Either this company had a large quantity of 10" disks when they built new distribution lines in this part of town or they were still following their 4kV specification, only using a 10" disk instead of 6" due to the higher distribution voltage. This pole was once retrofitted with a set of non-loadbreak disconnect switches, but it seems in the years since I moved away from ND, this company chose to remove the switches and restore the jumpers (I can't see why they chose to run the middle phase jumper over the crossarm rather than returning it to the long-empty pole pin).