SMS Kronprinz (1867)


 * For the German battleship that served during World War I, see SMS Kronprinz

SMS Kronprinz  was a unique German ironclad warship built for the Prussian Navy in 1866–1867. Kronprinz was laid down in 1866 at the Samuda Brothers shipyard at Cubitt Town in London. She was launched in May 1867 and commissioned into the Prussian Navy that September. The ship was the fourth ironclad ordered by the Prussian Navy, after SMS Arminius, SMS Prinz Adalbert (1865), and SMS Friedrich Carl (1867), though she entered service before Friedrich Carl. Kronprinz was built as an armored frigate, armed with a main battery of sixteen 21 cm (8.3 in) guns; several smaller guns were added later in her career.

Kronprinz saw limited duty during the Franco-Prussian War of 1870–1871. Engine troubles aboard the ship, along with the two other armored frigates in her squadron, prevented operations against the French blockade. Only two sorties in which Kronprinz participated were conducted, both of which did not result in combat. The ship served in the subsequent Imperial Navy until she was converted into a training ship for boiler room personnel in 1901. The ship was ultimately broken up for scrap in 1921.

General characteristics and propulsion
Kronprinz was 88.2 m long at the waterline and 89.44 m long overall. She had a beam of 15.2 m and a draft of 7.85 m forward and 7.45 m aft. The ship was designed to displace 5767 MT at a normal loading, and up to 6760 MT with a combat load. The ship's hull was constructed with transverse and longitudinal iron frames. It contained nine watertight compartments and a double bottom that ran for 43 percent of the length of the vessel. The ship was an excellent sea boat; the ship was responsive to commands from the helm but had a large turning radius. The ship's crew numbered 33 officers and 508 enlisted men. Kronprinz carried a number of smaller boats, including a large tender, two launches, a pinnace, two cutters, two yawls, and one dinghy.

The ship's propulsion system was built by J. Penn & Sons of Greenwich, England. A horizontal two-cylinder single expansion steam engine powered the ship. It drove a two-bladed screw 6.5 m in diameter. Eight trunk boilers, with four fireboxes in each, were divided into two boiler rooms. The boilers supplied steam to the engine at 2 atm. The propulsion system was rated at 4500 ihp and a top speed of 13.5 kn, though on trials Kronprinz managed to make 4870 ihp and 14.7 kn. The ship carried up to 646 MT of coal, which enabled a maximum range of 3200 nmi at a cruising speed of 10 kn and a range of 1730 nmi at 14 knots. A barque rig with a surface area of 1,980 square meters supplemented the steam engine. Steering was controlled with a single rudder.

Armament and armor
As built, Kronprinz was equipped with thirty-two rifled 72-pounder cannon. After her delivery to Germany, these guns were replaced with a pair of 21 cm L/22 guns and fourteen 21 cm L/19 guns. The L/22 gun could depress to −5 degrees and elevate to 13 degrees, which provided a range of 5900 m. The shorter barreled L/19 guns had a wider range of elevation, from −8 to 14.5 degrees, but the shorter barrel imposed a lower muzzle velocity, which correspondingly reduced the range of the gun to 5200 m. The two types of gun fired the same shell, of which the total supply numbered 1,656 rounds of ammunition. The fourteen L/19 guns were placed in a central battery amidships, seven on either broadside. The L/22 guns were placed on either end of the ship. Later in her career, six revolver cannon and five 35 cm torpedo tubes were added. Two of the tubes were placed in the bow, two on the ship's sides, and one in the stern on the port side. All were placed above water, and were supplied with 12 torpedoes.

Kronprinz's armor consisted of wrought iron backed with heavy teak planking. The iron component of the waterline armored belt ranged in thickness from 76 mm in the stern to 124 mm amidships and 114 mm toward the bow. The entire belt was backed with 254 mm of teak. The central battery was protected by 114 to 121 mm of sloped iron plating on 254 mm of timber. The battery's roof was protected by 9 mm thick iron plating.

Service history
Kronprinz was laid down in 1866 at the Samuda Brothers shipyard in London. The British naval architect Edward Reed designed the ship, and resulted in a vessel similar to the contemporary, French-built Prussian ironclad SMS Friedrich Carl. The ship was launched on 6 May 1867 and commissioned into the Prussian Navy four months later on 19 September 1867. On the voyage from England to Prussia, the ship lost her main mast in a storm. The ship immediately went into dock for refitting upon arrival in Prussia; the mast was repaired and the ship's armament was converted from the initial arrangement.

At the outbreak of the Franco-Prussian War in 1870, the greatly numerically inferior Prussian Navy assumed a defensive posture against a naval blockade imposed by the French Navy. Kronprinz and the broadside ironclads SMS Friedrich Carl (1867) and SMS König Wilhelm (1868), along with the small ironclad ram SMS Prinz Adalbert (1865), had been steaming in the English Channel before the French declared war; they had left Plymouth on 10 July with the intention of steaming to Fayal in the Azores. On the 13th, however, they put into port and learned of the rising tension between France and Prussia. The ships therefore returned to Wilhelmshaven immediately, arriving on 16 July. France declared war on Prussia three days later on 19 July. Kronprinz, Friedrich Carl, and König Wilhelm were concentrated in the North Sea at the port of Wilhelmshaven.They were subsequently joined there by the turret ship SMS Arminius, which had been stationed in Kiel. For the duration of the conflict, Kronprinz was commanded by Captain Reinhold von Werner.



Despite the great French naval superiority, the French had conducted insufficient pre-war planning for an assault on the Prussian naval installations, and concluded that it would only be possible with Danish assistance, which was not forthcoming. The four ships, under the command of Vice Admiral Jachmann, made an offensive sortie in early August 1870 out to the Dogger Bank, though they encountered no French warships. Kronprinz and the other two broadside ironclads thereafter suffered from chronic engine trouble, which left Arminius alone to conduct operations. Kronprinz, Friedrich Carl, and König Wilhelm stood off the island of Wangerooge for the majority of the conflict, while Arminius was stationed in the mouth of the Elbe river. On 11 September, the three broadside ironclads were again ready for action; they joined Arminius for another major operation into the North Sea. It too did not encounter French opposition, as the French Navy had by this time returned to France.

Engine problems plagued the ship throughout her career; Kronprinz's engines broke down during the fleet maneuvers in May 1883. Two of the three other armored frigates also broke down, which forced the cancellation of the maneuvers. Kronprinz had anti-torpedo nets installed in 1885; these were removed in 1897. The ship served on active duty with the fleet until 22 August 1901, when she was stricken from the naval register. She was reconstructed at the Imperial Dockyard in Kiel that year. The propulsion system was overhauled and the eight J Penn & Sons boilers were removed. Two Dürr and two Thornycroft boilers were installed in their place. Her barque rig was cut down to 1409 m2. After emerging from the reconstruction, Kronprinz served as a training ship for engine-room personnel, based in Kiel. The ship was ultimately sold to Bonn, a German ship-breaking firm, on 3 October 1921 for 5,000,000 marks. Kronprinz was broken up for scrap in Rendsburg-Audorf later that year.