California Code of Regulations › Title 8 - Industrial Relations › Division 1 - Department of Industrial Relations › Chapter 4 - Division of Industrial Safety › Subchapter 20 - Tunnel Safety Orders › Article 2 - Definitions › Section 8405 - Definitions

Current through Register 2024 Notice Reg. No. 28, July 12, 2024
The following definitions shall apply in the application
						of these orders.
Acceptable. Acceptable to the Division.
Access Shaft. A shaft used as a regular means of worker
						access to or from underground operations.
Air Supply Lines. Pipe, hose, or combination of pipe and
						hose, that supplies compressed air to equipment.
Approved. Those products, devices, systems, or
						installations meeting the requirements of Section
						3206 of the General Industry Safety
						Orders.
Automatic Coupler. A connecting device between rail
						equipment that automatically engages when one car strikes another.
Back. The roof, ceiling or arch of a tunnel.
Barricade. To obstruct by use of planking, sawhorses,
						etc., placed around an excavation, sump, shaft or drop off to prevent entry of
						persons, vehicles or flying materials.
Barrier. A fence, wall or other structure built to bar
						passage with openings no greater than 2 inches.
Barricade Natural. Natural features of the terrain such
						as hills.
Block System. A switching system which prevents trains
						from entering specific sections of track occupied by another train.
Brakeman. An employee who performs switching, loading, or
						other train operations and assists the motorman.
Bulkhead. A tight partition, brattice or stopping in a
						tunnel, raise, or shaft.
California Switch. A movable switching track resting on
						top of the regular track upon which trains can be diverted for passing.
Car Passer. A device by which rail equipment can be moved
						to one side of the regular tunnel track to permit passage of the train or for
						other purposes.
Chamber. An opening, room, or vault excavated completely
						or partially underground which may be open to the surface at the top or
						connected to the surface by a tunnel or shaft.
Cherry Picker. A lifting device used to pick up muck cars
						or other equipment, from the track so as to set it to one side or raise it high
						enough for passage on the track of trains or equipment.
Combustible. Capable of being ignited and consumed by
						fire. Wherever combustible substances or materials are mentioned in these
						Orders, flammable and extremely flammable substances and materials are
						included.
Certified Person. A person certified by the
						Division.
Competent Person. One who is capable of identifying
						existing and predictable hazards in the surroundings or working conditions
						which are unsanitary, hazardous, or dangerous to employees, and who has
						authorization to take prompt corrective measures to eliminate them.
Conveyance. A cage, cab, enclosure, bucket conveyor or
						similar device used to lift, hoist or otherwise carry employees and/or
						materials.
Crown. Highest point of a tunnel cross-section.
Crown Bars. Timber or steel beams that extend ahead of
						the jumbo, the last set of timber or rib steel supports for temporary tunnel
						support and protection of workers near the face.
Cut and Cover. A work method which places a temporary
						roof over open excavation while doing further excavation or other work beneath
						the cover.
Division. The Division of Occupational Safety and Health
						(DOSH).
Exhaust Purifying Device (scrubber). Any of a number of
						devices, such as water bath scrubbers or catalytic scrubbers that reduce
						contaminants from internal combustion engine exhausts to an acceptable
						level.
Explosion Relief Mechanism. Explosion-doors, weak-wall,
						panel or other equivalent devices so located to relieve the pressure that would
						be created by an explosion underground and reduce possible damage to a
						ventilation system.
Extremely Flammable. Having a flash point of 20 degrees
						Fahrenheit or less, when tested by the Tagliabue open-cup method.
Face-Underground. That part of any adit, tunnel, or raise
						where excavating is progressing, or was last done.
Fan-Auxiliary. A fan used to provide ventilation or
						circulate air to areas off the main fresh air course.
Fan-Booster. A fan installed in the ventilation system to
						increase the ventilation flow rates of the system.
Fan-Main. A fan or system of fans that are located at the
						surface which controls the primary ventilation of a tunnel or underground
						chamber.
Fire Resistant. Protected against fire by a covering
						equivalent to a one-hour fire resistant covering applied in a manner acceptable
						to the Division.
Fire Resistant Hydraulic Fluids. An approved fluid of
						such chemical composition and physical characteristics that it will resist the
						propagation of flame, or meet the requirements of 30 CFR Part 35.
Flammable. Capable of being easily ignited or burning
						rapidly.
Flammable Gas. A mixture which when once ignited will
						allow flame to be self-propagated throughout the mixture, independent of and
						away from the source of ignition.
Flash Point. The temperature at which a material gives
						off flammable vapor in sufficient quantity to burn instantaneously at the
						approach of a flame or spark.
Ground Support System. Wood, steel, concrete, rock bolts,
						or other materials used for bracing or supporting the ground.
Highway. Any street, alley, or road, publicly or
						privately maintained and open to use for the public for purposes of vehicular
						travel.
Hoist-Material. A hoist for lifting, lowering, or pulling
						materials. It includes tugger-type and slusher.
