Coaster Hero wrote:
^^Actually, Sander Kernacs explained why Intamin created the double spine in an interview (by TPR) at IAAPA. He said it was because King's Dominion specifically requested that Intamin reduce the amount of supports and footers. In order to have fewer supports, Intamin developed the double spine, and this was especially important in the development of Skyrush, as that ride is in a very tight space. With the double spine, they can build support columns up to 100 feet apart. So basically, it's not the size of the ride, but the amount of supports that determines whether a ride gets the double spine or not.
Wow, I didn't know that! Really cool!