free from holes, splits, blisters, or other imperfections 

and must be as smooth and concentric as is consistent with the best 

commercial practice. 
 RUS BULLETIN 1753F-601a

 Page 21 of 44 

(3) The jacket must contain an antioxidant to provide long term stabilization 

and must contain a minimum of 2.35 percent concentration of furnace 

black to provide ultraviolet shielding measures as required by paragraph 

5.4.2 of ANSI/ICEA S-87-640, except that the concentration of furnace 

black does not necessarily need to be initially contained in the raw 

material and may be added later during the jacket making process. 

(4) The raw material used for the outer jacket must be one of the types listed 

below. 

(a) Type L1. Low density, polyethylene (LDPE) must conform to the 

requirements of paragraph 5.4.2 of ANSI/ICEA S-87-640. 

(b) Type L2. Linear low density, polyethylene (LLDPE) must 

conform to the requirements of paragraph 5.4.2 of 

ANSI/ICEA S-87-640. 

(c) Type M. Medium density polyethylene (MDPE) must conform to 

the requirements of A paragraph 5.4.2 of ANSI/ICEA S-87-640. 

(d) Type H. High density polyethylene (HDPE) must conform to the 

requirements of paragraph 5.4.2 of ANSI/ICEA S-87-640. 

(5) Particle size of the carbon selected for use must not average greater than 

20 nm. 

(6) The outer jacketing material removed from or tested on the cable must be 

capable of meeting the performance requirements of Table 5.1 found in 

ANSI/ICEA S-87-640. (See reproduced Table 5.1 from ANSI/ICEA S-87-

640 on next page for jacket requirements.) 
 RUS BULLETIN 1753F-601a

 Page 22 of 44 

Table 5.1 - Requirements for jackets removed from completed cable (1)

Polyethylene Material PHYSICAL PERFORMANCE BY 

JACKET TYPE

PROPERTY (2) Test 

Method L1 L2 M H

Density(3) - g/cm3 

- Minimum 

- Maximum

7.7 0.920 

0.940

0.925 

0.945

0.940 

0.955

0.952 

0.973

Ultimate Elongation 

- Unaged % Minimum 7.8 400 400 400 300

Yield Strength 

- Mpa (psi) Minimum 7.8 6.9 

(1000)

8.3 

(1200)

11.0 

(1600)

19.3 

(2800)

Absorption Coefficient (4)

- ABS/mm Minimum 7.9 400 400 400 400

Environmental Stress 

Crack Resistance (5)

- Hours – Minimum 

- Failures Allowed 

- ASTM D 1693 Cond

7.10 48 

2/10 

A

48 

2/10 

A

48 

2/10 

B

48 

2/10 

B

Environmental Stress 

Crack Resistance (6)

(small diameter cables) 

- Failures Allowed

7.10

0/1 0/1 0/1 0/1

Jacket Shrinkback 

- Oven Temp. - °C 

- Test Time – hours 

- Shrinkback % Maximum

7.11 100 ± 1 

4 

5

100 ± 1 

4 

5

115 ± 1 

4 

5

115 ± 1 

4 

5

Notes: 

1) Jackets shall be removed from bonded sheath constructions in accordance with one of the two 

procedures provided under the "Jacket Notch Test" of ASTM D 4565. 

2) Test methods designating "clean sample" require that any residual flooding or bonding compounds 

be removed from the surface of the sample by other than chemical means. Those not so designated 

shall include these materials if they cling to the jacket. 

For jackets with embedded strength members, all tests except Environmental Stress Crack Resistance 

are for the material without the strength members. 

3) The material densities are listed in terms of the as-received resin. The density of the natural resin is 

characteristically lower by some amount, due to the addition of carbon black and other additives. As a 

rule-of-thumb, the density of the natural resin is 0.012 g/cm3 lower when using the nominal 

concentration of carbon black (2.6% by weight). 

4) Requirements for Absorption Coefficient of the raw material may be substituted for tests on 

completed cable. 

5) This Stress Crack Resistance requirement applies only to cables having an outside diameter of 30 

mm (1.2 in) or greater. 

6) For cables with outside diameters less than 30 mm (1.2 in), Stress Crack Resistance requirements 

shall be accomplished by testing the cable as a whole in accordance with 7.10.2.
 RUS BULLETIN 1753F-601a

 Page 23 of 44 

(7) Testing Procedures. The procedures for testing the jacket specimens for 

compliance with paragraph 2l(6) of this bulletin must be as follows: 

(a) Jacket Material density Measurement. Test per paragraphs 7.7.1 

and 7.7.2 of ANSI/ICEA S-87-640. 

(b) Tensile Strength, Yield Strength, and Ultimate Elongation. Test 

per paragraphs 7.8.1 and 7.8.2 of ANSI/ICEA S-87-640. 

(c) Jacket Material Absorption Coefficient Test. Test per paragraphs 

7.9.1 and 7.9.2 of ANSI/ICEA S-87-640. 

(d) Environmental Stress Crack Resistance Test. For large cables 

(outside diameter ≥ 30 mm (1.2 inch), test per paragraphs 7.10.1 

through 7.10.1.2 of ANSI/ICEA S-87-640. For small cables 

(Diameter < 30 mm (1.2 inch)), test per paragraphs 7.10.2 through 

and 7.10.2.2 of ANSI/ICEA S-87-640. A crack or split in the 

jacket constitutes failure. 

(e) Jacket Shrinkage Test. Test per paragraphs 7.11.1 and 7.11.2 of 

ANSI/ICEA S-87-640. 

