Safety Standards for Roof Bolts in Metal and Nonmetal Mines and Underground Coal Mines

DEPARTMENT OF LABOR

Mine Safety and Health Administration

30 CFR Parts 56, 57, and 75

RIN 1219-AB00

Safety Standards for Roof Bolts in Metal and Nonmetal Mines and

Underground Coal Mines

AGENCY: Mine Safety and Health Administration, Labor.

ACTION: Proposed rule.

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SUMMARY: The Mine Safety and Health Administration (MSHA) is revising

its safety standards for roof and rock bolts at metal and nonmetal

mines and underground coal mines by updating the reference to the

American Society for Testing and Materials (ASTM) standard for roof and

rock bolts and accessories. The new reference reflects technological

advances in the design of roof and rock bolts and support materials. It

would improve the level of protection provided by the standards

currently in use.

DATES: Submit written comments on or before June 27, 1997. Submit

written comments on the information collection requirements by June 27,

1997.

ADDRESSES: Send written comments on this proposed rule to the Mine

Safety and Health Administration, Office of Standards, Regulations, and

Variances, 4015 Wilson Boulevard, Room 631, Arlington, Virginia 22203.

Commenters are encouraged to send comments on a computer disk or via e-

mail to [email protected], along with an original hard copy. Submit

written comments on the information collection requirements to the

Office of Information and Regulatory Affairs, OMB, New Executive Office

Bldg., 725 17th St. NW., Room 10235, Washington, DC 20503, Attn: Desk

Officer for MSHA.

FOR FURTHER INFORMATION CONTACT: Patricia W. Silvey, Director; Office

of Standards, Regulations, and Variances, MSHA; phone: 703-235-1910,

fax: 703-235-5551.

SUPPLEMENTARY INFORMATION:

I. Paperwork Reduction Act

On August 29, 1995, the Office of Management and Budget (OMB)

published a final rule in the Federal Register (60 FR 44978)

implementing the new Paperwork Reduction Act of 1995 (PRA 95).

Consistent with PRA 95, these OMB rules expanded the definition of

``information'' to clarify that a ``certification'' would involve the

collection of ``information'' if the Agency used it to monitor

compliance. Mine operators currently are required to obtain a

certification statement that the testing and manufacture of roof and

rock bolts comply with the specified standard, and to keep a copy of

this certification statement so that it can be made available to

miners' representatives and representatives of the Secretary of Labor

(the Secretary). Although the proposed rule would not change this

requirement, it is now considered an information collection burden

because of the expanded definition of ``information'' under PRA 95. The

burden hours and costs associated with roof bolt certifications,

therefore, do not reflect any increase for the mining industry.

The collection of information contained in this proposal is subject

to review by OMB under the PRA 95. The title, description, and

respondent description of the information collection are discussed

below with an estimate of the annual information collection burden.

Included in the estimate is the time to obtain the manufacturer's

signature and file the form.

With respect to the following collection of information, MSHA

invites comments on: (1) Whether the proposed collection of information

is necessary for proper performance of MSHA's functions, including

whether the information will have practical utility; (2) the accuracy

of MSHA's estimate of the burden of the proposed collection of

information, including the validity of the methodology and assumptions

used; (3) ways to enhance the quality, utility, and clarity of the

information to be collected; and (4) ways to minimize the burden of the

collection of information on respondents, including through the use of

automated collection techniques, when appropriate, and other forms of

information technology.

Description: Sections 56.3203(a)(1), 57.3203(a)(1), and

75.204(a)(1) would require the mine operator to obtain a manufacturer's

certification that the material was manufactured and tested in

accordance with the specifications of ASTM F432-95. Sections

56.3203(a)(2), 57.3203(a)(2), and 75.204(a)(2) require that the

certification be made available to an authorized representative of the

Secretary. MSHA estimates that it would take the mine operator about 3

minutes to obtain a signature and file the form. Agency experience has

shown that major roof and rock bolt manufacturers routinely provide a

certification to mine operators at the time of the initial contract and

update the certification annually. Smaller manufacturers provide a

certification at the time of initial contract and upon request from the

mine operator.

