the bow. One spar torpedo was hinged on each side of the ship on a boom that was extended until it was angled at 90° to the ship's side. Furthermore, two towed Harvey torpedoes were mounted at the rear of the ship. While Petr Veliky was not really maneuverable enough to make full use of these weapons, they were a formidable deterrent to other ships trying to ram. Armor Petr Veliky had a complete waterline belt of wrought iron, imported from Charles Cammell & Co. of Sheffield, England, that was intended to extend below the waterline at the designed displacement. The belt was 14 inches thick for the middle of the ship, but reduced, in steps, to at the bow and at the stern. It was backed by multiple layers of teak and iron, thought to be equivalent of another of armor. The breastwork was also 14 inches thick, although the curved portions at the end of the breastwork were Hughes compound armor because very thick plates could not be bent easily. The compound armor consisted of two plates separated by a layer of teak. This type of armor was also used to protect the gun turrets. Outside the breastwork, the ship's deck was armored with three 1-inch mild steel plates. The deck protection over the redoubt was either or three inches thick: sources vary. Service Petr Veliky was built by the state-owned Galernii Island Shipyard in Saint Petersburg. Construction began on 1 June 1869, although her keel was not laid down until 23 July 1870. Launched on 27 August 1872, she entered service with the Baltic Fleet on 14 October 1876. She cost a then-staggering sum of over five and a half million rubles. Two 9-inch mortars were fitted on her quarterdeck during the war scare with Britain during the Russo-Turkish War of 1877–78, but they were removed in 1880 without ever having been used in combat. Two frames for launching Whitehead torpedoes were added to the ship's sides in that same year, but they proved ineffective. Her original machinery proved unsatisfactory, and the Baird Works forfeited a payment of 254,000 rubles as penalty. The Imperial Russian Navy began to investigate replacing the ship's machinery in 1878, and a contract was finally signed with John Elder & Co., in Glasgow, Scotland, in October 1880, based on the Navy's favorable experience with the company's construction of the Imperial yacht .