warfare; once again the fleet destroyers were ill-equipped for combatting these new targets. They were fitted with new anti-aircraft guns, radar, and forward-launched ASW weapons, in addition to their existing light guns, depth charges, and torpedoes. By this time the destroyers had become large, multi-purpose vessels, expensive targets in their own right rather than expendable vessels for the protection of others; moreover, they were one of the most sunk kinds of ships even though they were mass produced. This led to the introduction of smaller and cheaper specialized anti-submarine warships called corvettes and frigates by the Royal Navy and destroyer escorts by the USN. These ships had the size and displacement of the original torpedo boat destroyers the contemporary destroyer had evolved from.

Post-war

Some conventional destroyers were completed inthe late 1940s and 1950s which built on wartime experience. These vessels were significantly larger than wartime ships and had fully automatic main guns, unit Machinery, radar, sonar, and antisubmarine weapons such as the Squid mortar. Examples include the British Daring class, US Forrest Sherman-class, and the Soviet Kotlin-class destroyers.

Some World War II-vintage ships were modernised for anti-submarine warfare, and to extend their service lives, to avoid having to build (expensive) brand-new ships. Examples include the US FRAM I programme and the British Type 15 frigates converted from fleet destroyers.

Modern destroyers

The Canadian Navy currently operates the Iroquois-class destroyers, a class of four helicopter-carrying, anti-aircraft, guided missile destroyers. Launched in the 1970s, the Iroquois were the first Canadian all gas turbine powered military ships, using two turbines for cruise