Description of Respondents: The respondents are mine operators.

MSHA estimates that this provision annually affects 653 surface metal

and nonmetal mines; 185 underground metal and nonmetal mines; and 973

underground coal mines.

Information Collection Burden: The total estimated annual

information collection burden for surface metal and nonmetal mines is

about 33 hours at an estimated annual cost of about $1,180. The total

estimated annual information collection burden for underground metal

and nonmetal mines is about 9 hours at an estimated annual cost of

about $330. The total estimated annual information collection burden

for underground coal mines is about 49 hours at an estimated annual

cost of about $2,040.

The following chart summarizes MSHA's estimates by section.

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Number of

Regulation in 30 CFR Number of Hours per Number of responses per Annual costs Total hours

respondents response responses respondent per regulation

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56.3203(a)(1)........................................... 653 0.05 653 1 $1,175 32.65

57.3202(a)(1)........................................... 185 0.05 185 1 333 9.25

75.204(a)(1)............................................ 973 0.05 973 1 2,043 48.65

Total............................................. 1,811 0.05 1,811 1 3,551 90.55

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The burden hours and costs associated with roof bolt certifications do

not reflect any increase for the mining industry because mine operators

currently are required to perform these activities.

Under section 3507(o) of PRA 95, the Agency has submitted a copy of

this proposed rule to OMB for its review and approval of these

information collections. Interested persons are requested to send

comments regarding

[[Page 22999]]

these burden estimates or any other aspect of these collections of

information, including suggestions for reducing these burdens, (1)

directly to the Office of Information and Regulatory Affairs, OMB;

Attention: Desk Officer for MSHA; 725 17th Street NW., Room 10235;

Washington, DC 20503, and (2) to Patricia W. Silvey, Director; Office

of Standards, Regulations, and Variances, MSHA; 4015 Wilson Boulevard,

Room 631; Arlington, VA 22203.

II. Background

A. Metal and Nonmetal Mines

On October 8, 1986, MSHA published a final rule (51 FR 36194)

revising its safety standards for ground control at metal and nonmetal

mines. This rulemaking included comprehensive rock bolt standards in

Title 30 Code of Federal Regulations (CFR) Secs. 56/57.3203 which

addressed the quality of rock fixtures and their installation. Roof and

rock bolts and accessories are an integral part of ground control

systems and are used to prevent the fall of roof, face, and ribs.

Accidents involving falls of roof in underground mines or falls of

highwall in surface mines have resulted in injuries and fatalities.

These standards currently require that metal and nonmetal mine

operators obtain a certification from the manufacturer that rock bolts

and accessories are manufactured and tested in accordance with the 1983

American Society for Testing and Materials (ASTM) publication

``Standard Specification for Roof and Rock Bolts and Accessories''

(ASTM F432-83). The ASTM standard for roof and rock bolts and

accessories is a consensus standard used throughout the United States.

It contains specifications for the chemical, mechanical, and

dimensional requirements for roof and rock bolts and accessories used

for ground support systems.

The manufacturer's certification is made available to an authorized

representative of the Secretary to attest to the appropriate testing

and manufacture of the rock bolts and accessories. Requiring that the

mine operator obtain a certification from the manufacturer assures mine

operators that the material they use meets technical requirements

established to promote safety.

B. Underground Coal Mines

MSHA published a final rule on February 8, 1990, (55 FR 4592)

revising paragraphs (a) and (b) of Sec. 75.204. This standard

references ASTM publication ``Standard Specification for Roof and Rock

Bolts and Accessories'' (ASTM F432-88), which was the most recent

revision available at that time. The final rule also requires mine

operators to obtain a certification from the manufacturer that roof

bolts and accessories are manufactured and tested in accordance with

ASTM F432-88. To comply with this rule, mine operators are required to

provide the certification document, upon request, to an authorized

representative of the Secretary to establish that their roof bolts are

designed and tested in accordance with the ASTM standard.

