My bad.
Here's some quotes regarding it's firing tho:
Deep in the bowels of the Argus, the fifty-metre wide door of the nova cannon’s breech groaned shut as thousands of sweating naval ratings dragged the massive weapon’s recoil compensators into position. Hot steam and noise filled the long chamber, its cavernous structure fogged with the furnace heat of lifting mechanisms that hauled the enormous projectiles from the armoured magazines below.
The chamber ran almost the entire length of the ship and stank of grease, sweat and blood. A booming hymnal echoed from ancient brass speakers set into grilled alcoves in the wall accompanied by the droning chant of thousands of men. Senior gunner Mabon watched from his gantry above the firing chamber as a series of bells chimed and a row of lights lit up along a battered iron panel before him. He couldn’t hear the bells, his long service as a gunner in the Imperial Navy having deafened him decades ago.
The shell was loaded and he muttered the gunner’s prayer to the warhead as he squinted through a bronze optical attachment that lifted on groaning hinges from the panel. He clamped his augmetic monocle to the optical, lining up the thin crosshairs on the red triangle that represented his target. The target was closing on them so he didn’t have to make any adjustments for crosswise motion. It was a simple shot, one he could have easily made, even in the earliest days following his press-ganging on Carpathia. Satisfied that the shell would be on target, he lifted his head and ran his gaze across the chamber, checking that his gunnery crew gangs were clear of the greased rails that ran the length of the chamber and that each had their green flag raised to indicate that all the blast dampers had been closed. He reached up and took hold of the firing chain that hung above his station.
He grunted in satisfaction and pulled hard on the chain, shouting, ‘Spirits of war and fire, I invoke thee with the wrath of the Machine God. Go forth and purify!’
Steam hissed from juddering pipes and a high-pitched screech filled the weapon chamber as the gravometric impellers built up power in the breech. Mabon rushed to the edge of the gantry and gripped the iron railings. Seeing a weapon of such power discharge was a potent symbol of the might of the Imperial Navy and he never tired of the sight.
The screeching rose to an incredible volume, though Mabon was oblivious to it, until the nova cannon fired, and the enormous pressure wave slammed through the chamber. The weapon’s firing sent the three-hundred metre barrel hurtling back with the ferocious recoil. The air blazed with sparks and burning steam as the grease coating the rails vaporised in the heat of the recoil, the stench of scorched metal and propellant filling the chamber with choking fumes. Mabon roared in triumph, gagging on the stinking clouds of gas that boiled around him. Juddering vibrations attempted to topple him from the gantry, but he had long since grown used to them and easily kept his balance.
The smoke started to clear and his gunnery overseers began whipping their gangs into dragging the massive weapon back into its firing position once more. The armoured bays in the floor groaned open and the looped chains descended to be attached to a fresh shell. Mabon had drilled his gunnery teams without mercy and he prided himself that he could have the nova cannon ready to fire again within thirty minutes. This time would be no different.
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