(8) Jacket Thickness. The outer jacket must meet the requirements of 

paragraphs 5.4.5.1 and 5.4.5.2 of ANSI/ICEA S-87-640. (See reproduced 

Table 5.2 from ANSI/ICEA S-87-640 below jacket thickness.) 

Table 5.2 - Jacket thickness requirements

Attribute Construction Measured Value

Minimum Jacket Thickness 

at any point

Inner jacket, multiple-jacket cables Per manufacturers 

specification

Outer jacket, multiple-jacket cables 0.8 mm (0.031 in.)

Single jacket, no armor 0.9 mm (0.035 in.)

Single jacket, armor 1.0 mm (0.039 in.)

Embedded strength members 0.5 mm (0.020 in.)

Maximum Eccentricity All types 40%

(9) Jacket Repairs. Repairs are allowed per paragraph 5.5 of ANSI/ICEA S87-640. 
 RUS BULLETIN 1753F-601a

 Page 24 of 44 

m Armor

(1) A steel armor, plastic coated on both sides, is required for direct buried 

cable manufactured under this section. Armor is optional for duct and 

aerial cable, as required by the end user. The plastic coated steel armor 

must be applied longitudinally directly over the core wrap or the 

intermediate jacket and have a minimum overlap of 3.0 millimeters (118 

mils), except for small diameter cables with diameters of less than 10 mm 

(394 mils) for which the minimum overlap must be 2 mm (79 mils). 

When a cable has a shield, the armor should normally be applied over the 

shielding tape. 

(2) The uncoated steel tape must be electrolytic chrome coated steel (ECCS) 

and must meet the requirements of paragraph B.2.4 of ANSI/ICEA S-87-

640. (See reproduced Table B.7 from ANSI/ICEA S-87-640 below for 

tape thickness.) 

Table B.7 - Thickness of steel tapes

Material Specification 

Number

Tape Thickness - mm (in)

Nominal Minimum

Carbon Steel ASTM A 625 0.15 (0.006) 0.14 (0.0055

Black plate steel ASTM A 308 0.15 (0.006) 0.14 (0.0055

Terne coated steel ASTM A 624 0.15 (0.006) 0.14 (0.0055

Electrolytic chrome coated steel, 

(ECCS) ASTM A 657 0.15 (0.006) 0.14 (0.0055

Tin-plated electrolytic chrome coated 

steel, (ECCS)

ASTM A 624 & 

ASTM A 657 0.15 (0.006) 0.14 (0.0055

(3) The reduction in thickness of the armoring material due to the corrugating 

or application process must be kept to a minimum and must not exceed 10 

percent at any spot. 

(4) The armor of each length of cable must be electrically continuous with no 

more than one joint or splice allowed in any length of one kilometer of 

cable. This requirement does not apply to a joint or splice made in the raw 

material by the raw material manufacturer. 

(5) The breaking strength of any section of an armor tape, containing a factory 

splice joint, must not be less than 80 percent of the breaking strength of an 

adjacent section of the armor of equal length without a joint. 
 RUS BULLETIN 1753F-601a

 Page 25 of 44 

(6) For cables containing no flooding compound over the armor, the overlap 

portions of the armor tape must be bonded in cables having a flat, noncorrugated armor to meet the mechanical requirements of paragraphs 2r(1) 

through 2r(16)(b). If the tape is corrugated, the overlap portions of the 

armor must be sufficiently bonded and the corrugations must be 

sufficiently in register to meet the requirements of paragraphs 2r(1) 

through 2r(16)(b). 

(7) The armor tape must be so applied as to enable the cable to pass the Cable 

Low (-30°C (-22°F)) and High (60°C (140°F)) Temperatures Bend Test, 

as required by paragraph 2r(3). 

(8) The protective coating on the steel armor must meet the Bonding-toMetal, Heat Sealability, Lap-Shear and Moisture Resistance requirements 

of Type I, Class 2 coated metals per ASTM B 736. 

(9) When the jacket is bonded to the plastic coated armor, the bond between 

the plastic coated armor and the outer jacket must not be less than 525 

Newtons per meter (36 pound-force) over at least 90 percent of the cable 

circumference when tested per ASTM D 4565. For cables with strength 

members embedded in the jacket, and residing directly over the armor, the 

area of the armor directly under the strength member is excluded from the 

90 percent calculation. 

n Figure 8 Aerial Cables 

(1) When self-supporting aerial cable containing an integrated support 

messenger is supplied, the support messenger must comply with the 

requirements specified in paragraphs D.2.1 through D.2.4 of ANSI/ICEA 

S-87-640, with exceptions and additional provisions as follows: 

(a) Any section of a completed strand containing a joint must have 

minimum tensile strength and elongation of 29,500 Newtons 

(6,632 pound-force) and 3.5 percent, respectively, when tested per 

the procedures specified in ASTM A 640. 

(b) The individual wires from a completed strand which contain joints 

must not fracture when tested per the "Ductility of Steel" 

procedures specified in ASTM A 640, except that the mandrel 

diameter must be equal to 5 times the nominal diameter of the 

individual wires. 
 RUS BULLETIN 1753F-601a

 Page 26 of 44 

(c) The support strand must be completely covered with a flooding 

compound that offers corrosion protection. The flooding 

compound must be homogeneous and uniformly mixed. 

(d) The flooding compound must be nontoxic and present no dermal 

hazard. 

(e) The flooding compound must be free from dirt, metallic particles, 

and other foreign matter that may interfere with the performance of 

the cable. 

