Crack? And if so, repairable within reason?
 

this is a ridiculously clean 1987 Schwinn Voyageur. Everything seemed original and with low miles. This surprised me.
https://cimg0.ibsrv.net/gimg/bikefor...02b72d4ab.jpeg
https://cimg2.ibsrv.net/gimg/bikefor...42b333531.jpeg

I had to check to see if this was an old thread because I swear there have been a couple of these posted here. I am not sure that it's repairable. Franklin frames used to do it for a very reasonable amount of money, if the seat tube isn't cracked. You might be able to tell if it's cracked if you took out the bb and looked from the inside. I suspect it's toast though.

It's definitely cracked. Its hard to tell if the tube failed and that caused the shell to crack at the front or if the joint failed and the tube slid out and caused the crack. Either way, it will be a labor intensive repair.

There was a thread in here about a bb shell replacement where the owner of Franklin Frames was quoted as saying "young guys can't do this" or something like that. I'm not young, but I took that as a challenge. I wasted quite a bit of gas and time taking a bb shell off. It wasn't as bad as I thought, but I really wouldn't want to do it again. If I had to, I think I would want to set up some firebrick with a couple of torches going and then it might not be so bad.

The thing I think happened with OP's bike is the tube separated because of improper brazing and then the crack went into the bb shell. If it's possible for that to happen without cracking the tube, I'm not sure.

I went back and looked for previous threads and didn't find the most recent one I was thinking of. I don't think it's in C&V. Maybe.

I agree with @unterhausen; the BB shell can be replaced, but it's a big job and likely not cost-effective unless you can do the work yourself (which I've done). Think carefully about how sentimental value compares with practical cost in making your decision.