Theorem I

Preface

T1 Attack Submarine, Version 1.0 (Stable). If you like my design, please give it a thumbs up. Thank you!

The Theorem series, to which Theorem I belongs, was initiated after the Lemma Series and Corollary Series. Specialized in millitary operations while continuing its fluid dynamics principles. It is designed to replace various outdated transport submarines. The entire series comes with the following standard configurations:

• Lock: Controls locking of the containment chamber

• Hatch: Manually controls the upper docking hatch airlock

• Ballast Valve Mode: Additional ballast tank

• Armor: Reinforced hardened armor, core chamber encased in an armor box

• Safe Egress System: Built-in upper and lower egress elevators

• Irradiation Drone: Periscope-controlled drone capable of loading volatile fuel rods

• BVR Strike System: Rangefinder drone + automatic trajectory calculator, capable of striking targets up to 200m away, see details here

Spec model Features

• Fabrication Equipment: Equipped only with a fabricator and deconstructor, but with enhanced efficiency

• Unique System: 2 x direct-flight torpedoes, 1 x mine, equipped with VT and contact fuses, linked to sonar and periscope

In the campaign set in Hellish difficulty with Jupiter radiation enabled, it offers a satisfying gaming experience.Lightweight design, thus no fancy decorations, but it ensures a smooth gameplay experience without any lag. Please read the instruction manual before embarking.

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](https://steamcommunity.com/sharedfiles/filedetails/?id=3321894706)

** Theorem I**

Theorem I is a small attack submarine specially developed by the Europa Union Design Bureau for riot control and clearance missions in the Cold Cavern Sea, intended to replace the aging and fragile Barsuk class.

Initially, the Union leadership was not optimistic about this technology and only installed it experimentally on specialized models of the Lemma-class reconnaissance submarines. Over time, feedback from the captains who dared to experiment with it gradually clarified the system's application scenarios. Due to the nature of the BVR strike system requiring integration with heavy artillery, installing heavy artillery on small submarines would occupy valuable turret mounts, offering limited enhancement while significantly reducing the overall performance of the small submarines. In contrast, large submarines, with their powerful firepower and armor, are less concerned about enemy encounters head-on.

Faced with such a dilemma, a completely new design concept was proposed: to internalize the heavy artillery within the submarine and deploy it externally only when needed. More importantly, this internal design made the extreme modifications envisioned by the weapons team possible. After several Earth months of development, the Theorem I-Class was born.

The Theorem I-Class features a beautifully sleek hull and a classic three-point artillery layout, giving it the appearance of a traditional reconnaissance submarine at first glance. However, upon entering, one can immediately sense the strong militaristic design, with its layout focused tightly on combat capability and reliability. The previously convenient through-hull exit hatch design was replaced by a safer exit elevator, which connects to a dedicated egress preparation room. The upper exit hatch is also equipped with an additional safety gate, which remains locked during navigation.

The core feature of this series is the deployable stern island equipped with an internal heavy artillery system, which also serves as the upper exit elevator during navigation. In deployment mode, the heavy railgun within the chamber extends outward, and its BVR fire control system with indirect fire capability transforms it into a heavy mortar, capable of shattering enemies with unexpected ballistic trajectories.

As an attack military submarine, the core chamber of the Theorem I-Class is encased in an armored box, providing better protection for the crew when facing Giant Spineling. Considering its potential role in nest-clearing missions, the stern island is equipped with micro mirror-controlled drones that can be upgraded to irradiated drones by installing volatile fuel rods. In terms of conventional armament, the three-point electromagnetic cannon layout has been modified to include two attack modes: shotgun and chaingun, which can be quickly switched by the gunner to handle different types of enemies.

During the sea trials of the Theorem I-Class prototype, the Union eagerly placed orders with major shipyards, most of which were for the integrated type. However, a select few specialized models were assigned to promising new captains for more challenging missions, reportedly to deal with abyssal beasts that had wandered from the Europa Ridge Abyss to the Cold Cavern Sea. The truth of this claim is difficult to verify, as there have been no recorded sightings of abyssal beasts in the Cold Cavern Sea in recent decades. On the contrary, the once-dormant Jovian separatist activities have become increasingly frequent. Yet, the ever-intensifying Jovian radiation constantly reminds us that the future is uncertain.

The specialized version of the Theorem I-Class features enhanced armor and is additionally equipped with two powerful weapons: direct-flight torpedoes and mines with advanced fuses. The fuses of both are disarmed within seconds of launch, after which any collision or hostile creature entering their sensor range will trigger an immediate explosion. The torpedoes are installed on the rails of the forward ballast tank, each capable of accommodating a standard-depth charge. In contrast, the mines can load up to three at once. With such explosive power, few creatures can survive. Both weapons are equipped with fiber optics, allowing control of their sonars and providing visual feedback. As a trade-off, much of the engineering bay has been converted into a mine bay, leaving just enough space for a fabricator.

As the flagship of the Theorem series, the Theorem I-Class adopts many new technologies for the first time, and its true effectiveness remains to be experienced firsthand by the captains of Europa. The hull design for subsequent models in this series has been completed, but the internal layout still requires further exploration.