136. Means of communication.- The employer shall ensure at a construction site of a building or other construction work that- (a) reliable and effective means of communication such as telephone or walkie-talkie are provided and are maintained in working order for arranging better and effective communication at an excavation or tunnelling work at the following locations, namely,- (i) working chamber of an excavation; (ii) intervals of hundred meters along the tunnel; (iii) working chamber side of a man lock near the door of such man lock; (iv) interior of each chamber of a man lock; (v) location conspicuous lock attendant's situation; (vi) a compressor plant; (vii) a first-aid station; and (viii) outside the portal or the top of a shaft; (b) such number of bells and whistles are made available at all times at the locations referred to in sub-clause (i) to sub-clause (viii) of clause (a) as are necessary for the safety of persons at such locations. | 
