So my googlefu and forums search has failed me.  I've noticed that there seems to be an imposed limit on superweapons by player, but is there also a limit to the number of superweapons on a map?

I have been playing a game for several hours, 1 Enemy TEC Loyalist, 1 Enemy Vasari Loyalist, and myself as Advent Loyalist.  After being bombarded by the TEC superweapon a few times I decided to train one up myself to return fire with some good ole fashioned culture-bombing only to find out that *MY* superweapon limit has been reached.  I had never built one and cannot figure out why this is the case?  Can only one player on the map build one and in order for me to make one I need to kill his?