Can someone provide an explanation regarding the etymology of the adjective "hell-bent?"

Question

It's etymology is given as:

hell-bent, 1835, U.S., originally slang, from hell + bent

How do the the words "hell + bent," when taken together, form the definition "determined to achieve something at all costs?"

Edit (thanks to Medica's response):

In this context, could somehow "hell" imply going to disproportionate or irrational lengths to achieve an end? The term "selling one's soul to the devil" comes to mind as well in this sense.

Answer 1

To be bent on something is to be determined to do it, from to bend meaning to go in a certain direction, with implications of “determined, resolute.” To be hell-bent should mean going in the direction of hell but it doesn't; it means to be wholeheartedly determined to get something done, where hell acts as an intensifier (e.g., "What the hell are you doing?” and "Hell yes!" don’t really have anything to do with hell.) The OED cites:

1731 Ab-origines in Arms..did then resort, In Haste to Susquehanna Fort, Hell bent on Thoughts of Massacree.
1835 A large encampment of savages,..‘hell-bent on carnage’.
1891 The state of Texas, or at least its legislature, went hell-bent for the reform of railroads.

There is a book out with hell bent in the title:

Hell-Bent: Obsession, Pain, and the Search for Something Like Transcendence in Competitive Yoga

_{Too good a pun to pass up!}