The SSF-5 Barracuda is a large patrol submarine used by the Grand Duchy of the Balearic Islands on (the FS planet) Smolensk. This independent city-state is, like Singapore, a handful of islands with a large interest in oceanic shipping and views its main lines of defense (should the planetary Duke or even the First Prince decide to finally end the Grand Duchy's 800-year independence) as aerospace and naval superiority.

The SSF-5 Barracuda is the primary means of achieving naval superiority for the Grand Duchy. The Barracuda is built around a 340 fusion engine derated to 330, basically the same engine as used by the Balearic's last line of defense, the "Immortals," a group of mechwarriors piloting only Battlemasters. The 330 fusion engine allows normal flank speeds of 54kph and provides the vehicle with exceptional submerged endurance.

The SSF-5 is a double-hulled vehicle. The pressure hull is a dome-capped cylinder 3.5 meters in diameter and 13.5 meters long, a 120-ton displacement. Outside this hull is an unpressurized, flooded section holding ballast tanks, trim tanks, and propulsor motors. The SSF-5 has a sail, a "conning tower," a superstructure shaped like half of a tear drop. This is the vehicle's unpressurized turret and sole location for its weapons. The turret is actually sphere; a lightweight composite faring streamlines the turret but also prevents it from firing directly backward.

The interior is relatively cramped for the crew of 8. A command section about in the midbody of the submarine has positions for all 8 crew, though 2 will typically be in the rear engine section during combat. Toward the bow is the cramped crew quarters: 8 bunks in 2 stacks of 4, a combined head/shower (like in RVs), and a mini-galley. Enough cargo space is available for food for a 6-week deployment. Whether or not the crew can stay sane in the minisub for 6 weeks is the subject of classified Grand Duchy military studies.

Behind the command center and ahead of the engine room is the airlock. This has 4 hatches spaced around the disk-shaped room (dorsal, ventral, port, and starboard) to guarantee rescue vehicles an available door no matter what angle the Barracuda has sunk at. It's also the primary means to send divers out to conduct underwater reloading operations.

The topic of reloading brings us to the Barracuda's weapons array. Like the Immortals' Battlemasters, the Barracudas have a (marinized) Magna Hellstar PPC in the turret. This provides some limited shore bombardment abilities and a decent amount of firepower should the LRM-Torpedo tubes run empty, which is quite possible. The turret also carries ten LRM-T 5s, fifty mini-torpedo tubes to hunt and peck targets to death from outside the underwater range of most Inner Sphere energy weapons. Each 5-tube launcher is loaded with a separate, slightly negatively buoyant clip of 120 torpedoes that relatively easily to handle underwater. The entire turret is carefully isolated from the pressure hull with what amounts to CASE; the turret can be
flooded without losing the whole vessel.

This weapons array is intended to take advantage of the vulnerability of vehicles and mechs to flooding. About 1 in 12 to 1 in 6 hits will flood a section of a target, hence the utility of 50 LRM tubes (high chance of flooding the target plus the ability to stay out of range of return fire). Because flooding occurs in targets almost irrelevant of armor thickness, the SSF-5's "only" have 11.5 tons of ferro-fibrous armor. With the turret, the SSF-5 should not need to approach targets head on and can thus keep the distance open.

The Grand Duchy has less population than many independent Periphery planets, but the resources it can call upon exceed those of the Outworld Alliance and Marian Hegemony. The Grand Duke's family owns a corporation that has been producing and operating large, civil fusion power plants for centuries. Tens of billions of FS citizens sign checks for their electrical bills to Balearic Power & Light. A small fraction of the net income makes the Grand Duchy tax free to its citizens; a small fraction more gives the Grand Duchy's military a billion C-bills to play with annually, billions more if it has an idea that amuses the Grand Duke or seems necessary. New military inventions tend to amuse the Grand Duke, especially after he reaped huge profits while modernizing fusion power plants with rediscoveries in the Star League Memory Core.

Based on hints from FS tourists (which the ideally situated Grand Duchy has a lot of), the Grand Duchy has been playing with several innovations appropriate to underwater warfare. Recordings from SCUBA diving tourists (also NAIS scientists) captured high frequency, very directional sound pulses. Analysis by MIIO suggests this is some sort of semi-active sonar guidance system for torpedoes, probably comparable to an underwater Artemis fire control system.

Day sailors have also seen "ink blooms" in the crystal waters around the Balearics. One group of AFFS soldiers on leave captured a "pencil dart" that surfaced near an "ink bloom." Study of the dart revealed two things. One, the soldiers were lucky they didn't get their hands blown off or scorched by the volatile dart. Two, the dart generated a vigorous chemical reaction internally that spewed dark dust into the surrounding water. The dart was probably one of several dozen delivered by a standard sized short or long ranged torpedo. At a pre-set range, the darts were probably ejected into a cone pattern and set up a wall of ink. Analysis of the ink revealed that, when mixed in water, it formed a virtually laser-impenetrable barrier. It did nothing against sonar, torpedoes, or particle beams, but it truly stopped lasers in their tracks.

Whether the Balearics' Barracudas have been refitted with either technology is uncertain.

It is thought that the Grand Duchy has 24 SSF-5 Barracudas, but this is uncertain. The stats given below are based on a tour given to visiting AFFS officers in 3022, and the deployment numbers are based on the number of slips observed at the Balearic naval base. There may have been more, hidden bases, or the slips may have been shared with the more prominent PTH-4 hydrofoil patrol boats. No major Inner Sphere faction has ever concerned itself with the Grand Duchy enough to seriously investigate the city-state. It has co-existed quietly in the Federated Suns for...actually, it predates the FS. Since 10 million people that heavily dependent on trade with the Federated Suns are not going to ever conquer the Great House, no one really cares about it.

For the same reason (and its avowed neutrality), the Grand Duchy has never seen combat. Well, that's not correct. It frequently sends its units off to serve as "mercenaries" with the AFFS/AFFC/AFFS for combat experience. However, the SSF-5s have only stayed at home. They don't travel well. They did target some Loyalist units during the FC Civil War, but the Lyran commander soon called off the attack when he read a history book and discovered the Balearic's defenders were serious that they were not part of the FS/FC.