A mechanical torpedo, also known as a self-propelled torpedo, refers to a type of underwater missile that is powered by an engine and can be controlled remotely to seek and destroy underwater targets. Some synonyms for this type of torpedo include powered torpedo, guided torpedo, and autonomous torpedo. These torpedoes can be deployed from ships, submarines, or even aircraft and are a significant part of naval weaponry. As technology has advanced, newer types of torpedoes have been developed, such as electric torpedoes and acoustic homing torpedoes, which can be more accurate and deadly than their mechanical counterparts.