KMS Deutchland Design
In an attempt to limit the powerand range of the German Navy, the allies placed a 10,000-ton displacement limit on newships. The intent of the limit was to keep the Germans from developing anything beyond small, coastal defense ships. However, innovations in welding techniques, new alloys, and lighter diesel engines allowed the German Navy to produce the lightweight Deutschland class ships that had formidable range and fire-power. These "pocket battleships" proved tobe a deadly sea force during World War II in spite of earlier treaty limitations.
A number of technical innovations were used by the Germans to build a powerful warship within displacement limit. Among these innovations were the large-scale use of welding to join hull components (as opposed to the then-standard rivets), triple-gun main armament turrets (first used by the Austro-Hungarian Navy in the Viribus Unitis class battleships of 1912), and the use of diesel engines for propulsion. Even so, all members of the class were well over that displacement limit (first constructed as 10,600 tons, later enlarged to 12,100 tons).
The result was a pocket battleship that had guns (6 x 280mm/11" calibre) large enough to out-gun any enemy cruiser fast enough to catch them, while being fast enough to outrun any enemy battleship powerful enough to sink them. The pocket battleship's speed and main armament made them very difficult to engage, as they could generally avoid any fight they did not like. The intent was not to engage a main battle fleet, but commerce raiding.
The main guns were six 280 mm (11 in) guns in two turrets (one forward and one aft). Secondary armament was eight 150 mm (5.9 in) guns, fitted in single shielded mounts (four to port and four to starboard). Anti aircraft defense consisted of three World War One vintage 88 mm (3.5 in) guns were provided (one on each side of the funnel, and one on the centerline aft), along with eight 37 mm (1.5 in) guns in twin mounts and four single 20 mm (0.8 in) machineguns. Eight torpedo tubes were mounted at the stern aft of the turret, four on each side. Before World War II the single 88 mm guns were replaced with twin mounts, and further modifications to the light guns were made throughout the war.
The armor was designed to save weight wherever possible, with reduced thickness inside the longitudinals and tapering forward and aft. The main belt was 80 mm (3.1 in) thick, with 45 mm (1.8 in) deck armor outside the longitudinal armor and 30 mm (1.2 in) inside. The turrets had 140 mm (5.5 in) front, 80 mm (3.1 in) sides and 105 mm (4.1 in) roof. The conning tower had 140 mm (5.5 in) protection.
Diesel engines were chosen for the main machinery, in contrast to the steam turbines fitted in ships of other navies, as it was hoped that this would save weight. Eight engines provided power to the two propeller shafts, for 56,800 shp, giving a maximum speed of 28 knots. Fuel capacity was 3,347 m3 (118,198 ft3), sufficient to allow 18,650 nm at 15 knots, or 7,149 nm at 26 knots.
The displacement did not permit more than a modest scale of armor protection, a 3.25-inch belt and a 3.75-inch deck, which was no better than the best heavy cruisers in other navies. Her speed was only 26 knots, enough to outrun contemporary battleships but nowhere near enough to outrun cruisers. The diesels proved disappointing in service, and as battleship speeds soon rose to 28-30 knots, the rationale of the design disappeared. Finally, her armament of two triple 11-inch turrets, although impressive, was ludicrously heavy for a mere commerce-raider, and not capable of rapid fire against a fast-moving target.
Two more of the class were added. They featured a high, dominant control tower that replaced the somewhat slender tower of the first unit. The Admiral Scheer was laid down by Wilhelmshaven Navy on 25 June 1931, launched on 12 April 1933, and commissioned on 12 November 1934. The Graf Spee was laid down by Wilhelmshaven Navy on 01 October 1932, launched on 30 June 1934, and commissioned on 06 January 1936. The pocket battleship Graf Spee was named after the World War I Vizeadmiral Maximilian Johannes Maria Hubert Reichsgraf von Spee, commnder of the South East Asian cruiser squadron who died at the Battle of the Falkland Islands on 08 December 1914.
Modifications to the second unit increased displacement by several hundred tons, and increased protection on the third ship increased tonnage again. Germany then launched two "fully grown" battle cruisers of the Scharnhorst class in 1936, to be followed two years later by two even mightier ships of the Bismarck class. By the mid-1930s the international naval arms race became unstoppable.
The pocket-battleship Graf Spee was the first ship to sail with a pulsed radar system. In January 1934 the Gema company began development of an experimental Funkmessgeräet, or radio-measurement equipment which was demonstrated on March 20th in Kiel harbor. Something of the sort had been offered to the Imperial Navy as early as 1912, but in view of the inadequate development of wireless technique in those days the device had not been taken seriously and it was not until the 'thirties that Germany began to experiment with the idea again, first using centimetre wave-lengths. Later that year, this apparatus successfully demonstrated to naval officials, spotting ships over seven miles away and, by chance, spotting a seaplane moving in front of the radar. Naval officials were impressed and granted development funds to the Gema company. The experimental radar was improved with pulsed transmissions to measure target ranges and higher frequencies, resulting in a useable prototype for the navy.
In September 1935 Admiral Raeder, the German Navy's Commander-in-Chief, observed demonstrations of the radar's ability to spot from a fixed shore location ships at a range of twelve miles and the capability to detect ships from a moving ship-borne location at a range of five miles. From here the Gema company rapidly improved the prototype by altering of the frequency used which extended its range and accuracy. These improvements gave the new radar the ability to spot aircraft as well as ships. This system would become the most important German early-warning radar and demonstrated an aircraft detection range of fifty miles at the end of 1936 garnering orders from both the Luftwaffe and navy.
This radar, named Freya, was delivered to the German navy in 1938. Freya had excelled in the unexpected area of aircraft detection, but the navy was more interested in the creation of highly accurate gun ranging for its ships. Gema was able to build a higher frequency, 375 megacycles, short range, up to nine miles, gun ranging radar. This radar, named Seetakt, was undergoing ship trials in 1937 and was spotted in use on the pocket battleship, Graf Spee, in 1938 during its intervention in the Spanish Civil War. The British also had photo intelligence of the radar array on the scuttled pocket battleship Graf Spee. This refusal to speculate on the existence of German radar is curious, given the amount of intelligence available.
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