(2) Other methods of providing self-supporting cable specifically not 

addressed in this section may be allowed if accepted. Justification for 

acceptance of a modified design must be provided to substantiate product 

utility and long term stability and endurance. To obtain the Agency's 

acceptance of a modified design, refer to the product acceptance 

procedures available at 

http://www.usda.gov/rus/telecom/listing_procedures/index_listing_proced

ures.htm, as well as RUS Bulletin 345-3. 

(3) Jacket Thickness Requirements. Jackets applied over an integral 

messenger must meet the following requirements:

(a) The minimum jacket thickness at any point over the support 

messenger must meet the requirements of paragraph D.3 of 

ANSI/ICEA S-87-640. (See reproduced Table D.1 from 

ANSI/ICEA S-87-640 below for jacket thickness over messenger.) 

Table D.1 - Outer jacket thickness requirements for figure-8 

messenger cables

Calculated Average Diameter (D) 

Under Jacket

Acceptable Thickness Calculated 

Average - mm (in.)

Minimum 

Average

Minimum

Jacket Over The Core(1) 1.02 ( 0.040 ) 0.86 ( 0.034 )

Jacket Over The Messenger 1.37 ( 0.054 ) 1.14 (0.045)

Note (1) Jackets are also subject to a maximum eccentricity requirement of 50% for 

bonded sheaths and 40% for all other sheaths, with eccentricity calculated as 

required by ASTM D 4565.
 RUS BULLETIN 1753F-601a

 Page 27 of 44 

(b) The web dimension for self-supporting aerial cable must meet the 

requirements of paragraph D.3 of ANSI/ICEA S-87-640. (See 

reproduced Table D.2 from ANSI/ICEA S-87-640 below for web 

dimensions.) 

Table D.2 - Dimension requirements for messenger webs

Web Dimensions and Tolerances - mm (inch)

Thickness of Web Height of Web

1.52 +0.51/-0.25 

(0.060 + 0.020/-0.010) 

2.29 ± 0.76 

(0.090 ± 0.030) 

o Sheath Slitting Cord

(1) A sheath slitting cord or ripcord is optional. 

(2) When a sheath slitting cord is used it must be capable of slitting the jacket 

or jacket and armor, at least one meter (3.3 feet) length without breaking 

the cord at a temperature of 23 ± 5°C (73 ± 9°F). 

(3) The sheath slitting cord must meet the sheath slitting cord test described in 

paragraph 2r(1). 

p Identification Markers

(1) Each length of cable must be permanently identified. The method of 

marking must be by means of suitable surface markings producing a clear 

distinguishable contrasting marking meeting paragraph 6.1.1 of 

ANSI/ICEA S-87-640, and must meet the durability requirements of 

paragraphs 7.5.2 through 7.5.2.2 of ANSI/ICEA S-87-640. 

(2) The color of the initial marking must be white or silver. If the initial 

marking fails to meet the requirements of the preceding paragraphs, it will 

be permissible to either remove the defective marking and re-mark with 

the white or silver color or leave the defective marking on the cable and 

re-mark with yellow. No further re-marking is permitted. Any re-marking 

must be done on a different portion of the cables circumference where the 

existing marking is found and have a numbering sequence differing from 

any other marking by at least 3,000. Any reel of cable that contains more 

than one set of sequential markings must be labeled to indicate the color 

and sequence of marking to be used. The labeling must be applied to the 

reel and also to the cable.

(3) Each length of cable must be permanently labeled OPTICAL CABLE, 

OC, OPTICAL FIBER CABLE, or OF on the outer jacket and identified 

as to manufacturer and year of manufacture. 
 RUS BULLETIN 1753F-601a

 Page 28 of 44 

(4) Each length of cable intended for direct burial installation must be marked 

with a telephone handset in compliance with requirements of the Rule 

350G of the ANSI/IEEE C2-2007. 

(5) Each length of cable must be identified as to the manufacturer and year of 

manufacturing. The manufacturer and year of manufacturing may also be 

indicated by other means as indicated in paragraphs 6.1.2 through 6.1.4 of 

ANSI/ICEA S-87-640. 

(6) The number of fibers on the jacket must be marked on the jacket. 

(7) The completed cable must have sequentially numbered length markers in 

METERS or FEET at regular intervals of not more than 2 feet or not more 

than 1 meter along the outside of the jacket. Continuous sequential 

numbering must be employed in a single length of cable. The numbers 

must be dimensioned and spaced to produce good legibility and must be 

approximately 3 millimeters (118 mils) in height. An occasional illegible 

marking is permissible when it is located within 2 meters of a legible 

making for cables marked in meters or 4 feet for cables marked in feet. 

(8) Agreement between the actual length of the cable and the length marking 

on the cable jacket must be within the limits of +1 percent and -0 percent. 

(9) Jacket Print Test. Cables must meet the Jacket Print Test described in 

paragraphs 7.5.2.1 and 7.5.2.2 of ANSI/ICEA S-87-640. 
 RUS BULLETIN 1753F-601a

 Page 29 of 44 

q Performance of a Finished Cable

(1) Zero Dispersion Optical Fiber Cable. Unless otherwise specified by the 

end user, the optical performance of a finished cable must comply with the 

attributes of Table 2, G.652.B attributes, found in ITU Recommendation 

G.652. However, when the end user stipulates a low water peak fiber the 

finished cable must meet the attributes of Table 4, G.652.D attributes, 

found in ITU-T Recommendation G.652; or when the end user stipulates a 

low bending loss fiber, the finished cable must meet the attributes of 

Table 7-1, G.657 class A attributes, found in ITU-T Recommendation 

G.657. 

