Looking down the 48 in. Gauss cannon (MAC reminds me too much of McDonald's).
Here are the 28 in. Gauss cannon turrets. These are mainly for taking out the weaponry on larger ships for defense. Also shown is the viewport, where the ship can be controlled if the sensors fail. (I bet you thought that was the bridge, didn't you. Do you really think I would put the bridge in a spot where it could be shot off? The real bridge is buried deep in the superstructure.)
Speaking of superstructure, the Indiana Class has a honeycomb beam construction, giving it superior structural integrity.
The wings allow for atmosheric flight, a useful advantage.