2718
THE NEW ZEALAND GAZETTE.
No. 89

(h.) Where the cables in levels or main haulage-roads cannot be kept at least 1 ft. from any part of the truck or tram, they shall be specially protected. When separate cables are used they shall, if reasonably practicable, be fixed on opposite sides of the road.

The fixing with metallic fastenings of cables and wires not provided with metallic covering to walls or timbers is prohibited.

Where main or other roads are being repaired, or blasting is being carried out, suitable temporary protection must be used, so that the cables are reasonably protected from damage.

(i.) Trailing cables for portable machines shall be specially flexible, heavily insulated, and protected with either galvanised steel-wire armouring, extra stout braiding, hose-pipes, or other effective covering. Trailing cables shall be examined at least once in each shift by the person in charge of the machine, and any defects in them promptly repaired.

Except as hereinafter provided, at points where the flexible conductors are joined to the main cables, a fixed terminal box must be provided, and a switch shall be fixed close to or in the terminal box capable of entirely cutting off the supply from the terminal box and motor.

Suitable clips may, however, be used for the temporary connection of portable motors where the voltage does not exceed low pressure.

V. Switches, Fuses, and Cut-outs.

(a.) Fuses and automatic cut-outs shall be so constructed as effectively to interrupt the current when a short circuit occurs, or when the current through them exceeds by 200 per cent. the working-current in the case of motors, or by 100 per cent. the permissible current of the cables which the fuses protect. Fuses shall be stamped or marked, or shall have a label attached indicating the current with which they are intended to be used, or, where fuse-wire is used, each coil in use shall be so stamped or labelled. Fuses shall only be adjusted or replaced by an authorised person.

(b.) All switches, fuses, and cut-outs must have incombustible bases of marble, slate, or porcelain. All live parts of switches, fuses, and cut-outs not in machine-rooms, or in compartments specially arranged for the purpose, must be covered. These covers must be of incombustible material, and must be either non-conducting or of rigid metal, and, as far as practicable, clear of all internal mechanism.

(c.) Except as provided in Regulation IV, (i), all points at which a circuit other than those for signals has to be made or broken shall be fitted with proper switches. The use of hooks or other makeshifts is prohibited.

VI. Motors.

(a.) All motors, together with their starting resistances, shall be protected by switches capable of entirely cutting off the pressure and fixed in a convenient position near the motor, and every motor of 50-horse power or over in a machine-room underground shall be provided with a suitable ammeter to indicate the load put upon the machine.

(b.) Where the unarmoured cables or wires pass through metal frames or into boxes or motor-casings, the holes must be substantially bushed with insulating bushes, and, where necessary, with gas-tight bushings which cannot readily become displaced.

(c.) Terminal boxes or portable motors must be securely attached to the machine, or be designed to form a part thereof.

(d.) The casing or inspection-doors of all portable motors used underground, and the casings of their switches and other appliances, shall at least once a week be opened by a competent person appointed by the manager, and the parts so disclosed shall be cleaned and examined before the coverings are replaced. In special cases requiring a motor to run continuously longer than one week, the motor shall be examined at the end of the run. A report of all such examinations shall be entered in a report-book.

(e.) The person in charge of a drilling-machine shall not leave the machine while it is working, and shall, before leaving the working-place, see that the current is cut off from the trailing cables. No repairs shall be made to any portable machine until the pressure has been cut off from the trailing cables.

(f.) If, owing to any defect, any electric sparking or arc be produced outside a portable motor or by the cables or rails, the machine shall be stopped and not be worked again until the defect is repaired, and the occurrence shall be reported to an official of the mine.

VII. Electric Locomotives.

When electrical haulage by locomotives upon the trolley-wire system is used underground, no pressure exceeding the limits of low pressure shall be employed, except where an alternative road for travelling is provided, when medium pressure may be used.

In underground roads the trolley-wires must be placed so that they are at least 7 ft. above the level of the road or track, or the pressure must be cut off from the wires during such hours as the roads are used for travelling on foot in places where trolley-wires are fixed. The hours during which travelling on foot is permitted shall be clearly indicated by notices and signals placed in a conspicuous position at the ends of the roads. At other times no one other than a duly authorised person shall be permitted to travel on foot along the road.

When the current is on, no person shall be allowed to travel along a level or other underground excavation with any tool which, when carried on the shoulder, is of sufficient length to come into contact with the bare wires overhead.

On this system either insulated returns or uninsulated metallic returns of low resistance may be employed.

VIII. Electric Lighting.

(a.) Arc lamps shall only be used after written consent has been obtained from the Minister. They shall be so guarded as to prevent pieces of ignited carbon falling from them, and shall not be used in situations where there is likely to be danger of fire in consequence of their use. They shall be so screened as to prevent risk of contact with persons. The Minister may at any time withdraw the consent given under this regulation.

(b.) Small wires for lighting-circuits must be either conveyed in pipes or casings, or suspended from porcelain insulators, or tied to them with some non-conducting material which will not cut the covering, and so that they do not touch any timbering or metal-work. On no account must staples be used. If metallic pipes are used, they must be electrically continuous and earthed. If separate uncased wires are used, they must be kept at least 2 in. apart, and not brought together except at lamps, or switches, or fittings.

(c.) In all machine-rooms and other places underground, where a failure of electric light is likely to cause danger, some other suitable lights shall be kept for use in the event of such failure.

IX. Shot-firing.

Electricity from lighting or power cables shall not be used for firing shots.

When shot-firing cables or wires are used in the vicinity of power or lighting cables, sufficient pre-