 It was expected that, by mounting the turrets in this way, at least one gun from each turret could fire fore and aft along the keel line, and all four guns could fire on broadside bearings; it was intended that every part of the horizon could be covered by at least two guns.In practice it was found that firing too close to the keel line caused unacceptable blast damage to the superstructure, and cross-deck firing similarly caused damage to the deck.Before "Edinburgh" the positioning of the conning tower in British ironclads had produced a variety of solutions; the difficulty was that the two important factors involved, maximum protection and maximum visibility, were essentially mutually incompatible.