had a small light, only visible from the rear. Two steel drums were mounted one behind the other inside the torpedo, each carrying several thousand yards of high-tensile steel wire. The drums connected via a differential gear to twin contra-rotating propellers. If one drum was rotated faster than the other, then the rudder was activated. The other ends of the wires were connected to steam-powered winding engines, which were arranged so that speeds could be varied within fine limits, giving sensitive steering control for the torpedo. The torpedo attained a speed of using a wire in diameter but later this was changed to to increase the speed to . The torpedo was fitted with elevators controlled by a depth-keeping mechanism, and the fore and aft rudders operated by the differential between the drums. Brennan traveled to Britain, where the Admiralty examined the torpedo and found it unsuitable for shipboard use. However, the War Office proved more amenable, and in early August 1881, a special Royal Engineer committee was instructed to inspect the torpedo at Chatham and report back directly to the Secretary of State for War, Hugh Childers. The report strongly recommended that an improved model be built at government expense. In 1883 an agreement was reached between the Brennan Torpedo Company and the government. The newly appointed Inspector-General of Fortifications in England, Sir Andrew Clarke, appreciated the value of the torpedo and in spring 1883 an experimental station was established at Garrison Point Fort, Sheerness, on the River Medway, and a workshop for Brennan was set up at the Chatham Barracks, the home of the Royal Engineers. Between 1883 and 1885 the Royal Engineers held trials and in 1886 the torpedo was recommended for adoption as a harbor defense torpedo. It was used throughout the British Empire for more than fifteen years. Use in conflict The Royal Navy frigate was the first naval vessel to fire a self-propelled torpedo in anger during the Battle of Pacocha against rebel Peruvian ironclad on 29 May 1877. The Peruvian ship successfully outran the device. On 16 January 1878, the Turkish steamer Intibah became the first vessel to be sunk by self-propelled torpedoes, launched from torpedo boats operating from the tender under the command of Stepan Osipovich Makarov during the Russo-Turkish War of 1877–78. In another early use of the torpedo, during the War of the Pacific, the Peruvian ironclad Huáscar commanded by