The thumbnail is on a different page - https://farallones.noaa.gov/heritage/doghole_fortross.html

Chutes and hoists were a West Coast innovation because of the high cliffs along the coast and the lack of harbors.

https://en.wikipedia.org/wiki/Dog-hole_ports

I googled “doghole” because I’m watching the Korean horror movie Hope and that was a very odd translation word. The movie usage is something like hidey hole used by tigers moving from Siberia through North Korean into South Korea.