Specification for Filled Fiber Optic Cables

DEPARTMENT OF AGRICULTURE

Rural Electrification Administration

7 CFR Part 1755

RIN 0572-AA57

Specification for Filled Fiber Optic Cables

AGENCY: Rural Electrification Administration, USDA.

ACTION: Final rule.

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SUMMARY: The Rural Electrification Administration (REA) amends its

regulations on Telecommunications Standards and Specifications for

Materials, Equipment and Construction by rescinding REA Bulletin 345-

90, REA Specification for Totally Filled Fiber Optic Cable, PE-90, and

codifying the revised specification. The revised specification: Allows

the use of dispersion-shifted single mode fibers; allows use of 62.5/

125 micrometer multimode fibers; includes a section on self-supporting

aerial fiber optic cable; and establishes end product requirements

associated with the options stated above. This revised specification

updates the end product performance requirements of filled fiber optic

cables brought about through technological advancements made during the

last seven years.

DATES: Effective date: August 4, 1994.

Incorporation by reference: Incorporation by reference of certain

publications listed in this final rule is approved by the Director of

the Federal Register as of August 4, 1994.

FOR FURTHER INFORMATION CONTACT: Garnett G. Adams, Chief, Outside Plant

Branch, Telecommunications Standards Division, Rural Electrification

Administration, room 2844, South Building, U.S. Department of

Agriculture, Washington, DC 20250-1500, telephone number (202) 720-

0667.

SUPPLEMENTARY INFORMATION:

Executive Order 12866

This final rule is issued in conformance with Executive Order

12866.

Executive Order 12778

This final rule has been reviewed under Executive Order 12778,

Civil Justice Reform. If adopted, this final rule will not:

(1) Preempt any State or local laws, regulations, or policies;

(2) Have any retroactive effect; and

(3) Require administrative proceedings before parties may file suit

challenging the provisions of this rule.

Regulatory Flexibility Act Certification

The Administrator of REA has determined that this final rule will

not have a significant impact on a substantial number of small

entities, as defined by the Regulatory Flexibility Act (5 U.S.C. et

seq.). This final rule involves standards and specifications, which may

increase the direct short-term costs to the REA borrower. However, the

long-term direct economic costs are reduced through greater durability

and lower maintenance cost over time.

Information Collection and Recordkeeping Requirements

In compliance with the Office of Management and Budget (OMB)

regulations (5 CFR Part 1320) which implements the Paperwork Reduction

Act of 1980 (Pub. L. 96-511) and section 3504 of that Act, information

collection and recordkeeping requirements contained in this final rule

have been submitted to OMB for approval. Comments concerning these

requirements should be directed to the Office of Information and

Regulatory Affairs of OMB, Attention: Desk Officer for USDA, room 3201,

New Executive Office Building (NEOB), Washington, DC 20503. When OMB

has approved the information and recordkeeping requirement contained in

this final rule, REA will publish an amendment to this final rule to

add the OMB control number and statement to the regulatory text.

National Environmental Policy Act Certification

The Administrator of REA has determined that this final rule will

not significantly affect the quality of the human environment as

defined by the National Environmental Policy Act of 1969 (42 U.S.C.

4321 et seq.). Therefore, this action does not require an environmental

impact statement or assessment.

Catalog of Federal Domestic Assistance

The program described by this final rule is listed in the Catalog

of Federal Domestic Assistance programs under No. 10.851, Rural

Telephone Loans and Loan Guarantees; and No. 10.852, Rural Telephone

Bank Loans. This catalog is available on a subscription basis from the

Superintendent of Documents, United States Government Printing Office,

Washington, DC 20402.

Executive Order 12372

This final rule is excluded from the scope of Executive Order

12372, Intergovernmental Consultation, which may require consultation

with State and local officials. A Notice of Final rule titled

Department Programs and Activities Excluded from Executive Order 12372

(50 FR 47034) exempts REA and RTB loans and loan guarantees, and RTB

bank loans, to governmental and nongovernmental entities from coverage

under this Order.

Background

REA issues publications titled ``Bulletin'' which serve to guide

borrowers regarding already codified policy, procedures, and

requirements needed to manage loans, loan guarantee programs, and the

security instruments which provide for and secure REA financing. REA

issues standards and specifications for the construction of telephone

facilities financed with REA Loan Funds. REA is rescinding Bulletin

345-90, ``REA Specification for Totally Filled Fiber Optic Cable, PE-

90,'' and codifying this specification at 7 CFR 1755.900, REA

Specification for Filled Fiber Optic Cables.

Filled fiber optic cable is used in outside plant by REA telephone

borrowers as a physical transport medium for voice and data. The

current REA Specification PE-90 limits the type of single mode fiber to

dispersion-unshifted. The limitation was established because REA

borrowers' lightwave systems operate at the 1310 nanometer wavelength

for which the dispersion-unshifted fiber is optimally designed. The

dispersion-unshifted single mode fiber can also be used in lightwave

systems operating at the 1550 nanometer wavelength window but with a

degradation in signal transmission. To provide REA borrowers with a

quality fiber optic cable to be used in lightwave systems operating at

1550 nanometers without signal degradation, the revised specification

will include single mode dispersion-shifted fiber as an option to

single mode dispersion-unshifted fiber.

The current REA Specification PE-90 limits multimode fiber to 50/

125 micrometers because at the time the specification was written, it

was the only diameter multimode fiber in existence. Since that time the

fiber optic industry has developed several multimode fiber designs of

which the 62.5/125 micrometer design has become the de facto standard.

Now that 62.5/125 micrometer multimode fiber is an accepted industry

standard, the revised specification will include the 62.5/125 multimode

fiber as an option to the 50/125 multimode fiber.

The current REA Specification PE-90 does not include a self-

supporting aerial fiber optic cable because when the specification was

written, no such cable design existed. Since issuance of the current

specification, fiber optic cable manufacturers have developed such

cable designs. These designs have been installed in operating telephone

systems and are providing satisfactory field performance. The

installation cost of self-supporting aerial fiber optic cable is less

than the installation cost of lashed aerial fiber optic cable. To

provide REA borrowers with a less costly aerial fiber optic cable

installation, the revised specification will include a section on self-

supporting aerial fiber optic cable.

The current specification includes only end product requirements

associated with filled fiber optic cable utilizing only dispersion-

unshifted single mode fibers and 50/125 micrometers multimode fibers

and lashed aerial fiber optic cables. Since the revised specification

will allow dispersion-shifted single mode fibers, 62.5/125 micrometers

multimode fibers, and self-supporting aerial fiber optic cables, end

product requirements have been included to assure quality products for

these applications.

This action establishes REA requirements for a wider range of

filled fiber optic cables without affecting current designs or

manufacturing techniques. This widened selection of cables will afford

REA telephone borrowers the opportunity to increase subscriber services

in an economical and efficient manner through enhanced cable designs

brought about by technological advancements made during the past seven

years.

Comments

On September 1, 1993, REA published a proposed rule (58 FR 46097)

to rescind REA Bulletin 345-90, REA Specification for Totally Filled

Fiber Optic Cable, PE-90, and to codify the revised specification at 7

CFR 1755.900, REA Specification for Filled Fiber Optic Cables. Comments

on this proposed rule were due by October 1, 1993. Comments and

recommendations were received from several companies by this due date.

The comments, recommendations, and responses are summarized as follows:

One respondent commented that the language in paragraphs (a)(1)(i)

through (a)(1)(iv) of 7 CFR 1755.900 should be changed to reflect fiber

optic cable designs currently being used by REA borrowers.

Response: REA reviewed the proposed language submitted by the

commenter and as a result of our review will change the present

language in paragraphs (a)(1)(i) through (a)(1)(iv) of 7 CFR 1755.900

to the language proposed by the commenter.

One respondent commented that the language ``twenty-four colors''

in paragraph (a)(2) of the specification should be changed to ``twelve

colors'' because the Electronic Industries Association/

Telecommunications Industries Association (EIA/TIA) 598 Standard, Color

Coding of Fiber Optic Cables, defines twelve standard colors with black

and yellow striping used to expand identification up to twenty-four

colors.

Response: Since the EIA/TIA 598 Standard allows for identification

of twenty-four fibers using a twenty-four color coding scheme that is

identical to the twenty-four color coding scheme specified in 7 CFR

1755.900, REA will not change the language ``twenty-four colors'' to

the commenter proposed language of ``twelve colors.''

Three respondents commented that the issue dates of the Electronic

Industries Association (EIA) and the Electronic Industries Association/

Telecommunications Industries Association (EIA/TIA) Standards

referenced in paragraphs (a)(8) and (a)(9) of the specification should

be changed to reflect their current issue dates.

Response: REA agrees with the commenters recommendations and will

change paragraphs (a)(8) and (a)(9) of the specification to reflect the

current issue dates of the EIA and EIA/TIA Standards.

One respondent commented that the mode-field diameter requirement

of 7.51.3 micrometers for dispersion-shifted single mode

fibers specified in paragraph (b)(4) of the specification will

eliminate the use of their currently manufactured dispersion-shifted

single mode fiber by REA borrowers.

Response: Since it is not REA's intent to eliminate the use of

dispersion-shifted single mode fibers which are currently manufactured

and used on non-REA telecommunication systems with satisfactory

results, REA will change the mode-field diameter requirement for

dispersion-shifted single mode fibers from 7.51.3

micrometers to 7.5+1.5 micrometers/-1.3 micrometers to allow use of the

manufacturer's dispersion-shifted single mode fiber by REA borrowers.

Two commenters recommended that paragraph (b)(14) of the

specification which requires that all optical fibers in any single

length of cable of the same type be eliminated from the specification

because it would deny REA borrowers the opportunity of purchasing

hybrid cables which contain both single mode and multimode fibers.

Response: In reviewing past REA 515 Contracts containing fiber

optic cables, REA borrowers never purchased hybrid cables containing

both single mode and multimode optical fibers. Review of current REA

515 Contracts reveal that REA borrowers are still not purchasing these

hybrid fiber optic cables. In fact REA borrowers only purchase single

mode fiber optic cables. Since there is no current interest by REA

borrowers in purchasing hybrid cables containing both single mode and

multimode optical fibers, REA at this time will not eliminate paragraph

(b)(14) from the specification as recommended by the commenters.

Two respondents commented on the shrinkback test to be performed on

both loose tube and tight tube buffers. The first respondent indicated

that tight tube buffers containing the optical fibers cannot meet

criterion specified in the specification. The second respondent

recommended that the shrinkback test be eliminated from the

specification because they consider this test to be a cable component

test and not a completed cable performance test.

Response: In regard to the first commenter's comment, REA has no

data from other manufacturers indicating that tight tube buffers

containing the optical fibers cannot comply with the shrinkback

requirement of the specification. In addition the respondent did not

provide test data as to what the requirement should be for tight tube

buffers containing the optical fibers. Finally paragraph (c)(6) of the

specification allows the manufacturer the option of removing the

optical fibers from the tight tube buffers prior to performance of the

shrinkback test. Since the respondent did not provide an alternative

requirement and the fact that the specification allows for removal of

the fibers from the buffer tubes prior to shrinkback testing, REA will

not change the shrinkback requirement specified in the specification.

Regarding the second respondent's comment, REA considers the

shrinkback test for loose and tight tube buffers to be a completed

cable performance test because the shrinkback test provides REA with

one means of assuring that the buffer tubes can withstand the rigors of

the field cable splicing operation. Since REA considers the performance

of the buffer tubes to be a critical requirement of the field cable

splicing operation, REA will not eliminate the shrinkback test from the

specification as recommended by the respondent.

One respondent recommended that the cold bend test for loose and

tight tube buffers be eliminated from the specification because they

consider this test to be a cable component test and not a completed

cable performance test. The same respondent also recommended that if

REA maintained the cold bend test that the mandrel diameter be changed

from 5 times the tube diameter to 10 times the tube diameter.

Response: REA considers the cold bend test for loose and tight tube

buffers to be a completed cable performance test because the cold bend

test provides REA with one means of assuring that the buffer tubes can

withstand the rigors of the field cable splicing operation. Since REA

considers the performance of the buffer tubes to be a critical

requirement of the field cable splicing operation, REA will not

eliminate the cold bend test from the specification as recommended by

the respondent.

In response to the commenter's recommendation for changing the size

of the test mandrel diameter, REA would like to point out that mandrel

diameter of 5 times the buffer tube diameter is the same mandrel

diameter as specified in REA Bulletin 345-90. Since manufacturers have

been performing the cold bend test using the mandrel diameter of 5

times the buffer tube diameter as specified in REA Bulletin 345-90 for

more than seven years without any reported problems, REA will not

change the mandrel diameter for the cold bend test specified in 7 CFR

1755.900 to the mandrel diameter recommended by the commenter.

Three respondents recommended that reference in paragraph (d)(2) of

the specification for defining the color limits of the colored optical

fibers be changed from EIA-359-A-1984 to EIA/TIA-598.

