Ratline or old fashioned rope ladder (no wooden rungs)

Hello, all.

I am seeking leads or other information on hoe to make a rope ladder (or
ratline) like one sees on ships hundreds of years old. Every "lead" I have
so far found on the Internet is to the more moddern type with wooden rungs.
But I'm looking to make the whole thing out of rope. And I want it to be
useable (weight bearing).

Any clues?

Thanks in advance for all your help.