Enjoy this ladder going into an underground high voltage duct : r/submechanophobia
Ladder and duct hi-res stock photography and images - Alamy
4"x5" Ladder Rack Support Kit for Cable Raceway/Fibre Duct Routing System - FS.com United Kingdom
An airman stands on a ladder to tie another section of fabric duct to the calling of a tent during Operation Desert Shield - NARA & DVIDS Public Domain Archive Public Domain
Find Wholesale cable duct ladder For Business or Home Use - Alibaba.com