This reference to the ASTM standard performs the same function as

the reference to the 1983 ASTM standard for metal and nonmetal mining

application. That is, the certificate assures mine operators that the

material they use meets technical requirements established to promote

safety.

III. Discussion

MSHA has found that the existing certification requirement has been

successful in maintaining compliance with requirements for roof and

rock bolts and accessories. MSHA is proposing to retain the

certification requirement and to update existing Secs. 56.3203,

57.3203, and 75.204 by replacing the references to outdated ASTM F432-

83 and ASTM F432-88 with a new reference to ASTM F432-95.

MSHA participated in the development of ASTM F432-95 through active

representation at meetings of the American Mining Congress (predecessor

organization to the National Mining Association) Roof Support Group. It

was that committee that prepared the revised document for consideration

by ASTM. The committee was open to all manufacturers of roof and rock

bolts and accessories, and considered comments from all participants in

developing the new specifications. MSHA Technical Support personnel

conducted both laboratory and field studies which provide supporting

data for the various changes. This proposed rulemaking has been

followed closely by the National Mining Association, the United Mine

Workers of America, and the United Steelworkers, and the Agency does

not anticipate any opposition.

MSHA is updating the standards because the Agency believes that

ASTM F432-95 is more comprehensive than those referenced in existing

standards, that it reflects advances in rock and roof bolt technology,

and that it would provide better protection for miners than the

standards currently in place. As discussed below, these revisions will

not reduce the protection afforded miners by the MSHA standards

currently in place.

A. New Products Addressed

ASTM F432-95 covers products not addressed by the current standards

including grouting materials, large diameter bolts, thread deformed

bars, and formable anchorage devices.

1. Grouting Materials

Grouting materials, which were not addressed by either ASTM F432-88

or ASTM F432-83, are extensively covered by ASTM F432-95. The term

``grouting materials'' is used in ASTM F432-95 to include any chemical

materials (such as polyester, polyurethane, or epoxy resins) that are

used to anchor mine roof bolts. While grouted bolts have been used

successfully to support mine roofs since the 1970's, each manufacturer

has a different method to describe proper application of grouting

materials and their performance characteristics. This lack of

standardization has caused confusion and occasional misapplication of a

particular grout formulation and, therefore, has resulted in improperly

grouted boreholes. Improperly grouted boreholes can result in poor bolt

performance and, potentially, an inadequately supported roof. A survey

of MSHA field personnel revealed that improper borehole grouting has

been a contributing factor in roof fall accidents. Under ASTM F432-95,

there are specific requirements regarding strength, cure rate,

cartridge volume, and labeling that will standardize the production and

application of grouting materials and reduce the likelihood that

grouted bolts will be improperly installed.

2. Large Diameter Bolts

Similarly, large diameter bolts, ranging in size from 1\1/8\ inch

to 1\1/2\ inch, are now addressed by ASTM F432-95. MSHA field personnel

report that these large diameter bolts are growing in popularity and

are being used in areas of adverse roof conditions where smaller

diameter bolts would fail. ASTM F432-95 provides standard strength and

thread tolerance limits that ensure minimum performance levels and the

interchangeability of components produced by different manufacturers.

Compatibility is essential in ensuring that components acquired from

different sources function properly when used together, such as

mechanical anchors from one manufacturer and bolts from another, and

provide an adequate margin of safety.

3. Thread Deformed Bars and Formable Anchorage Devices

Two new technologies, thread deformed bars and formable anchorage

[[Page 23000]]

devices, also are addressed by ASTM F432-95. These bolting systems were

not in use at the time ASTM F432-83 and ASTM F432-88 were adopted; but,

their effectiveness has been demonstrated at a number of mines, which

has led MSHA to approve their use in roof control plans. ASTM F432-95

provides specific manufacturing, strength, and identification

requirements for these products to ensure that minimum performance

levels are met and that reliable products are available to the mine

operator. Updating the roof control standards which reference the ASTM

specifications covering these systems would reduce the time required by

mine operators to receive approval to use these devices in the roof

control plan, and eliminate the need for repetitive and time consuming

underground tests.

