Hotline1, I "think" I'm referring to the typical 2 for 1 arrangement, like Cutler Hammer's (takeover of Bryant?)BD1515, or Seimen's QO1515, etc. I'm not sure what breaker type my ole JW was referring to because by the time I had a chance to think about it enough to realize that what he said just didn't add up, the guy was transferred to another job! For all I know he might have been referring to Zinsco breakers. I doubt that he was referring to the normally thin GE breakers. Anyway, it stuck in my memory enough to nag me whenever I come across these twin breaker types, so I'm just trying to settle my nagging doubts. Its a bum deal when an apprentice gets misinformation...which is what I expect has happened in this case for me.

Jim M, what you said certainly is appropriate, and I suppose that is why the provisions for twinning breakers are located down in the bottom of the panels.