Response: The reason that REA referenced the EIA-359-A-1984 copper

cable standard for defining the color limits of the colored optical

fibers except for rose and aqua colors in 7 CFR 1755.900 is because at

the time of its writing no EIA standard existed for defining the color

limits for fiber optic cables. Since EIA has now published a color

coding standard solely for fiber optic cables which includes the rose

color, REA will change the reference in paragraph (d)(2) of 7 CFR

1755.900 from EIA-359-A-1984 to EIA/TIA-598.

Five respondents recommended that the color limits specified in

paragraph (d)(2)(i) of the specification for rose be eliminated and the

aqua limits be changed to the proposed EIA limits.

Response: The reason for specifying the rose and aqua color limits

in 7 CFR 1755.900 was because the EIA-359-A-1984 standard did not

contain limits for these colors. Since the EIA/TIA-598 Standard

specifies the rose color limits, REA will eliminate the rose color

limits from paragraph (d)(2)(i) of 7 CFR 1755.900.

Regarding the aqua color limit, EIA/TIA-598 contains a color limit

for aqua but the fiber optic cable industry is dissatisfied with the

limits of the EIA/TIA standard. In fact EIA/TIA is revising the current

standard to reflect the new aqua limits being proposed by the industry.

Therefore to assure that the aqua color limits of 7 CFR 1755.900 will

coincide with the proposed aqua limits of the revised EIA/TIA-598

Standard, REA will change the aqua limits currently specified in 7 CFR

1755.900 to the aqua color limits proposed for incorporation into the

revised EIA/TIA-598 Color Standard.

One respondent commented that paragraph (d)(2)(ii) of the

specification which states that REA will not accept alternative

coloring schemes which deviate from the color coding scheme specified

in paragraph (d)(1) of 7 CFR 1755.900 be eliminated from the

specification.

Response: The reason for this requirement is to provide REA

borrowers with one color coding standard for identification of buffer

tubes and optical fibers to facilitate the splicing of fiber optic

cables in the field. If REA allowed alternative coloring schemes for

identification of buffer tubes and optical fibers as recommended by the

commenter, REA would be doing a disservice to our borrowers by negating

the requirement's intended purpose of facilitating field splicing of

fiber optic cables by REA borrowers. Since this requirement will

facilitate the splicing of fiber optic cables in the field by REA

borrowers, REA will not eliminate paragraph (d)(2)(ii) from the

specification as recommended by the commenter.

Two respondents commented on the splicing of strength members as

specified in paragraph (e)(4) of the specification. The first

respondent recommended that the 1 kilometer splicing limitation for

strength members be changed to 500 meters. The second respondent

questioned the rationale for limiting the number of strength member

splices.

Response: REA limits the number of strength member splices to 1 per

kilometer in the completed cable to avoid strength member splices being

in close proximity to one another which in the opinion of REA could

lead to failure of the cable during installation as a result of splice

breakage. Since REA borrowers have been installing fiber optic cables

with the above strength member splice requirement for the past seven

years without any reported installation failures, REA will not change

the requirement specified in paragraph (e)(4) of 7 CFR 1755.900.

Two respondents commented that the language of paragraph (f)(3)

should be modified to allow the cable manufacturer the option of using

natural colored threads and tapes as core binders.

Response: REA has reviewed the suggested change in language and the

reasons for the change in language presented by the commentators.

Because REA agrees with the reasons for their suggested change in

language, REA will modify the language in paragraph (f)(3) of the

specification to allow manufacturers the option of providing natural

colored threads and tapes as core binders.

One respondent commented that the language in paragraph (f)(4) of 7

CFR 1755.900 should be changed to better reflect the functional needs

of fiber optic cables currently being used by REA borrowers.

Response: REA reviewed the reason for the proposed change in

language submitted by the commenter and as a result of our review will

change the present language in paragraph (f)(4) of 7 CFR 1755.900 to

the language proposed by the commenter.

Two respondents commented on the core wrap section of 7 CFR

1755.900. The first commenter recommended that the core wrap section

(paragraph (h) of the specification) be revised to more clearly

indicate that the use of core wraps in the manufacture of fiber optic

cable is an option. The second commenter recommended that the core wrap

section be further modified to allow one or more core wraps in the

manufacture of fiber optic cable.

Response: In regards to the first respondent's comment, REA has

reviewed the present language of paragraph (h) and agrees with the

respondent's comment that the core wrap section does not clearly

indicate that the use of a core wrap in the manufacture of the cable is

at the option of the manufacturer. Since REA agrees with the

commenter's comment, REA will revise paragraph (h) of 7 CFR 1755.900 to

clearly indicate that the use of a core wrap is at the option of the

manufacturer.

Regarding the second respondent's comment, the latest issues of

REA's copper cable specifications covered under 7 CFR 1755.390 and 7

CFR 1755.890 allow the use of multiple core wraps in manufacture of

these type cables provided at the filling compound is applied between

each core wrap layer. Since REA allows the use of multiple core wraps

in the manufacture of copper cables, REA will also allow the use of

multiple core wraps in the manufacture of fiber optic cables. Therefore

paragraph (h) of 7 CFR 1755.900 will be modified to allow the use of

multiple core wraps by fiber optic cable manufacturers. REA will also

modify paragraph (h) to indicate that when multiple core wraps are used

that the filling compound must be applied between each core wrap layer

to prevent the ingress of water between each core wrap layer.

Two respondents commented that the testing of the inner jacket for

fungus resistance as specified in paragraph (i)(3) of the specification

should be eliminated because the polyethylene compounds used for the

inner jackets are inherently resistant to fungus attack.

Response: The current REA Bulletin 345-90 allows fiber optic cable

manufacturers the option of using any available material for producing

inner jackets. To assure that these inner jacket materials would

provide satisfactory field service, the bulletin required that they

pass a fungus resistance test. Since 7 CFR 1755.900 now specifies that

only polyethylene compounds can be used to produce inner jackets and

REA knows that these compounds are inherently resistant to fungus

attack, REA will eliminate the fungus resistance test, paragraph

(i)(3), for inner jacket materials from 7 CFR 1755.900.

One respondent commented that paragraph (j)(2) of 7 CFR 1755.900

should be modified to indicate that a flooding compound is only

required for armored cable and that jacket slip test reference in the

paragraph be clarified to indicate that it only applies to flooded

cable designs.

Response: In reviewing the present language of the flooding

compound section, paragraphs (j)(1) through (j)(4), of 7 CFR 1755.900,

paragraph (j)(1) clearly indicates that flooding compound applies only

to armored fiber optic cable designs. Also the present language of the

jacket slip test, paragraph (III)(3), Appendix A, clearly indicates

that this test is only performed on flooded cable designs. Because the

present language in both paragraphs clearly indicate the intent of the

commenter's recommendation, REA will not revise paragraph (j)(2) of 7

CFR 1755.900 as recommended by the commenter.

One respondent commented that ``water blocking tape'' language of

paragraph (j)(4) be changed to ``water blocking material'' to allow for

the use of water blocking tapes or powders in lieu of a flooding

compound.

Response: REA has allowed the use of water blocking tapes in place

of flooding compounds in filled fiber optic cables for several years

with satisfactory field performance, but the use of water blocking

powders in place of the flooding compound is a new application for

fiber optic cables with limited field experience. Until fiber optic

cables using water blocking powders as replacements for flooding

compounds gain more field experience to assure reliable service, REA

will not change the language in paragraph (j)(4) of 7 CFR 1755.900 to

the language recommended by the commenter.

One respondent recommended that armor overlap be changed from 3.0

millimeters to either 1.8 millimeters or sufficient to meet the

requirements of paragraph (q) of 7 CFR 1755.900.

Response: The reason 7 CFR 1755.900 specifies a minimum armor

overlap of 3.0 millimeters is to assure proper forming of the armor

overlap is achieved to avoid longitudinal splitting of the jacket

during installation. Since REA is concerned that armor overlaps less

than 3.0 millimeters can result in longitudinal splitting of the jacket

during installation because of improper forming, REA will not change

the present requirement of 3.0 millimeters to the recommended comments

of the respondent.

One commenter recommended that reduction in thickness of the

armoring material due either to corrugating or the application process

be changed from 10 percent to 5 percent.

Response: REA would like to point out that the 10 percent

requirement for the reduction in armor thickness is the same

requirement as specified in REA Bulletin 345-90. Since manufacturers

have been meeting the 10 percent armor reduction thickness requirement

as specified in REA Bulletin 345-90 for more than seven years without

any reported problems, REA will not change the 10 percent armor

reduction thickness requirement in 7 CFR 1755.900 to the 5 percent

armor reduction thickness requirement as recommended by the commenter.

Two respondents recommended changing the present language of

paragraph (k)(6) to more clearly define the intent of the requirement.

Response: REA has reviewed the proposed language submitted by both

commentators and agrees that their proposed language will more clearly

define the intent of the requirement. Therefore, REA will change the

present language of paragraph (k)(6) specified in 7 CFR 1755.900 to the

proposed language recommended by the commenters.

One respondent recommended that paragraphs (k)(8), (k)(9), and

(k)(10) of the specification be eliminated from the specification

because they consider these tests to be cable component tests and not

completed cable performance tests.

Response: REA considers the tests specified in paragraphs (k)(8),

(k)(9), and (k)(10) of the specification to be completed cable

performance tests because these tests provide REA with the means of

assuring that the plastic coated steel armor of the cable will

withstand the rigors of the installation as well as a means of assuring

that the plastic coated steel armor of the cable will provide

satisfactory service over the life of the completed cable. Since REA

considers the performance of the plastic coated steel armor to be a

critical requirement in the installation and service life of completed

cables, REA will not eliminate paragraphs (k)(8), (k)(9), and (k)(10)

from 7 CFR 1755.900 as recommended by the respondent.

One respondent recommended that paragraph (k)(10) of 7 CFR 1755.900

be modified to exclude from the 90 percent calculation the area of the

armor under the strength members for cables containing embedded

strength members in the outer jacket because these type cables can

still pass the armor to jacket bond strength requirement specified in

paragraph (k)(10) of the specification.

Response: A review of recent armor to jacket bond strength data for

cables containing embedded strength members in the outer jacket when

the area of the armor under the strength members is excluded from the

90 percent calculation revealed that these type cables can pass the

requirement specified in paragraph (k)(10) of the specification without

difficulty. Since test data indicate that these type cables can pass

the armor to jacket bond strength requirement, REA will modify

paragraph (k)(10) of 7 CFR 1755.900 to allow the exclusion of the area

of the armor under the strength members for cables containing embedded

strength members in the outer jacket from the 90 percent calculation.

One respondent recommended that low density polyethylene, low

density ethylene copolymer, and linear low density polyethylene

compounds not be allowed as outer jacket materials. The reason for

their comment is that installation damage to the cable can occur as a

result of the above materials becoming soft at the high temperatures

experienced during hot summer weather.

Response: Low density polyethylene, low density ethylene copolymer,

and linear low density polyethylene compounds have been used by REA as

outer jacket materials for copper cables for over twenty years and for

fiber optic cables for over seven years without any reported high

temperature installation problems associated with hot summer weather.

Since REA has never received complaints from borrowers installing

cables using any one of the above compounds during hot summer weather,

REA will not eliminate the use of low density polyethylene, low density

ethylene copolymer, and linear low density polyethylene compounds as

outer jacket materials from the specification as recommended by the

commenter.

One respondent recommended that melt flow rate, environmental

stress crack, and impact tests for jacketing materials be eliminated

from the specification because they consider these tests to be cable

component tests and not completed cable performance tests.

Response: REA considers the melt flow rate, environmental stress

crack, and impact tests for jacketing materials to be completed cable

performance tests because these tests provide REA with the means of

assuring that the jacketing material of the cable will withstand the

rigors of installation as well as a means of assuring that the

jacketing material of the cable will provide satisfactory service over

the life of the completed cable. Since REA considers the performance of

jacket material to be a critical requirement in the installation and

service life of completed cables, REA will not eliminate the melt flow

rate, environmental stress crack, and impact tests for jacketing

materials from 7 CFR 1755.900 as recommended by the respondent.

One commenter recommended replacing the ASTM D 4565-90a test method

referenced for both jacket tensile strength/elongation and jacket

shrinkback in 7 CFR 1755.900 with the EIA-455-89A test method for

jacket tensile strength/elongation and the EIA-455-86 test method for

jacket shrinkback because these test methods are the current fiber

optic industry standards for these jacket properties.

Response: A review of the ASTM and EIA test methods for jacket

tensile strength/elongation and jacket shrinkback properties indicates

that the EIA test methods are more applicable for the testing of fiber

optic cables than the ASTM test method. Since the EIA test methods are

more applicable to the testing of fiber optic cables, REA will replace

the reference to ASTM D 4565-90a in paragraphs (m)(5)(ii) and

(m)(5)(iv) of 7 CFR 1755.900 with EIA-455-89A and EIA-455-86,

respectively.

