On Sat, 8 Dec 2018 18:00:17 -0600, Dean Hoffman
wrote:

I was watching a show called Maine Cabin Masters. They were redoing
a camphouse
and built a Shipman's ladder for second floor access. Another name is
alternating tread stair. It looks something like this:
http://www.stairsuk.co.uk/assets/images/alternating-tread-staircase-gallerie/images/birch_24_spacesaver_jpg.jpg
Has anyone actually seen one?


That's a new one to me.
Looks like it's used in steep climb areas - safer than a ladder.
John T.