SMS Prinz Heinrich SMS " Prinz Heinrich " was a unique German armored cruiser built at the turn of the 20th century for the Imperial German Navy , named after Kaiser Wilhelm II ' s younger brother Prince Henry . " Prinz Heinrich " was built at the Imperial Dockyard in Kiel . She was laid down in 1898 and completed in March 1902 , at the cost of 16 , 588 , 000 Marks . " Prinz Heinrich " s design was a modification of the previous armored cruiser , , and traded a smaller main battery for higher speed and more comprehensive armor protection . The ship set a precedent for subsequent German armored cruisers by concentrating her secondary armament amidships , as opposed to " Fürst Bismarck " , which spread the secondary armament along the length of the ship . " Prinz Heinrich " served with the German fleet for the majority of her career . After the outbreak of World War I in August 1914 , the ship participated in the operation against the British coast in December 1914 , after which she was transferred to the Baltic Sea . Here , she operated against the Russian navy and was involved in the Battle of the Gulf of Riga in August 1915 , where she damaged a Russian destroyer . In 1916 , the ship was withdrawn from active duty and was used in several secondary roles in Kiel , including acting as a floating office for naval staff . " Prinz Heinrich " was ultimately sold in 1920 and broken up for scrap later that year . Design . The Second Naval Law in Germany , passed in 1900 , envisioned a force of fourteen armored cruiser s intended for overseas service in the German colonies . However , the German Navy required cruisers for operations with the fleet as well , and attempted to design ships that could fulfill both roles , primarily due to budget constraints . The first product of the 1900 Naval Law , " Prinz Heinrich " was an alteration of an earlier vessel , , and was equipped with fewer guns and thinner armor in a trade - off for higher speed and lower cost . The design also set the precedent of concentrating the secondary battery amidships ; " Fürst Bismarck " secondary guns had been spread along the length of the hull . All subsequent armored cruisers were developments of " Prinz Heinrich " . " Prinz Heinrich " was laid down in 1898 at the Imperial Dockyard in Kiel . She was launched on 22 March 1900 and completed just under two years later , on 11 March 1902 . The new cruiser cost 16 , 588 , 000 Marks . Dimensions and machinery . " Prinz Heinrich " was long at the waterline and overall . She had a beam of and a draft of forward and aft . The ship displaced as built , and at full combat load . The hull was constructed with transverse and longitudinal steel frames , and incorporated thirteen watertight compartments and a double bottom that extended for 57 percent of the length of the ship . The German navy considered the ship to be a good sea boat with gentle motion , though she suffered from severe roll . Her transverse metacentric height was . " Prinz Heinrich " was manned by a crew of 35 officers and 532 enlisted men . For the duration of her career as the second command flagship of the Cruiser Division , the standard crew was augmented by an additional nine officers and 44 enlisted men . She carried a number of smaller vessels , including two picket boats , a launch , a pinnace , two cutters , two yawls , and two dinghies . The ship was propelled by three vertical 4 - cylinder triple expansion engines ; the center shaft drove a four - bladed screw in diameter while the two outer shafts drove wide four - bladed screws . Fourteen Dürr boilers , produced by " Düsseldorf - Ratinger Röhrenkesselfabrik " , supplied steam to the engines at pressures up to . The propulsion system was rated at and gave the ship a top speed of , though on sea trials , " Prinz Heinrich " s engines reached but a top speed of only . She was designed to carry of coal , though additional storage allowed up to . This enabled a maximum range of at a speed of and at a cruising speed of . Armor . " Prinz Heinrich " was protected by Krupp armor . Her armor belt was thick in the central portion of the ship , which protected the ammunition magazines , machinery spaces , and other vital areas of the cruiser . The belt was reduced to on either end of the main belt , and the bow and stern were unarmored . The entire length of the belt was backed by equal thicknesses of teak planks . The armored deck was thick and was connected to the belt by thick sloped armor on the broadside . The forward conning tower had thick sides and a thick roof . The aft conning tower was much less thoroughly protected ; it was covered by only of steel plating . The main battery gun turrets had 150 mm - thick sides and 30 mm - thick roofs . The 15 cm gun turrets had 100 mm - thick armor , while the casemated weapons were protected by gun shields . The casemates themselves were armored with 100 mm worth of steel plating . Armament . " Prinz Heinrich " was armed with a variety of weapons . Her primary armament consisted of two SK L / 40 quick - firing guns mounted in single turrets , one on either end of the superstructure . These guns were supplied with 75 rounds each ; they could depress to −4° and elevate to 30° , which enabled a maximum range of . The guns fired a round at a muzzle velocity of per second . A secondary battery of ten SK L / 40 quick - firing guns rounded out her offensive armament . Six of these guns were mounted in amidships casemate s on either side of the vessel , and the remaining four were mounted in turrets in the ship ' s hull above the casemates . These guns were supplied with 120 rounds each . The shells weighed and were fired at a muzzle velocity of per second . The guns could elevate to 25° for a maximum range of . The cruiser carried ten SK L / 30 quick - firing guns for defense against torpedo boat s . Each of these guns was supplied with 250 shells . The shells weighed and were fired at a muzzle velocity of per second . This enabled a maximum range of at an elevation of 20° . The ship ' s gun armament was rounded out by four autocannons , though these were subsequently removed . The ship was also fitted with four torpedo tubes . One was mounted on the stern in a swivel mount , one was mounted submerged in the bow , and one was placed