A minimum of two persons, one of whom must be a qualified person, must be used for line patrol duty at night when observing the overhead line and driving the vehicle must be done simultaneously. If repair to lines or equipment is found to be of such nature as to require two qualified employees, work shall not proceed until additional help has been obtained provided that in cases of emergency where delay would increase the danger to life, limb, or substantial property, one employee may clear the hazard without assistance. Whenever natural light is insufficient to illuminate the worksite, artificial illumination must be provided to enable the employee to perform the work safely.