Just three separate turrets with one gun each. You know, leave no stone unturned and all.
:)
It is a common misnomer to refer to Gatling guns (rotary cannons) as chain guns; even in some video games, such as Wolfenstein 3D and Doom, the player carries a minigun referred to as a chain gun. In fact, most Gatling-type gunsweapons such as the M61 Vulcan, the M197, the GShG-7.62, the M134, and the XM214are externally-powered but are not chain guns.
They instead function by directing the power source (usually electricity) to a unit known as a rotor, which contains each of the multiple barrel-and-breech assemblies that make up the distinctive shape of a rotary gun and is free to rotate within a fixed outer sleeve. A cam projecting from each breech unit runs in a shaped, recessed track within the sleeve. To fire, power is applied to rotate the rotor which in turn causes each breech to cycle as its cam is forced to follow the recessed track. Each barrel therefore fires independently.
There is no one place on the face of this Earth than FR where you have to be REALLY careful about describing guns, and the nomenclature thereof...