Quick-firing guns build the first anti-torpedo-boat layer

HMS Lightning entered service in 1876, a decade after the initial Whitehead design and five years after the Royal Navy bought production rights. The Royal Navy answered the threat from lightly built torpedo boats with 47 mm three-pounders and 57 mm six-pounders that could destroy fragile attackers with one or two hits. HMS Collingwood of the Admiral class illustrates their adoption, following gradual fitting and improvement across the fleet. These light weapons were easy to maintain and compact enough to distribute around a battleship without obstructing its primary armament. They formed a close defensive layer intended to stop a torpedo boat before it reached a reliable launch range. The comparison with aircraft defence and the Type 31 frigate's weapons against uncrewed systems concerns the recurring need for compact, rapid-firing guns against small attackers.