Siegfried-class coastal defense ship

The Siegfried class was a group of six coastal defense ships built by the German Kaiserliche Marine in the late 19th century. The ships were intended to protect the German coastline from naval attacks. The class comprised the lead ship, along with her sisters,,,, and. All six ships were named after Norse mythological figures. Two further vessels, the, were built to a similar design but were not identical.
The Siegfried-class ships were obsolete by the outbreak of World War I, and saw only limited service in their intended role before they were withdrawn from active duty. The ships then served in a variety of secondary duties, including barracks ships, target ships, and in the case of Beowulf, an icebreaker in the Baltic Sea. All six ships were struck from the naval register on 17 June 1919, days before the Treaty of Versailles was signed. Five of the ships were sold for scrapping immediately after they were struck from the register, but Frithjof was purchased by a shipping company, and converted into a freighter. She served in this capacity until she too was scrapped in 1930.

Development

Dietrich's proposal for a 2,500-ton coastal defense ship from the 1886 memorandum was selected for development into the ship that was to be built. The vessel was to incorporate the following set of characteristics: a main battery of two guns supported by a secondary battery of six Hotchkiss revolver cannon; four torpedo tubes; a speed of. This was to be achieved at a cost of 3.5 million marks. The two heavy guns were carried in open barbettes side-by-side forward, as German naval theorists still favored ramming attacks that required a capability for end-on fire. They carried the guns in individual barbette mounts that could be independently aimed, rather than a single rotating barbette as had been done with the s. In addition, the hull was given a pronounced tumblehome shape to provide as wide a field of fire as possible. German tactical doctrine envisioned the ships breaking through an enemy line of battle, and the arrangement would have allowed each ship to engage multiple targets.
Displacement quickly rose to, which permitted the installation of a third 24 cm gun aft. The third gun was deemed necessary to improve the ability to fire astern if the ships were forced to retreat into the rivers near the ends of the canal. Weapons tests were held at the Krupp testing grounds at Meppen in 1888, using mock-ups of contemporary torpedo-boat designs. It was determined that the 37 mm Hotchkiss was unable to inflict serious damage at the expected battle range of, and so the secondary battery was replaced with guns, though these had not performed entirely adequately in the tests either. The first vessel received six of the new guns, while all subsequent ships were fitted with eight.
As construction work on the initial vessels proceeded in the early 1890s, alterations to the program continued. Of the ten vessels initially requested and slowly approved, the last pair were removed from the building program. Vessels seven and eight were altered slightly, becoming the, which Dirk Nottelmann and David Sullivan refer to as "somewhat of a sub-class." The most radical proposal for the Odin class would have seen them rearmed with four 24 cm guns, but placed in a pair of twin-gun turrets, as German tactical doctrine had returned to the line of battle by that time, meaning that a heavier broadside of four guns was seen as more important than two guns able to fire ahead independently. Additional changes would have been made to the hull to compensate for the weight of the fourth gun, including the adoption of lighter Krupp armor instead of the old compound armor used in the earlier ships, but the plan came to nothing, and the two Odins were completed with the basic Siegfried layout.

Design

General characteristics and machinery

The ships of the Siegfried class were long at the waterline and long overall. The ships had a beam of and a draft of between forward and aft. The ships had a designed displacement of, and a maximum displacement of. The ships used transverse and longitudinal steel frames in the hull. They had eight watertight compartments and a double bottom that ran for 60% of the hull. The hulls had a pronounced ram bow and tumblehome shape, and their upper deck extended from the bow to the main mast, where it stepped down one level. Their superstructures consisted of an armored conning tower forward and a smaller secondary platform further aft. Each ship was fitted with a pair of pole masts for signaling purposes.
The ships were described as good sea boats; they had gentle motion and were very responsive to commands from the helm. Steering was controlled via a single rudder. The ships lost significant speed in heavy seas, however, and suffered from severe weather helm. The ships had a crew of 20 officers and 256 enlisted men, with an additional 6 officers and 22 men when serving as a flagship. The ships carried a number of smaller boats, including one picket boat, one pinnace, two cutters, one yawl, and one dinghy.
The ships were powered by two sets of 3-cylinder triple-expansion engines, each in its own engine room. This was the first use of triple-expansion machinery in a major German warship. These engines drove a pair of three-bladed screws that were in diameter. The ships had eight marine type boilers, with the exception of Hagen, which was equipped with eight Thornycroft boilers. On all vessels, the boilers were vented through a single funnel located amidships. The ships' propulsion systems produced between, which produced top speeds of ; Beowulf was the fastest and Heimdall was the slowest. The ships stored up to of coal and of fuel oil, which enabled a range of at a cruising speed of. At, the ships could only steam. Each ship had three electric generators that provided between 29–26 kilowatts at 67 volts.

Armament

The ships' primary armament consisted of three 24 cm K L/35 guns. These were placed in an unusual arrangement for such large guns, two of which were mounted in a pair of rotating barbettes forward side-by-side, while the third was mounted in a single barbette aft. The barbette mounts were the MPL C/88. Each gun had a range of elevation from -3 to +25 degrees, and at maximum elevation, the guns had a range of. Ammunition storage amounted to 204 rounds, or 68 shells per gun. The ships were initially supplied with C/80 armor-piercing and common shells, which weighed ; these were later replaced by C/01 shells and eventually a C/01/07 semi-armor-piercing shell that weighed. Muzzle velocity for the guns was initially, using the C/80 shell, but increased to with the C/01 and later variants.
For close-range defense against torpedo boats, the ships had a secondary battery of eight 8.8 SK L/30 guns with 1,500 rounds of ammunition, though Siegfried only had six of these guns. Their ammunition came in the form of a fixed cartridge that weighed. The 8.8 cm gun fired a projectile at a muzzle velocity of. At a maximum elevation of 20 degrees, the guns could engage targets out to ; the guns could be depressed to -10 degrees, since they were intended to engage targets at very close range.
The ships were also equipped with four torpedo tubes. One tube was mounted in the stern in an above-water swivel mount, two were placed laterally, also above water, and the fourth was in the bow. The torpedo tubes were supplied with a total of 10 torpedoes.