One respondent recommended that the minimum jacket thickness over

the strength members for cables containing embedded strength members in

the outer jacket be changed from 0.5 millimeter to 0.9 millimeter.

Response: REA has accepted one manufacturer of fiber optic cable

containing embedded strength members in the outer jacket using the 0.5

millimeter minimum jacket thickness over the embedded strength members.

That manufacturer's cable has been used by REA borrowers for over four

years without any reported field failures. Since REA has satisfactory

field performance history on fiber optic cables with embedded strength

members using the minimum 0.5 millimeter jacket thickness over the

embedded strength members, REA will not change the 0.5 millimeter

minimum jacket thickness specified in 7 CFR 1755.900 to the minimum

jacket thickness recommended by the commenter.

One respondent recommended that the maximum tolerance limit for the

web width of self-supporting cable be changed from +0.51 millimeters to

+1.58 millimeters.

Response: The reason that the maximum tolerance limit for the web

width of self-supporting cables is specified at +0.51 millimeters is to

assure that the web of self-supporting cables can be slit by

craftpersons during installation using existing slitting tools.

Increasing the maximum web width tolerance to +1.58 millimeters as

recommended by the commenter would require the development of special

slitting tools to assure satisfactory installation of these thicker

webbed self-supporting cables by craftpersons. Since it is not the

intent of REA to burden craftpersons with special tools needed to

install theses thicker webbed self-supporting cables, REA will not

change the maximum tolerance limit for the web width of self-supporting

cables specified in 7 CFR 1755.900 to the maximum tolerance limit

recommended by the respondent.

One respondent recommended that the sheath slitting cord be made a

mandatory component of the cable instead of an optional cable

component.

Response: The reasons 7 CFR 1755.900 specifies that the sheath

slitting cord is an optional component of the cable are because not all

cable installers use the sheath slitting cord to open the cable jacket

during installation and during extremely cold weather installation. The

sheath slitting cord does not aid the installer in opening the cable

jacket because of the stiffness of the jacket. Because of the above

reasons, REA will not make the sheath slitting cord a mandatory cable

component in 7 CFR 1755.900.

Two respondents commented that the language in paragraph (n)(2) of

7 CFR 1755.900 should be changed to better reflect the functional needs

of fiber optic cables currently being used by REA borrowers and to

quantify the sheath slitting cord requirement.

Response: REA reviewed the reasons for the proposed change in

language submitted by the commentators and as a result of our review

will change the present language in paragraph (n)(2) of 7 CFR 1755.900

to better reflect the functional needs of fiber optic cables currently

being used by REA borrowers and to quantify the sheath slitting cord

requirement.

One respondent recommended that the numbering sequence for re-

marked cables be changed from 3,000 to 1,000.

Response: REA would like to point out that the 3,000 numbering

sequence for re-marked cables specified in 7 CFR 1755.900 is the same

numbering sequence for re-marked cables as specified in REA Bulletin

345-90. Since manufacturers have been using the 3,000 numbering

sequence for re-marked cables as specified in REA Bulletin 345-90 for

more than seven years without any reported problems, REA will not

change the numbering sequence for re-marked cables specified in 7 CFR

1755.900 to the numbering sequence for re-marked cables recommended by

the commenter.

One respondent recommended adding a new identification marking

requirement to 7 CFR 1755.900 that requires a telephone handset symbol

to be marked on the outer jacket of fiber optic cables intended for

direct burial installation in accordance with Rule 350G of the 1993

National Electric Safety Code (NESC).

Response: Since the REA Form 515 Construction Contract requires

that all types of construction comply with the safety requirements

specified in the NESC, REA will change paragraph (o)(2) in 7 CFR

1755.900 to require that all direct buried fiber optic cables be marked

with the telephone handset symbol in accordance with Rule 350G of the

1993 NESC. This change will cause existing paragraphs (o)(2) through

(o)(11) to be renumbered as paragraphs (o)(3) through (o)(12) in 7 CFR

1755.900.

Two respondents commented on the attenuation requirements specified

in paragraph (p)(1)(i) of 7 CFR 1755.900. The first respondent

recommended deleting the reference to EIA/TIA-455-59 because this

standard is used to determine point discontinuities and not

attenuation. The second respondent recommended changing the attenuation

values specified in 7 CFR 1755.900 for dispersion-unshifted and

dispersion-shifted single mode optical fibers to 0.4 dB/km and 0.25 dB/

km, respectively.

Response: With regard to the EIA/TIA-455-59 reference, REA agrees

with the commenter and will eliminate the reference to EIA/TIA-455-59

in paragraph (p)(1)(i) of 7 CFR 1755.900.

In regard to the change in attenuation requirements, REA is

satisfied that the 0.5 dB/km maximum attenuation requirement for both

dispersion-unshifted and dispersion-shifted single mode optical fibers,

although considered very loose when compared to other industry

standards, will provide REA borrowers with satisfactory optical signal

transmission. REA would also like to point out that the REA Form 515

Construction Contract allows REA borrowers the opportunity to specify

lower attenuation values than the 0.5 dB/km maximum specification value

for these type optical fibers and when such values are specified in the

contract they must be met by the cable supplier to execute the

contract.

Since REA is satisfied that 0.5 dB/km maximum attenuation for both

dispersion-unshifted and dispersion-shifted single mode optical fibers

will provide satisfactory optical transmission and the knowledge that

REA borrowers can specify lower attenuation values than the

specification value to successfully execute the REA Form 515

Construction Contract, REA will not change the attenuation values

specified in 7 CFR 1755.900 to values recommended by the commenter.

One respondent recommended deleting the requirement to conduct

attenuation measurements at the wavelength specified for the

application as stated in paragraphs (p)(1)(iv) and (p)(2)(iii) of 7 CFR

1755.900. The reason for the respondent's recommendation is the

possibility of REA borrowers specifying attenuation requirements at

nonstandard wavelengths which would require the development of new test

equipment. The development of this new equipment would in turn result

in added cable costs.

Response: A review of past REA Form 515 Construction Contracts

indicated that REA borrowers were specifying attenuation requirements

at the accepted industry wavelengths of 850 and 1300 nanometers for

multimode fibers, and 1310 and 1550 for single mode fibers. A review of

present construction contracts also reveals that REA borrowers are

still specifying attenuation requirements at the accepted industry

wavelengths of 850 and 1300 nanometers for multimode fibers, and 1310

and 1550 for single mode fibers.

Since REA borrowers are specifying attenuation requirements at the

industry accepted wavelengths and not at nonstandard wavelengths, the

requirement to conduct attenuation measurements at the wavelength

specified in paragraphs (p)(1)(iv) and (p)(2)(iii) of 7 CFR 1755.900

will not be deleted from the specification as recommended by the

commenter.

One respondent commented that the dispersion and dispersion slope

requirements of 2.7 ps/nmkm and 0.085 ps(nm\2\km),

respectively for dispersion-shifted single mode fibers specified in

paragraph (p)(1)(vii) of the specification will eliminate the use of

their currently manufactured dispersion shifted single mode fiber by

REA borrowers.

Response: Since it is not REA's intent to eliminate the use of

dispersion-shifted single mode fibers which are currently manufactured

and used on non-REA telecommunication systems with satisfactory

results, REA will change the dispersion and dispersion slope

requirements for dispersion-shifted single mode fibers from 2.7 ps/

nmkm and 0.085 ps(nm\2\km), respectively to 3.5 ps/

nmkm and 0.095 ps(nm\2\km), respectively to allow use

of the manufacturer's dispersion shifted single mode fiber by REA

borrowers.

Three respondents recommended changing the 1250 nanometer cut-off

wavelength for single mode fibers specified in paragraph (p)(1)(viii)

of 7 CFR 1755.900 to the industry accepted wavelength of 1260

nanometers.

Response: If 7 CFR 1755.900 maintained the 1250 nanometer cut-off

wavelength for single mode fibers, REA would force manufacturers to

maintain two separate fiber optic cable inventories based solely on the

different cut-off wavelength requirements. This in turn would result in

higher fiber optic cable prices to REA borrowers. By changing the cut-

off wavelength requirement for single mode fibers from 1250 nanometers

to 1260 nanometers, REA would eliminate the need for manufacturers to

maintain separate fiber optic cable inventories. This change would

reduce fiber optic cable costs to REA borrowers. Therefore, REA will

change the single mode fiber cut-off wavelength requirement in

paragraph (p)(1)(viii) of 7 CFR 1755.900 from 1250 nanometers to 1260

nanometers.

One respondent commented on the mechanical requirements for

multimode fiber optic cables specified in 7 CFR 1755.900. The first

comment recommended deleting the mechanical requirements for multimode

fiber optic cables specified in paragraphs (q)(1) through (q)(5) of the

specification because they feel that the qualification of single mode

fiber optic cable designs to the mechanical requirements are adequate

to qualify multimode fiber optic cable designs. The second comment

recommended that if REA retained the mechanical requirements for

multimode fiber optic cables that the allowable change in attenuation

be changed from a maximum of 0.030 dB to a maximum of 0.040 dB since

this is the present de facto industry requirement for multimode optical

fibers.

Response: In regards to the first comment, 7 CFR 1755.900 requires

both multimode and single mode fiber optic cables to be tested for the

mechanical properties specified in paragraphs (q)(1) through (q)(5) of

the specification to assure that both cable types will withstand the

rigors of field installation and provide satisfactory service over

their useful lives. REA is of the opinion that both multimode and

single mode fiber optic cable designs must be tested for the mechanical

requirements specified in paragraphs (q)(1) through (q)(5) of the

specification to assure REA borrowers that these designs will withstand

the rigors of field installation and provide satisfactory performance

over their useful service lives. Therefore, REA will not eliminate the

mechanical requirements for multimode fiber optic cables specified in

paragraphs (q)(1) through (q)(5) of 7 CFR 1755.900.

Regarding the second comment, since it is REA's intent to use de

facto industry requirements; where applicable, REA will change the

maximum allowable change in attenuation for multimode fiber optic

cables from 0.30 dB to 0.40 dB in paragraphs (q)(1) through (q)(5) of 7

CFR 1755.900.

Two respondents recommended that mechanical testing specified in

paragraphs (q)(1) through (q)(5) of 7 CFR 1755.900 for dispersion-

unshifted single mode fiber optic cables be performed at only the 1550

nanometer wavelength in place of the required testing at both 1310 and

1550 nanometer wavelengths. The reasons for their comments are based on

the data indicating that testing of optical fibers at the 1550

nanometer wavelength is considered the worst case condition because the

fibers are more sensitive to bends at this wavelength.

Response: 7 CFR 1755.900 requires mechanical testing of dispersion-

unshifted single mode fiber optic cables at both the 1310 nanometer and

1550 nanometer wavelengths. The reason for the mechanical testing of

dispersion-unshifted single mode fiber optic cables at both the 1310

and 1550 nanometer wavelengths is to assure satisfactory transmission

of the optical signals at these wavelengths when specified by REA

borrowers. Although REA agrees with the commentators comments, data

from the REA Form 515 Construction Contracts indicate that the majority

of lightwave systems installed by REA borrowers operate at the 1310

nanometer wavelength and not at the 1550 nanometer wavelength.

Since the majority of REA borrower lightwave systems operate at the

1310 nanometer wavelength, REA must require mechanical testing of

dispersion-unshifted single mode fiber optic cables at the 1310

nanometer wavelength to assure that cables installed by REA borrowers

with lightwave systems operating at the 1310 nanometer wavelength will

provide satisfactory optical signal transmission. Therefore, REA will

not eliminate the mechanical testing of dispersion-unshifted single

mode fiber optic cables at the 1310 nanometer wavelength as recommended

by the commenters.

One respondent recommended changing the cable bend test temperature

of -46 deg.C, Test Condition C of EIA/TIA-455-37A, specified in

paragraph (q)(1)(iii) of 7 CFR 1755.900 to -30 deg.C, Test Condition E

of EIA/TIA-455-37A, because this is the de facto industry test

temperature for fiber optic cables.

Response: Since it is REA's intent to use de facto industry

requirements where applicable, REA will change the cable bend test

temperature of -46 deg.C, Test Condition C of EIA/TIA-455-37A, to

-30 deg.C, Test Condition E of EIA/TIA-455-37A, in paragraph

(q)(1)(iii) of 7 CFR 1755.900.

Three respondents recommended replacing the cable bend test mandrel

diameter of 15 times the cable diameter specified in paragraph

(q)(1)(iii)(A) of 7 CFR 1755.900 with a test mandrel diameter of 20

times the cable diameter because this is the de facto industry

requirement for fiber optic cables.