Hoist, Personnel. A hoist equipped with the necessary
						safeguards to raise or lower personnel as required by Section
						8495(b).
Horsepower-Brake (BHP). The power of an engine or other
						motor as calculated from the force exerted on a friction brake or absorption
						dynamometer applied to the flywheel or the shaft.
Incline. Shaft greater than 20 degrees from the
						horizontal but less than 70 degrees.
Intrinsically Safe. A device or system which is incapable
						of releasing enough electrical or thermal energy under normal or abnormal
						conditions to cause ignition of a mixture of flammable gas and air in its most
						ignitable composition.
Invert. The floor of a tunnel.
Jumbo. A mobile platform or series of platforms, usually
						on wheels, to provide work areas for employees and the machines, tools, or
						materials being used.
Lanyard. A flexible line to secure a wearer of a safety
						belt or harness to a drop line, lifeline, or fixed anchorage.
Laser. Light Amplification by Stimulated Emission of
						Radiation and is used as a coherent beam of light for alignment.
LEL. Lower explosive limit of a flammable gas or
						vapor.
L.P.G. Liquified Petroleum Gas.
Magazine. A building, other than the explosives
						manufacturing building, or other structures especially designed for the storage
						of explosives, or any cave or other structure adapted to the storage of
						explosives.
Mechanical Tunneling Equipment. Equipment such as
						mechanical excavators, tunnel boring machines, shields, roadheaders, and raise
						boring machines.
Motorman. The operator of a locomotive or other similar
						rail mounted equipment.
MSHA. The United States Department of Labor Mine Safety
						and Health Administration.
Muck. Excavated rock, earth or other materials.
Permissible. A machine, material, apparatus, or device
						which has been investigated, tested, and approved by the Mine Safety and Health
						Administration, and is maintained in accordance with the requirements of the
						approving agency.
Personnel or Person. Those persons affected by the
						referenced standard, including those other than employees of the
						employer.
Pneumatic Loader. A device for injecting an explosive or
						blasting agent into a bore hole or other cavity, using compressed air as the
						propulsive force. There are two basic types of air loaders; the pressure vessel
						system that forces the explosive or blasting agent through a loading hose, and
						the ejector system which operates on the venturi principle, in that the
						explosive or blasting agent is sucked out of an open container and carried into
						the bore hole by the air stream.
Qualified Person, Attendant or Operator. A person
						designated by the employer, who by reasons of their training and experience has
						demonstrated their ability to safely perform their duties and, where required,
						is properly licensed and/or certificated in accordance with federal, state or
						local laws and regulations.
Railroad. Any railroad or tramway which carries
						passengers for hire on the particular line or branch in the vicinity where
						explosives are stored, or where explosives-manufacturing buildings are
						situated.
Raise. A vertical or inclined underground excavation
						driven from bottom to top.
Raise Climber. A mechanical powered work platform used to
						provide access to the raise face.
Ramp. A sloping passageway connecting two different
						levels.
Return Air. The portion of the ventilation system between
						the point where fresh air is introduced into the underground environment and
						its point of release into the outside atmosphere.
Safety Factor. The ratio of the ultimate strength of the
						material to the actual working stress or safe load when in use.
Scrubber. A device used on internal combustion engines to
						reduce discharge of harmful exhaust gases. See "exhaust purifying
						device".
Shaft. Any excavation where its depth is at least twice
						its greatest cross section dimension. The sides are nearly parallel or
						cylindrical. A shaft is considered to be vertical if its alignment is within 20
						degrees of vertical. For the purpose of these safety orders, shaft shall
						include incline and raise (also see Incline and Raise).
Shall. Mandatory.
Skip. A shaft conveyance, generally for hoisting muck and
						materials.
Spoil. See "Muck."
Switch. A device for enabling rail-mounted equipment to
						pass from one track to another.
Tunnel. An underground passageway, 30 inches in diameter
						or greater, excavated by employees working below the earth's surface, that
						provides a subterranean route along which employees, equipment or substances
						can move; other than passageways excavated by mine or quarry operators in
						connection with such operations. For the purpose of these safety orders,
						"tunnels" include shafts, raises, underground chambers and premises appurtenant
						thereto.
Two-Block. A condition in hoisting where the load, or
						termination assembly is hoisted to the point of making contact with an
						obstruction normally present in the hoisting system which can result in parting
						of the hoisting cable and damage to the hoisting system. Generally, a condition
						resulting from the load or termination assembly being hoisted under power into
						a headframe assembly or crane boom-tip.
1.
						Amendment of section and new NOTE filed 3-5-96; operative 4-4-96 (Register 96,
						No. 10).
2. Amendment filed 7-11-2003; operative 8-10-2003 (Register
						2003, No. 28).
Note: Authority cited: Sections
						  142.3 and
						  7997, Labor
						  Code. Reference: Sections
						  142.3 and
						  7997, Labor
						  Code.