K1-class gunboat

The K1 class was a type of gunboat designed by the Kriegsmarine before World War II. The class was to have comprised four ships, which had been ordered under the provisional names K1, K2, K3, and K4. The four ships were ordered in November 1938, and were scheduled to have been completed by early 1942. However, the contracts for the four ships were canceled on 19 September 1939, two weeks after the start of World War II.

General characteristics and machinery
The K1 class gunboats were 79 m long at the waterline, and 82.5 m long overall. The ships had a beam of 11.4 m, a draft of 3.38 m, 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 had 11 watertight compartments. The ships were to have used a pair of 4-cylinder triple expansion diesel engines that provided 4600 ihp, which would have driven two propellers. The ships were to have had a top speed of 18.5 knots, and a range of 3000 nautical miles at 12 knots. The ships were designed to carry 176 tons of fuel oil.

Armament
The K1 class ships primary armament consisted of four 10.5 cm 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 58.4 kg high explosive shell and a 51.8 kg incendiary round. Both types of ammunition used a single propellant charge: the 11.46 kg RPC/32 charge. The guns could elevate to 80 degrees, and could hit targets flying at 12500 m. When the guns were used to engage surface targets, they could hit targets 17700 m away, at an elevation of 45 degrees.

The ships were also armed with two 3.7 cm L/83 Flak guns, and four heavy machine guns. The 3.7 cm guns fired 0.742 kg high-explosive shells at a rate of fire of about 30 rounds per minute, and a muzzle velocity of 1,000 m/s (3,281 ft/s). The guns could elevate to 85 degrees and hit targets flying at 6800 m, although the tracers were limited to 4800 m.

Construction and cancellation
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 meant that construction priorities was shifted away from less critical projects. As a result, the K1 class was canceled on 19 September 1939.