Mechanical Anatomy: The Retractable turret

In keeping with an old tradition of explaining the mechanics of how some of the devices in the Nexus RP work, today I'm going to cover the Retractable Turret as seen on the Umbra class.

Mechanically the idea of a retractable turret is a simple one, as it draws from the mechanically sound idea of a retractable ball turret as seen on a B-24 Liberator bomber of WW2.
You can look up the diagrams for the ball turret all over the internet but a good resource that shows the full operations of the ball turret can be found here:

[link]

The turret assembly itself is one of great efficiency, as very little of the ships space is used to mount the machinery, munitions, or provide for the gun crews that operate and service the turrets. In this case the 20" gun systems aboard the umbra are mounted in pairs, each gun being able to elevate and depress individually as well as retract into the turret if damaged.

Overall the entire gun system is cylindrical in shape and in the case of the 20" guns aboard the Umbra class this 'gun well' as the crews call it extends ten decks into the hull of the ship with the mower most portions housing the Munitions, Fire control systems, and all the machinery that makes the turret move and provides power to all gun systems.

The turret is elevated by means of a mechanical piston, munitions are lifted up into the turret by means of a collapsible ammunition hoist. The hoist itself folds in on itself when the turret is retracted and is extended by the motion of the lift piston as the guns are extended.

The munitions for the 20" guns are handled in a unique way, since the designers realized the guns might be trained in any direction possible during combat it became important to create a loading system that was direction-insensitive. The solution was to install eight smaller munitions handling bays that were heavily protected in a ring around the munitions feeding points. The effect is that the gun can reload from a munitions bay regardless of which angle the turret's face is pointed.

When retracted the base of the turret sits flush with the floor of the second deck below the hull itself when in resting position. While the specifics on what guns are mounted in the turrets of the Umbra class are not clear it is noted that the guns themselves have the ability to contract both within the turret and into themselves to further save space. Each gun apparently retracts along with it's protective gun shield into the turret while armored doors of some sort if not shielding seals the turret off from the ravages of space.

One other thing to note is the gun pivots, The main guns themselves when extended can turn 360 degrees in the azimuth and 95 degrees in elevation with a depression of 10 degrees; though at -10 degrees the gun crew is likely to hit some part of the Umbra.


In short, the system is composed of rugged time tested components, can be repaired reasonably quickly and bears provisions to handle the rigors of modern warfare in space.