Response: Since it is REA's intent to use de facto industry

requirements where applicable, REA will change the cable bend test

mandrel diameter of 15 times the cable diameter to a test mandrel

diameter of 20 times the cable diameter in paragraph (q)(1)(iii)(A) of

7 CFR 1755.900.

Two respondents recommending deleting the cable bend test

requirement that the armor overlap be on the outside of the bend when

bend testing armored cables in accordance with paragraph (q)(1)(iii)(C)

of 7 CFR 1755.900.

Response: REA would like to point out that the cable bend test

requirement stipulating that the armor overlap be on the outside of the

bend when bend testing armored cables specified in 7 CFR 1755.900 is

the same requirement for armored cables as specified in REA Bulletin

345-90. Since manufacturers have been bend testing armored cables using

this requirement in REA Bulletin 345-90 for more than seven years

without any reported problems, REA will not delete the requirement that

the armor overlap be on the outside of the bend when bend testing

armored cables in 7 CFR 1755.900.

One respondent recommended that the requirement that there be no

delamination of jacket bond after cable bend testing specified in

paragraph (q)(1)(iv) of 7 CFR 1755.900 be deleted from the

specification.

Response: REA would like to point out that the cable bend test

requirement stipulating that there be no delamination of jacket bond

after cable bend testing specified in 7 CFR 1755.900 is the same

requirement as specified in REA Bulletin 345-90. Since manufacturers

have been bend testing cables using this requirement in REA Bulletin

345-90 for more than seven years without any reported problems, REA

will not delete the requirement that there be no delamination of jacket

bond after cable bend testing in paragraph (q)(1)(iv) of 7 CFR

1755.900.

Two respondents commented on the cable compression test, paragraph

(q)(3)(iii), of 7 CFR 1755.900. The first respondent recommended

changing the rate for applying the compressive force from a nominal of

5 millimeters per minute to a range of 3 millimeters to 20 millimeters

per minute to make the cable compression test of 7 CFR 1755.900

compatible with the de facto industry standard. The second respondent

recommended changing holding time of the compressive force from 15

minutes to 10 minutes because the 10 minute requirement is the de facto

industry requirement for fiber optic cables.

Response: Since it is REA's intent to use de facto industry

requirements where applicable, REA will change the rate for applying

the compressive force from a nominal of 5 millimeters per minute to a

range of 3 millimeters to 20 millimeters per minute and will also

change the holding time of the compressive force from 15 minutes to 10

minutes in paragraph (q)(3)(iii) of 7 CFR 1755.900.

Three respondents commented on the cable flex test requirements

specified in paragraph (q)(5)(iv) of 7 CFR 1755.900. Two of the

respondents recommended that a fracture length of no more than 5

millimeters be allowed on the armor after flexing since this is the de

facto industry requirement for fiber optic cables. The third respondent

recommended deleting the requirement that there be no delamination of

jacket to armor bond in nonflooded cables after flex testing.

Response: 7 CFR 1755.900 requires that there be no visible evidence

of fracture of the armor after flexing. Reason for the requirement is

one means of assuring that continuity of the armor will be maintained

after the rigors of installation. Maintaining the armor continuity

after installation is important requirement in assuring protection of

the telephone equipment and telephone company personnel against

hazardous electrical currents. If REA allowed a minimum fracture length

of the armor after flexing but before installation, the possibility

exists that these small fracture lengths in the armor could develop

into complete breaks of the armor at these fractured locations as a

result of difficulties encountered during installation. These breaks in

the armor would result in loss of armor continuity. The loss of armor

continuity in turn would subject the telephone equipment and telephone

company personnel to possible hazardous electrical currents which could

result in damaged equipment or personal injury to telephone company

personnel. Since REA has a responsibility to its borrowers to assure

that their telephone equipment and personnel are protected against

hazardous electrical currents, REA will not change the present

requirement of no visible evidence of fracture of the armor after

flexing specified in 7 CFR 1755.900 to the recommendation requested by

the first two commenters.

In regard to the requirement that there be no delamination of

jacket to armor bond in nonflooded cables after flex testing, REA

specified this requirement on nonflooded cables to assure that the bond

strength between the outer jacket and the plastic coated armor would be

maintained after installation to assure that water could not enter

nonflooded cables at the outer jacket/armor interface. If REA

eliminated this requirement as recommended by the third commenter,

voids at the outer jacket/armor interface could develop in nonflooded

cables after installation. These voids could allow the entry of water

into nonflooded cables resulting in possible degradation of the optical

signal over time. Since REA has a responsibility to our borrowers to

assure that optical signal of nonflooded cables will not degrade as a

result of water entry, REA will not eliminate the requirement that

there be no delamination of jacket to armor bond in nonflooded cables

after flex testing as recommended by the third commenter.

Seven respondents recommended replacing Appendix A of 7 CFR

1755.900 with de facto industry tests to determine the long term

stability of their fiber optic cables.

Response: The tests specified in Appendix A of 7 CFR 1755.900 have

been used by REA for over sixteen years for determining the long term

performance of copper cables with satisfactory results. Since these

test have proven invaluable for determining the long term stability of

copper cables, REA decided to apply these same proven tests to

determine the long term stability of fiber optic cables. Therefore REA

will not replace Appendix A with de facto industry tests as recommended

by the commenters.

List of Subjects in 7 CFR Part 1755

Incorporation by reference, Loan programs--communications,

Reporting and recordkeeping requirements, Rural areas, Telephone.

For the reasons set out in the preamble, REA amends chapter XVII of

title 7 of the Code of Federal Regulations as follows:

PART 1755--TELECOMMUNICATIONS STANDARDS AND SPECIFICATIONS FOR

MATERIALS, EQUIPMENT AND CONSTRUCTION.

1. The authority citation for part 1755 continues to read as

follows:

Authority: 7 U.S.C. 901 et seq., 1921 et seq.

Sec. 1755.97 [Amended]

2. Section 1755.97 is amended by removing the entry REA Bulletin

345-90 from the table.

3. Section 1755.900 is added to read as follows:

Sec. 1755.900 REA specification for filled fiber optic cables.

(a) Scope. (1) This section covers the requirement for filled 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 either by trenching or by direct plowing.

(i) 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, or in tight buffer

tubes.

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

complete the cable core.

(iii) 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 to exclude

water.

(iv) The cable structure is completed by an extruded overall

plastic jacket. This jacket may have strength members embedded in it,

in some designs.

(v) Buried installation requires an armor under the outer jacket.

(vi) For self-supporting cable the outer jacket may be extruded

over the support messenger and cable core.

(2) The cable is fully color coded so that each fiber is

distinguishable from every other fiber. A basic color scheme of twenty-

four colors allows individual fiber identification. Colored tubes,

binders, threads, stripings, or markings provide fiber group

identification.

(3) Cable manufactured to this section must demonstrate compliance

with the qualification testing requirements to ensure satisfactory end-

use performance characteristics for the intended applications.

(4) Optical cable designs not specifically addressed by this

section may be allowed if accepted by REA. Justification for acceptance

of a modified design must be provided to substantiate product utility

and long term stability and endurance.

(5) All cables sold to REA borrowers for projects involving REA

loan funds under this section must be accepted by REA Technical

Standards Committee ``A'' (Telephone). For cables manufactured to the

specification of this section, all design changes to an accepted design

must be submitted for acceptance. REA will be the sole authority on

what constitutes a design change.

(6) The American National Standard Institute/Institute of

Electrical and Electronics Engineers, Inc (ANSI/IEEE), 1993 National

Electrical Safety Code (NESC) referenced in this section is

incorporated by reference by REA. This incorporation by reference was

approved by the Director of the Federal Register in accordance with 5

U.S.C. 552(a) and 1 CFR part 51. Copies of ANSI/IEEE 1993 NESC are

available for inspection during normal business hours at REA, room

2845, U.S. Department of Agriculture, Washington, DC 20250-1500 or at

the Office of the Federal Register, 800 North Capitol Street, NW.,

suite 700, Washington, DC. Copies are available from IEEE Service

Center, 445 Hoes Lane, Piscataway, NJ 08854, telephone number 1 (800)

678-4333.

(7) American Society for Testing and Materials Specifications

(ASTM) A 640-91, Standard Specification for Zinc-Coated Steel Strand

for Messenger Support of Figure 8 Cable; ASTM B 736-92a, Standard

Specification for Aluminum, Aluminum Alloy, and Aluminum-Clad Steel

Cable Shielding Stock; ASTM D 1238-90b, Standard Test Method for Flow

Rates of Thermoplastics by Extrusion Plastometer; ASTM D 1248-84

(1989), Standard Specification for Polyethylene Plastic Molding and

Extrusion Materials, ASTM D 1535-89, Standard Test Method for

Specifying Color by the Munsell System; ASTM D 3349-86, Standard Test

Method for Absorption Coefficient of Carbon Black Pigmented Ethylene

Plastic; ASTM D 4565-90a, Standard Test Methods for Physical and

Environmental Performance Properties of Insulations and Jackets for

Telecommunications Wire and Cable; ASTM D 4566-90, Standard Test

Methods for Electrical Performance Properties of Insulations and

Jackets for Telecommunications Wire and Cable; ASTM D 4568-86, Standard

Test Methods for Evaluating Compatibility Between Cable Filling and

Flooding Compounds and Polyolefin Cable Materials; and ASTM E 29-90,

Standard Practice for Using Significant Digits in Test Data to

Determine Conformance with Specifications, referenced in this section

are incorporated by reference by REA. These incorporations by

references were approved by the Director of the Federal Register in

accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies of ASTM

standards are available for inspection during normal business hours at

REA, room 2845, U.S. Department of Agriculture, Washington, DC 20250-

1500 or at the Office of the Federal Register, 800 North Capitol

Street, NW., suite 700, Washington, DC. Copies are available from ASTM,

1916 Race Street, Philadelphia, Pennsylvania 19103-1187, telephone

number (215) 299-5585.

(8) Electronic Industries Association Standards (EIA)-455-20,

Measurement of Change in Optical Transmittance; EIA-455-41, Compressive

Loading Resistance of Fiber Optic Cables; EIA-455-86, Fiber Optic Cable

Jacket Shrinkage; EIA-455-89A, Fiber Optic Cable Jacket Elongation And

Tensile Strength; and EIA-455-174, Mode Field Diameter of Single-Mode

Optical Fiber by Knife-Edge Scanning in the Far Field, referenced in

this section are incorporated by reference by REA. These incorporations

by references were approved by the Director of the Federal Register in

accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies of EIA

standards are available for inspection during normal business hours at

REA, room 2845, U.S. Department of Agriculture, Washington, DC 20250-

1500 or at the Office of the Federal Register, 800 North Capitol

Street, NW., suite 700, Washington, DC. Copies are available from

Global Engineering Documents, 15 Inverness Way East, Englewood, CO

80112, telephone number (303) 792-2181.

(9) Electronic Industries Association/Telecommunications Industries

Association Standards (EIA/TIA)-455-25A, Repeated Impact Testing of

Fiber Optic Cables and Cable Assemblies; EIA/TIA-455-30B, Frequency

Domain Measurement of Multimode Optical Fiber Information Transmission

Capacity; EIA/TIA-455-31B, Fiber Tensile Proof Test Method; EIA/TIA-

455-37A, Low or High Temperature Bend Test for Fiber Optic Cable; EIA/

TIA-455-45B, Method for Measuring Optical Fiber Geometry Using a

Laboratory Microscope; EIA/TIA-455-46A, Spectral Attenuation

Measurement for Long-Length, Graded-Index Optical Fibers; EIA/TIA-455-

48B, Measurement of Optical Fiber Cladding Diameter Using Laser-Based

Instruments; EIA/TIA-455-51A, Pulse Distortion Measurement of Multimode

Glass Optical Fiber Information Transmission Capacity; EIA/TIA-455-53A,

Attenuation by Substitution Measurement for Multimode Graded-Index

Optical Fibers or Fiber Assemblies Used in Long Length Communications

Systems; EIA/TIA-455-55B, End-View Methods for Measuring Coating and

Buffer Geometry of Optical Fibers; EIA/TIA-455-58A, Core Diameter

Measurement of Graded-Index Optical Fibers; EIA/TIA-455-59, Measurement

of Fiber Point Defects Using an OTDR; EIA/TIA-455-61, Measurement of

Fiber or Cable Attenuation Using an OTDR; EIA/TIA-455-78A, Spectral-

Attenuation Cutback Measurement for Single-Mode Optical Fibers; EIA/

TIA-455-81A, Compound Flow (Drip) Test for Filled Fiber Optic Cable;

EIA/TIA-455-82B, Fluid Penetration Test for Fluid-Blocked Fiber Optic

Cable; EIA/TIA-455-85A, Fiber Optic Cable Twist Test; EIA/TIA-455-104A,

Fiber Optic Cable Cyclic Flexing Test; EIA/TIA-455-164A, Single-Mode

Fiber, Measurement of Mode Field Diameter by Far-Field Scanning; EIA/

TIA-455-165A, Mode Field Diameter Measurement Near Field Scanning

Technique; EIA/TIA-455-167A, Mode Field Diameter, Variable Aperture in

the Far Field; EIA/TIA-455-168A, Chromatic Dispersion Measurement of

Multimode Graded-Index and Single-Mode Optical Fibers by Spectral Group

Delay Measurement in the Time Domain; EIA/TIA-455-169A, Chromatic

Dispersion Measurement of Single-Mode Optical Fibers by the Phase-Shift

Method; EIA/TIA-455-170, Cable Cutoff Wavelength of Single-Mode Fiber

by Transmitted Power; EIA/TIA-455-173, Coating Geometry Measurement for

Optical Fiber Side-View Method; EIA/TIA-455-175A, Chromatic Dispersion

Measurement of Single-Mode Optical Fibers by the Differential Phase

Shift Method; EIA/TIA-455-176, Method for Measuring Optical Fiber

Cross-Sectional Geometry by Automated Grey-Scale Analysis; EIA/TIA-455-

177A, Numerical Aperture Measurement of Graded-Index Optical Fibers;

EIA/TIA-455-178, Measurements of Strip Force Required for Mechanically

Removing Coatings from Optical Fibers; and EIA/TIA-598, Color Coding of

Fiber Optic Cables, referenced in this section are incorporated by

reference by REA. These incorporations by references were approved by

the Director of the Federal Register in accordance with 5 U.S.C. 552(a)

and 1 CFR part 51. Copies of EIA/TIA standards are available for

inspection during normal business hours at REA, room 2845, U.S.

