This may not fit in Mike's forum, so moderators feel free to tell me. Part of my job duty is building 34.5 KV distribution lines (jack of all trades...). When exceeding a standard span of 150' to 200' spacing (standard 9' wood arm, 45' class 3 pole, 3 phases of 336 mcm ACSR (Merlin) 2 on the arm and 1 on a pole top insulator with raptor safe spacing, 4/0 ACSR ground (Penguin) 7'6" below the arm on a spool bolt; what are some specs for longer spans using heavy arms, double arms, taller poles etc.? I may need to span 300-400' due to terrain and want to know some maximum specs for single pole construction with the above referenced conductors before going to H-structures. TIA