Transmission Tower

Nothing special about this one – it just struck me that this high tension transmission tower was standing over the streetlight like the Giant might stand over Jack:

I’m not an expert in this stuff, but it struck me that the cables are in pairs – rather than in bundles of threes. Does this mean that this is ordinary two-phase AC power, rather than the more common three phase that you’d expect to be transmitted on a overhead power line? Or, is each phase carried on a separate tier of the structure?