Those arches are embedded deep underground in concrete thrust blocks. They are connected by a ring of steel that goes all the way round the entire stadium - the weight of the arches holds the roof up as they "lean back" against each other, counterbalancing the weight by pulling the roof up into...
Not sure I get you. Are you talking about adding another tier on top of the existing one, or just expanding the single tier back further ? (thus wiping out the police box and the TV studio). Either way, I think its a complete non-starter. There just isn't the room to build more seats and a...