(a) The attenuation methods must be per Table 8.4, Optical 

attenuation measurement methods, of ANSI/ICEA S-87-640 (See 

reproduced Table 8.4 from ANSI/ICEA S-87-640 below for 

measurement methods.) 

Table 8.4 - Optical attenuation measurement methods

Fibers Measurement Method

Multimode, Graded 

Index only FOTP-78 

Single-mode, 

Dispersion Unshifted FOTP-78 

Single-mode only, 

Non-zero Dispersion-shifted FOTP-78 

(b) The cable must have a maximum attenuation of 0.1 dB at a point of 

discontinuity (a localized deviation of the optical fiber loss). (See 

reproduced Table 8.3 from ANSI/ICEA S-87-640 for acceptance 

criteria for points of discontinuity.) Per paragraphs 8.4 and 8.4.1 

of ANSI/ICEA S-87-640, measurements must be conducted at 

1310 and 1550 nm, and at 1625 nm when specified by the end 

user. 

Table 8.3 - Point discontinuity acceptance criteria 

(dB)requirements (dB/km)methods

Fiber Type Maximum Attenuation at Specified

Operating Wavelengths

Multimode (all) 0.2(1)

Single-mode (Class IVa) 0.1(2)

Single-mode (Class IVd) 0.1(3)

Notes: 

1) The operational wavelengths for Multimode fibers are 850 and 1300 nm. 

2) The operational wavelengths for Class IVa fibers are 1310 and 1550 nm, but may also 

include 1383 nm and 1625 nm as agreed upon between manufacturer and end-user. 

3) The operational wavelengths for Class IVd fibers is 1550 nm, but may also include 

1625 nm as agreed upon between manufacturer and end-user.
 RUS BULLETIN 1753F-601a

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(c) The cable cutoff wavelength (γcc) must be reported per paragraph 

8.5.1 of ANSI/ICEA S-87-640. 

(2) Nonzero Dispersion Optical Fiber Cable. Unless otherwise specified by 

the end user, the optical performance of the finished cable must comply 

with the attributes of Table 1, G.656 attributes, found in ITU-T 

Recommendation G.656. When the buyer specifies Recommendation A, 

B, C, D or E of ITU-T Recommendation G.655, the finished cable must 

comply with the attributes of ITU-T Recommendation G.655. 

(a) The attenuation methods must be per Table 8.4, Optical 

attenuation measurement methods of ANSI/ICEA S-87-640. (See 

reproduced Table 8.4 from ANSI/ICEA S-87-640 below for 

attenuation methods.) 

Table 8.4 - Optical attenuation measurement methods

Fibers Measurement Method

Multimode, Graded 

Index only FOTP-78 

Single-mode, 

Dispersion Unshifted FOTP-78 

Single-mode only, 

Non-zero Dispersion-shifted FOTP-78 

(b) The cable must have a maximum attenuation of 0.1 dB at a point of 

discontinuity (a localized deviation of the optical fiber loss). (See 

reproduced Table 8.3 from ANSI/ICEA S-87-640 for acceptance 

criteria for points of discontinuity.) Per paragraphs 8.4 and 8.4.1 

of ANSI/ICEA S-87-640, measurements must be conducted at 

1310 and 1550 nm, and at 1625 nm when specified by the end 

user. 

Table 8.3 - Points discontinuity acceptance criteria (db)

(dB)requirements (dB/km)methods

Fiber Type Maximum Attenuation at Specified

Operating Wavelengths

Multimode (all) 0.2(1)

Single-mode (Class IVa) 0.1(2)

Single-mode (Class IVd) 0.1(3)

Notes: 

1) The operational wavelengths for Multimode fibers are 850 and 1300 nm. 

2) The operational wavelengths for Class IVa fibers are 1310 and 1550 nm, but may also 

include 1383 nm and 1625 nm as agreed upon between manufacturer and end-user. 

3) The operational wavelengths for Class IVd fibers is 1550 nm, but may also include 

1625 nm as agreed upon between manufacturer and end-user.
 RUS BULLETIN 1753F-601a

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(c) The cable cutoff wavelength (γcc) must be reported per paragraph 

8.5.1 of ANSI/ICEA S-87-640. 

(3) Multimode Optical Fiber Cable. Unless otherwise specified by the end 

user, the optical performance of the fibers in a finished cable must comply 

with Table 8.1, Attenuation coefficient performance requirement (dB/k),

Table 8.2, Multimode bandwidth coefficient performance requirements 

(MHz-km) and Table 8.3, Points discontinuity acceptance criteria (dB), of 

ANSI/ICEA S-87-640. (See reproduced Table 8.1 and 8.3 from 

ANSI/ICEA S-87-640 below for attenuation and acceptance criteria for 

points of discontinuity, respectively.) 

Table 8.1 - Attenuation coefficient performance requirements 

(dB/km)methods

Fiber Type Maximum Attenuation

Multimode (50/125 ⎧m) – All 3.5/1.0 @ 850/1300 nm 

Multimode (62.5/125 μm) 3.5/1.0 @ 850/1300 nm 

Single-mode (Class IVa) 0.4/0.3 @ 1310/1550 nm(1)

NZDS Single-mode (Class IVd) 0.3 @ 1550 nm(2)

Notes: 

1) The attenuation coefficient for Class IVa fibers may also be specified at 1383 nm and 

1625 nm as agreed upon between manufacturer and end-user. 

2) The attenuation coefficient for Class IVd fibers may also be specified at 1625 nm as 

agreed upon between manufacturer and end-user.

