[Federal Register Volume 59, Number 127 (Tuesday, July 5, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-14104]


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[Federal Register: July 5, 1994]


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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 
    <0.41 (Initial Melt Index)......................                100                                         
    0.41-2.00 (Initial Melt Index)..................  .......................              50                   
Tensile Strength:                                                                                               
    Minimum, Megapascals............................                 12                    12              16.5 
Ultimate Elongation:                                                                                            
    Minimum, Percent................................                400                   400               300 
Environmental Stress Cracking:                                                                                  
    Maximum, Failures...............................               0/10                  2/10              2/10 
Shrinkback:                                                                                                     
    Maximum, Percent................................                  5                     5                 5 
Impact:                                                                                                         
    Maximum, Failures...............................               2/10                  2/10              2/10 
----------------------------------------------------------------------------------------------------------------

    (5) Testing procedures. The procedures for testing jacket specimens 
for compliance with paragraph (m)(4) of this section must be as 
follows:
    (i) Melt flow rate. The melt flow rate must be determined by ASTM D 
1238-90b, Condition E. Jacketing material must be free from flooding 
and filling compound.
    (ii) Tensile strength and ultimate elongation. Test in accordance 
with EIA-455-89A, using a jaw separation speed of 500 millimeters per 
minute for low density material and 50 millimeters per minute for high 
and medium density materials.
    (iii) Environmental stress cracking. Test in accordance with ASTM D 
4565-90a.
    (iv) Shrinkback. Test in accordance with the procedures specified 
in EIA-455-86 using a temperature of 100  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                                                           
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                                    Attenuation--1310 nm dB/km                                           Attenuation--1550 nm dB/km                     
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                                                            Heat Aging Test--Multimode Cable                                                            
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                                                           Heat Aging Test--Combination Cable                                                           
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                        Attenuation--1310 nm dB/km                     Attenuation--1550 nm dB/km                         Bandwidth MHz-km              
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                                                      Temperature/Humidity Test--Single Mode Cable                                                      
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                                    Attenuation--1310 nm dB/km                                           Attenuation--1550 nm dB/km                     
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                                                       Temperature/Humidity Test--Multimode Cable                                                       
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                                        Attenuation--1300 nm dB/km                                              Bandwidth MHz-km                        
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                                                      Temperature/Humidity Test--Combination Cable                                                      
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                        Attenuation--1310 nmdB/km                       Attenuation--1550 nm dB/km                         Bandwidth MHz-km             
  Fiber No.  -------------------------------------------------------------------------------------------------------------------------------------------
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                                                      Temperature Cycling Test--Single Mode Cable                                                       
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                                    Attenuation--1310 nm dB/km                                           Attenuation--1550 nm dB/km                     
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                                                          Temperature Cycling--Multimode Cable                                                          
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                                                       Temperature Cycling Test Combination Cable                                                       
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                         Attenuation--1310 nmdB/km                     Attenuation--1550 nm dB/km                          Bandwidth MHz-km             
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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