im not completely familiar with the halo universe but in Halo ODST it showed the orbital elevator being destroyed in mid day but on Halo 4 forward unto dawn, it showed the orbital elevator being destroyed at night
-
They would probably only be on the equator so they could take advantage of the centrifugal force.. To help them not fall toward the center of the earth.. It is possible for them to be built in London, they would just have to be built stronger and would cost a lot more.. And if something went wrong and began to fall apart more of it would fall back down onto the city... Where as if it was built on the equator the inertia would shoot the majority of it into space.