Assault class

From Memory Alpha, the free Star Trek reference

The Assault-class was a type of starship utilized by the Hierarchy in the 24th century. It is equipped with short and long range sensors, stealth technology and phasers that can be set to fire with rotating frequencies.

These ships are used to survey passing ships for future raids, on at least one occasion while hiding in nebulae . The hierarchy uses the ships sensors to assess the tactical risk of attacking passing vessels and the available loot. They use the ships cloak tehnology to sneak up on other ships. The Hierarhy apply several attack patterns for use aboard this type of ship, such as a Type 3 stealth assault and a Type 4 assault, which is based on energy consumption (See Hierarchy for elaboration). A special communication system aboard these ships are used by the crew for consulting with the actual Hierarchy. On these ships every crew member has one duty and work station, hardly any social contacts and limited access to the ship.

In 2376, three vessels of this type attacked the Federation starship USS Voyager, the ships eventually withdrew in fear of the photonic cannon, an imaginary weapon of the Doctor's design. (VOY: "Tinker Tenor Doctor Spy")