Department of Agriculture, Washington, DC 20250-1500 or at the Office

of the Federal Register, 800 North Capitol Street, NW., suite 700,

Washington, DC. Copies are available from Global Engineering Documents,

15 Inverness Way East, Englewood, CO 80112, telephone number (303) 792-

2181.

(10) REA intends that the optical fibers contained in the cables

manufactured in accordance with 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.

(2) The optical fiber types must be one of the following:

(i) Dispersion-unshifted single mode fiber EIA Class IVa;

(ii) Dispersion-shifted single mode fiber EIA Class IVb;

(iii) 50/125 micrometer multimode fiber EIA Class Ia; or

(iv) 62.5/125 micrometer multimode fiber EIA Class Ia.

(3) The dispersion-unshifted single mode fiber core must have

either a matched or depressed clad step refractive index profile with a

mode-field diameter of 9.01.0 micrometers when measured at

1300 nanometers and 10.5+1.0 micrometers/-1.5 micrometers when measured

at 1550 nanometers in accordance with any one of the following test

methods:

(i) EIA/TIA-455-164A;

(ii) EIA/TIA-455-165A;

(iii) EIA/TIA-455-167A; or

(iv) EIA-455-174.

(4) The dispersion-shifted single mode fiber core must have either

a segmented core design or depressed clad step refractive index profile

with a mode-field diameter of 7.5+1.5 micrometers/-1.3 micrometers when

measured at 1550 nanometers in accordance with any one of the test

procedures specified in paragraph (b)(3) of this section.

(5) The core clad off-set of the dispersion-unshifted and

dispersion-shifted single mode fibers must not be greater than 1.0

micrometer when measured in accordance with either EIA/TIA-455-45B or

EIA/TIA-455-176.

(6) The multimode fiber cores must have graded (parabolic)

refractive index profiles with core diameters of 50.03.0

micrometers or 62.53.0 micrometers when measured in

accordance with either EIA/TIA-455-58A, or EIA/TIA-455-176.

(7) The core noncircularity of multimode fibers must not exceed 6

percent when measured in accordance with either EIA/TIA-455-45B or EIA/

TIA-455-176.

(8) The outside diameter of the glass fiber for both single mode

and multimode fibers must be 1252.0 micrometers when

measured in accordance with any one of the following test methods:

(i) EIA/TIA-455-45B;

(ii) EIA/TIA-455-176; or

(iii) EIA/TIA-455-48B, Methods A or B.

(9) The outside diameter of the glass fiber must be nominally

concentric with the fiber core as is consistent with the best

commercial practice.

(10) The individual fibers must be proof tested at a minimum

tensile stress of 0.35 gigapascal for approximately one second when

measured in accordance with EIA/TIA-455-31B.

(11) Factory splices of fibers are allowed provided that prior

acceptance from REA is obtained for the splice technique, that all

splices are documented and reported to the customer and that the

spliced fiber meets all requirements of this section.

(12) The optical fiber must be coated with a suitable material to

preserve the intrinsic strength of the glass having an outside diameter

of 25015 micrometers when measured in accordance with

either EIA/TIA-455-55B or EIA/TIA-455-173.

(13) The maximum force required to remove 25 millimeters of

protective fiber coating must not exceed 13 newtons when measured in

accordance with EIA/TIA-455-178.

(14) All optical fibers in any single length of cable must be of

the same type.

(c) Buffer/coating. (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

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 movement.

(2) 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.

(3) All protective coverings in any single length of cable must be

continuous and be of the same material except at splice locations.

(4) 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.

(5) Repairs to the fiber coatings are not allowed except at splice

locations.

(6) 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 tubes.

(i) Shrinkback. Testing must be conducted in accordance with ASTM D

4565-90a, paragraph 14.1, using a talc bed at a temperature of 95

deg.C. Shrinkback must not exceed 5 percent of the original 150

millimeter length of the specimen. The total shrinkage of the specimen

must be measured.

(ii) Cold bend. Testing must be conducted on at least one tube from

each color in the cable. Stabilize the specimen to -201

deg.C 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 not greater than five times the

tube diameter. The tube must show no evidence of cracking when observed

with normal or corrected-to-normal vision.

Note: Channel cores and similar slotted single component core

designs need not be tested for cold bend.

(d) Fiber and buffer tube identification. (1) The colors designated

for identification of loose buffer tubes, tight tube buffer fibers and

individual fibers in multifiber tubes, slots or bundles are shown in

the following table:

------------------------------------------------------------------------

Buffer tube and fiber No. Color

------------------------------------------------------------------------

1..................................... Blue.

2..................................... Orange.

3..................................... Green.

4..................................... Brown.

5..................................... Slate.

6..................................... White.

7..................................... Red.

8..................................... Black.

9..................................... Yellow.

10.................................... Violet.

11.................................... Rose.

12.................................... Aqua.

13.................................... Blue/Black Tracer.

14.................................... Orange/Black Tracer.

15.................................... Green/Black Tracer.

16.................................... Brown/Black Tracer.

17.................................... Slate/Black Tracer.

18.................................... White/Black Tracer.

19.................................... Red/Black Tracer.

20.................................... Black/Yellow Tracer.

21.................................... Yellow/Black Tracer.

22.................................... Violet/Black Tracer.

23.................................... Rose/Black Tracer.

24.................................... Aqua/Black Tracer.

------------------------------------------------------------------------

(2) Standards of color. Except for the aqua color, the colors of

fibers and tubes supplied in accordance with this section are specified

in terms of the Munsell Color System (ASTM D 1535-89) and must comply

with the color limits as defined in EIA/TIA-598. (A visual color

standard meeting these requirements and entitled ``Munsell Color Charts

for Color Coding,'' may be obtained from the Munsell Color Company,

Inc., 2441 North Calvert Street, Baltimore, Maryland 21218. The latest

edition of the color standard should be used.)

(i) The aqua color limits using the Munsell Color System must be as

follows:

Munsell Notation

------------------------------------------------------------------------

Symbol Aqua color

------------------------------------------------------------------------

Centroid................................................. 10BG 7/6

H++...................................................... 5B 7/6

H--...................................................... 5BG 7/6

V++...................................................... 10BG 8/4

V--...................................................... 10BG 6/6

C++...................................................... None

C--...................................................... 10BG 7/4

------------------------------------------------------------------------

(ii) Other coloring schemes used for providing identification of

buffer tubes and optical fibers which deviate from the requirements of

paragraph (d)(1) of this section will not be accepted by REA.

(e) Strength members. (1) Strength members must be an integral part

of the cable construction, but are not considered part of the support

messenger for self-supporting optical cable.

(2) The combined strength of all the strength members must be

sufficient to support the stress of installation and to protect the

cable in service.

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

support member or filler, as fillers between the fiber packages, as an

annular 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.

(4) 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.

(5) Strength member materials and splicing techniques must be

accepted by REA prior to their use.

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

member, the dielectric strength between the armor and the metallic

center member must withstand at least 15 kilovolts direct current for 3

seconds.

(f) Forming the cable core. (1) Protected fibers must 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 shall consist of

4, 6, 8, 10, 12, 16, 18, 20, or 24 fibers. Cylindrical groups or core

designs larger than the sizes shown above must meet all the

requirements of this section.

(3) When threads or tapes are used as core binders, they must be

colored either white or natural and must be a nonhygroscopic and

nonwicking dielectric material.

(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 colored in accordance with the table listed

below and must be a nonhygroscopic and nonwicking dielectric material

or be rendered such by the filling compound. The colors of the binders

must be in accordance with paragraphs (d)(2) introductory text and

(d)(2)(i) of this section.

------------------------------------------------------------------------

Unit No. Binder color

------------------------------------------------------------------------

1..................................... Blue.

2..................................... Orange.

3..................................... Green.

4..................................... Brown.

5..................................... Slate.

6..................................... White.

7..................................... Red.

8..................................... Black.

9..................................... Yellow.

10.................................... Violet.

11.................................... Rose.

12.................................... Aqua.

13.................................... Blue-Black.

14.................................... Orange-Black.

15.................................... Green-Black.

16.................................... Brown-Black.

17.................................... Slate-Black.

18.................................... White-Black.

19.................................... Red-Black.

20.................................... Black-Black-Yellow.

21.................................... Yellow-Yellow-Black.

22.................................... Violet-Black.

23.................................... Rose-Black.

24.................................... Aqua-Black.

------------------------------------------------------------------------

(g) Filling compound. (1) To prevent the ingress of water into the

core, a filling compound 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 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 must be homogeneous and uniformly mixed; free

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

nontoxic and present no dermal hazards.

(3) The individual cable manufacturer must satisfy REA that the

filling compound selected for use is suitable for its intended

application. The filling compound must be compatible with the cable

components when tested in accordance with ASTM D 4568-86 at a

temperature of 80 deg. C.

(h) Core wrap (optional). (1) At the option of the manufacturer,

one or more layers of nonhygroscopic and nonwicking 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.

(3) When core wraps are used, sufficient filling compound must be

applied to the core wraps so that voids or air spaces existing between

the core wraps and between the core the inner side of the core wrap are

minimized.

(i) Inner jacket. (1) Inner jackets may be applied directly over

the core or over the strength members.

(i) For armored cable an inner jacket is optional but recommended.

The inner jacket may absorb stresses in the cable core that may be

introduced by armor application or by armored cable installation.

(ii) For unarmored cable an inner jacket is optional.

(2) The inner jacket material and test requirements must be as for

the outer jacket material per paragraphs (m)(3) introductory text

through (m)(3)(v) of this section, except that either black or natural

polyethylene may be used. In the case of natural polyethylene, the

requirements for absorption coefficient and the inclusion of furnace

black are waived.

(j) Flooding compound. (1) Sufficient flooding compound 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 floodant between the armor and outer jacket is not required

when uniform bonding, per paragraph (k)(10) of this section, is

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

(2) The flooding compound must be compatible with the jacket when

tested in accordance with ASTM D 4568-86 at a temperature of 80 deg. C.

The floodant must exhibit adhesive properties sufficient to prevent

jacket slip when tested in accordance with the requirements of Appendix

A, paragraph (III)(3), of this section.

(3) The individual cable manufacturer must satisfy REA that the

flooding compound selected for use is acceptable for the application.

(4) In lieu of a flooding compound, water blocking tapes may be

applied between the inner jacket and armor and between the armor and

outer jacket to prevent water migration. The use of the water blocking

tape between the armor and outer jacket is not required when uniform

bonding, per paragraph (k)(10) of this section, is achieved between the

plastic-clad armor and the outer jacket.

(k) Armor. (1) A steel armor, plastic coated on both sides, is

required for direct buried cable manufactured under the provisions of

this section. An armor is optional for duct and aerial cable as

required by the purchaser. 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.

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

steel (ECCS) with a thickness of 0.155 0.015 millimeters.

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

corrugating or to the 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 per 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.

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

portions of the armor tape must be bonded in cables having a flat,

noncorrugated armor to meet the requirements of paragraphs (q)(1)

through (q)(7)(ii) of this section. If the tape is corrugated, the

overlap portions of the armor tape must be sufficiently bonded and the

corrugations must be sufficiently in register to meet the requirements

of paragraphs (q)(1) through (q)(7)(ii) of this section.

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

pass the bend test as specified in paragraph (q)(1) of this section.

