{HEAD ~ The electric power supplies} are provided with {TAIL ~ respective positioning and actuating devices} controlled to actuate them independently from one another during setting in contact and detachment of the bars 
are provided with
{ HEAD ~ The electric power supplies } are provided with { TAIL ~ respective positioning and actuating devices } controlled to actuate them independently from one another during setting in contact and detachment of the bars
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH