Battleship/Battle Barge size?
How big are Imperial Navy Battleships and Space Marine Battle Barges supposed to be? I know they are crewed by millions, but what is their actual size.
I've just read a line in Dan Abnett's Legion where two characters are looking out over the fleet and it describes them viewing the Alpha Legion's Battle Barge seven hundred kilometres away.
If it can be seen from that far away, it must be huge, i.e. hundreds of kilometres in length.