The first of the Royal Navy's new 'D' Class destroyers are set to be launched early next year. HMS Daring, the seventh vessel to carry the name, will be the first of the Royal Navy's batch of Type 45 air defence destroyers. Armed with a new weapon system, Principal Anti-Air Missile System (PAAMS), at around 7,350 tonnes, the ships are the biggest and most powerful vessels of their type ever built for the Royal Navy. The Ministry of Defence has placed a contract with BAE Systems and other suppliers for the first three ships of the class, and negotiations continue for three more hulls. Destroyers are the workhorses of the fleet, optimised for air defence, while the smaller frigates are primarily designed to engage fast moving surface and subsurface targets. At home in large task groups or working independently, both types of ships may operate in enforcement, humanitarian relief or anti-drug patrol roles. Traditionally in naval terminology, a destroyer is a fast and manoeuvrable yet long-range warship intended to escort larger vessels in a fleet or battle group. Originally providing defence capabilities against smaller, short-range attackers, such as motor torpedo boats, though latterly submarines and aircraft, the destroyer's role is vital to many sea-borne operations.