On Sun, 30 Mar 2014 23:02:55 +0000, DerbyDad03 wrote:

BTW, what is the purpose of this swivel contraption?
http://farm4.staticflickr.com/3717/1...baf3c454_b.jpg

My guess is a vent.

What do I win if I'm right?

It sure looks and acts like a vent.

Is that normal for a kitchen sink trap to have a vent which is open
to the underside of the sink?

And, why bother swiveling?

Do you think the vent contraption had anything to do with this,
which I removed in order to make room for me to work down there?
http://farm8.staticflickr.com/7367/1...1f76c48e_c.jpg