Paul-- the primary isolation matter was just a question of curiosity more than anything. Line-clearance practices can be expected to be different everywhere—but based on longstanding, well-understood procedures that get us to accomplish tasks safely and consistently. Differences don’t necessarily make something right or wrong—safe or unsafe.
In overhead systems being able to be in sight of a visible open is desirable, but with underground circuits and metal-enclosed gear, it gets a bit more grey, and measures change accordingly. For given conditions, the most important thing can be that everybody’s on the same page of the manual, so to speak.
