From the discussion in ICON Digest of Nov. 28, 2005 concerning SEDIVIER insulators:

This is a photo I took from an adjacent 500kv structure of Nothwestern Energy crews performing an insulator change out in the Crazy Mountains in central Montana. The insulators are Sedivier 40,000# clear toughened (tempered) glass. All linemen are energized at line voltage on the left and working to pick the string and take tension so the shot out glass can be replaced. If you look closely, you can see the top string is slack and the third bell in from the "hot" end is broken. Broken insulators closest to the hot end or hot yoke plate are the most in need of replacement by linemen due to corona. All orange sticks in this photo are ffiberglass and non conductive. The bucket with the energized linemen at left has the new replacement bell. Photo copyright Ropes That Rescue Ltd. taken during work September 2005.

Thanks for looking!