Table 8.3 - Points discontinuity acceptance criteria 

(dB)requirements (dB/km)methods

Fiber Type Maximum Attenuation at Specified 

Operating Wavelengths

Multimode (all) 0.2(1)

Single-mode (Class IVa) 0.1(2)

Single-mode (Class IVd) 0.1(3)

Notes: 

1) The operational wavelengths for Multimode fibers are 850 and 1300 nm. 

2) The operational wavelengths for Class IVa fibers are 1310 and 1550 nm, but may also 

include 1383 nm and 1625 nm as agreed upon between manufacturer and end-user. 

3) The operational wavelengths for Class IVd fibers is 1550 nm, but may also include 

1625 nm as agreed upon between manufacturer and end-user.

(4) Because the accuracy of attenuation measurements for single mode fibers 

becomes questionable when measured on short cable lengths, attenuation 

measurements are to be made utilizing characterization cable lengths. 

Master Cable reels must be tested and the attenuation values measured 

will be used for shorter ship lengths of cable. 
 RUS BULLETIN 1753F-601a

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(5) Because the accuracy of attenuation measurements for multimode fibers 

becomes questionable when measured on short cable lengths, attenuation 

measurements are to be made utilizing characterization cable lengths. If 

the ship length of cable is less than one kilometer, the attenuation values 

measured on longer lengths of cable (characterization length of cable) 

before cutting to the ship lengths of cable may be applied to the ship 

lengths. 

(6) Attenuation must be measured per Table 8.4, Optical Attenuation 

Measurement Methods, of ANSI/ICEA S-87-640. (See reproduced Table 

8.4 from ANSI/ICEA S-87-640 below for measurement method.) 

Table 8.4 - Optical attenuation measurement methods

Fibers Measurement Method

Multimode, Graded 

Index only FOTP-78 

Single-mode, 

Dispersion Unshifted FOTP-78 

Single-mode only, 

Non-zero Dispersion-shifted FOTP-78 

(7) The bandwidth of multimode fibers in a finished cable must be no less 

than the values specified in ANSI/ICEA S-87-640, Table 8.2 per 

paragraphs 8.3.1 and 8.3.2. (See reproduced Table 8.2 from ANSI/ICEA 

S-87-640 below for bandwidth of multimode fibers.) 

Table 8.2 - Multimode bandwidth coefficient performance 

requirements (MHz•km)

Source 

Conditions

Minimum Modal Bandwidth

50/125 62.5/125

492AAAB 492AAAC

OFL 850nm 

1300 nm 

EMB 850 nm

500 

500 

NA

1500 

500 

2000

160 

500 

NA
 RUS BULLETIN 1753F-601a

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r Mechanical Requirements.

Fiber optic cables manufactured under the requirements of this section must be 

tested by the manufacturer to determine compliance with such requirements. 

Unless otherwise specified, testing must be performed at the standard conditions 

defined in paragraph 7.3.1 of ANSI/ICEA S-87-640. (See table below for testing 

conditions.) The standard optical test wavelengths to be used are 1550 nm single 

mode and 1300 nm multi-mode, unless otherwise specified in the individual test. 

Standard Conditions for Testing per TIA/EIA-455

Condition Standard Ambient

Temperature 23 + 5 °C

Relative Humidity 20 to 70 %

Atmospheric Pressure Site Ambient

(1) Sheath Slitting Cord Test. All cables manufactured under the 

requirements of this section must meet the Ripcord Functional Test 

described in paragraphs 7.18.1 and 7.18.2 of ANSI/ICEA S-87-

640.

(2) Material Compatibility and Cable Aging Test. All cables 

manufactured under the requirements of this section must meet the 

Material Compatibility and Cable Aging Test described in 

paragraphs 7.19 through 7.19.2.4 of ANSI/ICEA S-87-640.

(3) Cable Low and High Bend Test. Cables manufactured under the 

requirements of this section must meet the Cable Low (-30°C (-

22°F)) and High (60oC (140oF)) Temperatures Bend Test per 

paragraphs 7.21 and 7.21.2 of ANSI/ICEA S-87-640. 

(4) Compound Flow Test. All cables manufactured under the 

requirements of this section must meet the test described in 

paragraphs 7.23, 7.23.1, and 7.23.2 of ANSI/ICEA S-87-640. 

(5) Cyclic Flexing Test. All cables manufactured under the 

requirements of this section must meet the Flex Test described in 

paragraphs 7.27 through 7.27.2 of the ANSI/ICEA S-87-640. 

(6) Water Penetration Test. All cables manufactured under the 

requirements of this section must meet paragraphs 7.28 through 

7.28.2 of ANSI/ICEA S-87-640. 
 RUS BULLETIN 1753F-601a

 Page 34 of 44 

(7) Cable Impact Test. All cables manufactured under the 

requirements of this section must meet the Cable Impact Test 

described in paragraphs 7.29.1 and 7.29.2 of ANSI/ICEA S-87-

640. 

(8) Cable Tensile Loading and Fiber Strain Test. Cables 

manufactured under the requirements of this section must meet the 

Cable Loading and Fiber Strain Test described in paragraphs 7.30 

through 7.30.2 of ANSI/ICEA S-87-640. This test does not apply 

to aerial self-supporting cables. 

(9) Cable Compression Test. All cables manufactured under 

requirements of this section must meet the Cable Compressive 

Loading Test described in paragraphs 7.31 through 7.31.2 of 

ANSI/ICEA S-87-640. 

(10) Cable Twist Test. All cables manufactured under the requirements 

of this section must meet the Cable Twist Test described in 

paragraphs 7.32 through 7.32.2 of ANSI/ICEA S-87-640. 