B. Additional Safety Benefits

ASTM F432-95 provides a number of additional safety benefits,

including strength standards for couplers, tolerances for external and

internal threads, dimensions for hardened washers, and bolt grading and

identification systems.

1. Couplers

Couplers are devices which connect two bolt sections. ASTM F432-95

increases the strength standard for couplers and requires couplers to

withstand the full breaking loads of the bolts with which they are

used. In comparison, ASTM F432-88 requires only that couplers support

the minimum yield and tensile loads of the connected bolts. In

practice, roof bolt strengths often exceed the minimum strength

requirements of ASTM F432-88 by a substantial margin, often in excess

of 8,000 pounds. The new coupler requirements will ensure that the full

strength of the bolting system is achieved and that catastrophic bolt

failure, through premature coupler breakage, is prevented.

2. Internal and External Threads

New tolerances have been established under ASTM F432-95 for both

external threads primarily used for bolts, as well as internal threads

used in couplers, anchor plugs, and nuts. MSHA experience indicates

that the current thread tolerances of ASTM F432-88 and ASTM F432-83 are

relatively tight and have been linked to thread seizure problems

occasionally experienced during the installation of tensioned roof

bolts. Thread seizure or binding can be caused by expansion anchor

compression on bolt threads or the jamming of threads by small metal

shards produced during the planned shearing of torque inhibiting pins

or plugs. Thread seizure during roof bolt installation can

significantly influence the torque-tension relationship. In turn, the

torque check required by Secs. 56.3203(f)(2), 57.3203(f)(2), and

75.204(f) (3), (4), and (5) may not indicate bolt tension accurately

and, thus, fail to detect bolt installations that are not in compliance

with those standards. The revised requirements of ASTM F432-95 would

allow a slightly looser fit between mating threads (0.003 inch), which

would reduce the possibility of thread seizure without affecting the

strength of the component parts. The net result would be the improved

reliability of roof bolt installations through more consistent bolt

tensioning.

3. Hardened Washers

ASTM F432-95 provides revised dimensions and tolerances for

hardened washers that are used to enhance the uniformity of installed

roof bolt tension. Current dimensions listed in ASTM F432-83 and ASTM

F432-88 are such that it is impossible to use hardened washers with

many deformed bars because the center hole dimensions are too small. In

addition, the restricted outside diameter (2 inches nominal) prevents

the effective use of hardened washers with large diameter bolts (i.e.,

1\1/2\ inch diameter) because of the grossly reduced bearing surface.

The revised hardened washer dimensions of ASTM F432-95 are compatible

with the bolts currently in use and ensure that the benefits of uniform

bolt tension can be achieved with those systems.

4. Uniform Grading Systems

ASTM F432-95 also contains a revised bolt grading system that would

cover existing products and establish grade intervals for high strength

bolts that may be developed in the future. The current reference

standards of ASTM F432-83 and ASTM F432-88 are limited to grades

currently in use. This essentially precludes the immediate use of

higher strength bolts. The use of higher strength bolts now requires

often unnecessary and time consuming tests to allow for MSHA approval

of these bolts for use in an individual mine.

In addition, the current system uses a single symbol for bolt head

identification to designate both grade and diameter. Given the variety

of bolting systems in use (\5/8\, \3/4\, \7/8\, 1, and 1\1/8\ inch

diameters; grades 40, 55, 60, 75; plain and rebar bolts), a large

number of symbols are used. Consequently, under the current system,

identifying the grade and diameter of a bolt used underground, from the

bolt head, has become difficult and extremely confusing. This increases

the potential for the inadvertent use of bolt types either not

prescribed by the roof control plan or not suitable for the roof

conditions encountered. The revised grading and identification system

of ASTM F432-95 would allow for the introduction of new high strength

bolting systems and make it easier for miners to verify the grade and

diameter of the bolts in use by looking at the bolt head.

A grading system also has been established in ASTM F432-95 for

threaded tapered plugs used in expansion anchors that specify minimum

non-seizure and non-stripping loads for the bolt and plug threads. This

system would enable mine operators to select expansion anchors with

strength characteristics that are compatible with the bolting system in

use, and ensure that thread seizure will not occur during bolt

installation.

