Those springs have a weak point where the end is bent to form a locking-tab.

I had a similar situation where I DID have a chain tool, the rollers on a new uniglide chain started cracking and falling off the pins; as you can imaging shifting etc. was severely affected.
I was solo and about 800 miles from home.
I think I finished the tour on the inner front and without the lowest rear gear as the remaining chain wouldn't wrap.