The U-22 (codenamed ‘Cabbage’ by the UESN) entered service in 2155, and was one of the most commonly encountered Romulan Cruisers during the war. The design was created to allow fleet advances across interstellar distance. They were equipped with a formidable arsenal of cluster missiles and Star Bombs, and also mounted the most powerful plasma weapon yet produced, and this could be carried for distances further than any other Romulan Cruiser save for the U-13A.

However, this massive capability came at a price; the amount of deuterium fuel required by the fusion reactors to give the required range meant that the ships weighed an estimated 500,000mt. Plans to use the twin-engine system developed for the U-20 were abandoned due to delays in that program, and a modified version of the long serving RFTL-3 was adopted in a triple nacelle arrangement. The massive mass of this class badly affected its manoeuvrability and performance at warp (2.5 maximum speeds).

Early in the War the U-22 was used to great effect, the firepower overwhelming many Earth Alliance ships, and the sheer size of the vessel meant that the damage inflicted on the U-22 was easily absorbed. Later in the war as newer designs entered service with Earth and its allies, the slow ponderous U-22s became easy prey.

The vulnerability of the U-22 was demonstrated very clearly at the battle of Hell’s Gate on 21-23 October 2157. This battle saw the Earth Alliance forces crush a massive Romulan Invasion attempt. 27 U-22 Cruisers were committed to this battle, and not even one survived, it is estimated that the Romulan loss of life in this battle was in excess of 30,000 crew and troops.

The cruiser was designated as the U-22A, at the start of the war some 75 U-22As were in service, and these were joint by a further 30 built during the war. Numerous variants of the U-22 also served during the war, despite the change in roles they were all classified as part of the same series and retained the U-22 designation. The U-22B (Codename ‘Tonsil’) was a tanker built to support long-range U-22A operations, production totalled 15. Armament was reduced to just the defensive cluster missiles.

U-22C (Codename ‘Rodent’) was used as a subspace sensor/communications ship, often deployed on long intelligence gathering sorties. This class retained the plasma cannon and cluster missile, but dispensed with the star bombs to allow for the fitment of advanced sensor equipment. Only 10 of these specialist intelligence ships were built. U-22D (Codename ‘Syrup’) was a specialist troop transport/assault ship; it could carry some 2000 troops. The weapons fit dispensed with plasma weapon, but retained a full missile arsenal for self-defence and planetary assault. The U-22D was the second most common variant, with some 35 seeing service.

The U-22 suffered from the compromise made in its design, Romulan fusion engine technology meant that the only way to gain a long range was to carry massive amounts of deuterium fuel, this fuel meant that the ship’s power efficiency and speed would always be inferior to ships built for speed and manoeuvrability, especially when those ships also used matter/antimatter propulsion.