All companies, corporations, lessees, owners, operators, or receivers of any railroad or railway company operating a railroad or railway in whole or in part in this state shall equip, maintain and use upon every locomotive being operated in road service in this state in the nighttime a power headlight of not less than 1,500 candle power brilliancy, measured with the aid of a suitable reflector. Nothing in this division shall be so construed as to prevent a locomotive engine, whose headlight has become defective while on the road, from proceeding to the most convenient terminal or division point where the necessary facilities exist for remedying such defect. This section shall not apply to industrial roads, such as tram roads, mill roads, and roads engaged principally in lumber or logging transportation in connection with mills, and the provisions of this section shall not apply during the first 90 days of a strike of the particular employees, whose duties are to repair and maintain headlights.