Legoli-class

S801 Sombra, the lead ship of the Udine-class.
Class overview
Name:	Undine-class
Builders:	Pereda Construción Naval Consolidada (PCNC) DCNS
Operators:	Temuair File:Cossack State Flag.png Dniegua Sieuxerr
Preceded by:	Agosta-class
Succeeded by:	Highland-class (Planned)
Subclasses:	Victorieux-class
Cost:	$330 million URD
Built:	1996 - 2006
In commission:	2002 - present
Planned:	22
Completed:	22
General characteristics
Type:	Attack submarine (SSP)
Displacement:	Surfaced: 1450 tons Submerged: 1830 tons
Length:	57.2 m (187.66 ft)
Beam:	7 m (22.96 ft)
Draft:	6 m (19.68 ft)
Propulsion:	Electric propulsion motor on permanent magnets Storage battery with increased service life 2 diesel Air Independent Propulsion (AIP) systems based on oxygen-hydrogen fuel cells 1 shaft 2,700 hp (2,013 kW).
Speed:	Submerged: 21 knots (24 mph; 39 km/h) Surfaced: 10 knots
Range:	8,000 nm (14,800 km, or 9,196 miles) at 8 knots (15 km/h) surfaced
Endurance:	3 weeks without snorkeling, 12 weeks overall
Test depth:	over 700 m (2,296 ft)
Complement:	5 officers, 22 men
Sensors and processing systems:	Hybrasil Eco-I integrated sonar system Graymayre 210 I-band navigation radar Hybrasil Sussurro communications system Dachaidh satellite navigation system.
Electronic warfare & decoys:	Dall electronic warfare suite
Armament:	6 x 533 mm torpedo tubes (in 2 forward pointing groups of 3) with a mixture of 20 torpedoes or Espada missiles 12 Lanza surface to air missiles 1 x Srad CA.301 30 mm recoilless autocannon on retractable mast 24 external naval mines (optional)
Aircraft carried:	3 x unmanned aerial vehicles

The Undine-class submarine is a conventional powered attack submarine developed by Pereda Construción Naval Consolidada (PCNC). It is in service with the Imperial Navy of Temuair. It features diesel propulsion and an additional air-independent propulsion (AIP) system using a proton exchange membrane (PEM) hydrogen fuel cells, the second known vessel to use a fuel cell propulsion system. The submarine is capable of high speed operation using its diesel powered engine or use its AIP system for silent operations, allowing it to stay submerged for up to three weeks continuously. The system is also said to be vibration-free and extremely quiet, while the submarine itself is entirely undetectable by magnetic anomaly detector thanks to its non-magnetic steel hull.

Development

The Undine-class was designed to replace the aging Rucesion-class submarines in service with the Imperial Navy. In addition, the vessel was intended to replace the Agosta-class vessels as well, but the Imperial Navy instead decided to overhaul the existing Agosta-class vessels instead, installing newly developed MESMA air-independent propulsion (AIP) systems amoung other upgrades.

In 2015, with the announcement of the development of the Highland-class submarine, several planned vessels were cancelled, including ships intended for the Gratislavian and Aisling navies. It is expected that these nations will place orders for the Highland-class submarines as replacements for the canceled Undine-class vessels.

Description

The Undine-class is designed for anti-shipping and anti-submarine operations both at sea and within the a littoral zone. The design and arrangement of the stern planes allows the vessel to operate within waters as shallow as 17 m (55 ft). This feature, relatively unique among modern attack submarines, facilitates covert operations by allowing combat swimmers to be deployed closer to shore.

The Undine-class was designed with stealth in mind, both when operating underwater and when surfaced. The vessels prismatic hull cross-section and smoothly faired transitions from the hull to the sail, vastly improve the boat's stealth characteristics by reducing its radar cross section. The hull and internal compartments are all constructed of nonmagnetic materials, thereby reducing the vessels magnetic signature and rendering it undetectable by magnetic anomaly detectors

The vessels unique air-independent propulsion allows for virtual silent running while operating underwater, even at high speed. To reduce the inherent dangers of hydrogen–oxygen propulsion, namely fires and explosions, the storage tanks for the fuel and oxidizing agent are located between the pressure hull and outer light hull, thereby placing them outside of the crew area. The gases are piped through the pressure hull to the fuel cells as needed to generate electricity, however, this arrangement minimizes the amount of gas present in the crew area at a given time.