5. Low Strength Bolts

Finally, ASTM F432-95 would eliminate the use of low strength grade

30 bolts permitted by both ASTM F432-83 and 88, and delete certain

chemical and grade requirements contained in those versions that

unnecessarily restrict new technology. As a result, ASTM F432-95,

through its improved specifications, would provide additional safety to

miners as compared to the current specifications.

MSHA expects that the elimination of the use of grade 30 bolts

would not adversely impact the mining industry. MSHA allows a year for

mine operators to use existing inventory. Further, MSHA experience

indicates that the majority of mine operators are no longer using the

30 grade bolts and that they are no longer being manufactured.

C. Existing Inventory

This proposal would allow mine operators to use inventories of roof

support components meeting the design criteria of ASTM F432-83 and ASTM

F432-88 for up to one year from the effective date of the final rule.

After that year, only roof support components meeting ASTM F432-95

would be permitted to be installed. This one-year period will not

result in a diminution of safety to miners and will allow mine

operators, including small mines and seasonal operations, to exhaust

existing supplies of roof support materials on site. It also would

allow miners who use roof support materials to become sufficiently

trained in the use of roof bolts and accessories that meet the

requirements of ASTM F432-95. MSHA

[[Page 23001]]

specifically solicits comments from the mining community as to the

suitability of this time period. MSHA is proposing that mine operators,

however, could start using components meeting the ASTM F432-95 standard

upon the effective date of the final rule.

MSHA also believes that the one-year time period gives sufficient

time for roof bolt manufacturers to consume present tooling, exhaust

inventories of products meeting current specifications, and produce and

make available to mine operators quantities of roof bolts meeting the

design criteria of ASTM F432-95. MSHA specifically solicits comments

from the mining community on whether this time period is adequate to

supply mine operators with the kind and quantity of roof bolts needed.

IV. Executive Order 12866 and Regulatory Flexibility Act

Executive Order 12866 requires that regulatory agencies assess both

the costs and benefits of proposed regulations. MSHA estimates that the

cost impact of the proposed rule is the same as under the existing

rule. The primary benefit of the proposed rule is that it provides for

advancements in roof bolt technology and, therefore, would increase

protection for miners. MSHA has determined that this proposed rule does

not meet the criteria of a significant regulatory action and,

therefore, has not prepared a separate analysis of costs and benefits.

The analysis contained in this preamble meets MSHA's responsibilities

under Executive Order 12866 and the Regulatory Flexibility Act.

The Regulatory Flexibility Act (RFA) requires regulatory agencies

to consider a rule's impact on small entities. Under the RFA, MSHA must

use the Small Business Administration (SBA) definition for a small mine

of 500 or fewer employees or, after consultation with the SBA Office of

Advocacy, establish an alternative definition for the mining industry

by publishing that definition in the Federal Register for notice and

comment. MSHA traditionally has considered small mines to be those with

fewer than 20 employees. For the purposes of the RFA and this

certification, MSHA has analyzed the impact of the proposed rule on all

mines, on those with fewer than 20 employees, and on those with fewer

than 500 employees, and has concluded that there is no cost impact on

the mining industry.

The Agency has provided a copy of this proposed rule and regulatory

flexibility certification statement to the SBA Office of Advocacy. In

addition, MSHA will mail a copy of the proposed rule, including the

preamble and regulatory flexibility certification statement, to all

affected mine operators.

Regulatory Flexibility Certification

In accordance with section 605 of the RFA, MSHA certifies that this

proposed rule would not have a significant economic impact on a

substantial number of small entities. No small governmental

jurisdictions or nonprofit organizations are affected.

Under the Small Business Regulatory Enforcement Fairness Act

(SBREFA) amendments to the RFA, MSHA must include in the proposed rule

a factual basis for this certification. The Agency also must publish

the regulatory flexibility certification in the Federal Register, along

with its factual basis.

