>Resurfacing a rink requires a finite amout of time then the rink needs at least
>a few minutes to freeze.  Intermissions shorter than 12 minutes are probably
>not possible.
 
Two Zambonis (Zambona? Zamboni?) circling at the same time has been often
suggested as a method of cutting down the time needed to resurface the ice
between periods.
 
As for the ice getting too choppy after a thirty minute half, I doubt that
halves would actually be 30 minutes long would that come to pass...(perish
the thought...fewer intermissions in which to pop out and grab beer).
 
-SG