submerged in the hull on either side abreast of the forward gun turret . Service history . Following her commissioning in 1902 , " Prinz Heinrich " served with the fleet . She was the flagship of the Cruiser Division , along with the protected cruiser and eight light cruiser s . In January 1904 , the cruiser and two passenger ships went to the Norwegian town of Ålesund in the aftermath of a fire that destroyed the town . The ships carried supplies and medical stores to the port and assisted with the relief effort . She was reassigned to the II Subdivision of the Cruiser Division of the Active Fleet in 1905 , after the arrival of the new armored cruiser . The II Subdivision also included the light cruisers , , and , and was attached to the II Squadron of the Active Fleet . A second subdivision , composed of an armored cruiser and three light cruisers was attached to the I Squadron . " Prinz Heinrich " conducted a series of tests with the Miller apparatus , a device used by the US Navy to resupply warships at sea , in February 1907 . The ship engaged in the experiments with the collier " Hermann Sauber " ; the first test took place on 17 February , and resulted in the crew being able to transfer of coal per hour . On the 22nd , another test was undertaken , under harsh weather conditions , and similar results were reached . In 1914 , " Prinz Heinrich " went into drydock at the Imperial Dockyard in Kiel for modernization . The arrangement of the searchlights was modified , the superstructure deck bulwark was removed , and the masts were modernized . Following the improvements , she returned to the fleet . World War I . Following the wave of declarations of war between the major European powers at the end of July 1914 , Britain declared war on Germany on 5 August . " Prinz Heinrich " participated in the second major German offensive in the North Sea , the operation to bombard Hartlepool on 15 – 16 December 1914 . " Prinz Heinrich " , along with and a flotilla of torpedo boats , was assigned to the van of the High Seas Fleet , commanded by Admiral Friedrich von Ingenohl . The main fleet was providing distant cover to Rear Admiral Franz von Hipper ' s battlecruisers , which were conducting the bombardment . During the night of the 15th , the German battle fleet of some twelve dreadnought s and eight pre - dreadnought s came to within of an isolated squadron of six British battleships . However , skirmishes between the rival destroyer screens in the darkness convinced von Ingenohl that he was faced with the entire Grand Fleet . Under orders from Kaiser Wilhelm II to avoid risking the fleet unnecessarily , von Ingenohl broke off the engagement and turned the battle fleet back toward Germany . After the operation , it was determined that the twelve - year old " Prinz Heinrich " had no place in operations against the powerful British Grand Fleet , and she was transferred to the Baltic Sea to operate against the Russian Baltic Fleet . Rear Admiral Hopman , the commander of the reconnaissance forces in the Baltic , conducted a major assault on Libau , in conjunction with an attempt by the German Army to seize the city . The attack took place on 7 May , and consisted of " Prinz Heinrich " and the armored cruisers and , the elderly coast defense ship , and the light cruiser s , , and . They were escorted by a number of destroyers , torpedo boats , and minesweepers . The IV Scouting Group of the High Seas Fleet was detached from the North Sea to provide cover for the operation . The bombardment went as planned , though the destroyer struck a mine in Libau ' s harbor , which blew off her bow and destroyed the ship . German ground forces were successful in their assault however , and took the city . On 1 July , the minelayer , escorted by the cruisers " Roon " , " Augsburg " , and " Lübeck " and seven destroyers , laid a minefield north of Bogskär . While returning to port , the flotilla separated into two sections ; " Augsburg " , " Albatross " , and three destroyers made for Rixhöft while the remainder of the unit went to Libau . " Augsburg " and " Albatross " were intercepted by a powerful Russian squadron commanded by Rear Admiral Bakhirev , consisting of three armored and two light cruisers . Commodore Johannes von Karpf , the flotilla commander , ordered the slower " Albatross " to steam for neutral Swedish waters and recalled " Roon " and " Lübeck " . " Albatross " was grounded off Gotland and " Augsburg " escaped , and the Russian squadron briefly engaged " Roon " before both sides broke contact . Upon being informed of the situation , Hopman sortied with " Prinz Heinrich " and " Prinz Adalbert " to support von Karpf . While en route , the cruisers encountered the British submarine , which scored a hit on " Prinz Adalbert " . Hopman broke off the operation and returned to port with the damaged cruiser . German naval forces in the Baltic were reinforced by elements of the High Seas Fleet during the Battle of the Gulf of Riga in August 1915 . The Germans sought to drive out the Russians in the Gulf of Riga and to lay defensive minefields that would prevent a Russian counterattack . The battleship s of the I Battle Squadron were the primary force , though " Prinz Heinrich " and the rest of the older vessels assigned to the Baltic fleet participated . On 10 August , " Prinz Heinrich " and " Roon " bombarded Russian defenses at Zerel , on the southernmost tip of the Sworbe Peninsula on the island of Ösel . Several Russian destroyers were anchored off Zerel , and were caught unawares by the German bombardment . " Prinz Heinrich " and " Roon " damaged one of the destroyers during their attack . A combination of tenacious Russian defense and reports of British submarines in the area — proved by the torpedoing of the battlecruiser on 19 August — caused the German navy to break off the operation . Beginning in 1916 , " Prinz Heinrich " was removed from front - line service and used as a floating office in Kiel . After she left active duty , the ship had her armament removed . She was subsequently used as a tender , also in Kiel , for the remainder of her service career . She was stricken from the navy list on 25 January 1920 and sold later that year . The ship was ultimately broken up for scrap at Audorf - Rendsburg .