HMS Shah and Amethyst in Action against the Peruvian Renegade Huascar, 29 May 1877 (NMM)
The dilemma of how to protect British interests overseas and police the world’s sea lanes without armored warships became apparent off the west coast of South America in May 1877, where the 6,250-ton Shah, iron-hulled but not armored, served as Pacific flagship at a time when Britain temporarily had no ironclads in the Pacific Ocean. On 7 May naval officers sympathetic to a Peruvian coup seized the 2,030-ton armored turret ship Huáscar. After leaving Callao, the Huáscar stopped at least four British merchant steamers on the high seas, stealing coal, taking mail addressed to the government of Peru, and taking some passengers prisoner. These violations of international law were brought to the attention of the British navy, and on 29 May the Shah and its escort, the 1,970-ton wooden screw corvette Amethyst, intercepted the Huáscar in the bay of Pacocha. During two hours of combat the Shah alone fired 237 rounds and the two British ships together registered more than 50 hits on the Huáscar, without seriously damaging it. The Shah also fired the first self-propelled torpedo ever used in a naval action, which missed its target. The Huáscar carried two 10-inch muzzle-loading rifles in a Coles turret protected by 8-inch wrought iron armor, but because its gunners were inexperienced and its turret had to be cranked by hand (with sixteen men manning the levers, it could make one revolution in fifteen minutes), it fired only a half-dozen rounds and registered no hits. That night, the Huáscar escaped Pacocha under cover of darkness and steamed for Iquique, where it surrendered to Peruvian authorities the following day. The incident demonstrated that even a lone relatively antiquated ironclad could defy the will of the world’s greatest naval power if the latter had no armored warship in the area. Britain responded by sending two ironclads to the Pacific, and after 1881 maintained at least one there.