(8) The protective coating on the steel armor must meet the

Bonding-to-Metal, Heat Sealability, Lap-Shear and Moisture Resistance

requirements of Type I, Class 2 coated metals in accordance with ASTM B

736-92a.

(9) The ability of the plastic-clad metal to resist the flooding

compound must be determined as required by ASTM D 4568-86 using a one

meter length of coated steel which must be aged for 7 days at

681 deg.C. There must be no delamination of the coating

from the steel at the conclusion of the test.

(10) 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 over at least 90 percent of the cable

circumference when tested in accordance with ASTM D 4565-90a. 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.

(l) Optional support messenger (aerial cable). (1) When a self-

supporting aerial cable containing an integrated support messenger is

supplied, the support messenger must comply with the requirements

specified in paragraphs (l)(2) introductory text through (l)(6) of this

section.

(2) The fully flooded, stranded support messenger must be 6.35

millimeters diameter, 7 wire, extra high strength grade, Class A

galvanized steel strand conforming to ASTM A 640-91 with exceptions and

additional provisions as follows:

(i) The maximum lay of the individual wires of the strand must be

140 millimeters.

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

minimum tensile strength and elongation of 29,500 newtons and 3.5

percent, respectively, when tested in accordance with the procedures

specified ASTM A 640-91.

(iii) The individual wires from a completed strand which contain

joints must not fracture when tested according to the ``Ductility of

Steel'' procedures specified in ASTM A 640-91 except that the mandrel

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

individual wires.

(3) The support strand must be completely covered with a corrosion

protective floodant. The floodant must be homogeneous and uniformly

mixed.

(4) The floodant must be nontoxic and present no dermal hazard.

(5) The floodant must be free from dirt, metallic particles, and

other foreign matter that may interfere with the performance of the

cable.

(6) The floodant must be compatible with the polyethylene outer

jacket and must be acceptable to REA.

(7) Other methods of providing self-supporting cable specifically

not addressed in this section may be allowed if accepted by REA.

Justification for acceptance of a modified design must be provided to

substantiate product utility and long term stability and endurance.

(m) 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 shall be as smooth and concentric as is consistent

with the best commercial practice.

(3) The raw material used for the outer jacket must be one of the

five types listed in paragraphs (m)(3)(i) through (m)(3)(v) of this

section. The raw material must contain an antioxidant to provide long

term stabilization and the materials must contain a

2.600.25 percent concentration of furnace black to provide

ultraviolet shielding. Both the antioxidant and furnace black must be

compounded into the material by the raw material supplier.

(i) Low density, high molecular weight polyethylene (LDHMW) must

conform to the requirements of ASTM D 1248-84(1989), Type I, Class C,

Category 4 or 5, Grade J3.

(ii) Low density, high molecular weight ethylene copolymer (LDHMW)

must conform to the requirements of ASTM D 1248-84(1989), Type I, Class

C, Category 4 or 5, Grade J3.

(iii) Linear low density, high molecular weight polyethylene

(LLDHMW) must conform to the requirements of ASTM D 1248-84(1989), Type

I, Class C, Category 4 or 5, Grade J3.

(iv) High density polyethylene (HD) must conform to the

requirements of ASTM D 1248-84(1989), Type III, Class C, Category 4 or

5, Grade J4.

(v) Medium density polyethylene (MD) must conform to the

requirements of ASTM D 1248-84(1989), Type II, Class C, Category 4 or

5, Grade J4.

(vi) Particle size of the carbon selected for use must not average

greater than 20 nanometers.

(vii) Absorption coefficient must be a minimum of 400 in accordance

with the procedures of ASTM D 3349-86.

(4) The outer jacketing material removed from or tested on the

cable must be capable of meeting the following performance

requirements:

----------------------------------------------------------------------------------------------------------------

HD or

Property LLDHMWethylenecopolymer LDHMWpolyethylene MDpolyethylene

----------------------------------------------------------------------------------------------------------------

Melt Flow Rate:

Percent increase from raw material, Maximum..... ....................... 50 50

1 deg. C for a 4

hour period for low density material and a test temperature of 115

1 deg. C for a 4 hour period for high and medium density

materials.

(v) Impact. The test must be performed in accordance with ASTM D

4565-90a using an impact force of 4 newton-meters at a temperature of

-20 2 deg. C. A cracked or split jacket constitutes

failure.

(6) Jacket thickness. The nominal outer jacket thickness must not

be less than 1.3 millimeters. The test method used must either be the

End Sample Method (paragraph (m)(6)(i) of this section) or the

Continuous Uniformity Thickness Gauge Method (paragraph (m)(6)(ii) of

this section).

(i) End sample method. The jacket must be capable of meeting the

following requirements:

Minimum Average Thickness: 90 percent (%) of nominal thickness

Minimum Spot Thickness: 70 % of nominal thickness

(ii) Continuous uniformity thickness gauge. (A) The jacket must be

capable of meeting the following requirements:

Minimum Average Thickness: 75 % of nominal thickness

Minimum Thickness: 70 % of nominal thickness

Maximum Eccentricity: 40 % of nominal thickness

TR05JY94.000

(B) The maximum and minimum thickness values shall be based on the

average of each axial section.

(7) For jackets having embedded strength members, the jacket

thickness must meet the requirements of paragraph (m)(6) of this

section except that the jacket thickness over the strength members must

not be less than 0.50 millimeters.

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

messenger for self-supporting aerial cable utilizing such an element

must be 1.1 millimeters.

(9) The web dimension for self-supporting aerial cable utilizing

such a feature must be as follows:

TR05JY94.001

(n) Sheath slitting cord (optional). (1) A sheath slitting cord is

optional.

(2) When a sheath slitting cord is used it must be nonhygroscopic

and nonwicking or be rendered such by the filling or flooding compound,

continuous throughout a length of cable and of sufficient strength to

open the sheath over at least a one meter length without breaking the

cord at a temperature of 235 deg.C.

(o) Identification marker and length marker. (1) Each length of

cable must be permanently labeled either Optical Cable, OC, Optical

Fiber Cable, or OF on the outer jacket and identified as to

manufacturer and year of manufacture.

(2) Each length of cable intended for direct burial installation

shall be marked with a telephone handset in compliance with Rule 350G

of the 1993 National Electrical Safety Code (NESC).

(3) Mark the number of fibers on the jacket.

(4) The markings must be printed on the jacket at regular intervals

of not more than 2 meters.

(5) An alternative method of marking may be used if acceptable to

REA.

(6) The completed cable must have sequentially numbered length

markers in Meters or Feet at regular intervals of not more than 2

meters along the outside of the jacket.

(7) Continuous sequential numbering must be employed in a single

length of cable.

(8) The numbers must be dimensioned and spaced to produce good

legibility and must be approximately 3 millimeters in height. An

occasional illegible marking is permissible if there is a legible

marking located not more than 2 meters from it.

(9) The method of marking must be by means of suitable surface

markings producing a clear distinguishable contrasting marking

acceptable to REA. Where direct or transverse printing is employed, the

characters should be indented to produce greater durability of marking.

Any other method of length marking must be acceptable to REA as

producing a marker suitable for the field. Size, shape and spacing of

numbers, durability and overall legibility of the marker will be

considered in acceptance of the method.

(10) Agreement between the actual length of the cable and the

length marking on the cable jacket must be within the limits of +1

percent, -0 percent.

(11) 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 on a different portion of

the cable circumference than any existing marking when possible and

have a numbering sequence differing from any other existing marking by

at least 3,000.

(12) 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.

(p) Optical performance. (1) The optical performance of the single

mode fibers must be in accordance with the requirements specified in

paragraphs (p)(1)(i) through (p)(1)(viii) of this section.

(i) The attenuation values of the single mode fibers within the

cable must not exceed 0.5 decibel per kilometer (dB/km) for dispersion-

unshifted single mode fiber at 1310 and 1550 nanometers and must not

exceed 0.5 dB/km for dispersion-shifted single mode fiber at 1550

nanometers. The test method used for measuring the attenuation must be

in accordance with either:

(A) EIA/TIA-455-78A; or

(B) EIA/TIA-455-61.

(ii) The attenuation values for wavelengths between 1285 and 1330

nanometers and between 1525 and 1575 nanometers for dispersion-

unshifted fibers must not exceed the attenuation at 1310 and 1550

nanometers by more than 0.1 dB/km. The attenuation values for

wavelengths between 1525 and 1575 nanometers for dispersion-shifted

fibers must not exceed the attenuation at 1550 nanometers by more than

0.1 dB/km. The test method used for measuring the attenuation must be

in accordance with any one of the methods specified in paragraph

(p)(1)(i) of this section.

(iii) Attenuation discontinuities in the fiber's length must not

exceed 0.1 decibel (dB) for dispersion-unshifted fiber at

131020 and 155020 nanometers and must not

exceed 0.1 dB for dispersion-shifted fiber at 155020

nanometers when measured in accordance with EIA/TIA-455-59.

(iv) Measurement of the attenuation must be conducted at the

wavelength specified for application and must be expressed in decibels

per kilometer.

(v) 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. 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.

(vi) For dispersion-unshifted fiber the zero dispersion wavelength

must be between 1300 and 1322 nanometers, and the value of the

dispersion slope at the zero-dispersion wavelength must not be greater

than 0.092 picosecond per nanometer squared times kilometer (ps/

(nm2km) when measured in accordance with either:

(A) EIA/TIA-455-168A;

(B) EIA/TIA-455-169A; or

(C) EIA/TIA-455-175A.

(vii) For dispersion-shifted fiber, the dispersion over the

wavelength range between 1525 and 1575 nanometers must not exceed 3.5

picosecond per nanometer times kilometer (ps/(nm2km)) and

must have a maximum dispersion slope of 0.095 ps/(nm2km)

at the zero dispersion wavelength when measured in accordance with any

one of the test procedures specified in paragraph (p)(1)(vi) of this

section.

(viii) The cut off wavelength of the dispersion-unshifted and the

dispersion-shifted fibers in a cable must be less than 1260 nanometers

when measured in accordance with EIA/TIA-455-170.

(2) The optical performance of the multimode fibers must be in

accordance with the requirements specified in paragraphs (p)(2)(i)

through (p)(2)(vi) of this section.

(i) The attenuation values of the 50/125 and 62.5/125 micrometer

multimode fibers within the cable must not exceed 1.5 dB/km at 1300

nanometers when measured in accordance with either:

(A) EIA/TIA-455-46A;

(B) EIA/TIA-455-53A; or

(C) EIA/TIA-455-61.

(ii) Attenuation discontinuities in the fiber's length must not

exceed 0.2 dB for both multimode fiber types at 130020

nanometers when measured in accordance with EIA/TIA-455-59.

(iii) Measurement of the attenuation must be conducted at the

wavelength specified for application and must be expressed in decibels

per kilometer.

(iv) 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.

(v) The bandwidth of the multimode fibers at the -3 dB optical

power of the optical fibers within the cable must be within the limits

prescribed in the purchase order.

(vi) The test methods used to measure bandwidth must be in

accordance with either EIA/TIA-455-30B or EIA/TIA-455-51A.

(3) Numerical aperture (NA) for each multimode optical fiber in the

cable must be 0.200.015 for the 50/125 micrometer design

and 0.2750.015 for the 62.5/125 micrometer design when

measured in accordance with EIA/TIA-455-177A.

(q) Mechanical requirements--(1) Cable bend test. (i) All cables

manufactured in accordance with the requirements of this section must

be capable of meeting the following bend test without exhibiting an

increase in fiber attenuation greater than 0.10 dB for single mode

fibers and 0.40 dB for multimode fibers.

(ii) Measure the attenuation of dispersion-unshifted single mode

fibers at 131020 and 155020 nanometers,

dispersion-shifted single mode fibers at 155020 nanometers

and multimode fibers at 1300 20 nanometers.

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

the cable sample in accordance with EIA/TIA-455-37A, Test Condition E,

Turns Test Level 3. The following detailed test conditions shall apply:

(A) Section 4.2--Mandrel diameter must be 20 times the cable

diameter.

(B) Section 4.5--Measure the attenuation increase of the wound

sample at the test temperature and specified wavelengths in accordance

with EIA-455-20.

(C) For armored cable, the armor overlap must be on the outside of

the bend.

(D) For self-supporting cable, the jacketed support messenger and

connection web must be removed prior to testing.

(iv) The cable may be allowed to warm to room temperature before

visual inspection. The bent area of the cable must show neither visible

evidence of fracture of the jacket nor delamination of the bond at the

overlap and to the outer jacket in nonflooded cable. After removal of

the jacket, there must be no visible evidence of fracture of the armor,

when present, and of the components in the core.

(2) Cable impact test. (i) All cables manufactured in accordance

with the requirements of this section must be capable of meeting the

following impact test without exhibiting an increase in fiber

attenuation greater than 0.10 dB for single mode fibers and 0.40 dB for

multimode fibers, and without cracking or splitting of the cable

jacket.