The command and control systems aboard the Undine-class are highly integrated and based on a high-performance databus and a distributed computer system. These systems include sophisticated command and weapons control systems and a sophisticated submarine communications buoy system manufactured by Hybrasil. The ships Eco integrated sonar, also by Hybrasil, includes four medium frequency passive sonar sets arranged in a cylindrical array, as well as a low frequency towed array, a flank array sonar for low / medium-frequency detection, and a high frequency mine detection system. In addition, the ship is equipped to preform passive sonar ranging, and is equipped with a hostile sonar interception device.

The periscope, produced by Nuadhaich, is equipped with an laser rangefinder, as well as infrared and thermal vision equipment. The periscope is linked into the submarines Dachaidh satellite navigation system.

Weapons

The Undine-class is equipped with a variety of weapons systems, including torpedo, missiles, and a 30 mm cannon in a retractable mast. The 30 mm cannon, produced by Srad, can be fired without the vessel surfacing, and is designed to support diver operations as well as to engage light surface targets or fire warning shots.

The Undine class is equipped wth 6 torpedo tubes, all 533 mm in diameter. A variety of torpedoes can be utilized, including the Temuairian Peixe IV heavyweight torpedo and the Sieuxerrian F17. In addition, the vessel is capable of utilizing the Torped 2000F produced in Dniegua, which is a supercavitating torpedo.

Submarines in the Imperial Navy are equipped to fire the Areiva Espada missile, which is designed for anti-ship, anti-submarine, and land attack missions and is capable of being fired from a variety of naval platforms, including submarines and surface vessels.

For defense against anti-submarine warfare aircraft, the Undine-class is capable of utilizing the Areiva Lanza, a short range fiber-optic guided missile fired from the submarines torpedo tube. This missile can be fired while the submarine is submerged and is designed to minimizing the boats detection after launching the missile. It allows the Undine class to defend itself from ASW aircraft without being located or exposing itself to enemy fire. Although primarily intended for use against aircraft, the Lanza can be used against surface or coastal land targets. These missiles are stored inside the launch tube in magazine containing four missiles.

Operational history

In July of 2015, S701, the Sombra was heavily damaged during Operation: Long Runwhen vessels of the Gratislavian Republican Navy opened fire on Aisling vessels during the exercise. This friendly fire incident was the result of an accidental border clash between Aisling and Gratislavian forces around Bochanan Gap in southwester Temuair. According to Gratislavian naval commanders, the nation believed it was under attack by an Aisling invasion force, and believed Aisling vessels would open fire on the Gratislavian vessels participating in the exercise. The Sombra suffered extensive damage when it was attacked with depth charges by a Gratislavian destroyer, and two other Agosta-class submarines were lost. In addition, two Aisling Le Guyader-class frigates and a single Shashka-class were heavily damaged Gratislavian losses included the loss of a destroyer, two frigates and a single ASW helicopter, and heavy damage to a second destroyer and the Pavle Levi, a Elicanstvenost-class guided missile cruiser.

Operators

• Temuair
  • Imperial Navy of Temuair

Ships in class

Country	Pennant number	Name
Temuair	S801	Sombra
Temuair	S802	Fantasma
Temuair	S803	Recolector
Temuair	S804	Banshee
Temuair	S805	Diaño
Temuair	S806	Espírito
Temuair	S807	Sussurro
Temuair	S808	Besta
Temuair	S809	Quimera
Temuair	S810	Demo
Temuair	S811	Espectro
Temuair	S812	Alma
Temuair	S813	Escuridade
Temuair	S814	Rouge
Temuair	S815	Homelobo
Temuair	S816	Aniquilador
Temuair	S817	Desaparición
Temuair	S818	Caída
Temuair	S819	Esquecemento
Temuair	S820	Ruína
Temuair	S821	Veneno
Temuair	S822	Revenante