Armor

The ships' armor consisted of compound steel for the first three ships and Krupp armor for the last three, coupled with teak. The upper section of the main armored belt was thick in the central citadel of the ship and reduced to at either end. This was mounted on of timber. The lower section of the belt was thick in the central area, and on the bow and stern. This portion of the armored belt was mounted on of timber. The main armored deck was thick, though on Hagen and Heimdall this was increased to. The conning tower had a roof that was thick and sides that were thick; the armor protection on the conning tower sides was also increased on Hagen and Heimdall, to.

Modifications

All six ships were heavily rebuilt, each undergoing refits at various times between 1898 and 1904. During the rebuilding, the ships were lengthened, to at the waterline and overall, which included the addition of another watertight compartment. The ships' beams remained the same, but their draft was slightly decreased, to forward and aft. After the reconstruction, the displacement was increased to between, depending on the ship. With the refit, fuel bunkerage was more than doubled, to of coal and of oil. This dramatically increased the sailing range, to at 10 knots and at 14 knots. Siegfried received completely oil-fired boilers during her refit in 1895, but these boilers proved to be very inefficient and she later received the mixed-firing boilers installed on the other vessels. Each vessel received a second funnel to improve ventilation from the boilers.
The refit also revised the ships' armament slightly, including increasing the number of 8.8 cm guns to ten, including Siegfried. The munition storage for these weapons correspondingly increased to 2,500 rounds. The stern and lateral torpedo tubes were replaced with weapons, but the lateral torpedo tubes were submerged. They had 8 torpedoes between them. The bow tube was retained, but also moved below the waterline; it had three torpedoes. The refit increased crew requirements, to an additional 31 sailors normally, and the extra flagship crew increased to 9 officers and 34 men.

Ships in class

Ship name	Builder	Contract name	Laid down	Launched	Commissioned	Decommissioned	Fate
	Germaniawerft, Kiel	O	1888	10 August 1889	29 April 1890	14 January 1916	Sold for scrap, 1920
	AG Weser, Bremen	P	January 1890	8 November 1890	1 April 1892	30 November 1918	Sold for scrap, 1921
	AG Weser, Bremen	Q	February 1890	21 July 1891	23 February 1893	16 January 1916	Sold for scrap, 1930
	Kaiserliche Werft Wilhelmshaven, Wilhelmshaven	U	2 November 1891	27 July 1892	7 April 1894	2 March 1916	Sold for scrap, 1921
	Kaiserliche Werft Kiel, Kiel	R	9 December 1890	6 August 1892	28 October 1893	16 January 1916	Sunk while en route to scrapping, 1919; raised and scrapped, 1933
	Kaiserliche Werft, Kiel	S	September 1891	21 October 1893	2 October 1894	1 September 1915	Sold for scrap, 1919

Service history

The ships of the Siegfried class saw only limited service in their intended roles. The revolutions in capital ship building in the first decade of the 20th century rapidly made these ships obsolete. The Second Naval Law, passed on 27 March 1908, reduced the service life of all capital ships from 25 years to 20 years. This meant that the Siegfried-class ships, along with a number of other vessels, were to be replaced as soon as possible. Siegfried, Beowulf, and Frithjof were replaced by the s,, and. Heimdall, Hildebrand, and Hagen were replaced by the s,, and, respectively.
As the new battleships were intended for offensive operations, the Siegfried class was still retained for coast defense duties. The ships served in this capacity through the start of World War I, until they were withdrawn from active service in 1915. Afterward, all six ships served in a variety of secondary roles, primarily as barracks ships. All six ships were struck from the naval register on 17 June 1919, shortly before the Treaty of Versailles, which ended the First World War, was signed. Siegfried was a barracks ship in Wilhelmshaven from 1916. She was intended to be rebuilt as a salvage ship, but this plan was abandoned and the vessel was sold to H. Peters, Wewelsfleth, in 1919 for 425,000 marks. She was broken up in 1920 in Kiel. Beowulf served as a target ship for U-boats from 1916 to 1918, when she transitioned to ice-breaking duty in the Baltic Sea. Frithjof was a barracks ship in Danzig after 1916. Following her removal from navy service, she was sold to A Bernstein in Hamburg. She was rebuilt as a freighter by Deutsche Werke, and served in this capacity until she was broken up in 1930. She was the longest serving Siegfried-class ship.
Heimdall was a barracks ship for the crews of U-boats and the Ems coast defense flotilla based in Emden. Like Siegfried, Heimdall was intended to be reconstructed as a salvage ship, and this was likewise abandoned. She was broken up for scrap metal in 1921. Hildebrand was a barracks ship in Windau after she was removed from active duty. She was sold to a Dutch ship-breaking firm in 1919, but while en route to the scrapyard, she became grounded on the Dutch coast. The wreck was blown up in 1933, and eventually scrapped in situ. Hagen was a barracks ship in Libau, Danzig, and Warnemünde during the remainder of World War I. She was sold for scrapping to Norddeutsche Tiefbaugesellschaft after the end of the war.