No real need to look hard for a photo, either. Look through any book that shows pictures of climbers on Everest, most typically, and you'll find lots of photos of climbers traversing ladders on the infamous Khumbu Icefall. Of course, one thing I can't help you with is the engineering science to support what you see happening in the picture. When you take a ladder designed for vertical use and lay it out horizontally, heavenor a good structural engineeronly knows what's happening to the force vectors and safety margin. I can't recall ever reading about a case where one of these site-built "bridges" buckled and took its hapless passenger with it into the icy depths (granted, you should be roped up when traversing these things).
So, it's off to the hardware store for you. Probably 16-footers will be the most maneuverable, yet give you enough reach.