what's with the double zippers on the traditional german/swiss carpenter pants?

The double zipper is a fertility symbol relating to the ancient pagan mating ritual that Northern European Carpenters were key participants in.

After traditionaly constructing a post and beam male and female effigy the carpenters would strip naked, light the effigy a fire, drink copious quantities of Ale and proceed to......

Well, I think you get the picture.

For further reading on the subject see;

Alfred Winslow's "Mating Ritual's And The European Carpenter AD 806-1278" Sub-titled" Double Zippers And Their True Meaning.

-Collin

Now I've heard everything ... time to go back to some serious reading and catch up on the spam ...

I do not know about the German pants but the Amish style work pants have a wide full front drop flap that buttons to the waste band. It's (imo) a more comfortable and stronger design than a zipper and snap style pants. No belt loops, suspenders needed.