There are a whole bunch online under the heading Humanity F*** Yeah.
The Deathworlders is the main one, currently 51 plus (there is at least one multi-page chapter, I don't remember whether there are more) pages, each page about 2-3 hours of reading. I have the current page bookmarked but there's no obvious way from there to the first page.
There are these two in the same setting by different authors, currently on hiatus for at least six months, I don't remember the last time either posted, but they are a decent length per page, but nothing like as long per page as the main one:
https://www.reddit.com/r/HFY/wiki/series/salvage
https://www.reddit.com/r/HFY/wiki/se...make_good_pets