Section 43.1. Definitions

The following words and terms, when used in this subchapter, have the following meanings, unless the context clearly indicates otherwise:

Blaster—Any person designated by the superintendent to supervise blasting operations who shall be charged with the responsibility of properly thawing explosives, preparing and fixing charges, firing and approaching misfires.

Bulkhead—A longitudinal or transverse partition separating the tunnel into sections or chambers.

Caisson—A wood, steel, concrete, or reinforced concrete air and watertight chamber in which it is possible for men to work to excavate material.

Carrying capacity—Carrying a capacity of a given wire as prescribed for various insulated wires in Chapter 39, Subchapter B (relating to electric safety).

Constructor—The person, firm, or body corporate in immediate control of the construction of any tunnel or its accessories, and as such responsible for the condition and management thereof.

Difference of potential—The difference of electrical potential, as determined by a voltmeter, existing between any two points of an electrical system or between any point of such a system and the earth.

Employe or person employed—Any person receiving compensation for labor or services performed on the works.

Explosive—Any compound or mixture containing any ingredients in such proportions, quantities, or packing that an ignition of any part of the compound or mixture may cause pressures capable of destroying life, limb or contiguous objects.

Flammable—aterial which readily ignites or burns.

Foreman—A person in charge of a subdivision of work or of the entire work and under the instructions of the superintendent.

Grounding—Connecting any part of an electrical system to the earth so that there is no material difference of potential between such part and the earth.

Guarded, encased, or enclosed—An object so covered, fenced or surrounded that contact at the point of danger is remote.

High voltage supply—The supply of electricity if the difference of potential between any two points of the circuit may at any time exceed 650 volts.

Lock—A chamber designed to facilitate the passage of men and materials from an air pressure greater than normal, as in a compartment, caisson or tunnel, to the ground or water level or normal air pressure. This term shall include the following:

(i) Emergency lock—A lock designed to hold and permit the quick passage of an entire shift.

(ii) Man lock—A lock through which only men pass.

(iii) Medical lock—A lock to which men suffering from compressed air diseases (bends) may be removed for medical attention.

Low voltage supply—The supply of electricity if the difference of potential between any two points of the circuit does not exceed 300 volts.

Magazine—Any building or other structure or place in which explosives are stored or kept, whether above or below ground.

Medium voltage supply—The supply of electricity if the difference of potential between any two points of the circuit may, at any time, exceed 300 volts, but which shall not exceed 650 volts.

Nuisance—Any horseplay or any offensive or obnoxious practice that endangers the lives, limbs, or health of persons employed.

Person—A firm or corporation as well as natural persons.

Potential or voltage—Electrical pressure.

Potential of a circuit—The potential normally existing between the conductors of such circuit or the terminals of such machines or apparatus.

Shaft—An excavation made from the surface of the ground, the longer axis of which is steeper than 45° with the horizontal.

Shafting—An air and watertight shaft built in the roof of the caisson and extended upward until above the normal water level.

Superintendent—The person resident on the work having general supervision and responsibility.

Tunnel—A subterranean passage or chamber.

Tunnel heading—The section of a tunnel where excavation work for driving the tunnel is being carried on.

Underground—Within the limits of any shaft or tunnel.

Underground station—Any place where electrical machinery is permanently installed in the tunnel.

Works—Any or all parts of a tunnel excavated or being excavated as well as shafts and approaches, powerhouses, lumberyards, storage yards and structures of all kinds in the immediate vicinity used in connection with the excavation or the immediate disposal of excavated material or in connection with the construction of the tunnel lining.