Why Tribals paired heavy guns with quadruple torpedoes

Why did navies choose 5-inch/38 or 4.5-inch dual-purpose guns, and why did Tribal-class destroyers use quadruple torpedo launchers?

Gun choice reflected different priorities for shell weight and rapid general-purpose fire; a quadruple launcher put more Tribal torpedoes into one spread and improved the chance of a hit.

The US Navy preferred the larger 5-inch/38, while the Royal Navy sought to make the 4.5-inch gun a rapid-firing general-purpose weapon. The choices reflect different balances between shell weight, anti-ship effect, and sustained dual-purpose fire. On the Tribal-class destroyers, a quadruple launcher concentrated the available torpedoes in one mount. More weapons in a single spread increased the chance that at least one would hit. Later quintuple launchers and the T-class submarine provide further examples of the same broad-salvo logic.