Top: An erroded hook found on tower No. 81 on PG&E's Caribou-Palermo transmission line. Bottom: Two sets of hooks and steel plates from tower No. 01-14 and 14-117 show the area where fretting erosion occurs.
Photos: Obtained by NBC Bay Area
Top: An erroded hook found on tower No. 81 on PG&E's Caribou-Palermo transmission line. Bottom: Two sets of hooks and steel plates from tower No. 01-14 and 14-117 show the area where fretting erosion occurs.
Photos: Obtained by NBC Bay Area