You want two halyards.
Eric:You really want 2 halyards when you go UP the stick. Even if you only had 1/4" line you would probably have better than 1400 lbs breaking strength, but that is probably not the issue.This is just a general safety issue. Having a backup halyard in case of any problem is a good thing to do when you climb. I suggest that you tie a bowline knot or some other good knot with boat halyards.It is also a good idea to have TWO people hoist you up the mast, unless you are using a block and tackle setup. Then you really only need one person to take up the slack in the secondary halyard. It is a little scary the first time, but really not that bad.