Meggit had semi-trailer range boxes that were self-contained. Given that my brother is now involved in the airport debacle, I'm aware of your issues. I don't see how you could buy enough of the range trailers to run all 1700 plus folks you need to qualify every year, never mind specialist, rifle and SWAT training. maybe buy 3-4 of those Meggit trailers and park 'em at the San Bruno jail and give them to the SFSD when you're done with them.