Okla. Stat. tit. 45, § 45-518: Ventilating fans and doors

All ventilating fans shall be kept in operation night and day

unless operations are indefinitely suspended, except written

permission is given by the mine inspector of the district to stop

the same, and the said written permission shall state the particular

hours the said fan may not be in operation, and the mine inspector

shall have the power to withdraw or modify such permission as he may

deem best, but in all cases the fan shall be started three (3) hours

before the time for work to begin, and such written permission to

stop the fan shall not apply to fans in use at mines wherein

explosive gas is generated. When the fans may be stopped by the

permission of the mine inspector, a notice printed in the various

languages used by persons employed in the mine, stating at what

hours the fan will be stopped and the time it will again be set in

motion, shall be posted by the mine foreman in a conspicuous place

at the entrance or entrances to the mine: Provided, that should it

at any time become necessary to stop the fan on account of accident

or needed repairs to any part of the machinery connected therewith,

or by reason of any other unavoidable cause, it shall then be the

duty of the mine foreman, or any other official in charge, after

first having provided for the safety of the persons employed in the

mine, to order said fan to be stopped so as to make the necessary

repairs or to remove any other difficulty that may have been the

cause of its stoppage, and all ventilating furnaces in mines shall

be started three (3) hours before the appointed time to begin work

and during working hours be properly attended by a person employed

for that purpose; in mines generating fire damp in sufficient

quantities to be detected by the ordinary safety lamps, all main

breakthroughs between slopes and aircourses, airbridges or overcasts

shall be built of masonry or other noncombustible material of ample

strength, or be driven through the solid strata. In all mines the

doors used for guiding and directing the ventilation of the mine

shall be so hung and adjusted that they will close themselves, or be

supplied with springs or pulleys so that they cannot be left

standing open, and an attendant shall be employed at all doors,

through which cars are hauled, for the purpose of opening and

closing said doors when trips of cars are passing to and from the

workings, unless approved selfacting doors are used which doors

shall be determined by the mine inspector and mine foreman. A hole

for shelter shall be provided at each door, so as to protect said

attendant from being run over by the cars while attending to his

duties; and persons employed for this purpose shall at all times

remain at their post of duty during working hours: Provided, that

the same person may attend two doors where the distance between them

is not more than one hundred (100) feet. At all principal doors and

every inclined plane or roadway in any mine where haulage is done by

machinery, and where a door is used, an extra door shall be provided

to be used in case of necessity.