(ii) Measure the attenuation of the optical fibers in accordance

with paragraph (q)(1)(ii) of this section.

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

the cable in accordance with EIA/TIA-455-25A.

(3) Cable compression test. (i) All cables manufactured in

accordance with the requirements of this section must be capable of

meeting the following compressive strength test without exhibiting an

increase in fiber attenuation greater than 0.10 dB for single mode

fibers and 0.4 dB for multimode and without cracking or splitting of

the cable jacket when subjected to a minimum compressive load of 440

newtons per centimeter for armored cable and 220 newtons per centimeter

for nonarmored cable.

(ii) Measure the attenuation of the optical fibers in accordance

with paragraph (q)(1)(ii) of this section.

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

the cable in accordance with EIA-455-41 using a rate of 3 millimeters

to 20 millimeters per minute and maintaining the load for 10 minutes.

(4) Cable twist test. (i) All cables manufactured in accordance

with the requirements of this section must be capable of meeting the

following twist test without exhibiting an increase in fiber

attenuation greater than 0.10 dB for single mode fibers and 0.40 dB for

multimode fibers, and without cracking or splitting of the cable

jacket.

(ii) Measure the attenuation of the optical fibers in accordance

with paragraph (q)(1)(ii) of this section.

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

the cable in accordance with EIA/TIA-455-85A, using a maximum cable

twisting length of 4 meters.

(5) Cable flex test. (i) All cables manufactured in accordance with

the requirements of this section must be capable of meeting the

following flex test without exhibiting an increase in fiber attenuation

greater than 0.10 dB for single mode fibers and 0.40 dB for multimode

fibers.

(ii) Measure the attenuation of the optical fibers in accordance

with paragraph (q)(1)(ii) of this section.

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

the cable in accordance with EIA/TIA-455-104A, Test Conditions I and

II, flexed for 25 cycles using a sheave diameter not less than 20 times

the cable diameter (Test condition letter B).

(iv) After completion of the test, the bent area of the cable must

show neither visible evidence of fracture of the jacket nor

delamination of the bond at the overlap and to the outer jacket in

nonflooded cable. After removal of the jacket, there must be no visible

evidence of fracture of the armor, when present, and of the components

in the core.

(6) Water penetration test. (i) A one meter length of completed

fiber optic cable must be preconditioned for 24 hours at

235 deg.C and then tested in accordance with EIA/TIA-455-

82B using a one meter water head over the sample or placed under the

equivalent continuous pressure for one hour.

(ii) After the one hour period, there must be no water leakage

through the sheath interfaces, under the core wrap, between the cable

core interstices or through the fiber buffers.

(iii) If water leakage is detected in the first sample, one

additional 3 meter sample from EACH END of the same reel must be tested

in accordance with paragraph (q)(6)(i) of this section. If either

sample exhibits water leakage, the entire reel of cable is to be

rejected. If the samples exhibit no leakage, the entire reel of cable

is considered acceptable.

(7) Compound flow test. (i) Three 300 millimeter long test samples

must be preconditioned for 24 hours at 235 deg.C and then

tested in accordance with EIA/TIA-455-81A using a test temperature of

80 1 deg.C.

(ii) The amount of filling or flooding compounds that flowed or

dripped from any of the suspended cable specimens must be less than or

equal to 0.5 grams of material. The measurement of an amount greater

than 0.5 grams for any of the suspended cable specimens constitutes

failure.

(r) Preconnectorized cable (optional). (1) At the option of the

manufacturer and upon request by the purchaser, the cable may be

factory terminated with connectors acceptable to REA.

(2) All connectors must be accepted by REA prior to their use.

(s) Acceptance testing and extent of testing. (1) The tests

described in Appendix A of 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 REA. 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.

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

(i) An original signature certification that the product fully

complies with each section of the specification;

(ii) Qualification Test Data, per Appendix A of this section;

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

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

(v) Agree to periodic plant inspections;

(vi) A certification that the product does or does not comply with

the domestic origin manufacturing provisions, of the ``Buy American''

requirements of the Rural Electrification Act of 1938 (52 Stat. 818);

(vii) Written user testimonials concerning field performance of

the product; and

(viii) Other nonproprietary data deemed necessary by the Chief,

Outside Plant Branch (Telephone).

(3) For requalification acceptance, the manufacturer must submit

an original signature certification that the product fully complies

with each section of the specification, excluding the Qualification

Section, and a certification that the product does or does not comply

with the domestic origin manufacturing provisions of the ``Buy

American'' requirements of the Rural Electrification Act of 1938 (52

Stat. 818), for acceptance by September 30 every three years. The

required data and certification must have been gathered within 90 days

of the submission.

(4) Initial and requalification acceptance requests should be

addressed to: Chairman, Technical Standards Committee ``A''

(Telephone), Telecommunications Standards Division, Rural

Electrification Administration, Washington, DC 20250-1500.

(5) Tests on 100 percent of completed cable. (i) The armor for

each length of cable must be tested for continuity using the procedures

of ASTM D 4566-90.

(ii) Attenuation for each optical fiber in the cable must be

measured.

(iii) Optical discontinuities must be isolated and their location

and amplitude recorded.

(6) Capability tests. Tests on a quality assurance basis must be

made as frequently as is required for each manufacturer to determine

and maintain compliance with:

(i) Numerical aperture and bandwidth of multimode fibers;

(ii) Cut off wavelength of single mode fibers;

(iii) Dispersion of single mode fibers;

(iv) Shrinkback and cold testing of loose tube and tight tube

buffers;

(v) Adhesion properties of the protective fiber coating;

(vi) Dielectric strength between the armor and the metallic

central member;

(vii) Performance requirements for the inner and outer jacketing

materials;

(viii) Performance requirements for the filling and flooding

compounds;

(ix) Bonding properties of the coated armoring material;

(x) Sequential marking and lettering;

(xi) Cable bend and cable impact tests;

(xii) Water penetration and compound flow tests;

(xiii) Cable twist, cable flex, and cable compression tests; and

(xiv) Performance requirements of support messenger.

(t) Records of optical and physical 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 this

section as set forth in paragraphs (s)(5) and (s)(6) of this section.

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

readily available to REA upon request. The optical data must be

furnished to the purchaser 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 according to

ASTM E 29-90.

(u) Manufacturing irregularities. (1) Repairs to the armor, when

present, are not permitted in cable supplied to end users under this

section.

(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 in accordance with good commercial practices

utilizing sheath grade compounds.

(3) Buffer tube repair is permitted only in conjunction with fiber

splicing.

(v) Packaging and preparation for shipment. (1) The cable must be

shipped on reels. The diameter of the drum must be large enough to

prevent damage to the cable from reeling and unreeling. 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

complying with the requirements of Appendix B of this section must be

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

against damage during storage and shipment.

(3) Cable manufactured to the requirements of this section must be

sealed at the ends to prevent entrance of moisture. The method of

sealing must be accepted by REA prior to its use.

(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

reel 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 in

diameter without binding. Steel arbor hole liners may be used but must

be accepted by REA prior to their use.

(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.

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

or on a tag firmly attached to the reel:

Optical Cable

Number of Fibers

Armored or Nonarmored

Year of Manufacture

Name of Cable Manufacturer

Length of Cable

Reel Number

REA 7 CFR 1755.900

Example:

Optical Cable

4 fiber

Armored

1988

XYZ Company

1050 meters

Reel Number 3

REA 7 CFR 1755.900

(10) When preconnectorized cable is shipped, the splicing modules

must be protected to prevent damage during shipment and handling. The

protection method must be accepted by REA prior to its use.

Appendix A to 7 CFR 1755.900 --Qualification Tests Methods

(I) The test procedures described in this appendix are for

qualification of initial cable designs and major modifications of

accepted designs. Included in (V) of this appendix are suggested

formats that may be used in submitting test results to REA.

(II) Sample selection and preparation. (1) All testing must be

performed on lengths removed sequentially from any of the same

cables listed below. The cables must not have been exposed to

temperatures in excess of 38 deg.C since their initial cool downs

after sheathing. The lengths specified are minimum lengths and if

desirable from a laboratory testing standpoint longer lengths may be

used:

(a) 12 single mode fiber jacketed cable consisting of 6 single

mode dispersion-unshifted fibers and 6 single mode dispersion-

shifted fibers.

(b) 12 multimode fiber jacketed cable consisting of 6 50/125

micrometer multimode fibers and 6 62.5/125 micrometer multimode

fibers.

(c) 24 fiber jacketed combination cable consisting of 6 single

mode dispersion-unshifted fibers; 6 single mode dispersion-shifted

fibers; 6 50/125 micrometer multimode fibers; and 6 62.5/125

micrometer multimode fibers.

(2) Length A shall be a minimum of 500 meters long. Coil the

sample with a diameter of 50 to 75 times its sheath diameter. Three

lengths are required if only requesting acceptance for either single

mode fiber cable (a), multimode fiber cable (b), or using the

combination fiber cable (c). Six lengths, 3 lengths of single mode

fiber cable (a), and 3 lengths of multimode fiber cable (b), are

required if requesting acceptance for both single mode and multimode

fiber cables.

(3) Length B shall be one meter long. Four lengths of either

single mode fiber cable (a), multimode fiber cable (b) or the

combination fiber cable (c) are required.

(4) Length C shall be 600 millimeters long. Four lengths of

either single mode fiber cable (a), multimode fiber cable (b) or the

combination fiber cable (c) are required.

(5) Data reference temperature. Unless otherwise specified, all

measurement shall be made at 235 deg.C.

(III) Environmental tests--(1) Heat aging test. (a) Test

samples. Place one or two samples of length A and one sample each of

lengths B and C in an oven or environmental chamber. The ends of

sample A must exit from the chamber or oven for optical tests.

Securely seal the oven exit holes.

(b) Sequence of tests. The samples are to be subjected to the

following tests after conditioning:

(i) Water Penetration Test outlined in paragraph (III ) (2) of

this appendix; and

(ii) Jacket Slip Strength Test outlined in paragraph (III) (3)

of this appendix. (For Flooded Designs Only)

(c) Initial measurements. (i) For sample(s) A measure the

attenuation for the single mode dispersion-unshifted fibers at 1310

and 1550 nanometers, for single mode dispersion-shifted fibers at

1550 nanometers and/or for multimode fibers at 1300 nanometers at a

temperature of 235 deg.C. Also measure the bandwidth of

the multimode fibers. Calculate the attenuation data on a per

kilometer basis. Calculate the bandwidth data on a megahertz-

kilometer (MHz-km) basis.

(ii) Record on suggested formats in (V) of this appendix or on

other easily readable formats.

(d) Heat conditioning. (i) Immediately after completing the

initial measurements, condition the sample(s) for 14 days at a

temperature of 652 deg.C.

(ii) At the end of this period note any exudation of cable

filler. Measure the parameters given in paragraph (III)(1)(c) of

this appendix. Record on suggested formats in (V) of this appendix

or on other easily readable formats.

(e) Overall optical deviation. (i) Calculate the change in all

parameters between the final parameters after conditioning with

initial parameters in paragraph (III)(1)(c) of this appendix.

(ii) The stability of the optical parameters after completion of

this test must be within the following prescribed limits:

(A) Attenuation. The attenuation of each multimode fiber must

not change by more than 0.3 db/km and the attenuation of each single

mode fiber must not change by more than 0.1 dB/km.

(B) Bandwidth. The bandwidth of each multimode fiber must not

change by more than 15 percent from their original values.

(2) Water penetration testing. (a) A watertight closure must be

placed over the jacket of length B from paragraph (III)(1)(a) of

this appendix. The closure must not be placed over the jacket so

tightly that the flow of water through pre-existing voids or air

spaces is restricted. The other end of the sample must remain open.

(b) Test per Option A or Option B. (i) Option A. Weigh the

sample and closure prior to testing. Fill the closure with water and

place under a continuous pressure of 10 0.7 kilopascals

for one hour. Collect the water leakage from the end of the test

sample during the test and weigh to the nearest 0.1 gram.

Immediately after the one hour test, seal the ends of the cable with

a thin layer of grease and remove all visible water from the

closure, being careful not to remove water that penetrated into the

core during the test. Reweigh the sample and determine the weight of

water that penetrated into the core.

(ii) Option B. Fill the closure with a 0.2 gram sodium

fluorscein per liter water solution and apply a continuous pressure

of 10 0.7 kilopascals for one hour. Catch and weigh any

water that leaks from the end of the cable during the one hour

period. If no water leaks from the sample, carefully remove the

water from the closure. Then carefully remove the outer jacket,

armor, if present, inner jacket, if present, and core wrap one at a

time, examining with an ultraviolet light source for water

penetration. After removal of the core wrap, carefully dissect the

core and examine for water penetration within the core. Where water

penetration is observed, measure the penetration distance.

