The Treaties that had ruled shipbuilding for nearly ten years failed in 1930. This allowed for an increase in the size and capabilities of all classes of warship, including destroyers. The Panagaean Navy wanted a 2,000 ton destroyer armed with dual purpose 4.5" guns in twin turrets with good speed and range. The Holy Trinity of shipbuilding. An improved Albacore was to be created. The Vendace would be fitted with three twin 4.5" turrets with power training and loading. Quad 2 pounder and 20mm Hispano-Suiza cannons for the light AA, with two sets of quadruple torpedo tubes.
The extra length required forward was to accommodate a bigger bridge superstructure and, most of all, larger magazine space for the forward 4.5". The power operated turrets and guns fired almost 50% faster than the manual single 4.5" on the Albacore Class. Advances in technology are wonderful. The Vendace had the first experimental radar predictor for the 2 pounder mounting fitted in 1938 and once proven, these were fitted to the class as their refit cycles came around. The bigger bridge was meant to allow any of the ships to be operated as a Flotilla Leader. In reality, eight of the class with two Tribal class would be the main screening vessels for the main fleet. The Fleet Admirals wanted the best ships around them.
The remainder of the class that made it to early 1943 looked like the above drawing. The twin 40mm, with predictors, replaced the older AA weapons, with much more capable guns. More depth charges and throwers, Hedgehog mortars, better Asdic, all were fitted to enhance the ASW capabilities. The class kept its torpedo tubes, being the main Fleet destroyers operating with the big carriers and battleships.