30 CFR § 75.523-3
Automatic emergency-parking brakes.
(a) Except for personnel carriers, rubber-tired, self-propelled
electric haulage equipment used in the active workings of underground coal
mines shall be equipped with automatic emergency-parking brakes in accordance
with the following schedule.
(a)(1) On and after May 23, 1989--
(a)(1)(i) All new equipment ordered; and
(a)(1)(ii) All equipment originally furnished with or
retrofitted with automatic emergency-parking brakes which meet the
requirements of this section.
(a)(2) On and after May 23, 1991, all other equipment.
(b) Automatic emergency-parking brakes shall--
(b)(1) Be activated immediately by the emergency
deenergization device required by 30 CFR 75.523-1 and
75.523-2;
(b)(2) Engage automatically within 5.0 seconds when the
equipment is deenergized;
(b)(3) Safely bring the equipment when fully loaded to a
complete stop on the maximum grade on which it is operated;
(b)(4) Hold the equipment stationary despite any contraction
of brake parts, exhaustion of any non-mechanical source of energy, or
leakage; and
(b)(5) Release only by a manual control that does not operate
any other equipment function.
(c) Automatic emergency-parking brakes shall include a means in the
equipment operator's compartment to--
(c)(1) Apply the brakes manually without deenergizing the
equipment; and
(c)(2) Release and reengage the brakes without energizing the
equipment.
(d) On and after November 24, 1989, rubber-tired, self-propelled
electric face equipment not covered by paragraph (a) of this section shall be
equipped with a means incorporated on the equipment and operable from each
tramming station to hold the equipment stationary--
(d)(1) On the maximum grade on which it is operated; and
(d)(2) Despite any contraction of components, exhaustion of
any non-mechanical source of energy, or leakage.
(e) The brake systems required by paragraphs (a) or (d) of this
section shall be applied when the equipment operator is not at the controls
of the equipment, except during movement of disabled equipment.
[54 FR 12412, Mar. 24, 1989]