(11) Cable Lighting Damage Susceptibility Test. Cables manufactured 

under the requirements of this section must meet the Cable 

Lighting Damage Susceptibility Test described in paragraphs 7.33 

and 7.33.1 of ANSI/ICEA S-87-640. 

(12) Cable External Freezing Test. All cables manufactured under the 

requirements of this section must meet the Cable External Freezing 

Test described in paragraphs 7.22 and 7.22.1 of ANSI/ICEA S-87-

640. 

(13) Cable Temperature Cycling Test. All cables manufactured under 

the requirements of this section must meet the Cable Temperature 

Cycling Test described in paragraph 7.24.1 of ANSI/ICEA S-87-

640. 

(14) Cable Sheath Adherence Test. All cables manufactured under the 

requirements of this section must meet the Cable Sheath 

Adherence Test described in paragraphs 7.26.1 and 7.26.2 of 

ANSI/ICEA S-87-640. 
 RUS BULLETIN 1753F-601a

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(15) Mid-Span Test. This test is applicable only to cables of a loose 

tube design specified for mid-span applications with tube storage. 

Cable of specialty design may be exempted from this requirement 

when this requirement is not applicable to such design. All buried 

and underground loose tube single mode cables manufactured per 

the requirements in this section and intended for mid-span 

applications with tube storage must meet the following mid-span 

test without exhibiting an increase in fiber attenuation greater than 

0.1 dB and a maximum average increase over all fibers of 0.05 dB. 

(a) The specimen must be installed in a commercially available 

pedestal or closure or in a device that mimics their 

performance, as follows: A length of cable sheath, equal to 

the mid-span length, must be removed from the middle of 

the test specimen so as to allow access to the buffer tubes. 

All binders, tapes, strength members, etc. must be removed. 

The buffer tubes must be left intact. The cable ends 

defining the ends of the mid-span length must be properly 

secured in the closure to the more stringent of the cable or 

hardware manufacturer's recommendations. Strength 

members must be secured with an end stop type clamp and 

the outer jacket must be clamped to prevent slippage. A 

minimum of 6.096 meters (20 feet) of cable must extend 

from the entry and exit ports of the closure for the purpose 

of making optical measurements. If a device that mimics 

the performance of pedestals or closures is used, the buffer 

tubes must be wound in a coil with a minimum width of 3 

inches and minimum length of 12 inches. 

(b) The expressed buffer tubes must be loosely constrained 

during the test. 

(c) The enclosure, with installed cable, must be placed in an 

environmental chamber for temperature cycling. It is 

acceptable for some or all of the two 20 feet (6.096 meters) 

cable segments to extend outside the environmental 

chamber. 

(d) Lids, pedestal enclosures, or closure covers must be 

removed if possible to allow for temperature equilibrium of 

the buffer tubes. If this is not possible, the manufacture 

must demonstrate that the buffer tubes are at temperature 

equilibrium prior to beginning the soak time. 
 RUS BULLETIN 1753F-601a

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(e) Measure the attenuation of single mode fibers at 1550 ± 10 

nm. The supplier must certify the performance of lower 

specified wavelengths comply with the mid-span 

performance requirements. 

(f) After measuring the attenuation of the optical fibers, test 

the cable sample per TIA/EIA Standard 455-3A. 

Temperature cycling, measurements, and data reporting 

must conform to TIA/EIA Standard 455-3A. The test must 

be conducted for at least five complete cycles. The 

following detailed test conditions must apply: 

A TIA/EIA Standard 455-3A, Section 4.1 – Loose 

tube single mode optical cable sample must be 

tested. 

B TIA/EIA Standard 455-3A, Section 4.2 – An 

Agency accepted 8 to 12 inch diameter optical 

buried distribution pedestal or a device that mimics 

their performance must be tested. 

C Mid-span opening for installation of loose tube 

single mode optical cable in pedestal must be 6.096 

meters (20 feet). 

D TIA/EIA Standard 455-3A, Section 5.1 – 3 hours 

soak time. 

E TIA/EIA Standard 455-3A, Section 5.2 – Test 

Condition C-2, minimum –40°C (-40°F) and 

maximum 70° Celsius (158°F). 

F TIA/EIA Standard 455-3A, Section 5.7.2 – A 

statistically representative amount of transmitting 

fibers in all express buffer tubes passing through the 

pedestal and stored must be measured. 

G The buffer tubes in the closure or pedestal must not 

be handled or moved during temperature cycling or 

attenuation measurements. 
 RUS BULLETIN 1753F-601a

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(g) Fiber cable attenuation measured through the express 

buffer tubes during the last cycle at -40°C (-40°F) and 

+70°C (158°F) must not exceed a maximum increase of 0.1 

dB and must not exceed a 0.05 dB average across all tested 

fibers from the initial baseline measurements. At the 

conclusion of the temperature cycling, the maximum 

attenuation increase at 23°C from the initial baseline 

measurement must not exceed 0.05 dB which allows for 

measurement noise that may be encountered during the 

test. The cable must also be inspected at room temperature 

at the conclusion of all measurements; the cable must not 

show visible evidence of fracture of the buffer tubes nor 

show any degradation of all exposed cable assemblies. 

(16) Aerial Self-Supporting Cables. The following tests apply to aerial 

cables only: 

(a) Static Tensile Testing of Aerial Self-Supporting Cables. 

Aerial self-supporting cable must meet the test described in 

paragraphs D.4.1.1 through D.4.1.5 of ANSI/ICEA S-87-

640. 

