Transporting the tall

When I heard that our local zoo had moved its giraffes elsewhere to allow renovations of their habitat, the first thing that came to mind was: They're too big for a horse trailer. How do they move?

South Africa tried moving some in shipping containers: one hit its head on an overpass and died. They're too big to easily sedate and just tie down; it seems that you have to pack them up as best you can (I assume they use slings, maybe lifted from the floor so you don't have to have somebody walking between the giraffe's legs), and drive carefully. Going around overpasses, I hope.