Factual Basis for Certification

MSHA has used a qualitative approach in concluding that the

proposed rule would not have a significant economic impact on a

substantial number of small entities. MSHA anticipates that the cost of

purchasing roof and rock bolts and accessories would not increase as a

result of the proposed requirement that they meet the new ASTM

specification (ASTM F432-95). This ASTM standard incorporates

technological advances that are currently available and being used by

the mining industry. Although MSHA does not expect any cost increases

as a result of this proposed rule, there may be minimal costs which the

Agency is not able to predict at this time. For this reason, MSHA

solicits comments from the mining industry, especially small mines and

roof bolt manufacturers, as to the impact of the proposed rule, both

costs and benefits. With respect to costs, the Agency requests that

commenters provide supporting information.

V. Unfunded Mandates Act

For purposes of the Unfunded Mandates Reform Act of 1995, as well

as E.O. 12875, this proposed rule does not include any Federal mandate

that may result in increased expenditures by State, local, and tribal

governments, or increased expenditures by the private sector of more

than $100 million.

List of Subjects

30 CFR Parts 56 and 57

Mine safety and health, Surface mining, Underground mining.

30 CFR Part 75

Coal, Mine safety and health, Underground mining.

Dated: April 17, 1997.

J. Davitt McAteer,

Assistant Secretary for Mine Safety and Health.

For the reasons set out in the preamble, MSHA proposes to amend

chapter I of title 30 of the Code of Federal Regulations as follows:

PART 56--SAFETY AND HEALTH STANDARDS--SURFACE METAL AND NONMETAL

MINES

1. The authority citation for part 56 continues to read as follows:

Authority: 30 U.S.C. 811.

2. Section 56.3203 is amended by revising the introductory text of

paragraph (a), paragraph (a)(1), and the introductory text of paragraph

(b) to read as follows:

Sec. 56.3203 Rock fixtures.

(a) On and after April 28, 1998, for rock bolts and accessories

addressed in ASTM F432-95, ``Standard Specification for Roof and Rock

Bolts and Accessories,'' the mine operator shall--

(1) Obtain a manufacturer's certification that the material was

manufactured and tested in accordance with the specifications of ASTM

F432-95; and

(2) * * *

(b) Fixtures and accessories not addressed in ASTM F432-95 may be

used for ground support provided they--

* * * * *

PART 57--SAFETY AND HEALTH STANDARDS--UNDERGROUND METAL AND

NONMETAL MINES

3. The authority citation for part 57 continues to read as follows:

Authority: 30 U.S.C. 811.

4. Section 57.3203 is amended by revising the introductory text of

paragraph (a), paragraph (a)(1), and the introductory text of paragraph

(b) to read as follows:

Sec. 57.3203 Rock fixtures.

(a) On and after April 28, 1998, for rock bolts and accessories

addressed in ASTM F432-95, ``Standard Specification for Roof and Rock

Bolts and Accessories,'' the mine operator shall--

(1) Obtain a manufacturer's certification that the material was

manufactured and tested in accordance with the specifications of ASTM

F432-95; and

(2) * * *

(b) Fixtures and accessories not addressed in ASTM F432-95 may be

[[Page 23002]]

used for ground support provided they--

* * * * *

PART 75--MANDATORY SAFETY STANDARDS--UNDERGROUND COAL MINES

5. The authority citation for part 75 continues to read as follows:

Authority: 30 U.S.C. 811.

6. Section 75.204 is amended by revising the introductory text of

paragraph (a), paragraph (a)(1), and the introductory text of paragraph

(b) to read as follows:

Sec. 75.204 Roof bolting.

(a) On and after April 28, 1998, for roof bolts and accessories

addressed in ASTM F432-95, ``Standard Specification for Roof and Rock

Bolts and Accessories,'' the mine operator shall--

(1) Obtain a manufacturer's certification that the material was

manufactured and tested in accordance with the specifications of ASTM

F432-95; and

(2) * * *

(b) Roof bolts and accessories not addressed in ASTM F432-95 may be

used, provided that the use of such materials is approved by the

District Manager based on--

* * * * *

[FR Doc. 97-10722 Filed 4-25-97; 8:45 am]

BILLING CODE 4510-43-P