If White and Black were working together: What is the MOST possible Queens that could be on a board?

Alekine's Harem (5 Queens on one board) got me thinking about this:

If white and black were working together, and they were adhering to the established modern rules of traditional chess:
What is the most possible queens that could be on a board at one time?

It is import to remember that neither king can be checkmated (unless it's on very last queen promotion) Or that ends the "game"

I haven't Googled it, but I suspect it is 11. White Promotes 5, Black Promotes 4, + the two original...
What are your thoughts?

I have heard of 8 queens, so 8+8=16 queens altogether on the board. Am I correct?

18 Queens in 48 moves.

Wow! Amazing! so 18 is the answer! (I also love the fact that Black wins!) Thanks!

What is amazing about 18 being the answer?

I guess all 18 can be done. Interesting topic for my next SPG assignment!

@MrPushwood said in #6:
> What is amazing about 18 being the answer?

It's the maximal possible (all pawns promote plus the 2 original queens).

@MrPushwood said in #6:
> What is amazing about 18 being the answer?

Same question here. Only the answer "42" would be amazing.

Well, it's not easy to do - getting every pawn past the other without capturing. Have you tried this with a cooperative player? What do you do with the other pieces? You also have to work hard to avoid checkmate.