The introduction of the Galaxy-X class dreadnought was seen traditionally as a response to the emerging new technologies of the Typhon Pact powers. Covertly, the class was built to fight the Borg Remnant and "terminate it with extreme prejudice".
The class features many upgrades to the classic Galaxy design: a quantum slipstream drive capable of reaching, in terms of traditional Warp scale, up to Warp 14, as well as iron-6 core transphasic phaser turrets mounted on small pylons. The additional "conning tower" houses many scientific and engineering facilities, as well as two work bee hangars and one large fightercraft hangar, making the Galaxy-X essentially a fighter carrier. The biggest imrovement was, of course, the Type XX Fixed-Arc Phaser Spinal Lance. Given that engineers like to live long descriptive names, whilst captains like to keep things siple, most captains gave alternate names to their own ship-mounted supergun. On the Resolute, it was called Light of Judgement, on the Saigon, it was called the Zeus Cannon, and on the Yamato, it was called the Wave-Motion Gun (what else?).
Model by me