In the mid-1930s, particularly after the Nazi party came to power in 1933 and signed the Anglo-German Naval Agreement in 1935, the German: [[Reichsmarine]] (after 1935 the German: [[Kriegsmarine]]) began to consider a major naval construction program. Various elements in the German navy and government favored different priorities, ranging from a large battle fleet like the Imperial-era High Seas Fleet to a force of long-range commerce raiders. The K1 design was prepared in 1938, while the discussions that resulted in the adoption of Plan Z in January 1939 were still on-going.
The K1-class gunboats were 79m (259feet) long at the waterline, and 82.5m (270.7feet) long overall. The ships had a beam of 11.4m (37.4feet), a draft of 3.38m (11.09feet), and a displacement of 1,600 metric tons designed, 1,390 tons standard, and 1,890 tons at maximum displacement. The ships were of steel construction, and their hulls would have been divided into eleven watertight compartments.
The ships were to have used a pair of 4-cylinder, triple-expansion engines that drove a pair of screw propellers. The number and type of boilers that would have provided steam to the engines is unknown, but they would have been vented through a pair of funnels. The engines were rated to provide 4600ihp, which would have given the ships a top speed of 18.5kn. At a more economical speed of, they would have had a cruising radius of 3000nmi. The ships were designed to carry 176 tons of fuel oil.
The K1-class ships primary armament consisted of four 10.5cm (04.1inches) L/65 quick-firing guns in two twin-turrets, one fore and one aft of the superstructure. The 10.5 cm guns fired two types of projectiles: a 58.4kg (128.7lb) high explosive shell and a 51.8kg (114.2lb) incendiary round. Both types of ammunition used a single propellant charge: the 11.46kg (25.26lb) RPC/32 charge. The guns could elevate to 80 degrees, and could hit targets flying at 12500m (41,000feet). When the guns were used to engage surface targets, they could hit targets 17700m (58,100feet) away, at an elevation of 45 degrees.[1]
The ships were also armed with two 3.7cm (01.5inches) L/83 Flak guns, and four heavy machine guns. The 3.7 cm guns fired 0.742kg (01.636lb) high-explosive shells at a rate of fire of about 30 rounds per minute, and a muzzle velocity of 1000m/s. The guns could elevate to 85 degrees and hit targets flying at 6800m (22,300feet), although the tracers were limited to 4800m (15,700feet).[2]
The four ships were ordered on 11 November 1938, at the cost of 6 million Reichsmarks apiece. K1 was planned to have been completed on 20 May 1941; K2 was to have followed on 15 September. K3 was to be completed by 15 January 1942, and K4, the final ship of the class, was to be completed a month later on 14 February. However, the outbreak of World War II in early September 1939 exacerbated the already fraught state of the German economy. The country had embarked on a massive rearmament program in the years after the Nazis rose to power, which included the German: [[German Army (1935–1945)|Heer]] (Army) and German: [[Luftwaffe]] (Air Force), all of which competed for scarce resources, especially high-grade steel. The start of war meant that construction priorities were shifted away from less critical projects to focus Germany's limited resources on projects that might influence the outcome of the war. As a result, the K1 class was canceled on 19 September 1939.