Aug. 5.] THE NEW ZEALAND GAZETTE. 2737

Electric Locomotives.

342. 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 pressure may be employed.

Electric Lighting.

343. 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.

344. 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 metalwork. 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.

345. 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.

Shot-firing.

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

347. When shot-firing cables or wires are used in the vicinity of power or lighting cables, sufficient precautions shall be taken to prevent the shot-firing cables or wires from coming in contact with the lighting or power cables.

(The foregoing regulations shall not apply to the telephone, telegraph, and signal wires, to which the rules of following section only shall apply.)

Signalling.

348. All proper precautions must be taken to prevent electric signal and telephone wires from coming into contact with other electric conductors, whether insulated or not.

349. Contact-makers or push buttons of electric signalling circuits shall be so constructed and placed as to prevent the circuit being accidentally closed.

[350. Table showing Maximum Current for Copper Conductors.

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