(3) Jacket slip strength test. (For Flooded Design Only) (a)

Sample selection. Test sample C from paragraph (III)(1)(a) of this

appendix.

(b) Sample preparation. Prepare test sample in accordance with

the procedures specified in ASTM D 4565-90a.

(c) Sample conditioning and testing. Remove the sample from the

tensile tester prior to testing and condition for one hour at 50

2 deg.C. Test immediately in accordance with the

procedures specified in ASTM D 4565-90a. A minimum jacket slip

strength of 67 newtons is required. Record the load attained on the

suggested formats in (V) of this appendix or on other easily

readable formats.

(4) Temperature and humidity exposure. (a) Repeat paragraphs

(III)(1)(a) through (III)(1)(c)(ii) of this appendix for separate

set of samples A, B and C which have not been subjected to prior

environmental conditioning.

(b) Immediately after completing the measurements, expose the

test sample to 100 temperature cyclings. Relative humidity within

the chamber shall be maintained at 90 2 percent. One

cycle consists of beginning at a stabilized chamber and test sample

temperature of 52 2 deg.C, increasing the temperature

to 57 2 deg.C, allowing the chamber and test samples to

stabilize at this level, then dropping the temperature back to 52

2 deg.C.

(c) Repeat paragraphs (III)(1)(d)(ii) through (III)(3)(c) of

this appendix.

(5) Temperature cycling. (a) Repeat paragraphs (III)(1)(a)

through (III)(1)(c)(ii) of this appendix for separate set of samples

A, B, and C which have not been subjected to prior environmental

conditioning.

(b) Immediately after completing the measurements, subject the

test sample to 10 cycles of temperature between -40 deg.C and

+60 deg.C. The test sample must be held at each temperature extreme

for a minimum of 1\1/2\ hours during each cycle of temperature. The

air within the temperature cycling chamber must be circulated

throughout the duration of the cycling.

(c) Repeat paragraphs (III)(1)(d)(ii) through (III)(3)(c) of

this appendix.

(IV) Control sample--(a) Test samples. A separate set of lengths

B and C must have been maintained at 23 5 deg.C for at

least 48 hours before the testing.

(b) Repeat paragraphs (III)(2) through (III)(3)(c) of this

appendix for these samples.

(V) The following suggested formats may be used in submitting

the test results to REA:

Heat Aging Test--Single Mode Cable

--------------------------------------------------------------------------------------------------------------------------------------------------------

Attenuation--1310 nm dB/km Attenuation--1550 nm dB/km

Fiber No. ------------------------------------------------------------------------------------------------------------------------------------------

Initial Final Change Initial Final Change

--------------------------------------------------------------------------------------------------------------------------------------------------------

1

--------------------------------------------------------------------------------------------------------------------------------------------------------

2

--------------------------------------------------------------------------------------------------------------------------------------------------------

3

--------------------------------------------------------------------------------------------------------------------------------------------------------

4

--------------------------------------------------------------------------------------------------------------------------------------------------------

5

--------------------------------------------------------------------------------------------------------------------------------------------------------

6

--------------------------------------------------------------------------------------------------------------------------------------------------------

7

--------------------------------------------------------------------------------------------------------------------------------------------------------

8

--------------------------------------------------------------------------------------------------------------------------------------------------------

9

--------------------------------------------------------------------------------------------------------------------------------------------------------

10

--------------------------------------------------------------------------------------------------------------------------------------------------------

11

--------------------------------------------------------------------------------------------------------------------------------------------------------

12

--------------------------------------------------------------------------------------------------------------------------------------------------------

Heat Aging Test--Multimode Cable

--------------------------------------------------------------------------------------------------------------------------------------------------------

Attenuation--1300 nm dB/km Bandwidth dB/km

Fiber No. ------------------------------------------------------------------------------------------------------------------------------------------

Initial Final Change Initial Final Change (%)

--------------------------------------------------------------------------------------------------------------------------------------------------------

1

--------------------------------------------------------------------------------------------------------------------------------------------------------

2

--------------------------------------------------------------------------------------------------------------------------------------------------------

3

--------------------------------------------------------------------------------------------------------------------------------------------------------

4

--------------------------------------------------------------------------------------------------------------------------------------------------------

5

--------------------------------------------------------------------------------------------------------------------------------------------------------

6

--------------------------------------------------------------------------------------------------------------------------------------------------------

7

--------------------------------------------------------------------------------------------------------------------------------------------------------

8

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9

--------------------------------------------------------------------------------------------------------------------------------------------------------

10

--------------------------------------------------------------------------------------------------------------------------------------------------------

11

--------------------------------------------------------------------------------------------------------------------------------------------------------

12

--------------------------------------------------------------------------------------------------------------------------------------------------------

Heat Aging Test--Combination Cable

--------------------------------------------------------------------------------------------------------------------------------------------------------

Attenuation--1310 nm dB/km Attenuation--1550 nm dB/km Bandwidth MHz-km

Fiber No. -------------------------------------------------------------------------------------------------------------------------------------------

Initial Final Change Initial Final Change Initial Final Change (%)

--------------------------------------------------------------------------------------------------------------------------------------------------------

1

--------------------------------------------------------------------------------------------------------------------------------------------------------

2

--------------------------------------------------------------------------------------------------------------------------------------------------------

3

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4

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5

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6

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7

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8

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9

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10

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11

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12

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13

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14

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15

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16

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17

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18

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19

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20

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21

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22

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23

--------------------------------------------------------------------------------------------------------------------------------------------------------

24

--------------------------------------------------------------------------------------------------------------------------------------------------------

Temperature/Humidity Test--Single Mode Cable

--------------------------------------------------------------------------------------------------------------------------------------------------------

Attenuation--1310 nm dB/km Attenuation--1550 nm dB/km

Fiber No. ------------------------------------------------------------------------------------------------------------------------------------------

Initial Final Change Initial Final Change

--------------------------------------------------------------------------------------------------------------------------------------------------------

1

--------------------------------------------------------------------------------------------------------------------------------------------------------

2

--------------------------------------------------------------------------------------------------------------------------------------------------------

3

--------------------------------------------------------------------------------------------------------------------------------------------------------

4

--------------------------------------------------------------------------------------------------------------------------------------------------------

5

--------------------------------------------------------------------------------------------------------------------------------------------------------

6

--------------------------------------------------------------------------------------------------------------------------------------------------------

7

--------------------------------------------------------------------------------------------------------------------------------------------------------

8

--------------------------------------------------------------------------------------------------------------------------------------------------------

9

--------------------------------------------------------------------------------------------------------------------------------------------------------

10

--------------------------------------------------------------------------------------------------------------------------------------------------------

11

--------------------------------------------------------------------------------------------------------------------------------------------------------

12

--------------------------------------------------------------------------------------------------------------------------------------------------------

Temperature/Humidity Test--Multimode Cable

--------------------------------------------------------------------------------------------------------------------------------------------------------

Attenuation--1300 nm dB/km Bandwidth MHz-km

Fiber No. -------------------------------------------------------------------------------------------------------------------------------------

Initial Final Change Initial Final Change

--------------------------------------------------------------------------------------------------------------------------------------------------------

1

--------------------------------------------------------------------------------------------------------------------------------------------------------

2

--------------------------------------------------------------------------------------------------------------------------------------------------------

3

--------------------------------------------------------------------------------------------------------------------------------------------------------

4

--------------------------------------------------------------------------------------------------------------------------------------------------------

5

--------------------------------------------------------------------------------------------------------------------------------------------------------

6

--------------------------------------------------------------------------------------------------------------------------------------------------------

7

--------------------------------------------------------------------------------------------------------------------------------------------------------

8

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9

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10

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11

--------------------------------------------------------------------------------------------------------------------------------------------------------

12

--------------------------------------------------------------------------------------------------------------------------------------------------------

Temperature/Humidity Test--Combination Cable

--------------------------------------------------------------------------------------------------------------------------------------------------------

Attenuation--1310 nmdB/km Attenuation--1550 nm dB/km Bandwidth MHz-km

Fiber No. -------------------------------------------------------------------------------------------------------------------------------------------

Initial Final Change Initial Final Change Initial Final Change (%)

--------------------------------------------------------------------------------------------------------------------------------------------------------

1

--------------------------------------------------------------------------------------------------------------------------------------------------------

2

--------------------------------------------------------------------------------------------------------------------------------------------------------

3

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4

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5

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6

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7

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8

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9

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10

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11

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12

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13

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14

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15

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16

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17

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18

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19

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20

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21

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22

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23

--------------------------------------------------------------------------------------------------------------------------------------------------------

24

--------------------------------------------------------------------------------------------------------------------------------------------------------

Temperature Cycling Test--Single Mode Cable

--------------------------------------------------------------------------------------------------------------------------------------------------------

Attenuation--1310 nm dB/km Attenuation--1550 nm dB/km

Fiber No. ------------------------------------------------------------------------------------------------------------------------------------------

Initial Final Change Initial Final Change

--------------------------------------------------------------------------------------------------------------------------------------------------------

1

--------------------------------------------------------------------------------------------------------------------------------------------------------

2

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3

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4

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5

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6

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7

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8

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9

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10

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11

--------------------------------------------------------------------------------------------------------------------------------------------------------

12

--------------------------------------------------------------------------------------------------------------------------------------------------------

Temperature Cycling--Multimode Cable

--------------------------------------------------------------------------------------------------------------------------------------------------------

Attenuation--1300 nm dB/km Bandwidth MHz-km

Fiber No. ------------------------------------------------------------------------------------------------------------------------------------------

Initial Final Change Initial Final Change (%)

--------------------------------------------------------------------------------------------------------------------------------------------------------

1

--------------------------------------------------------------------------------------------------------------------------------------------------------

2

--------------------------------------------------------------------------------------------------------------------------------------------------------

3

--------------------------------------------------------------------------------------------------------------------------------------------------------

4

--------------------------------------------------------------------------------------------------------------------------------------------------------

5

--------------------------------------------------------------------------------------------------------------------------------------------------------

6

--------------------------------------------------------------------------------------------------------------------------------------------------------

7

--------------------------------------------------------------------------------------------------------------------------------------------------------

8

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9

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10

--------------------------------------------------------------------------------------------------------------------------------------------------------

11

--------------------------------------------------------------------------------------------------------------------------------------------------------

12

--------------------------------------------------------------------------------------------------------------------------------------------------------

Temperature Cycling Test Combination Cable

--------------------------------------------------------------------------------------------------------------------------------------------------------

Attenuation--1310 nmdB/km Attenuation--1550 nm dB/km Bandwidth MHz-km

Fiber No. -------------------------------------------------------------------------------------------------------------------------------------------

Initial Final Change Initial Final Change Initial Final Change (%)

--------------------------------------------------------------------------------------------------------------------------------------------------------

1

--------------------------------------------------------------------------------------------------------------------------------------------------------

2

--------------------------------------------------------------------------------------------------------------------------------------------------------

3

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4

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5

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6

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7

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8

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9

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10

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11

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12

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13

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14

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15

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16

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17

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18

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19

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20

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21

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22

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23

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24

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Water Penetration Test

------------------------------------------------------------------------

Option A Option B

---------------------------------------

End Weight End

leakage gain leakage Penetration

grams grams grams millimeters

------------------------------------------------------------------------

Control.........................

Heat Age........................

Humidity Exposure...............

Temperature Cycling.............

------------------------------------------------------------------------

Jacket Slip Strength @ 50 deg.C

Load in Newtons

Control............

Heat Age...........

Humidity Exposure..

Temperature Cycling

Filler Exudation (grams)

Heat Age...........

Humidity Exposure..

Temperature Cycle..

Appendix B to 7 CFR 1755.900--Thermal Reel Wrap Qualification

(I) The test procedures described in this appendix are only for

qualification of initial and subsequent changes in thermal reel

wraps.

(II) Sample selection. All testing must be performed on two 450

millimeter lengths of cable removed sequentially from the same fiber

jacketed cable. This cable must not have been exposed to

temperatures in excess of 38 deg.C since its initial cool down

after sheathing.

(III) 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 jacket sample to a minimum of 71 deg.C. A GE

600 watt photoflood lamp or an equivalent lamp having the light

spectrum approximately that of the sun shall be used.

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

millimeters or an equivalent height that produces the 71 deg.C

jacket temperature on the unwrapped sample shall be used.

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

jacket temperatures of the samples shall be recorded after one hour

of exposure to the heat source.

(7) Compute the temperature difference between jackets.

(8) For the thermal reel wrap to be acceptable to REA, the

temperature difference between the jacket with the thermal reel wrap

and the jacket without the reel wrap shall be greater than or equal

to 17 deg.C.

Dated: June 2, 1994.

Bob J. Nash,

Under Secretary, Small Community and Rural Development.

[FR Doc. 94-14104 Filed 7-1-94; 8:45 am]

BILLING CODE 3410-15-P