(b) Cable Galloping Test. Aerial self-supporting cable made to 

the requirements of this section must meet the test 

described in paragraphs D.4.2 through D.4.2.3 of 

ANSI/ICEA S-87-640. 

s Pre-connectorized Cable

(1) At the option of the manufacturer and upon request by the end user, the 

cable may be factory terminated with connectors. 

(2) All connectors must be accepted by the Agency prior to their use. To 

obtain the Agency's acceptance of connectors, refer to product acceptance 

procedures available at

http://www.usda.gov/rus/telecom/listing_procedures/index_listing_proced

ures.htm as well as RUS Bulletin 345-3.
 RUS BULLETIN 1753F-601a

 Page 38 of 44 

t Acceptance Testing 

(1) The tests described in the Appendix to this section are intended for 

acceptance of cable designs and major modifications of accepted designs. 

What constitutes a major modification is at the discretion of the Agency. 

These tests are intended to show the inherent capability of the 

 manufacturer to produce cable products that have satisfactory performance 

characteristics, long life, and long-term optical stability but are not 

intended as field tests. After initial RUS product acceptance is granted, 

the manufacturer will need to apply for continued product acceptance in 

January of the third year after the year of initial acceptance. For 

information on Agency acceptance, refer to the product acceptance 

procedures available at 

http://www.usda.gov/rus/telecom/listing_procedures/index_listing_proced

ures.htm, as well as RUS Bulletin 345-3.

(2) Acceptance. For initial acceptance, the manufacturer must submit: 

(a) An original signature certification that the product fully complies 

with each paragraph of this section; 

(b) Qualification Test Data, per the Appendix to this section; 

(c) A set of instructions for handling the cable; 

(d) OSHA Material Safety Data Sheets for all components; 

(e) Agree to periodic plant inspections; 

(f) A certification stating whether the cable, as sold to RUS 

Telecommunications borrowers, complies with the following two 

provisions: 

(1) Final assembly or manufacture of the product, as the 

product would be used by an RUS Telecommunications 

borrower, is completed in the United States or eligible 

countries (currently, Mexico, Canada and Israel); and 

(2) The cost of United States and eligible countries' 

components (in any combination) within the product is 

more than 50 percent of the total cost of all components 

utilized in the product. The cost of non-domestic 

components (components not manufactured within the 

United States or eligible countries) which are included in 

the finished product must include all duties, taxes, and 

delivery charges to the point of assembly or manufacture; 
 RUS BULLETIN 1753F-601a

 Page 39 of 44 

(g) Written user testimonials concerning performance of the product; 

and 

(h) Other nonproprietary data deemed necessary. 

(3) Re-qualification acceptance. For submission of a request for continued 

product acceptance after the initial acceptance, follow paragraph 2t(1) and 

then, in January every three years, the manufacturer must submit an 

original signature certification stating that the product fully complies with 

each paragraph of this bulletin, excluding the qualification sections 

(paragraphs 2t(2), 2t(3) and (2t(4)), and a certification that the products 

sold to RUS Telecommunications borrowers comply with paragraphs 

2t(2)(f) through 2t(2)(f)(B) of this bulletin The tests of the Appendix to 

this section must be conducted and records kept for at least three years and 

the data must be made available to the Agency on request. The required 

data must have been gathered within 90 days of the submission. A 

certification must be submitted to the Agency stating that the cable 

manufactured to the requirements of this section has been tested per the 

Appendix of this section and that the cable meets the test requirements. 

(4) Initial and re-qualification acceptance requests should be addressed to: 

Chairman, Technical Standards Committee "A" (Telecommunications), 

STOP 1550, Rural Utilities Service, Advanced Services Division, 

Telecommunications Program, Washington, DC 20250-1500. 

(5) Tests on 100 Percent of Completed Cable. 

(a) The armor for each length of cable must be tested for continuity 

using the procedures of ASTM D 4566. 

(b) Attenuation for each optical fiber in the cable must be measured. 

(c) Optical discontinuities greater than 0.1 dB must be isolated and 

their location and amplitude recorded. 

(6) Capability Tests. The manufacturer must establish a quality assurance 

system. Tests on a quality assurance basis must be made as frequently as 

is required for each manufacturer to determine and maintain compliance 

with all the mechanical requirements and the fiber and cable attributes 

required by this section, including: 

(a) Numerical aperture and bandwidth of multimode fibers; 

(b) Cut off wavelength of single mode fibers; 
 RUS BULLETIN 1753F-601a

 Page 40 of 44 

(c) Dispersion of single mode fibers; 

(d) Shrinkback and cold testing of loose tube and tight tube buffers, 

and mid-span testing of cables of a loose tube design with tube 

storage; 

(e) Adhesion properties of the protective fiber coating; 

(f) Dielectric strength between the armor and the metallic central 

member; 

(g) Performance requirements for the fibers; 

(h) Performance requirements for the inner and outer jacketing 

materials; 

(i) Performance requirements for the filling and flooding compounds; 

(j) Bonding properties of the coated armoring material; 

(k) Sequential marking and lettering; and 

(l) Mechanical tests described in paragraphs 2r(1) through 2r(16)(b) 

of this bulletin. 

u Records Tests 

(1) Each manufacturer must maintain suitable summary records for a period 

of at least 3 years of all optical and physical tests required on completed 

cable by section as set forth in paragraphs 2t(5) and 2t(6) of this bulletin. 

The test data for a particular reel must be in a form that it may be readily 

available to the Agency upon request. The optical data must be furnished 

to the end user on a suitable and easily readable form. 

