93    Messengers.

Messengers which are grounded shall, where dead-ended or wrapped around a pole for any reason, be at least 6 feet vertically below all supply conductors of other circuits.  Should it be impracticable to maintain such vertical clearance, a reduction to 4 feet below supply conductors of 0-750 volts will be permitted, provided the messenger is suitably guarded with the equivalent of double guard arms placed directly above it and substantially parallel to it.