(2) Measurements and computed values must be rounded off to the number of 

places or figures specified for the requirement per paragraph 1.3 of

ANSI/ICEA S-87-640. 

v Manufacturing Irregularities

(1) Under this section, repairs to the armor, when present, are not permitted in 

cable supplied to the end user. 

(2) Minor defects in the inner and outer jacket (defects having a dimension of 

3 millimeter or less in any direction) may be repaired by means of heat 

fusing per good commercial practices utilizing sheath grade compounds. 
 RUS BULLETIN 1753F-601a

 Page 41 of 44 

w Packaging and Preparation for Shipment 

(1) The cable must be shipped on reels containing one continuous length of 

cable. The diameter of the drum must be large enough to prevent damage 

to the cable from reeling and unreeling. The diameter must be at least 

equal to the minimum bending diameter of the cable. The reels must be 

substantial and so constructed as to prevent damage during shipment and 

handling. 

(2) A circumferential thermal wrap or other means of protection must be 

secured between the outer edges of the reel flange to protect the cable 

against damage during storage and shipment. The thermal wrap must 

meet the requirements included in the Thermal Reel Wrap Test, described 

below. This test procedure is for qualification of initial and subsequent 

changes in thermal reel wraps. 

(a) Sample Selection. All testing must be performed on two 450 

millimeter (18 inches) lengths of cable removed sequentially from 

the same fiber jacketed cable. This cable must not have been 

exposed to temperatures in excess of 38°C (100°F) since its initial 

cool down after sheathing. 

(b) Test Procedure: 

(1) Place the two samples on an insulating material such as 

wood. 

(2) Tape thermocouples to the jackets of each sample to 

measure the jacket temperature. 

(3) Cover one sample with the thermal reel wrap. 

(4) Expose the samples to a radiant heat source capable of 

heating the uncovered sample to a minimum of 71°C (160 

°F). A GE 600 watt photoflood lamp or an equivalent lamp 

having the light spectrum approximately that of the sun 

must be used. 

(5) The height of the lamp above the jacket must be 380 

millimeters (15 inches) or an equivalent height that 

produces the 71°C (160 °F) jacket temperature on the 

unwrapped sample must be used. 
 RUS BULLETIN 1753F-601a

 Page 42 of 44 

(6) After the samples have stabilized at the temperature, the 

jacket temperatures of the samples must be recorded after 

one hour of exposure to the heat source. 

(7) Compute the temperature difference between jackets. 

(8) The temperature difference between the jacket with the 

thermal reel wrap and the jacket without the reel wrap must 

be greater than or equal to 17°C (63 °F). 

(3) Cables must be sealed at the ends to prevent entrance of moisture. 

(4) The end-of-pull (outer end) of the cable must be securely fastened to 

prevent the cable from coming loose during transit. The start-of-pull 

(inner end) of the cable must project through a slot in the flange of the 

reel, around an inner riser, or into a recess on the flange near the drum and 

fastened in such a way to prevent the cable from becoming loose during 

installation. 

(5) Spikes, staples or other fastening devices must be used in a manner which 

will not result in penetration of the cable. 

(6) The arbor hole must admit a spindle 63.5 millimeters (2.5 inches) in 

diameter without binding. 

(7) Each reel must be plainly marked to indicate the direction in which it 

should be rolled to prevent loosening of the cable on the reel. 

(8) Each reel must be stenciled or lettered with the name of the manufacturer. 
 RUS BULLETIN 1753F-601a

 Page 43 of 44 

(9) The following information must be either stenciled on the reel or on a tag 

firmly attached to the reel:

OPTICAL CABLE 

Type and Number of Fibers 

Armored or Non-armored 

Year of Manufacture 

Name of Cable Manufacturer 

Length of Cable 

Reel Number 

7 CFR 1755.902 

Minimum Bending Diameter for both Residual 

and Loaded Condition during installation 

Example: 

OPTICAL CABLE 

G.657 class A, 4 fibers 

Armored 

XYZ Company 

1050 meters 

Reel Number 3 

7 CFR 1755.902 

Minimum Bending Diameter: 

Residual (Installed): 20 times Cable O.D 

Loaded Condition: 40 times Cable O.D 
 RUS BULLETIN 1753F-601a

 Page 44 of 44 

APPENDIX TO RUS Bulletin 1753F-601a 

FIBER OPTIC CABLES 

Bulletin 1753F-601a (PE-90) Qualifications Test Data

Initial qualification and three year re-qualification test data required for 

TELECOMMUNICATIONS PROGRAM product acceptance. Please note that some 

tests may apply only to a particular cable design. 

Paragraph Test 

Initial 

Qualification 

3 Year 

Re-qualification 

2c(4)(a) Shrinkback X 

2c(4)(b) Cold Bend X 

2r(1) Sheath Slitting Cord X 

2r(2) Material Compatibility X 

2r(3) Cable Low & High Bend X X 

2r(4) Compound Flow X 

2r(5) Cyclic Flexing X X 

2r(6) Water Penetration X X 

2r(7) Cable Impact X X 

2r(8) Cable Tensile Loading & Fiber 

Strain X X 

2r(9) Cable Compression X 

2r(10) Cable Twist X X 

2r(11) Cable Lighting Damage 

Susceptibility X 

2r(12) Cable External Freezing X 

2r(13) Cable Temperature Cycling X X 

2r(14) Cable Sheath Adherence X 

2r(15) Mid-Span X X 

2r(16)(a) Static Tensile Testing of Aerial 

Self-Supporting Cables X X 

2r(16)(b) Cable Galloping X 

2y(2) Thermal Reel Wrap X